JP5810520B2 - Lane change control device and lane change stress evaluation method - Google Patents

Description

  The present invention relates to a lane change control device and a lane change stress evaluation method.

  Conventionally, in order to improve the safety of traffic at the junction where the merge lane merges with the main lane, the vehicle that passes through the merge point is monitored by a monitoring sensor provided near the junction. There is known a technique for determining whether or not a vehicle traveling on the vehicle can safely change the lane to the main lane and presenting the result of the determination to the driver of the vehicle traveling on the merged lane (for example, Patent Document 1).

JP 2001-134900 A

  However, in the prior art, only the lane change possibility based on the current driving situation is provided to the driver of the vehicle traveling in the merged lane, and the steering is performed at what timing and how. No specific information regarding lane changes such as whether to perform an operation was presented. For this reason, there has been a problem that the driving load on the driver when changing the lane at the merging point cannot be sufficiently reduced.

  The problem to be solved by the present invention is to provide a lane change control device capable of reducing a driver's driving load when changing lanes at a junction.

The present invention evaluates the driver's stress as the lane approaches the lane termination point, which is the end of the merging lane, in time series as the lane termination stress degree, and travels behind the vehicle in the main lane. The driver's stress on the rear vehicle is evaluated along the time series as the rear vehicle stress level . Then, the larger of the lane end stress degree and the rear vehicle stress degree at each time, were evaluated in chronological stress of the driver in the mix flow point as a converging stress degree, so that merging stress degree is reduced The above problem is solved by guiding the host vehicle to change the lane of the host vehicle at a proper timing.

  The driver's stress when changing lanes at the merge point by evaluating the lane end stress level when the vehicle approaches the lane end point and the rear vehicle stress level with respect to the rear vehicle at the merge point Thus, the host vehicle can be guided to change the lane of the host vehicle at a timing when the stress of the driver of the host vehicle at the junction is reduced. As a result, it is possible to reduce the driving load on the driver when the host vehicle changes lanes at the junction.

It is a block diagram of the lane change control apparatus which concerns on this embodiment. It is a block diagram of the microprocessor which concerns on this embodiment. It is a flowchart which shows the lane change control process which concerns on 1st Embodiment. It is a figure for demonstrating the lane change control process which concerns on 1st Embodiment. It is a figure which shows an example of the merging stress degree in 1st Embodiment. It is a figure for demonstrating lane change required time. It is a flowchart which shows the required time calculation process of step S111. It is a figure which shows an example of the target steering angle calculated in 1st Embodiment. It is a figure for demonstrating the lane change control process which concerns on 2nd Embodiment. It is a flowchart which shows the lane change control process which concerns on 3rd Embodiment. It is a figure which shows an example of the merging stress degree calculated in 3rd Embodiment. It is a figure which shows an example of the target steering angle calculated in 3rd Embodiment. It is a figure which shows an example of the merge stress degree calculated in 4th Embodiment. It is a flowchart which shows the lane change control process which concerns on 6th Embodiment. It is a flowchart which shows the back vehicle behavior prediction process of step S607.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, a lane change control device mounted on a vehicle will be described as an example.

<< First Embodiment >>
FIG. 1 is a configuration diagram of a lane change control device according to the present embodiment. As shown in FIG. 1, the lane change control device according to the present embodiment includes cameras 10a to 10d, a vehicle speed sensor 20, a stroke sensor 30, a steering angle sensor 40, a direction indication switch 50, a GPS unit 60, a road information database 70, It comprises a microprocessor 80, a motor controller 90, a steering assist motor 100, a power train controller 110, and an engine / drive system 120. Each of these components is connected by a CAN (Controller Area Network) or other in-vehicle LAN, and can exchange information with each other.

  As shown in FIG. 1, the cameras 10 a to 10 d are installed symmetrically in front and rear of the host vehicle. The camera 10 a installed on the left front side of the host vehicle images a region centered on the left front of the host vehicle and transmits the captured image to the microprocessor 80. Similarly, the cameras 10 b to 10 d respectively capture areas centered on the right front, left rear, and right rear of the host vehicle, and transmit the captured images to the microprocessor 80. In the present embodiment, two cameras are installed in front of and behind the host vehicle, so that not only the direction in which other vehicles (vehicles other than the host vehicle) exist around the host vehicle but also other vehicles. The relative position can also be detected.

  The vehicle speed sensor 20 detects the vehicle speed of the host vehicle. As the vehicle speed sensor 20, for example, a rotary encoder installed on the tire wheel of the front wheel of the host vehicle can be used. When a rotary encoder is used as the vehicle speed sensor 20, the vehicle speed of the host vehicle can be measured by detecting a pulse signal generated in proportion to the rotation of the tire wheel. The vehicle speed information of the host vehicle detected by the vehicle speed sensor 20 is transmitted to the microprocessor 80.

  The stroke sensor 30 is installed on the accelerator pedal, and detects the amount of depression (stroke amount) of the accelerator pedal by the driver. Information on the stroke amount detected by the stroke sensor 30 is transmitted to the microprocessor 80.

  The steering angle sensor 40 is installed in the steering column and detects the rotation angle (steering angle) of the steering wheel. Information on the steering angle detected by the steering angle sensor 40 is transmitted to the microprocessor 80.

  The direction indication switch 50 is installed on the steering column, and performs lighting control of the direction indicator of the host vehicle by the operation of the driver. In addition, the direction indication switch 50 transmits information on whether or not the direction indicator is lit to the microprocessor 80.

  A GPS (Global Positioning System) unit 60 detects radio waves transmitted from a plurality of satellite communications (not shown) and acquires position information of the host vehicle. The position information of the host vehicle acquired by the GPS unit 60 is transmitted to the microprocessor 80.

  The road information database 70 stores road information related to roads. Specifically, the road information database 70 includes, as road information, for example, information indicating whether the lane of each road is a main lane or a merge lane that merges with the main lane at a merge point, When is a merging lane, position information of a lane end point that is the end of the merging lane is stored.

  The microprocessor 80 executes a ROM (Read Only Memory) storing a program for controlling the lane change of the own vehicle at the junction point, as well as a program for performing route guidance, and a program stored in the ROM. It is composed of a CPU (Central Processing Unit) and a RAM (Random Access Memory) that functions as an accessible storage device. As an operation circuit, instead of or in addition to a CPU (Central Processing Unit), an MPU (Micro Processing Unit), a DSP (Digital Signal Processor), an ASIC (Application Specific Integrated Circuit), an FPGA (Field Programmable Gate Array), etc. Can be used.

  Then, as shown in FIG. 2, the microprocessor 80 includes a travel information acquisition unit 81 that acquires travel information of the host vehicle, a lane information acquisition unit 82 that acquires lane information of the lane in which the host vehicle travels, and the surroundings of the host vehicle. Other vehicle detection unit 83 for detecting another vehicle traveling, own vehicle behavior prediction unit 84 for predicting the behavior of the own vehicle at the junction, and backward vehicle behavior for predicting the behavior of the rear vehicle traveling behind the own vehicle in the main lane Prediction unit 85, lane end stress evaluation unit 86 that evaluates the driver's stress on the host vehicle when the host vehicle approaches the lane end point, and rear vehicle that evaluates the driver's stress on the rear vehicle at the junction It has the stress evaluation part 87 and the lane change control part 88 which controls the lane change of the own vehicle in a junction. FIG. 2 is a block diagram showing the microprocessor 80.

  The travel information acquisition unit 81 acquires the vehicle speed information of the host vehicle, the stroke amount information of the accelerator pedal, and the steering angle information from the vehicle speed sensor 20, the stroke sensor 30, and the steering angle sensor 40, respectively. The travel information acquisition unit 81 also acquires information on the current position of the host vehicle detected by the GPS unit 60.

  The lane information acquisition unit 82 extracts the road information of the road on which the host vehicle is traveling from the road information database 70 based on the current position of the host vehicle acquired by the traveling information acquisition unit 81. For example, when the lane in which the host vehicle is traveling is a merge lane, the lane information acquisition unit 82 acquires position information of a lane end point that is the end of the merge lane as road information.

  The other vehicle detection unit 83 acquires image data picked up by the cameras 10a to 10d, processes the acquired image data, detects other vehicles existing around the host vehicle, and detects the relative of the detected other vehicles. Calculate position and relative velocity. The relative speed of the other vehicle can be calculated based on the history of the relative position of the other vehicle detected along the time series.

  The own vehicle behavior predicting unit 84 predicts the behavior of the own vehicle at the joining point based on the traveling information of the own vehicle acquired by the traveling information acquiring unit 81. In the present embodiment, the host vehicle behavior prediction unit 84 calculates the travel position and the travel speed of the host vehicle at each time after the current time along the time series, so that the behavior of the host vehicle at the merge point is calculated. Predict.

  The rear vehicle behavior prediction unit 85 predicts the behavior of the rear vehicle at the junction when the other vehicle detection unit 83 detects a vehicle traveling behind the host vehicle in the main lane (hereinafter referred to as a rear vehicle). To do. In the present embodiment, the rear vehicle behavior prediction function 85 predicts the behavior of the rear vehicle by calculating the travel position and travel speed of the rear vehicle at each time after the current time along the time series. .

  The lane end stress evaluation unit 86 is based on the behavior of the host vehicle predicted by the host vehicle behavior prediction unit 84 and the position information of the lane end point of the merging lane on which the host vehicle travels acquired by the lane information acquisition unit 82. Thus, the stress of the driver of the host vehicle when the host vehicle approaches the lane end point is evaluated as the lane end point stress degree. In the present embodiment, the lane end stress evaluation unit 86 evaluates the lane end stress degree at each time after the current time along a time series.

  Based on the behavior of the host vehicle predicted by the host vehicle behavior prediction unit 84 and the behavior of the rear vehicle predicted by the rear vehicle behavior prediction unit 85, the rear vehicle stress evaluation unit 87 The vehicle driver's stress is evaluated as the rear vehicle stress level. In the present embodiment, the rear vehicle stress evaluation unit 87 evaluates the rear vehicle stress degree at each time after the current time along a time series.

  The lane change control unit 88 changes the lane of the host vehicle at the merging point based on the lane end stress degree calculated by the lane end stress evaluation unit 86 and the rear vehicle stress degree calculated by the rear vehicle stress evaluation unit 87. To control. Specifically, the lane change control unit 88 evaluates the stress of the driver of the host vehicle when changing the lane at the merging point as the merging stress degree based on the lane end stress degree and the rear vehicle stress degree. A lane change plan for controlling the lane change of the host vehicle at the merging point is created based on the merging stress degree. Then, the lane change control unit 88 guides the host vehicle from the merge lane to the main lane at the merge point by performing steering control of the own vehicle at the merge point based on the created lane change plan.

  Returning to FIG. 1, the motor controller 90 follows the actual steering angle of the host vehicle to the steering angle (target steering angle) necessary for the host vehicle to change the lane at the junction by the steering control by the microprocessor 80. The amount of steering torque for making it run is calculated. Then, the steering torque amount calculated by the motor controller 90 is transmitted to the steering assist motor 100 and acquired by the steering assist motor 100. The steering assist motor 100 applies a steering torque corresponding to the acquired steering torque amount to a steering system (not shown), so that the own vehicle moves from the merging lane to the main line according to the lane change plan calculated by the microprocessor 80. You will be guided to the lane.

  Further, the power train controller 110 obtains the target driving force according to the accelerator operation by the driver from the microprocessor 80, and calculates the engine throttle opening and the transmission gear ratio so as to output the obtained target driving force. To do. The power train controller 110 controls the engine / drive mechanism 120 in accordance with the calculated throttle opening of the engine and the transmission gear ratio.

  Next, the lane change control process of the present embodiment will be described with reference to FIG. FIG. 3 is a flowchart showing a lane change control process according to the first embodiment. Note that the lane change control process of the present embodiment is repeatedly performed by the microprocessor 80 at regular time intervals. Further, the lane change control process according to the present embodiment is performed in a scene in which the host vehicle is traveling on a merge lane at a merge point as shown in FIG. FIG. 4 is a diagram for explaining the lane change control process according to the present embodiment.

First, in step S101, the travel information acquisition unit 81 acquires travel information of the host vehicle. Specifically, the travel information acquisition unit 81 receives the vehicle speed v _{h of} the host vehicle, the stroke amount d _A of the accelerator pedal, the steering angle θ _s from the vehicle speed sensor 20, the stroke sensor 30, the steering angle sensor 40, and the GPS unit 60. And various information on the current position of the host vehicle is acquired as travel information. For example, in the example scene shown in Figure 4, since the vehicle is running on a position x _h at the speed v _h, traveling information acquisition unit 81, a travel information traveling position x _h and the traveling speed v _h of the vehicle get. In addition, when the position information of the own vehicle acquired from the GPS unit 60 is expressed in the GPS coordinate system, the travel information acquisition unit 81 displays the position information of the own vehicle, for example, as shown in FIG. The lane extending direction can be converted to the ground coordinate system set as the X axis and the direction perpendicular to the X axis as the Y axis. Thus, in the example shown in FIG. 4, the running position of the vehicle, X coordinate x _h, Y-coordinate is obtained as y _m.

In step S102, the lane information acquisition unit 82 acquires road information. Specifically, the lane information acquisition unit 82 extracts, from the road information database 70, road information of the lane in which the host vehicle travels based on the position information of the host vehicle acquired in step S101. Here, as the road information extracted from the road information database 70, for example, position information of the lane end point that is the end point of the merging lane may be mentioned. In the example of the scene illustrated in FIG. 4, the lane information acquisition unit 82 acquires the position x _end of the lane terminal point of the merging lane in which the host vehicle travels as road information.

In step S103, the other vehicle detection unit 83 acquires the image data captured by the cameras 10a to 10d, and the other vehicle that travels around the host vehicle is detected based on the acquired image data. And the other vehicle detection part 83 acquires the driving information of the detected other vehicle based on the acquired image data. In the present embodiment, the other vehicle detection unit 83 calculates the travel position and travel speed of the other vehicle as travel information of the other vehicle that travels around the host vehicle. For example, in the scene example shown in FIG. 4, there is a rear vehicle that travels behind the host vehicle in the main lane. Therefore, the other vehicle detection unit 83 detects the rear vehicle based on the image data transmitted from the cameras 10c and 10d that capture the rear of the host vehicle, and also detects the travel position _xr and the travel speed v of the detected rear vehicle. _r is calculated. The other vehicle detection unit 83 detects the traveling position of the rear vehicle as a relative position with respect to the traveling position of the host vehicle, and converts the detected relative position of the rear vehicle into the ground coordinate system, as shown in FIG. , it is possible to obtain the running position x _r of the following vehicle.

In step S104, the lane change control unit 88 determines whether it is necessary to create a lane change plan for controlling the lane change of the host vehicle at the junction. In the present embodiment, when both of the following two conditions are satisfied, it is determined that a lane change plan needs to be created. That is, firstly, as shown in FIG. 4, the host vehicle passes a point x _start where the lane can be changed from the merged lane to the main lane (first condition), and secondly A lane change plan is created when two conditions have been established that the steering control based on the lane change plan has not been performed (second condition) from when the first condition is satisfied to the present. Is determined to be necessary. If it is determined that it is necessary to create a lane change plan, the process proceeds to step S105. If it is determined that it is not necessary to create a lane change plan, the process proceeds to step S114.

In step S105, the own vehicle behavior predicting unit 84 predicts the behavior of the own vehicle at the junction. Specifically, the host vehicle behavior prediction unit 84 first creates a map created in advance from the vehicle speed v _h of the host vehicle and the stroke amount d _{A of the} accelerator pedal among the travel information of the host vehicle acquired in step S101. , An estimated target speed v ^* ^ for changing the lane at the junction and an estimated target acceleration a ^* ^ for reaching the estimated target speed v ^* ^ are calculated. In the estimated target speed v ^* ^ and the estimated target acceleration a ^* ^, “^” attached to the right shoulder indicates that the value is an estimated value. Hereinafter, v _h ^ (t), x _h ^ (t), v _r ^ (t), x _r ^ (t), v _f ^ (t), x _f ^ (t), a _h ^ ( The same applies to t).

ここで、上記式（１），（２）において、ｔ_０は現在時刻であり、ｔ_１は自車両の走行速度ｖ_ｈが推定目標速度ｖ^＊に到達すると予想される時刻であり、ｘ_１は時刻ｔ_１における自車両の走行位置である。また、上記式（１），（２）では、推定値であることを示す「＾」を、それぞれ、ｖ^＊の「ｖ」の真上、ａ^＊の「ａ」の真上、ｘ_ｈ（ｔ）の「ｘ」の真上、ｖ_ｈ（ｔ）の「ｖ」の真上としているが、下記式（３）に示すように、これはｖ^＊＾，ａ^＊＾，ｖ_ｈ＾（ｔ）およびｘ_ｈ＾（ｔ）と同義である。以下、ｖ_ｒ＾（ｔ），ｘ_ｒ＾（ｔ），ｘ_ｆ＾（ｔ），ａ_ｈ＾（ｔ）においても同様である。

Then, the own vehicle behavior prediction unit 84 determines the traveling speed v _h ^ (t) and the traveling position x _h ^ (t) of the own vehicle based on the calculated estimated target speed v ^* ^ and estimated target acceleration a ^* ^. It calculates according to following formula (1), (2). In the present embodiment, the host vehicle behavior prediction unit 84 determines the travel speed v _h ^ (t) and the travel position x _h of the host vehicle at each time t from the current time until the host vehicle reaches the lane end point. By calculating ^ (t), the behavior of the host vehicle at the junction is predicted.

Here, in the above formulas (1) and (2), t ₀ is the current time, t ₁ is the time when the traveling speed v _h of the host vehicle is expected to reach the estimated target speed v ^* , and x ₁ is the running position of the vehicle at time t _1. Further, in the above formulas (1) and (2), “^” indicating an estimated value is set to be just above “v” of v ^* , just above “a” of a ^* , and x _h ( just above the "x" _t), but is set to just above the "v" of _v h (t), as shown in the following formula (3), this is _{^{v * ^, a * ^,}} v h ^ ( t) and x _h ^ (t). The same applies to v _r ^ (t), x _r ^ (t), x _f ^ (t), and a _h ^ (t).

  Next, in step S106, the lane end stress evaluation unit 86 determines the lane end stress based on the behavior of the host vehicle predicted in step S105 and the position information of the lane end point of the merged lane acquired in step S102. The degree is evaluated. Here, the lane end stress degree represents the magnitude of the stress of the driver of the own vehicle when the own vehicle approaches the lane end point of the merging lane when the own vehicle changes lanes at the merging point. In the first embodiment, the evaluation is made in three stages of “high”, “medium”, and “low” in descending order of the stress of the driver of the host vehicle. Below, the evaluation method of the lane termination | terminus stress degree which concerns on 1st Embodiment is demonstrated.

First, the lane terminating stress evaluation unit 86, by using the above equation (2), on the basis of the position x _end of travel position x _h and lane end point of the vehicle, arrives at the lane end point of the vehicle junction The time t _end to be calculated is calculated. Then, the lane end stress evaluation unit 86 calculates a time T _end (t ₀ ) from the current time t ₀ to the time t _end when the _host vehicle reaches the lane end point based on the following equation (4).

Similarly, lanes terminating stress evaluation unit 86 on the basis of the following equation (5), from each time t of the current time _{t 0} after the time up to time _{t end} of the vehicle reaches the lane end point _{T end The} (t ) Is calculated along a time series.

Then, the lane end stress evaluation unit 86 uses the calculated time T _end (t) to evaluate the lane end stress degree at each time t after the current time t ₀ as shown in the following formula (6). . In the following formula (6), T _max and T _min are predetermined arrival times, and T _max is a time longer than T _min (T _max > T _min ).

Next, in step S107, the rear vehicle behavior predicting unit 85 predicts the behavior of the rear vehicle at the junction based on the travel information of the rear vehicle acquired in step S103. Specifically, the rear vehicle behavior predicting unit 85 assumes that the rear vehicle travels at a constant speed v _r , and the rear vehicle travel position x _{r at} each time t after the current time t ₀ according to the following equation (7). ^ (T) is calculated.

  In step S108, the rear vehicle stress evaluation unit 87 evaluates the rear vehicle stress degree based on the behavior of the host vehicle predicted in step S105 and the rear vehicle behavior predicted in step S107. Here, the rear vehicle stress level represents the magnitude of the driver's stress on the rear vehicle at the junction. Below, the evaluation method of the back vehicle stress degree which concerns on 1st Embodiment is demonstrated.

Specifically, the rear vehicle evaluation unit 87 firstly determines the travel position x _h ^ (t) of the host vehicle predicted in step S105 and the travel position x _r ^ (t) of the rear vehicle predicted in step S107. And the inter-vehicle time h _r (t) between the host vehicle and the rear vehicle at each time t after the current time t ₀ based on the current travel speed v _r of the rear vehicle acquired in step S103. Calculate according to (8).

Then, the rear vehicle stress evaluation unit 87 evaluates the rear vehicle stress degree at each time t after the current time t ₀ based on the calculated inter-vehicle time h _r (t) as shown in the following formula (9). To do. Note that h _max and h _min are predetermined inter-vehicle time, and h _max is larger than h _min (h _max > h _min ).

  Next, in step S109, the lane change control unit 88 evaluates the merging stress degree based on the lane end stress degree evaluated in step S106 and the rear vehicle stress degree evaluated in step S108. Here, the degree of merging stress represents the magnitude of stress of the driver of the host vehicle when the host vehicle changes lanes at the merging point. In the first embodiment, the lane change control unit 88 evaluates the merging stress level in two stages whether or not the host vehicle can change lanes at the merging point.

  Here, as described above, in the first embodiment, the lane end stress degree and the rear vehicle stress degree are evaluated in three stages of “high”, “medium”, and “low”. Therefore, can the lane change control unit 88 perform lane change at the merging point as shown in FIG. 5 for the merging stress degree with respect to nine combinations of the lane end stress degree and the rear vehicle stress degree? Evaluate in two stages: no. Here, FIG. 5 is a diagram illustrating an example of the merging stress degree in the first embodiment. In FIG. 5, the case where the merging stress level is evaluated as being able to change the lane at the merging point is displayed as “Mergeable”, and the lane change at the merging point cannot be performed. The case of being evaluated is displayed as “unable to join”. As shown in FIG. 5, the lane change control unit 88, when one of the lane end stress degree and the rear vehicle stress degree is evaluated as “high”, Since the driver's own vehicle's stress increases, the merging stress degree is evaluated as being unable to change the lane at the merging point ("unmerged" shown in FIG. 5). On the other hand, the lane change control unit 88, when the lane end stress degree is evaluated as “low” or “medium” and the rear vehicle stress degree is also evaluated as “low” or “medium”, The degree of merging stress is evaluated as being able to change lanes at the merging point (“Mergeable” shown in FIG. 5).

Here, FIG. 6 is a diagram showing an example of the merging stress degree evaluated along the time series. In FIG. 6 as well, the merging stress level is displayed in two stages: whether or not the own vehicle can change lanes at the merging point (“mergeable” or “mergeable”). For example, when the own vehicle accelerates due to a lane change at the junction and the time between vehicles increases with the passage of time, as shown in FIG. As a result, the rear vehicle stress level is lowered. As a result, in the example shown in FIG. 6, at time t _f from the current time t _0, the rear vehicle stress degree "high", and by this, at time t _f from the current time t _0, confluent stress degree, junction It is evaluated that it is not possible to change lanes at the station ("Cannot join").

On the other hand, the stress of the driver of the own vehicle with respect to the approach of the lane end point increases as the own vehicle approaches the lane end point. Therefore, as shown in FIG. 6, the lane end stress degree increases from the current time t ₀ toward the time t _end when the host vehicle reaches the lane end point. As a result, in the example shown in FIG. 6, after a lapse of time t _t, lane termination stress degree is evaluated as "high", Thus, merging stress degree even after a lapse of time t _t, at junction It is evaluated as a vehicle that cannot change lanes ("Cannot join").

On the other hand, in the example shown in FIG. 6, from the time t _f when the rear vehicle stress degree changes from “high” to “medium”, until the time t _t when the lane end stress degree changes from “medium” to “high”. In time, both the lane termination stress level and the rear vehicle stress level are evaluated as “medium”. Therefore, in the example shown in FIG. 6, the confluence stress degree, in the time from time t _f to time t _t, it is evaluated as being capable of performing lane change at the junction ( "merge possible").

And the lane change control part 88 calculates time until the lane change of the own vehicle is accept | permitted based on the evaluation result of a merging stress degree. For example, in the example illustrated in FIG. 6, the lane change control unit 88 performs the time T _f (T _f = t _f) from the current time t ₀ to the time t _f when the rear vehicle stress level changes from “high” to “medium”. the -t _0), is calculated as the shortest allowable time T _f is the shortest time from the current time to the time when the lane change in junction is allowed. In addition, lane change control unit 88, from the current time _{t 0,} time lane termination stress degree is from "medium" up to time _{t t} change to "high" _T t a _{(T t = t t -t 0} ), current It is calculated as the longest permissible time T _t that is the longest time from the time to the time when the lane change at the junction is permitted. Note that the shortest allowable time T _f and the longest allowable time T _t are used in steps S110 and S11 described later.

When there is no rear vehicle on the main lane, the shortest allowable time T _f until the lane change is allowed at the junction is 0. However, rapid turning is not desirable in order to safely change the lane of the host vehicle, and it is recommended that at least the minimum required time T _min ′ be secured when turning. Therefore, when there is no rear vehicle in the main lane, the lane change control unit 88 can calculate the shortest allowable time T _f according to the following equation (10). It should be noted that max () in the following equation (10) is selectively calculated as a maximum value among the time (t _t −t ₀ ) from the current time t ₀ to the time t _t and the minimum required time T _min ′. (Hereinafter, the same applies to formulas (25) and (30).)

Then, in step S110, the lane change control unit 88 determines whether or not there is a time during which the lane change is allowed at the merging point based on the evaluation result of the merging stress degree in step S109. In the present embodiment, for example, when the shortest allowable time _Tf and the longest allowable time _Tt cannot be calculated in step S109, or when the shortest allowable time _Tf is greater than the longest allowable time _Tt (T _t > T _{In f} ), it is determined that there is no time for which the lane change is allowed at the junction. If it is determined that there is a time during which the lane change is allowed at the junction, the process proceeds to step S111. On the other hand, if it is determined that there is no time allowed for the lane change at the junction, the process proceeds to step S115.

  Next, in step S111 and step S112, the lane change control unit 88 performs a process for creating a lane change plan. Here, the lane change plan defines a method of steering control at the merging point such as the timing of starting the steering when changing the lane at the merging point and the speed of the steering.

First, in step S111, the lane change control unit 88 performs a required time calculation process for calculating the lane change required time. Specifically, the lane change control unit 88 is based on the evaluation result of the degree of merging stress in step S109 within the time when the lane change of the host vehicle is allowed at the merging point (for example, in the example shown in FIG. time) from t _f to time t _t, as lane change of the vehicle is completed, the time for steering control in junction, is calculated as a lane change required time.

Here, the time when the host vehicle changes lanes at the merge point is the time during which the host vehicle continues to travel in the merge lane and the time from when the own vehicle starts turning until it ends. Can be divided. Therefore, the lane change control unit 88 continues traveling for a time during which the host vehicle continues to travel in the merged lane so that the lane change of the host vehicle is completed at the time when the lane change of the host vehicle is permitted at the junction. and calculates a time T _a, the time until exiting the turning of the vehicle is started by calculating the lane-changing time T _B, the travel duration T _a and lane change time T _B and the total time of _Is calculated as a lane change required time T _LC (T _LC = T _A + T _B ). In the following, the required time calculation process for calculating the lane change required time _TLC will be described with reference to FIG. FIG. 7 is a flowchart showing the required time calculation process in step S111.

First, in step S1101, the running time duration T _A where the vehicle continues to travel at the joining lane is set to 0 in the initial value (T A _{= 0),} until exiting the turning of the vehicle is started lane change time _{T B} of _{T min} of the initial value 'is set to _{(T B = T min').} Note that T _min ′ is the minimum required time that should be ensured at the minimum when turning, as described above.

In step S1102, the predetermined time [Delta] T _A is added to the running time duration _{T A,} the travel duration _{T A} is updated. In step S1103, the travel duration and _{T A} the predetermined time [Delta] T _A is added in step S1102, the total time of the lane change time _{T B} remains the initial value _{T min} 'is the longest allowable time _{T t} or more ( _A determination is made as to whether T _A + T _B ≧ T _t ). If the total time of the travel duration _{T A} and lane change time _{T B} is the maximum allowable time _{T t} or more, the process proceeds to step S1115, a the travel duration _{T A} at the present time, the initial value _{T min} 'lane change time T _B is calculated as the time to configure the lane change required time T _LC, it ends the required time calculation process. On the other hand, if the total time of the travel duration _{T A} and lane change time _{T B} is less than the maximum allowable time _{T t,} the process advances to step S1104.

In step S1104, the running duration _{T A} is a determination whether the host vehicle has reached the predetermined time _T ^{A 0} is performed. Here, the predetermined time T _A ⁰ can be, for example, a time required for the host vehicle to travel to a point suitable for starting the steering of the host vehicle. If the travel duration _{T A} has not reached the predetermined time _T ^{A 0,} the process returns to step S1102, until the travel duration _{T A} reaches a predetermined time _T ^{A 0,} increases stepwise travel duration _{T A} is Is done. On the other hand, if the travel duration T _A has reached the predetermined time T _A ⁰ , the process proceeds to step S1105.

In step S1105, is the total time of the travel continuation time T _A at the predetermined time T _A ⁰ and the lane change time T _B with the initial value T _min ′ smaller than the shortest allowable time T _f (T _A A determination is made as to whether + T _B <T _f ). If the total time of the travel duration _{T A} and lane change time _{T B} is the shortest allowable time _{T f} or more, the process proceeds to step S1115, traveling duration and _{T A} is a predetermined time _T ^{A 0,} the initial value T a lane change time T _B of the left _{min 'is,} is calculated as the time to configure the lane change required time T _LC, ends the required time calculation process. On the other hand, if the total time of the travel duration _{T A} and lane change time _{T B} is less than the shortest allowable time _{T f,} the process proceeds to step S1106.

In step S1106～S1109, similar to step S1102～S1104, after the lane change time _{T B} to the steering of the vehicle is ended from the start, it was increased stepwise until the predetermined time _T ^{B 0} (step S1106～S1108), or a predetermined time _T ^{a 0} and since traveling duration _{T a,} the total time of the predetermined time _T ^{B 0} and became lane change time _{T B} is less than the shortest allowable time _{T f (T a + T B <T} f) whether the determination is made (step S1109). That is, until the lane change time _{T B} reaches a predetermined time _T ^{B 0,} the predetermined time [Delta] T _B is repeatedly added to the lane change time _{T B} (step S1106), the lane change time _{T B} reaches the predetermined time _T ^{B 0} when (step S1108 = Yes), the total time of the travel duration _{T a} and lane change time _{T B} is less whether a determination is made than the shortest allowable time _{T f} (step S1109). If it is determined in step S1109 that the total time of the travel continuation time T _A and the lane change time T _B is equal to or longer than the shortest allowable time T _f , the process proceeds to step S1115, and is a predetermined time T _A ⁰ . a traveling duration T _a, the total time of the lane change time T _B which is a predetermined time T _B ⁰ is calculated as the time to configure the lane change required time T _LC, it ends the required time calculation process. On the other hand, the total time of the travel duration T _A and lane change time T _B is, if it is determined to be smaller than the shortest allowable time T _f, the process proceeds to step S1110. Incidentally, if the lane change time _{T B} is to reach the predetermined time _T ^{B 0,} the total time of the travel duration _{T A} and lane change time _{T B,} was the maximum allowable time _{T t} or more (step S1107 = the yes), the flow proceeds to step S1115, and the travel duration _{T a} is a predetermined time _T ^{a 0,} and a lane change time _{T B} at the present time is calculated as the time to configure the lane change required time _{T LC,} this The required time calculation process ends.

Further, in step S1110～S1113, similarly to step S1106～S1109, lane change time _{T B} is stepwise increased from the predetermined time _T ^{B 0} until a predetermined time _T ^{B 1} (step S1110～S1112), the predetermined time T Drive and duration _{T a} is _a ^0, the total time of the predetermined time _T ^{B 1} and became lane change time _{T B} is either less than the shortest allowable time _{T f (T a + T B} <T f) whether Is determined (step S1113). If it is determined in step S1113 that the total time of the travel continuation time T _A and the lane change time T _B is equal to or greater than the shortest allowable time T _f , the process proceeds to step S1115 and travels for a predetermined time T _A ^0. a duration T _a, the total time of the lane change time T _B which is a predetermined time T _B ¹ is calculated as the time to configure the lane change required time T _LC, it ends the required time calculation process. On the other hand, in step S1113, if the total time of the travel duration _{T A} and lane change time _{T B} is determined to be smaller than the shortest allowable time _{T f,} the process proceeds to step S1114. Note that the lane change time T _B, while stepwise increasing the predetermined time T _B ⁰ until a predetermined time T _B ^1, the total time of the travel duration T _A and lane change time T _B, the junction If the lane change has become acceptable maximum allowable time _{T t} above in (step S1111 = Yes), the process proceeds to step S1115, and the travel duration _{T a} is a predetermined time _T ^{a 0,} lane change time moment and T _B is calculated as the time to configure the lane change required time T _LC, it ends the required time calculation process.

In step S1114, the running duration _{T A} is set to the difference between the lane-changing time _{T B} is the shortest allowable time _{T f} and the predetermined time ^{_{T B 1 (T A = T}} f -T B 1). The configuration and lane change time T _B which is a predetermined time T _B ^1, the total time of the travel duration T _A is the difference between the shortest allowable time T _f and lane change time T _B is the lane change required time T _LC And the required time calculation process is terminated.

As described above, the travel duration T _A and lane change time T _B is calculated, required time calculation process in step S111 is performed.

At step S112, the lane change control section 88, based on the calculated lane change required time _{T LC} at step S111, calculation of the target steering angle is performed. Specifically, the lane change control unit 88 calculates the steering angle of the host vehicle when changing the lane at the merging point as a target steering angle along a time series. Hereinafter, a method for calculating the target steering angle will be described with reference to FIG. Here, FIG. 8 is a diagram illustrating an example of the target steering angle calculated in the first embodiment. In FIG. 8, the horizontal axis represents time, and the vertical axis represents the magnitude (amplitude) of the target steering angle.

As shown in FIG. 8, the lane change control unit 88 includes a travel continuation time T _A (in FIG. 8, from the current time t _{0) in} the lane change required time T _LC . in the time) until the time _t 0 + _{T a,} it calculates the target steering angle θ _s ^* as 0 °. Further, the lane change control unit 88, among the lane change required time T _LC, the lane change time T _{B (FIG.} 8 from the start to the end of the turning of the vehicle, the time from the time t _{0 +} T _A in t ₀ + _T a + T time to _B), the target steering angle theta _s ^*, for example, the period is produced as a sinusoidal steering pattern is changing lanes time _{T B.} Note that (the amplitude of the sinusoidal steering pattern) target steering angle theta _s ^* size in lane change time T _B, as shown in FIG. 8, to the center position of the main lane from the center position of the vehicle merging lane It is preferable that the value is set to a value sufficient to move. Then, the lane change control unit 88 (after the elapse of the time _{t 0 + T A + T B} ) after the expiration of lane change required time _{T LC} calculates the target steering angle theta _s ^* as 0 °.

Next, in step S113, the lane change control unit 88, among the target steering angle theta _s ^* calculated in step S112, the target steering angle theta _s ^* in accordance with the current time, it is outputted to the motor controller 90. As a result, the motor controller 90 calculates a turning torque amount corresponding to the target steering angle θ _s ^* at the current time, and sends the turning assist motor 100 to the steering system of the host vehicle according to the turning torque amount. Add steering torque. As a result, the steering control according to the lane change plan created in steps S111 and S112 is performed in the lane change of the host vehicle at the junction.

If it is determined in step S104 that it is not necessary to create a lane change plan, the process proceeds to step S114. In step S114, the lane change control unit 88 determines whether or not steering control of the host vehicle is being performed based on the lane change plan. The lane change control unit 88, for example, when the lane change plan is not created or when the lane change required time _TLC has elapsed and the steering control of the host vehicle based on the lane change plan has been completed, It can be determined that the steering control of the host vehicle based on the change plan is not performed. If it is determined that the steering control of the host vehicle is not performed based on the lane change plan, the lane change control process is terminated. On the other hand, if the steering control of the host vehicle is being performed based on the lane change plan, the process proceeds to step S113, and the target steering angle θ _s ^{* at the} current time is output to the motor controller 90.

  On the other hand, if it is determined in step S110 that there is no time for which the lane change is allowed at the junction, the process proceeds to step S115. In step S115, in this state, it is determined that it is difficult to change the lane at the junction, and a warning is given to the driver of the host vehicle. In addition, the method of warning to the driver of the own vehicle is not particularly limited, and for example, the warning can be given by a display or a speaker (not shown).

As described above, the lane change control device according to the present embodiment, when the host vehicle changes lanes at the junction, determines the stress of the driver of the host vehicle when the lane end point approaches as the lane end stress degree. In addition to evaluating the stress of the driver of the host vehicle with respect to the rear vehicle at the merge point as the rear vehicle stress degree, when changing the lane at the merge point based on the lane end stress degree and the rear vehicle stress degree The stress of the driver of the own vehicle is evaluated as the degree of merging stress. Then, the merged stress degree is low, the time to change lanes of the own vehicle in the merging point is allowed (e.g., in the example shown in FIG. 6, the time from the time t _f to time t _t), the lane change of the vehicle The vehicle is guided so that is completed. Thereby, in this embodiment, the stress of the driver of the own vehicle when the own vehicle changes lanes at the junction can be appropriately evaluated according to the situation around the own vehicle, and as a result, the junction The vehicle can be appropriately guided so as to reduce the stress on the driver of the vehicle when changing the lane in FIG. In particular, in the present embodiment, the time series data of the target steering angle for changing the lane at the merging point is reduced so that the stress on the driver of the own vehicle when the own vehicle changes the lane at the merging point is reduced. By creating a lane change plan and performing steering control based on the lane change plan, it is possible to reduce the driving load on the driver of the host vehicle when changing the lane at the junction.

  Further, in the lane change control device according to the present embodiment, the host vehicle continues to travel in the merging lane so that the lane change of the host vehicle is completed within a time when the lane change of the host vehicle is permitted at the junction. The travel continuation time and the lane change time from the start to the end of steering of the host vehicle are calculated, and the total time of the travel continuation time and the lane change time is calculated as the lane change required time. Thereby, in this embodiment, the timing which starts the turning of the own vehicle at the time of changing the lane of the own vehicle at a junction, and the turning speed of the own vehicle can be appropriately calculated.

<< Second Embodiment >>
Subsequently, the lane change control process according to the second embodiment will be described. Similar to the first embodiment, the second embodiment is the same as the first embodiment except that the vehicle having the configuration shown in FIG. 1 operates as described below. Specifically, in the lane change control process according to the second embodiment, as shown in FIG. 9, when there is another vehicle (hereinafter referred to as a forward vehicle) traveling in front of the host vehicle on the main road. Considering this preceding vehicle, the vehicle lane change control process according to the first embodiment is performed only in steps S103, S105, and S107 in order to guide the vehicle to change the lane of the vehicle at the junction. Different processes are performed, and other processes are performed in the same manner as in the first embodiment. Therefore, in the following, as shown in FIG. 9, steps S103, S105, and S107 according to the second embodiment will be described in a scene where a vehicle ahead is present. FIG. 9 is a diagram for explaining the lane change control process according to the second embodiment.

In step S <b> 103, the other vehicle detection unit 83 detects the other vehicle that travels around the host vehicle. Here, in the second embodiment, as shown in FIG. 9, since the front vehicle is traveling ahead of the host vehicle in the main lane, the other vehicle detection unit 83 uses the cameras 10 a and 10 b that capture the front of the host vehicle. based on the image data transmitted from, it detects the preceding vehicle, detecting a running position x _f and the traveling speed v _f of the detected forward vehicle.

  In step S105, the host vehicle behavior prediction unit 84 predicts the host vehicle behavior at the junction. Here, in the second embodiment, as in the example of the scene shown in FIG. 9, since the preceding vehicle is detected in step S <b> 103, the own vehicle behavior predicting unit 84 considers this preceding vehicle and joins the meeting point. Predict the behavior of your vehicle at Below, the prediction method of the behavior of the own vehicle which concerns on 2nd Embodiment is demonstrated.

Vehicle behavior prediction unit 84, first, based on the vehicle speed v _h and the stroke amount d _A of the vehicle, with reference to the map created in advance, calculates an estimated target velocity v ^{* ^} and estimated target acceleration a ^{* ^} To do. Here, as shown in FIG. 9, in the scene where the forward vehicle exists, the calculated estimated target speed v ^* ^ is compared with the traveling speed v _f of the forward vehicle detected in step S103. as a result, in case more of the estimated target speed v ^{* ^} traveling speed of the vehicle ahead than v _f is slow, the traveling speed v _f of the front of the vehicle is set as the estimated target speed v ^{* ^.}

Then, the vehicle behavior prediction unit 84 based on the travel position x _f and the traveling speed v _f of the detected forward vehicle in step S103, predicting the behavior of the front vehicle at the junction. Specifically, the host vehicle behavior prediction unit 84 calculates the traveling position x _f ^ (t) of the preceding vehicle at each time t after the current time t ₀ based on the following equation (11).

Then, the own vehicle behavior prediction unit 84 determines whether or not the own vehicle and the preceding vehicle are approaching at time t ₁ when the vehicle speed v _{h of the} own vehicle reaches the estimated target speed v ^* ^. Specifically, in order to determine whether or not the host vehicle and the preceding vehicle are approaching, the host vehicle behavior predicting unit 84 first determines the inter-vehicle time h _f (at the time t ₁₎ . t ₁ ) is calculated based on the following formula (12).

Then, the host vehicle behavior prediction unit 84 determines whether or not the inter-vehicle time h _f (t ₁ ) at the time t ₁ is equal to or greater than the predetermined inter-vehicle time h ^* , whereby the host vehicle and the preceding vehicle approach each other. Judge whether or not. That is, the own vehicle behavior prediction unit 84 determines that the own vehicle and the preceding vehicle are not approaching when the inter-vehicle time h _f (t ₁ ) at the time t ₁ is equal to or greater than the predetermined inter-vehicle time h ^*. . Thus, when the own vehicle and the preceding vehicle are not approaching, it is considered that the own vehicle performs acceleration / deceleration without being affected by the preceding vehicle. Therefore, in this case, the vehicle behavior prediction unit 84, similarly to the first embodiment, the equation (1), based on (2), the traveling speed v of the vehicle at each time t of the current time t ₀ after _h ^ (t) and travel position _xh ^ (t) are predicted.

ここで、上記式（１３）において、ｔ_０’は、自車両と前方車両とが接近することにより、自車両の運転者が加速を緩め始めると予想される時刻であり、ｔ_１’は、自車両の運転者が自車両の加速を緩めた後、自車両の走行速度が推定目標速度ｖ^＊＾に到達すると予想される時刻である。また、ｋは、下記式（１４）で求められるパラメータ値である。

また、ｔ_０’を所定時刻として設定し、上記式（１３）を２回積分して自車両の走行位置に関する予測を生成すると、下記式（１５）の条件を満たすｔ_１’を一意に定めることができる。

On the other hand, when the inter-vehicle time h _f (t ₁ ) at time t ₁ is less than the predetermined inter-vehicle time h ^* , the host vehicle behavior prediction unit 84 determines that the host vehicle and the preceding vehicle are approaching. . In this case, since it is considered that the traveling speed of the host vehicle is accelerated and decelerated so that the host vehicle does not approach the vehicle ahead, the host vehicle behavior prediction unit 84 calculates the current time based on the following equation (13). The acceleration of the host vehicle at each time t after t ₀ is calculated.

Here, in the above formula (13), t ₀ ′ is the time when the driver of the host vehicle is expected to start accelerating as the host vehicle approaches the preceding vehicle, and t ₁ ′ is This is the time when the driving speed of the host vehicle is expected to reach the estimated target speed v ^* ^ after the driver of the host vehicle relaxes the acceleration of the host vehicle. K is a parameter value obtained by the following formula (14).

When t ₀ ′ is set as a predetermined time and the above equation (13) is integrated twice to generate a prediction regarding the traveling position of the host vehicle, t ₁ ′ satisfying the following equation (15) is uniquely determined. be able to.

Thus, the own vehicle behavior prediction unit 84 calculates the acceleration a _h ^ (t) based on the above equation (13) when the preceding vehicle and the own vehicle are approaching, and calculates the calculated acceleration a By using _h ^ (t) to predict the traveling speed v _h (t) and the traveling position x _h (t) of the host vehicle at each time t after the current time t ₀ , Predict behavior.

In step S107, the rear vehicle behavior prediction unit 85 predicts the behavior of the rear vehicle. Here, when a forward vehicle is detected as in the example illustrated in FIG. 9, the backward vehicle behavior predicting unit 85 predicts the behavior of the backward vehicle, assuming that the backward vehicle travels in consideration of the presence of the forward vehicle. To do. Specifically, the rear vehicle behavior prediction unit 85, the preceding vehicle ahead vehicle was a rear vehicle and the following vehicle, using a known follow-up model, the travel position behind the vehicle at each time t of the current time t ₀ after By calculating x _f (t) and travel speed v _f (t), the behavior of the rear vehicle at the junction is predicted.

  As described above, the lane change control device according to the second embodiment, as shown in FIG. 9, when the forward vehicle is present in front of the own vehicle in the main lane, the own vehicle does not approach the forward vehicle too much. As described above, the behavior of the host vehicle is predicted on the assumption that the driver of the host vehicle performs acceleration and deceleration. Thereby, according to 2nd Embodiment, in addition to the effect of 1st Embodiment, the behavior of the own vehicle in the situation where the front vehicle exists can be estimated appropriately, and when performing a lane change at a junction The own vehicle can be guided appropriately. Furthermore, in 2nd Embodiment, the behavior of a back vehicle in the condition where a front vehicle exists can be appropriately estimated by estimating the behavior of a back vehicle as what a back vehicle follows a front vehicle.

«Third embodiment»
Subsequently, a lane change control device according to a third embodiment will be described. The lane change control device according to the third embodiment has the same configuration as the lane change control device shown in FIG. 1 and is the same as the first embodiment except that it operates as described below. . Hereinafter, the operation of the lane change control device according to the third embodiment will be described with reference to FIG. FIG. 10 is a flowchart showing a lane change control process according to the third embodiment. Note that the lane change control process according to the third embodiment is also repeatedly performed by the microprocessor 80 at regular time intervals.

  First, in steps S301 to S303, as in steps S101 to S103 of the first embodiment, the travel information of the host vehicle, the lane information including the lane end point of the merged lane, and the travel information of other vehicles are acquired. .

  In step S304, it is determined whether steering control based on the lane change plan is being performed. When the steering control based on the lane change plan is being performed, the process proceeds to step S314. On the other hand, when the steering operation based on the lane change plan is not being performed, the process proceeds to step S305.

  In step S305, the behavior of the host vehicle at the junction is predicted as in step S105 of the first embodiment.

In step S306, the lane end stress evaluation unit 86 calculates the lane end stress degree. In the third embodiment, as described below, the lane end stress degree is calculated as numerical data along the time series based on the arrival time TTC _end until the host vehicle reaches the lane end point of the merging lane. Is done.

That is, the lane end stress evaluation unit 86 first calculates the arrival time TTC _end until the _host vehicle reaches the lane end point x _end of the merged lane. Specifically, the lane end stress evaluation unit 86 uses the travel position x _h ^ (t) and the travel speed v _h ^ (t) of the host vehicle at each time t predicted in step S305, and the merge acquired in step S302. Based on the position information of the lane end point of the lane, the arrival time TTC _end (t) at each time t after the current time t ₀ is calculated according to the following equation (16).

Here, the smaller the arrival time TTC _end until the host vehicle reaches the lane end point, the greater the driver's stress on approaching the lane end point. Therefore, the lane end stress evaluation unit 86 sets the stress of the driver of the host vehicle when the host vehicle approaches the lane end point based on the calculated arrival time TTC _end as the lane end stress degree S _end (t). calculate. Specifically, the lane end stress evaluation unit 86 calculates the lane end stress degree S _end (t) as numerical data along a time series based on the following formula (17). In the following equation (17), a is a parameter value for scaling the lane end stress degree S _end (t) and the inverse value of the arrival time TTC _end (t).

  In step S307, similarly to step S107 of the first embodiment, the rear vehicle behavior prediction unit 85 predicts the behavior of the rear vehicle at the junction.

  In step S308, the rear vehicle stress evaluation unit 87 evaluates the rear vehicle stress level. In the third embodiment, as will be described later, the rear vehicle stress degree is calculated as numerical data along the time series based on the inter-vehicle time and the approach time between the host vehicle and the rear vehicle. Below, the evaluation method of the back vehicle stress degree which concerns on 3rd Embodiment is demonstrated.

First, the rear vehicle stress evaluation unit 87 calculates the travel position x _h ^ (t) of the host vehicle at each time t predicted in step S305 and the rear vehicle travel position x _r ^ (() predicted at each time t predicted in step S307. Based on t) and travel speed v _r ^ (t), an inter-vehicle time h _r (t) between the host vehicle and the rear vehicle at each time t is calculated according to the following equation (18).

Further, the rear vehicle stress evaluation unit 87 determines the travel position x _h ^ (t) and the travel speed v _h ^ (t) of the host vehicle at each time t predicted in step S305, and each time t predicted in step S307. Based on the traveling position x _r ^ (t) and the traveling speed v _r ^ (t) of the rear vehicle, the approach time TTC _r (t) between the host vehicle and the rear vehicle at each time t according to the following equation (19). Is calculated.

Here, it is considered that as the inter-vehicle time h _r (t) and the approach time TTC _r (t) become smaller, the stress of the driver of the own vehicle with respect to the rear vehicle at the joining point becomes larger. Therefore, the rear vehicle stress evaluation unit 87 calculates the rear vehicle stress degree S _r (t) based on the inter-vehicle time h _r (t) and the approach time TTC _r (t), as described below. Specifically, the rear vehicle stress evaluation unit 87 calculates the rear vehicle stress degree S _r (t) as numerical data along a time series based on the following formula (20). In the following equation (20), b and c are parameters indicating the magnitudes of the inter-vehicle time and the approach time that contribute to the rear vehicle stress degree.

In step S309, the lane change control unit 88 uses the lane end stress degree S _end (t) calculated in step S306 and the rear vehicle stress degree S _r (t) calculated in step S308 to determine the merging stress. The degree S _m (t) is calculated. Specifically, the lane change control unit 88 adds the lane end stress degree S _end (t) and the rear vehicle stress degree S _r (t) as shown in the following formula (21), thereby joining The degree of stress S _m (t) is calculated as numerical data along the time series.

Here, FIG. 11 is a diagram illustrating an example of the merging stress degree S _m (t) in the third embodiment. Since the time for the host vehicle to reach the lane terminal point decreases with time, the lane terminal stress degree S _end (t) increases with time as shown in FIG. Further, when the host vehicle is accelerated in order to change the lane at the merging point, and the inter-vehicle time and the approach time between the host vehicle and the rear vehicle increase with the passage of time, as shown in FIG. the rear vehicle stress degree S _r is smaller with the passage of time. When the lane end stress degree S _end (t) and the rear vehicle stress degree S _r (t) as shown in FIG. 11 are calculated, the merging stress degree S _m (t) is calculated as shown in FIG. , from the current time t _0, the confluence stress degree is reduced toward the minimum value and becomes time t ^*, increases toward from the time ^* to time t _end.

Next, in step S310, the lane change control unit 88 determines whether or not steering is started by the driver of the host vehicle in order to change the lane at the junction. In the present embodiment, for example, the lane change control unit 88 determines whether or not the steering angle θ _s acquired in step S301 is greater than or equal to a predetermined value, and if the steering angle θ _s is greater than or equal to a predetermined value, It is determined that steering is started by the driver of the host vehicle. If it is determined that the driver of the host vehicle has started steering, the process proceeds to step S311. On the other hand, if it is determined that the driver of the host vehicle has not started steering, the lane change control process ends. To do.

In step S311, the lane change control unit 88 determines whether or not the lane change of the host vehicle at the merge point can be performed based on the evaluation result of the merge stress degree in step S309. In the present embodiment, the lane change control unit 88 can change the lane of the host vehicle at the junction by determining whether or not there is a time during which the lane change of the host vehicle at the junction can be performed. Determine if you can. Specifically, as shown in FIG. 11, the lane change control unit 88 has a merging stress degree S _m (t) in the time from the current time t ₀ to the time t _end when the _host vehicle reaches the lane terminal point. there by determining whether there is a time below a predetermined value S _m ^a, and determines whether there is a time that can perform the lane change at a junction. In the example shown in FIG. 11, for example, at time t ^*, since the merging stress degree S _{m (t)} is below the predetermined value S _m ^a, it is determined that there is a time that can perform the lane change at junction Thus, it is determined that the lane change of the host vehicle at the junction can be performed. If it is determined that there is time to change the lane at the junction, the process proceeds to step S312 to create a lane change plan, while there is no time to change the lane at the junction. If it is determined, the process proceeds to step S315.

In step S312, in order to create a lane change plan, the lane change control unit 88 calculates the time t ^{* at} which the merging stress degree is minimum as the time when the host vehicle completes merging into the main lane, and the current time The time from t ₀ to time t ^{* at} which the merging stress degree S _m (t) is minimized is calculated as a lane change required time T _Lc ( _TLC = t ^* −t ₀ ).

In step S313, the lane change control unit 88 calculates the target steering angle θ _s ^* based on the lane change required time T _Lc calculated in step S312. Specifically, as shown in FIG. 12, the lane change control unit 88 calculates the target steering angle θ _s ^* along the time series based on the lane change required time T _Lc . Here, FIG. 12 is a diagram illustrating an example of the target steering angle θ _s ^* calculated in the third embodiment. For example, as shown in FIG. 12, the lane change control unit 88 performs a target steering angle at a lane change required time T _Lc from the current time t ₀ to the time t ^{* at} which the merging stress degree S _m (t) is minimum. θ _s ^* is calculated as a sinusoidal steering pattern whose cycle is the lane change required time _TLc . Note that the magnitude of the target steering angle θ _s ^* (the amplitude of the sinusoidal steering pattern) is preferably set to a value sufficient for the host vehicle to move from the center position of the merged lane to the center position of the main lane. It is.

Then, in step S314, the out of target steering angle theta _s ^* calculated in step S313, the target steering angle theta _s ^* in accordance with the current time is output to the motor controller 90, the motor con roller 90, turning assist The motor 100 is controlled. Thereby, steering control according to a lane change plan will be performed in the lane change of the own vehicle in a junction.

  In Step S311, when it is determined that the lane change cannot be performed at the junction, the process proceeds to Step S315. In step S315, in this situation, it is determined that it is difficult to change the lane at the junction, and a warning is given to the driver of the host vehicle. And after warning is performed in step S315, this lane change control process is complete | finished.

  As described above, in the lane change control device according to the third embodiment, numerical data (lanes) corresponding to the time until the host vehicle reaches the lane end of the merging lane along the time series in the lane end stress degree. As a function representing the time course of the end-point stress level), and the rear vehicle stress level is calculated along the time series with numerical data corresponding to the inter-vehicle time and the approach time between the host vehicle and the rear vehicle (rear vehicle stress level). It is calculated as a function representing a change with time. Then, by adding the numerical data along the time series of the lane end stress degree and the numerical data along the time series of the rear vehicle stress degree, or by selecting the maximum value at each time, the merging stress The degree can be appropriately calculated as numerical data along a time series. Thereby, in 3rd Embodiment, the time when the merging stress degree becomes the minimum can be calculated, and the lane change required time for changing the lane of the host vehicle so as to change the lane at the time when the merging stress degree becomes the minimum. Can be calculated. As a result, in the third embodiment, in addition to the effects of the first embodiment, guidance of the host vehicle is performed so that the host vehicle changes the lane in accordance with the timing when the driver's driver's stress is minimized. This can be performed, and the driving load on the driver of the vehicle at the junction can be further reduced.

<< Fourth Embodiment >>
Subsequently, a lane change control device according to a fourth embodiment will be described. The lane change control device according to the fourth embodiment has the same configuration as the lane change control device shown in FIG. 1, and step S306 for evaluating the lane end stress degree, step S308 for evaluating the rear end stress degree, Only in step S309 and step S311 for evaluating the merging stress degree, unlike the lane change control device according to the third embodiment, the other processes are performed in the same manner as in the third embodiment. Therefore, in the following, steps S306, S308, S309, and step S311 according to the fourth embodiment will be described.

In step S306, the lane end stress evaluation unit 86 evaluates the lane end stress degree. In the fourth embodiment, the lane end stress evaluation unit 86 first calculates the arrival time TTC _end (t) until the _host vehicle reaches the lane end point x _end of the merged lane, as in the third embodiment. To do.

ここで、ＴＴＣ_ｅｎｄ ^ｍｉｎは、到達時間ＴＴＣ_ｅｎｄ（ｔ）が小さいために、自車両の運転者のストレスが大きく、自車両の運転者により車線変更が許容されない状態であると考えられる到達時間である。また、ＴＴＣ_ｅｎｄ ^ｍａｘは、到達時間ＴＴＣ_ｅｎｄ（ｔ）が大きいために、車線終端点に接近することに対する自車両の運転者のストレスは小さく、自車両の運転者により車線終端点があまり意識されることがない状態であると考えられる到達時間である。 Then, the lane end stress evaluation unit 86 evaluates the lane end stress degree S _end (t) based on the calculated arrival time TTC _end (t). Specifically, the lane end stress evaluation unit 86 calculates the lane end stress degree S _end (t) as numerical data along a time series based on the following formula (22).

Here, TTC _end ^min is an arrival time that is considered to be a state in which the driver's own vehicle driver has a large stress because the arrival time TTC _end (t) is small and the driver of the own vehicle is not allowed to change lanes. is there. In addition, since TTC _end ^max has a large arrival time TTC _end (t), the stress on the driver of the own vehicle for approaching the lane end point is small, and the lane end point is less conscious by the driver of the own vehicle. It is the arrival time that is considered to be in a state where there is no problem.

Thus, the lane end stress evaluation unit 86, when the approach time TTC _end (t) is equal to or shorter than the predetermined time TTC _end ^min (TTC _end (t) ≦ TTC _end ^min ) according to the above equation (22), The lane end stress degree S _end (t) is calculated as an upper limit “1” (S _end (t) = 1), and the approach time TTC _end (t) is larger than the predetermined time TTC _end ^max (TTC _end ( If t)> TTC _end ^max ), the lane end stress degree S _end (t) is calculated as “0” which is the lower limit (S _end (t) = 0). Further, the lane termination stress evaluation unit 86 has the arrival time TTC _end (t) larger than the predetermined time TTC _end ^{min and not} more than the predetermined time TTC _end ^max (TTC _end ^min ≦ TTC _end (t) ≦ TTC _end ^max ), the higher the arrival time TTC _end (t), the lane end stress degree S _end (t) continuously changes from the upper limit “1” to the lower limit “0”. Calculate as follows.

In step S308, the rear vehicle stress evaluation unit 87 evaluates the rear vehicle stress level. In the fourth embodiment, first, as in the third embodiment, an inter-vehicle time h _r (t) between the host vehicle and the rear vehicle and an approach time TTC _r (t) between the host vehicle and the rear vehicle are calculated. Is done.

ここで、ｈ_ｒ ^ｍｉｎは、車間時間ｈ_ｒ（ｔ）が小さいため、後方車両に対する自車両の運転者のストレスが大きくなり、自車両の運転者により車線変更が許容されない状態であると考えられる車間時間である。同様に、ＴＴＣ_ｒ ^ｍｉｎは、接近時間ＴＴＣ_ｒ（ｔ）が小さいため、自車両の運転者により車線変更が許容されない状態であると考えられる接近時間である。一方、ｈ_ｒ ^ｍａｘは、車間時間ｈ_ｒ（ｔ）が大きいため、後方車両に対する自車両の運転者のストレスは小さく、自車両の運転者により後方車両があまり意識されない状態であると考えられる車間時間であり、同様に、ＴＴＣ_ｒ ^ｍａｘは、車間時間ＴＴＣ_ｒ（ｔ）が大きいため、自車両の運転者により後方車両があまり意識されない状態であると考えられる車間時間である。 Then, the rear vehicle stress evaluation unit 87, based on the calculated inter-vehicle time h _r (t), calculates the driver's stress due to the inter-vehicle time h _r (t) as shown in the following equation (23). and calculates a time headway stress degree _S h (t), based on the calculated approach time _TTC r (t), as shown in the following formula (24), the driver of the vehicle by the approaching time _TTC r (t) _Is calculated as an approach time stress degree S _TTC (t).

Here, h _r ^min is considered to be a state in which the driver's stress on the rear vehicle increases because the inter-vehicle time h _r (t) is small, and the driver of the host vehicle is not allowed to change lanes. It is the time between cars. Similarly, TTC _r ^min is an approach time that is considered to be a state in which a lane change is not permitted by the driver of the host vehicle because the approach time TTC _r (t) is small. On the other hand, h _r ^max has a large inter-vehicle time h _r (t), so that the driver's stress on the vehicle behind the vehicle is small, and the vehicle lane is considered to be a state in which the vehicle behind the vehicle is not much conscious by the driver of the vehicle. Similarly, TTC _r ^max is an inter-vehicle time that is considered to be a state in which the driver of the host vehicle is less aware of the rear vehicle because the inter-vehicle time TTC _r (t) is large.

Thus, the rear vehicle stress evaluation unit 87, when the inter-vehicle time h _r (t) is equal to or shorter than the predetermined time h _r ^min (h _r (t) ≦ h _r ^min ) according to the above equation (24), The inter-vehicle time stress degree S _h (t) due to the inter-vehicle time h _r is calculated as “1” which is the upper limit (S _h (t) = 1), and the inter-vehicle time h _r (t) is greater than the predetermined time h _r ^max. If it is larger (h _r (t)> h _r ^max ), the inter-vehicle time stress degree S _h (t) due to the inter-vehicle time h _r is calculated as “0” which is the lower limit (S _h (t) = 0). . Further, the rear vehicle stress evaluation unit 87 determines that the inter-vehicle time h _r (t) is greater than the predetermined time h _r ^{min and not} more than the predetermined time h _r ^max (h _r ^min <h _r (t) ≦ h If _r ^max) is an inter-vehicle time _h r (t) the time headway due to the stress degree _S h (t), the larger the inter-vehicle time _h r (t) is the lower limit value from a maximum value of "1", " It is calculated so as to continuously change to “0”. Similarly, the rear vehicle stress evaluation unit 87 calculates the approach time stress degree S _TTC (t) based on the approach time TTC _r (t).

Next, the rear vehicle stress evaluation unit 87 determines the degree of inter-vehicle time stress S _h (t) based on the inter-vehicle time h _r (t) at each time t and the approach time stress S based on the approach time TTC _r (t) at each time t. _{Based on TTC} (t), the rear vehicle stress degree S _r (t) at each time t is calculated. In the fourth embodiment, among the inter-vehicle time stress degree S _h (t) based on the inter-vehicle time h _r (t) and the approach time stress degree S _TTC (t) based on the approach time TTC _r (t), the stress degree Assuming that one of the larger ones greatly affects the driver of the host vehicle, the rear vehicle stress degree S _r (t) at each time t is calculated as shown in the following formula (25).

Here, in the above equation (25), when the inter-vehicle time stress degree S _h (t) with respect to the inter-vehicle time is selected as the merging stress degree S _r (t), the host vehicle and the rear vehicle travel in the same degree. It is assumed that the vehicle is traveling at a speed. As the relative speed between the host vehicle and the rear vehicle decreases, the approach time TTC _r (t) increases with respect to the inter-vehicle time h _r (t). Therefore, the stress degree S _h (t) based on the inter-vehicle time is This is because it is assumed that the rear vehicle stress degree S _TTC (t) is larger than the approach time. As described above, when the host vehicle and the rear vehicle are traveling at the same traveling speed, the distance between the host vehicle and the rear vehicle can be changed to the front of the rear vehicle. If the distance is secured, it is assumed that the rear vehicle predicts the lane change of the own vehicle and behaves so as not to approach the own vehicle. It is assumed that stress will also be reduced. Therefore, when the lane change control unit 88 selects the inter-vehicle time stress level S _h (t) based on the inter-vehicle time h _r (t) as the merging stress level S _r (t) in the above equation (25), The vehicle stress degree S _r (t) is set as described below.

なお、上記式（２６）において、Ｒ_ｍｉｎは、自車両が後方車両の前方に車線変更することが可能な自車両と後方車両との車間距離のうち、最小の車間距離である。 That is, first, the rear vehicle stress evaluation unit 87, the inter-vehicle distance between the host vehicle and the rear vehicle, the vehicle is calculated time t _R which is able to change lanes in front of the vehicle behind the vehicle distance as possible. Specifically, the rear vehicle stress evaluation unit 87 calculates time t _R according to the following formula (26).

In the above formula (26), R _min is the minimum inter-vehicle distance among the inter-vehicle distances between the host vehicle and the rear vehicle, in which the host vehicle can change lanes ahead of the rear vehicle.

Next, the rear vehicle stress evaluation unit 87 calculates a correction amount ΔS (t) for correcting the rear vehicle stress degree S _r (t) based on the time t _R according to the following equation (27). In the following equation (27), S _max represents a maximum value of the correction amount, and α represents a parameter value for adjusting the speed of increase of the correction amount.

  The rear vehicle stress evaluation unit 87 detects the operation state of the direction indicator of the host vehicle, and when the lighting of the direction indicator on the main lane side is detected, Is set to a larger value so that the lane change of the host vehicle can be predicted earlier and the lane change of the host vehicle can be performed at an earlier timing. Thus, the correction amount ΔS (t) may be calculated.

ここで、下記式（２８）においては、補正値であることを示す「^〜」を、Ｓ_ｒ（ｔ）の「Ｓ」の真上としているが、下記式（２９）に示すように、これはＳｒ^〜（ｔ）と同義である。

Then, the rear vehicle stress evaluation unit 87 uses the calculated correction amount ΔS (t) to calculate the rear vehicle stress degree S _r ^to (t) at each time t as shown in the following formula (28). . Note that S _r ^to (t) is the corrected rear vehicle stress degree S _r (t).

Here, in the following formula (28), “ ^˜ ” indicating a correction value is set immediately above “S” of S _r (t), but as shown in the following formula (29), Is synonymous with Sr ^~ (t).

In step S309, the lane change control unit 88 uses the lane end stress degree S _end (t) calculated in step S306, the rear vehicle stress degree S _r (t) calculated in step S308, or the corrected rear side. Based on the vehicle stress level S _r ^˜ (t), the merging stress level S _m (t) is calculated. For example, when the corrected rear vehicle stress degree S _r ^˜ (t) is calculated, as shown in FIG. 13, based on the following equation (30), the merging at each time t after the current time t ₀ The degree of stress S _m (t) is calculated. FIG. 13 is a diagram illustrating an example of the merging stress degree S _m (t) in the fourth embodiment.

なお、上記式（３０），（３１）は、後方車両ストレス度合Ｓ_ｒ（ｔ）が補正された場合の合流ストレス度合Ｓ_ｍ（ｔ）の算出方法を示すものであり、後方ストレス度合Ｓ_ｒ（ｔ）が補正されていない場合には、下記式（３０），（３１）における後方ストレス度合Ｓ_ｒ ^〜（ｔ）を、後方車両ストレス度合Ｓ_ｒに置き換えることで、合流ストレス度合Ｓ_ｍ（ｔ）を算出することができる。 Further, the lane change control unit 88 may calculate the merging stress degree S _m (t) according to the following equation (31).

The above formula (30), (31) shows a method of calculating the converging stress degree _S m (t) when the rear vehicle stress degree _S r (t) is corrected backward stress degree _{S r} When (t) is not corrected, the merging stress degree S _m (( _m ) is replaced by replacing the rear stress degree S _r ^to (t) in the following expressions (30) and (31) with the rear vehicle stress degree S _r. t) can be calculated.

In step S311, the lane change control unit 88 determines whether or not the lane change can be performed at the merging point based on the evaluation result of the merging stress degree. In the fourth embodiment, as shown in FIG. 13, the lane change control unit 88 has the merging stress degree S _m (t) at the time t _end from the current time t ₀ until the host vehicle reaches the lane end. By determining whether or not there is a time smaller than 1, it is determined whether or not a lane change can be performed at the junction.

As described above, in the lane change control device according to the fourth embodiment, when the arrival time TTC _end (t) is equal to or less than the predetermined value TTC _end ^min , the lane change is not permitted by the driver of the host vehicle. If it is determined that there is an upper limit value for the degree of lane change stress and the arrival time TTC _end (t) is greater than the predetermined value TTC _end ^max , the driver of the host vehicle will drive the lane termination point of the merging lane. Is set to a lower limit value for the degree of lane change stress. The lane change stress level is calculated within a range between the set upper limit value and lower limit value. Similarly, an upper limit value and a lower limit value are set for an inter-vehicle time stress level based on the inter-vehicle time h _r (t) and an approach time stress level based on the approach time TTC _r (t). In the range between, the inter-vehicle time stress degree due to the inter-vehicle time h _r (t) and the approach time stress degree due to the approach time TTC _r (t) are calculated. Thus, in the fourth embodiment, in addition to the effects of the first embodiment, it is possible to prevent either one of the lane end stress degree and the rear vehicle stress degree from becoming an excessive value, and the lane end stress degree. And the merging stress degree in which the rear vehicle stress degree is balanced can be calculated.

  Further, in the fourth embodiment, the host vehicle and the rear vehicle are traveling at the same level, and the distance between the host vehicle and the rear vehicle can change the lane to the front of the rear vehicle. If it is within the range, the rear vehicle predicts a lane change of the host vehicle, determines that a certain inter-vehicle distance is secured with respect to the host vehicle, and sets the rear vehicle stress level to be low. Further, in such a case, when lighting of the direction indicator of the host vehicle is detected, the driver of the rear vehicle determines that the lane change of the host vehicle is predicted earlier, and the lane of the host vehicle is determined. The rear vehicle stress level is set so that the change can be made at an earlier timing. Thus, in 4th Embodiment, according to the driving | running state of the own vehicle and a back vehicle, a back vehicle stress degree can be calculated appropriately, and the driving | running | working of the own vehicle at the time of changing a lane at a junction It is possible to more appropriately evaluate a person's stress.

«Fifth embodiment»
Subsequently, a lane change control device according to a fifth embodiment will be described. The lane change control device according to the fifth embodiment has the same configuration as the lane change control device shown in FIG. 1, and the lane change according to the first embodiment only in step S111 for calculating the lane change required time. Unlike the control device, the other processes are performed in the same manner as in the first embodiment. Therefore, step S111 according to the fifth embodiment will be described below.

In step S111 according to the fifth embodiment, the lane change control unit 88 calculates the lane change required time _TLC based on the operation state of the direction indicator of the host vehicle. Hereinafter, a method of calculating the lane change required time _TLC in the fifth embodiment will be described. Incidentally, lane until in the fifth embodiment, like the first embodiment, a traveling duration T _A where the vehicle continues to travel at the joining lanes, before exiting the turning of the vehicle is started by calculating the change time T _B, to calculate the lane change required time T _LC.

なお、現在時刻ｔ_０において自車両の方向指示器が点灯されていない場合には、自車両の運転者が、所定時間Ｔ_ｏｎ後に、自車両の方向指示器を点灯させるものと判断し、上記式（３２）のｔ_ｗを、現在時刻ｔ_０から所定時間Ｔ_ｏｎ経過した時刻（ｔ_ｗ＝ｔ_０＋Ｔ_ｏｎ）として設定してもよい。 Here, when the host vehicle changes the lane at the junction, the driver of the host vehicle operates the direction indicator switch 50 and turns on the direction indicator on the main lane side. In order for the driver of the vehicle behind to recognize that the host vehicle is changing lanes, it is recommended that the lane indicator is lit to continue running in the merged lane for a certain period of time. Therefore, the lane change control section 88 performs the detection of the operating status of the direction indicator of the main lane side, when detecting the lighting of the direction indicator, the travel duration T _A, the conditions of the following formula (32) Judge that it satisfies. In the following equation (32), _tw is the time when lighting of the direction indicator on the main lane is detected, and _Tw is the vehicle after the driver of the vehicle turns on the direction indicator. Is the recommended time to continue running in the merge lane.

In the case where the current time t ₀ the direction indicator of the vehicle is not lit, the driver of the vehicle, after a predetermined time T _on, determines that turns on the turn signal of the vehicle, the the _{t w} of formula (32) may be set from the present time _{t 0} as the predetermined time _{T on} elapsed time _{(t w} = t 0 _{+ T on).}

Then, from the equation (32), travel duration T _A is the time from the current time t ₀ to the time of lighting of the direction indicator of the vehicle is detected to (t w _{-t 0),} the direction of the vehicle after lighting of the indicator, the condition is satisfied and determines that the host vehicle is recommended time T _w the total time over which it is recommended to continue running at the joining lane _{(T a ≧ T w + t} w -t 0) Is done. Further, as described above, at the time of turning to change the lane, it is necessary to secure at least the minimum required time T _min ′. Therefore, among the lane change required time _{T LC,} lane change time _{T B} from the start to the end of the turning of the vehicle, the minimum required time _{T min} 'or _{(T B} ≧ _{T min'),} and therefore , provided that the travel duration _{T a} is the 'less time obtained by subtracting _{(T a ≦ T LC -T min} ' minimum required time _{T min} from the lane change required time _{T LC (T LC = T a} + T B)) Is also satisfied. Therefore, the lane change control unit 88 calculates a provisional value T _A ^ for the travel duration T _A according to the following equation (33). Note that min () in the following equation (33) is the recommended travel duration (T _w + t _w −t ₀ ) when the direction indicator is turned on, and the minimum required time T _min ′ required for turning. Of the travel duration ( _TLC− T _min ′) based on the value is selectively calculated (the same applies to equation (34) below).

Meanwhile, the lane change time T _B until the vehicle has been completed since the start of steering, in response to turning too fast is not permitted, a lane change time T _B is the minimum required time T _{min 'or} Although the constraint of (T _B ≧ T _min ′) is provided, turning that is too slow also causes a sense of discomfort for the driver. Therefore, the lane change control section 88, 'in case of the lane change time _{T B} is the maximum required time _{T max'} the maximum duration allowed for when performing turning _{T max} below _{(T B} ≦ _{T max} ' ) is to satisfy also the condition that a, calculates a lane change time T _B. Specifically, the lane change control unit 88 based on the calculated provisional value T _{A ^,} the lane change time T _B, is calculated according to the following equation (34).

Then, the lane change control unit 88, based on the calculated lane change time T _B, according to the following equation (35), calculates the travel duration T _A.

As described above, the lane change control device according to the fifth embodiment detects the operation status of the direction indicator of the host vehicle, and when the lighting of the direction indicator of the host vehicle is detected, the driver of the host vehicle. Determines that the vehicle will continue to travel in the merging lane for a certain period of time after the direction indicator is lit, in order for the driver of the rear vehicle to recognize that the lane change will occur. by calculating the vehicle traveling duration T _a to continue the running of, for calculating the lane change duration T _LC. As a result, in the fifth embodiment, in addition to the effects of the first embodiment, the steering control of the host vehicle can be performed by the recommended driving method according to the operation status of the direction indicator of the host vehicle. The vehicle can be guided more appropriately at the point.

<< Sixth Embodiment >>
Subsequently, a lane change control device according to a sixth embodiment will be described. The lane change control device according to the sixth embodiment has the same configuration as the lane change control device shown in FIG. 1 and is the same as the first embodiment except that it operates as described below. . Below, with reference to FIG. 14, operation | movement of the lane change control apparatus which concerns on 6th Embodiment is demonstrated. FIG. 14 is a flowchart showing a lane change control process according to the sixth embodiment. Note that the lane change control process according to the sixth embodiment is also repeatedly performed by the microprocessor 80 at regular time intervals.

  In steps S601 to S603, as in steps S101 to S103 of the first embodiment, the travel information of the host vehicle, the lane information including the lane termination point of the merged lane, and the travel information of other vehicles are acquired.

In step S604, the lane change control unit 88 determines whether or not the merging control mode for changing the lane at the merging point is on. Specifically, it is determined that the merge control mode is on when all of the following four conditions are satisfied. That is, first, the driver of the host vehicle is permitted to perform steering control at the junction (first condition), and second, the host vehicle is traveling in a range where the host vehicle can join the main lane. (2nd condition), 3rd, the lane change in a junction is not completed (3rd condition), 4th, the stop mode mentioned later is not ON (4th condition) When the four conditions are satisfied, it is determined that the merge control mode is on. Here, with respect to the first condition, for example, when a switch (not shown) for permitting steering control at the junction is turned on by the driver of the host vehicle, the driver of the host vehicle joins. It is determined that the steering control at the point is permitted. As for the second condition, for example, as shown in FIG. 4 or FIG. 9, the traveling position x _h of the host vehicle is within the range from the _mergeable start point x _start to the lane end point x _end (x _start ≦ x _h ≦ x _end ), it is determined that the host vehicle is traveling in a range where it can join the main lane. If it is determined that the merge control mode is on, the process proceeds to step S605. On the other hand, if it is determined that the merge control mode is off, the lane change control process is terminated.

  In steps S605 and S606, as in steps S105 and 106 of the first embodiment, the behavior of the host vehicle at the junction is predicted (step S605). Based on the predicted behavior of the host vehicle, the lane end stress degree is calculated. Is evaluated (step S606).

In step S607, the rear vehicle behavior prediction unit 85 predicts the behavior of the rear vehicle at the junction. Below, with reference to FIG. 15, the back vehicle behavior prediction process of step S607 is demonstrated. FIG. 15 is a flowchart showing the rear vehicle behavior prediction process in step S607. In the following, a method for predicting the behavior of the rear vehicle will be described assuming that the rear vehicle and the front vehicle exist around the host vehicle as in the scene example shown in FIG. Further, in this rear vehicle behavior prediction processing, the predetermined time Delta] t is set as the cycle time, the behavior of the rear vehicle in the merging point is predicted at each time t _p of each cycle time Delta] t.

First, in step S6701, the continuation time T _p in which the merging impossible state (details will be described later) continues is set to the initial value 0 (T _p = 0), and the continuation time T _p is obtained. time _{t p} of is set to the current time _{t 0} initial value _(t p _{= t} 0).

  Next, in step S6702, in order to predict the behavior of the rear vehicle at the merging point using a known following model, a target vehicle to be followed by the rear vehicle is set. Specifically, the rear vehicle behavior predicting unit 85 sets the own vehicle as a vehicle to be followed by the rear vehicle when the own vehicle starts turning at the joining point, while the own vehicle joins. When the steering is not started at the point, the front vehicle is set as a vehicle to be followed by the rear vehicle.

In step S6703, the prediction of the behavior of the host vehicle and the preceding vehicle at time _{t p} is performed. Specifically, the rear vehicle behavior prediction unit 85 calculates the traveling position of the vehicle _x h ^ _{(t p)} and the traveling speed _v h ^ _{(t p)} at a time _{t p,} the preceding vehicle at time _{t p} The travel position x _f ^ (t _p ) and the travel speed v _f ^ (t _p ) are calculated. Incidentally, the running position of the vehicle at time _{t p x h ^ (t p} ) and the traveling speed _v h ^ _{(t p)} is the running position of the vehicle predicted in Step S605 _x h ^ (t) and the traveling speed v _h ^ (t) can be used. The time _t traveling position of the forward vehicle in the _{p x} f ^ _{(t p)} and the traveling speed _v f ^ _{(t p)} is, for example, preceding vehicle speed of the forward vehicle as being constant, calculated in step S603 based of the current speed v _f, it can be calculated.

  In step S6704, it is determined whether or not the preceding vehicle is set as a vehicle to be followed by the following vehicle. If the preceding vehicle is set as the tracking target vehicle, the process proceeds to step S6705. If the host vehicle is set as the tracking target vehicle, the process proceeds to step S6710.

なお、Ｒ_０は、後方車両から自車両を視認することができる自車両と後方車両との車間距離のうち、最小の車間距離であり、また、Ｖ_０は、自車両と後方車両がほぼ同じ速度で走行していると判断できる相対速度のうち、最大の相対速度である。なお、自車両が合流不可能状態であるか否かを判定する際には、上記式（３６），（３７）に示す条件に加えて、自車両と後方車両との車間距離が、自車両が後方車両の前方に車線変更することができない範囲にあるという条件を満たすかを判定してもよい。 In step S6705, it is determined whether or not the host vehicle is in a merging impossible state where the lane cannot be changed to the main lane. Specifically, the rear vehicle behavior prediction unit 85 includes a running position of the vehicle at time _{t p} calculated _x h ^ _{(t p)} and the traveling speed _v h ^ _{(t p)} at step S6703, at time _{t p} By determining whether or not the traveling position x _r ^ (t _p ) and the traveling speed v _r ^ (t _p ) of the rear vehicle _{satisfy the} conditions shown in the following expressions (36) and (37), at time t _p, it is determined whether or not the own vehicle is merging impossible state.

Note that R ₀ is the minimum inter-vehicle distance of the inter-vehicle distance between the host vehicle and the rear vehicle in which the host vehicle can be visually recognized from the rear vehicle, and V ₀ is substantially the same for the host vehicle and the rear vehicle. It is the maximum relative speed among the relative speeds that can be determined to be traveling at a speed. When determining whether or not the host vehicle is in a state where it cannot join, in addition to the conditions shown in the above formulas (36) and (37), the inter-vehicle distance between the host vehicle and the rear vehicle is determined as follows. It may be determined whether the condition that the vehicle is in a range where the lane cannot be changed in front of the rear vehicle is satisfied.

In step S6705, when the vehicle is determined to be confluent impossible state at time t _p, the process proceeds to step S6706, whereas, if at time t _p, is determined that the vehicle is not in merging impossible state Advances to step S6709, and the duration T _p during which the unmerging state is continued is reset to zero.

In step S6706, since it is determined that the vehicle is merging impossible state, the duration T _p of merging impossible state continues, adds cycle time Δt as described above, the duration T _p is updated .

In step S6707, the duration _{T p} is greater whether a determination is made than the predetermined time _T ^{p 0.} If the duration T _p is determined to be greater than the predetermined time T _p ⁰ is the driver of the rear vehicle, the vehicle in front of the rear vehicle is expected to change lanes, the rear vehicle vehicle On the other hand, it is determined that the vehicle behaves so as to ensure a certain inter-vehicle distance, and the process proceeds to step S6708. In step S6708, the follow target vehicle is changed from the preceding vehicle to the own vehicle. On the other hand, if it is determined in step S6707 that the duration time T _p is equal to or shorter than the predetermined time T _p ⁰ , the preceding vehicle continues to be set as the tracking target vehicle and proceeds to step S6710.

The rear vehicle behavior predicting unit 85 detects the operation status of the turn indicator of the host vehicle, and when the turn indicator on the main lane is detected, the driver of the rear vehicle The predetermined time T _p ⁰ may be set to a smaller value by determining that it is possible to predict at an earlier timing that the host vehicle will change the lane ahead.

In step S6710, the behavior of the rear vehicle at the merging point is predicted based on a known tracking model. Specifically, the rear vehicle behavior prediction unit 85, the vehicle or the preceding vehicle is set as follow the target vehicle, as the rear vehicle to follow, to predict the behavior of the rear vehicle at time t _p. In step S6711, the time _{t p} is updated to the time that the cycle time Δt elapses described above.

In step S6712, it is determined whether or not the behavior of the rear vehicle is predicted until the time t _end when the host vehicle reaches the lane terminal point. In the present embodiment, the rear vehicle behavior prediction unit 85, the time t _p is the own vehicle is equal to or slower than the correct time t _end to reach the lane end point, time t _p the time t _{When the} time is later than _end, it is determined that the behavior of the rear vehicle is predicted until time t _end when the host vehicle reaches the lane terminal point. If the behavior of the rear vehicle to time t _end is determined to have been predicted to end the rear vehicle behavior prediction process. On the other hand, if it is determined that the behavior of the rear vehicle up to the time t _end is not predicted, the process returns to step S6703, and the behavior of the rear vehicle at the junction is reached until the time t _end when the host vehicle reaches the lane terminal point. A prediction is made.

  As described above, the rear vehicle behavior prediction process in step S607 is performed.

  Returning to FIG. 14, in steps S <b> 608 to S <b> 610, as in steps S <b> 108 to S <b> 110 of the first embodiment, the rear vehicle stress degree is evaluated (step S <b> 608), and after the merging stress degree is evaluated (step 608). S609), it is determined whether or not there is a time during which the lane change is allowed at the junction (step S610). In step S610, if it is determined that there is a time during which the lane change is allowed at the junction, the process proceeds to step S611. On the other hand, if it is determined that there is no time during which the lane change is allowed at the junction, The process proceeds to step S615.

なお、上記式（３８）において、ｔ_ｗ’は、自車両と後方車両とが上記式（３６），（３７）に示す条件を満たすことで、自車両が合流不可能状態となった最初の時刻である。また、Ｔ_ｗ’は、合流不可能状態が継続することで、後方車両の運転者が、自車両が後方車両の前方に車線変更することを予測し、自車両と一定の車間距離をとるように挙動するものと判断されるまでの時間であり、例えば、上述したステップＳ６７０７で導入した所定時間Ｔ_ｐ ^０を用いることができる。 In step S611, the lane change control unit 88 calculates the lane change required time. Here, in the sixth embodiment, the host vehicle travels in the merged lane until the rear vehicle behaves so as to predict a lane change of the host vehicle and secure a certain inter-vehicle distance with respect to the host vehicle. it is determined that the objects may calculate the travel duration T _a constituting the lane change required time T _LC. Specifically, the lane change control unit 88, travel duration T _A is as satisfy the condition represented by the following formula (38), calculates the travel duration T _A.

In the above formula (38), t _w ′ is the first time when the host vehicle and the rear vehicle satisfy the conditions shown in the above formulas (36) and (37), and the host vehicle becomes in a state where it cannot merge. It's time. In addition, T _w ′ predicts that the driver of the vehicle behind the vehicle will change lanes ahead of the vehicle behind the vehicle by taking a state where the merge is impossible, and takes a certain distance between the vehicle and the vehicle. For example, the predetermined time T _p ⁰ introduced in step S6707 described above can be used.

  Next, in steps S612 and S613, similarly to steps S112 and 113 of the first embodiment, the target steering angle is calculated and output, and the process proceeds to step S614.

In step S614, the lane change control unit 88 outputs the target driving force. Specifically, the lane change control unit 88 can calculate, for example, the driving force for obtaining the estimated target acceleration a ^* ^ calculated in step S601 as the target driving force, and output the target driving force to the power train controller 110. Thus, the power train controller 110 calculates the throttle opening of the engine and the transmission gear ratio in accordance with the target driving force, and controls the engine / drive mechanism 120.

  In step S610, when it is determined that there is no time for which the lane change is allowed at the junction, the process proceeds to step S615. In step S615, the lane change control unit 88 determines whether or not the distance from the current travel position of the host vehicle to the lane end point is equal to or less than a predetermined value. If the distance from the travel position of the host vehicle to the lane end point is less than or equal to the predetermined value, the process proceeds to step S617. On the other hand, if the distance from the travel position of the host vehicle to the lane end point is greater than the predetermined value, step The process proceeds to S616.

  In step S616, it is determined that the distance from the traveling position of the host vehicle to the lane end point is greater than a predetermined value, and that there is a time margin until the host vehicle reaches the lane end point. Therefore, the lane change control unit 88 instructs the power train controller 110 to maintain the current vehicle speed of the host vehicle while continuing the merge control mode, and ends this lane change control process. Thereby, in the lane change control processing after the next time, it is possible to guide the host vehicle at the junction.

  On the other hand, if it is determined in step S615 that the distance from the traveling position of the host vehicle to the lane end point is equal to or smaller than the predetermined value, the process proceeds to step S617. In step S617, since the host vehicle is approaching the lane end point, it is determined that it is difficult to change the lane of the host vehicle, the stop mode for stopping the host vehicle is turned on, and the host vehicle is stopped. As described above, the power train controller 110 is controlled. In addition, after the stop mode for stopping the traveling of the host vehicle is turned on, the merge control mode is not determined to be turned on in step S604 after the next processing, and the host vehicle is not guided at the junction point. It will be.

  As described above, in the lane change control device according to the sixth embodiment, the inter-vehicle distance between the host vehicle and the rear vehicle is within a range where the host vehicle can be visually recognized from the rear vehicle, and the host vehicle and the rear vehicle are the same. When traveling at a certain speed for a predetermined time or longer, the driver of the rear vehicle predicts that the host vehicle will change lanes ahead of the rear vehicle, and sets a certain distance between the host vehicle and the host vehicle. Judgment is taken and the behavior of the rear vehicle at the junction is predicted. Also, in such a case, when lighting of the direction indicator of the host vehicle is detected, the driver of the rear vehicle can change the lane of the host vehicle ahead of the rear vehicle at an earlier timing. Judging that it can be predicted, the behavior of the rear vehicle at the junction is predicted. Thereby, according to 6th Embodiment, in addition to the effect of 1st Embodiment, the behavior of the back vehicle in a junction can be predicted more appropriately according to the driving | running state of the own vehicle and a back vehicle. It is possible to more appropriately evaluate the driver's stress on the vehicle behind the vehicle at the junction.

  Furthermore, in the sixth embodiment, not only the steering control of the host vehicle at the junction point is performed, but also the driving force of the host vehicle at the junction point is controlled based on the estimated target acceleration. Therefore, in 6th Embodiment, the driving load of the driver | operator of the own vehicle at the time of changing a lane at a junction can be reduced more.

  The embodiment described above is described for facilitating understanding of the present invention, and is not described for limiting the present invention. Therefore, each element disclosed in the above embodiment is intended to include all design changes and equivalents belonging to the technical scope of the present invention.

  That is, the present invention is not limited to the above-described embodiment, and may be implemented by combining the above-described first to sixth embodiments.

  In the second and third embodiments described above, the merging stress degree is the sum of the lane end stress degree and the rear vehicle stress degree, or a value that is maximum at each time of the lane end stress degree and the rear vehicle stress degree. However, the present invention is not limited to this. For example, the merging stress level is selected as the minimum value at each time from the lane end stress level and the rear vehicle stress level. It is good also as a structure calculated by doing.

Furthermore, in the second and third embodiments described above, the configuration in which the rear vehicle stress degree is calculated based on the inter-vehicle time and the approach time between the host vehicle and the rear vehicle is exemplified, but the present invention is not limited to this configuration. For example, the rear vehicle stress degree may be calculated based on only one of the inter-vehicle time and the approach time between the host vehicle and the rear vehicle.
In addition, a travel information acquisition unit 81 that acquires travel information of the host vehicle (own vehicle position information), a lane information acquisition unit 82 that acquires lane information of the lane in which the host vehicle travels, and other vehicles that travel around the host vehicle are detected. The other vehicle detection unit 83, the own vehicle behavior prediction unit 84 that predicts the behavior of the host vehicle at the junction, the rear vehicle behavior prediction unit 85 that predicts the behavior of the rear vehicle traveling behind the host vehicle in the main lane, and the host vehicle A lane end stress evaluation unit 86 that evaluates the driver's stress on the host vehicle when the vehicle approaches the lane end point, a rear vehicle stress evaluation unit 87 that evaluates the driver's stress on the rear vehicle at the junction, and a lane The process up to the merge stress evaluation of the change control unit 88 is not stored in the vehicle in advance as a lane change stress evaluation method, but is communicated from the outside as program data. Receiving Te, it may be stored. As a result, the latest meeting point can be updated at any time, and the user can save time and effort.

  In the above-described embodiment, the travel information acquisition unit 81 of the microprocessor 80 is the travel information acquisition unit of the present invention, the lane information acquisition unit 82 is the lane information acquisition unit of the present invention, and the own vehicle behavior prediction unit 84 is the present invention. The other vehicle detecting unit 83 is used as the other vehicle detecting unit of the present invention, the rear vehicle behavior predicting unit 85 is used as the lane end stress for the rear vehicle behavior predicting unit and the incompatibility determining unit of the present invention. The evaluation unit 86 is a lane end stress evaluation unit of the present invention, the rear vehicle stress evaluation unit 87 is a rear vehicle stress evaluation unit and a mergeable state determination unit of the present invention, and the lane change control unit 88 is a merge stress evaluation unit of the present invention. The lane change planning means and the guidance means, and the motor controller 90 and the steering assist motor 100 correspond to the guidance means of the present invention.

DESCRIPTION OF SYMBOLS 10a-10d ... Camera 20 ... Vehicle speed sensor 30 ... Stroke sensor 40 ... Steering angle sensor 50 ... Direction indication switch 60 ... GPS unit 70 ... Road information database 80 ... Microprocessor 81 ... Travel information acquisition part 82 ... Lane information acquisition part 83 ... Other vehicle detection unit 84 ... own vehicle behavior prediction unit 85 ... rear vehicle behavior prediction unit 86 ... lane end stress evaluation unit 87 ... rear vehicle stress evaluation unit 88 ... lane change control unit 90 ... motor controller 100 ... steering assist motor 110 ... power Train controller 120 ... engine and drive system

Claims (13)

Traveling information acquisition means for acquiring traveling information including the steering angle of the host vehicle;
Based on the travel information of the host vehicle, it is determined whether the lane in which the host vehicle is traveling is a merge lane that merges with the main lane, and when the lane in which the host vehicle is traveling is the merge lane, Lane information acquisition means for acquiring position information of a lane terminal that is the terminal of the merging lane at a merging point where the main lane merges;
Based on the traveling information of the host vehicle, the host vehicle behavior prediction means for predicting the behavior of the host vehicle at the junction point;
Other vehicle detection means for detecting other vehicles traveling around the host vehicle and detecting the detected traveling information of the other vehicles;
When the other vehicle detected by the other vehicle detection means is a rear vehicle that travels behind the host vehicle in the main lane, based on the travel information of the other vehicle, the rear vehicle at the junction point. Rear vehicle behavior prediction means for predicting behavior,
Based on the positional information of the lane termination point and the prediction result of the behavior of the host vehicle at the merging point, the stress of the driver of the host vehicle when the host vehicle approaches the lane termination point is determined. As lane end stress evaluation means to evaluate along the time series ,
Based on the prediction result of the behavior of the host vehicle at the junction point and the prediction result of the behavior of the rear vehicle at the junction point, the stress of the driver of the host vehicle with respect to the rear vehicle at the junction point is determined as the degree of rear vehicle stress. As a rear vehicle stress evaluation means for evaluating along the time series ,
The larger value of the lane termination stress degree and the rear vehicle stress degree at each time, as the confluence stress degree is stress of the driver of the vehicle when the vehicle makes a lane change in the junction, when Merging stress evaluation means to evaluate along the series ,
A lane that creates time-series data of the steering angle of the host vehicle as a lane change plan so that the host vehicle can change the lane from the merging lane to the main lane at a timing such that the degree of merging stress decreases. Change planning means,
A lane change control device comprising: guidance means for guiding the host vehicle to the main lane by performing steering control of the host vehicle from the merging lane based on the lane change plan. The lane change control device according to claim 1 ,
The lane change planning means may change the lane from the merging lane to the main lane at a timing such that the numerical data of the merging stress degree calculated along the time series becomes relatively small. A lane change control device that creates the lane change plan so as to be able to do so. The lane change control device according to claim 2 ,
The lane change planning means, when creating the lane change plan, calculates a time when the degree of merging stress is minimum as a time when the own vehicle completes merging into the main lane. Change control unit. The lane change control device according to any one of claims 1 to 3 ,
The lane end stress evaluation means calculates the lane end stress degree as a function representing a change with time of the lane end stress degree,
The rear vehicle stress evaluation means calculates the rear vehicle stress degree as a function representing a temporal change of the rear vehicle stress degree,
The merging stress evaluation means represents the merging stress degree over time based on a function representing a temporal change in the lane end stress degree and a function representing a temporal change in the rear vehicle stress degree. A lane change control device characterized by calculating as a function. A lane change control device according to any one of claims 1 to 4 ,
The numerical data of the lane end stress degree and the numerical data of the rear vehicle stress degree are values that determine that the driver of the own vehicle cannot change the lane when the own vehicle changes the lane at the junction. The lane change control device is set to be within a range between an upper limit stress value that is a lower limit stress value that is a value at which the driver of the vehicle does not feel stress. The lane change control device according to claim 5 ,
The relative speed between the host vehicle and the rear vehicle is equal to or less than a predetermined value, and the inter-vehicle distance between the host vehicle and the rear vehicle is within a range in which the host vehicle can change lanes ahead of the rear vehicle. In this case, the vehicle further comprises a merging possible state judging means for judging that the host vehicle is in a merging possible state capable of merging with the main lane,
The lane change control device according to claim 1, wherein the rear vehicle stress evaluation unit sets the rear vehicle stress degree closer to the lower limit stress value as the duration time of the mergeable state is larger. The lane change control device according to claim 6 ,
The rear vehicle stress evaluation means detects the operation status of the direction indicator of the host vehicle, and when the direction indication operation of the direction indicator is detected, the merging possible state continues, whereby the rear vehicle A lane change control device characterized in that the degree of approaching the degree of stress to the lower limit stress value is increased. A lane change control device according to any one of claims 1 to 7 ,
The lane change planning means ends when the own vehicle starts turning for changing the lane, and a running duration time for which the own vehicle does not start turning and continues to run in the merged lane. A lane change time that is a time until the lane change is calculated, and the time when the total vehicle time that is a total time of the travel duration time and the lane change time has elapsed from the current time is calculated by the host vehicle as the main lane. A lane change control device, characterized in that the time is calculated as a time to complete the merge. The lane change control device according to claim 8 ,
The lane change planning means detects the operation status of the direction indicator of the host vehicle, and when detecting the direction indication operation of the direction indicator, a predetermined time from the time when the direction indication operation of the direction indicator is detected. Determines that the host vehicle continues to travel on the merged lane without starting steering, and calculates the travel duration based on the determination. A lane change control device according to any one of claims 1 to 9 ,
When the relative speed between the host vehicle and the rear vehicle is equal to or less than a predetermined value, and the distance between the host vehicle and the rear vehicle is within a range in which the host vehicle is visible from the rear vehicle, A merging impossible state determining means for determining that the merging is impossible in the main lane;
The rear vehicle behavior predicting means predicts that the rear vehicle behaves so as to ensure a certain inter-vehicle distance with respect to the own vehicle when the unmerged state continues for a predetermined duration or longer.
The rear vehicle stress evaluation means evaluates the rear vehicle stress degree based on a prediction result of the behavior of the rear vehicle. The lane change control device according to claim 10 ,
The rear vehicle behavior predicting means detects the operation status of the direction indicator of the host vehicle, and detects the direction indication operation of the direction indicator, and the rear vehicle behavior is shorter than the predetermined duration time. A lane change control device that predicts that the vehicle behaves so as to ensure a certain inter-vehicle distance with respect to the host vehicle. A lane change control device according to any one of claims 1 to 11 ,
The own vehicle behavior predicting means performs acceleration / deceleration so that the own vehicle does not approach the preceding vehicle too much when the other vehicle detecting means detects a forward vehicle traveling ahead of the own vehicle in the main lane. What to do, predict the behavior of your vehicle,
The lane end stress evaluation means evaluates the lane end stress degree based on a prediction result of the behavior of the host vehicle,
The rear vehicle stress evaluation means evaluates the rear vehicle stress degree based on a prediction result of the behavior of the host vehicle. Driving information acquisition means, own vehicle behavior prediction means, lane information acquisition means, lane end stress evaluation means, other vehicle detection means, rear vehicle behavior prediction means, rear vehicle stress evaluation means, and merging stress evaluation means When using a computer having a, a lane-changing stress evaluation method for evaluating a driver's stress when performing lane change as merging stress degree in junction,
The travel information acquisition means acquires travel information of the host vehicle,
Based on the acquired travel information of the host vehicle, the host vehicle behavior predicting means predicts the behavior of the host vehicle at the junction where the merge lane and the main lane merge ,
By the lane information acquisition means, acquire the position information of the lane end point that is the end of the merging lane,
Based on the position information of the lane termination point acquired by the lane termination stress evaluation means and the predicted behavior of the host vehicle, the driver's stress on the host vehicle when the vehicle approaches the lane termination point Is evaluated along the time series as the degree of lane termination stress,
The other vehicle detection means detects other vehicles around the host vehicle to obtain travel information of the other vehicles,
When the other vehicle is a rear vehicle traveling behind the host vehicle in the main lane by the rear vehicle behavior predicting means, the behavior of the rear vehicle at the junction is determined based on the travel information of the other vehicle. Predict,
Based on the predicted behavior of the other vehicle and the predicted behavior of the host vehicle, the stress of the driver of the host vehicle with respect to the rear vehicle at the junction is determined by the rear vehicle stress evaluation means. As a time series evaluation,
A lane change stress characterized in that the merging stress evaluation means evaluates a larger value of the lane end stress degree and the rear vehicle stress degree at each time as the merging stress degree in time series. Evaluation method.

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