JP7293831B2 - Stop support device - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a stop assist device for stopping a running vehicle at an appropriate stop point.

If the driver becomes unable to drive normally due to a sudden change in physical condition while driving, or if it becomes necessary to automatically stop the vehicle due to an incoming call on the mobile phone while driving, etc. Devices are known for stopping a vehicle by

For example, in Patent Document 1, when an abnormality is detected in the driver, the vehicle stops at a stop point with a long line of sight, such as a straight road, in cooperation with the vehicle's navigation device so that the following vehicle does not collide while the vehicle is stopped. It is disclosed to

JP 2017-190048 A

However, in the setting of a stop point based on the line-of-sight distance using information from the navigation device disclosed in Patent Document 1, the line-of-sight distance of the actual road environment such as obstacles and weather for which the navigation device does not have information. impact is not considered.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a stop support device that stops a vehicle at an appropriate stop point according to the actual road environment.

In order to solve the above problems, the stop assist device of the present invention includes: an information acquisition unit that acquires information about the own vehicle during travel and external environment information; and acquires the information based on the information acquired by the information acquisition unit. a candidate stop point detection unit that detects the candidate stop point with the lowest possibility of being rear-ended by using the position of the vehicle at the point in time as the observation point;
an information storage unit that associates and stores the information acquired by the information acquisition unit , the observation point, and the candidate stop point;
When there is a request to stop, a range in which the vehicle can be stopped is specified by referring to the information of the own vehicle and the external environment information at the time when the request to stop is made, and the range in which the vehicle can be stopped is selected from the plurality of candidate stop points stored in the information storage unit. and a target stop point setting unit that selects and sets, as a target stop point, a stop candidate point that is within the range in which the vehicle can be stopped and has the smallest possibility of being rear-ended.

According to this configuration, considering external environment information that is not reflected in map information such as a navigation device, the possibility of being rear-ended at each point within the section or time zone that the vehicle has traveled in the past is maximized. The vehicle can be stopped according to the actual road environment by setting the vehicle stop candidate point having the lowest possibility of being rear-ended from among the small vehicle stop candidate points as the target vehicle stop point.

Here, the possibility of being rear-ended means the possibility of being rear-ended by a following vehicle. The longer the line-of-sight distance of the own vehicle from the following vehicle at the stopping point, the smaller the possibility of being rear-ended.
Further, the line-of-sight distance is the maximum value of the distance from the following vehicle to the vehicle in a state where the stopped vehicle can be visually recognized from the following vehicle.

In the present invention, the candidate stop point detection unit sets the distance from the observation point at the time when the information acquisition unit acquires the information to the farthest point where the driving lane can be visually recognized as the line of sight distance, and the front side from the farthest point. Nearby driving lanes or roadside points are detected as candidate stopping points. According to this configuration, it is possible to detect, as a stop candidate point, the point with the longest line-of-sight distance, that is, the point with the lowest possibility of being rear-ended at the time when the information is acquired.

In the present invention, the target stop point setting unit has a stop model formula for specifying a range in which the own vehicle can be stopped based on the information acquired by the information acquisition unit. Contains a formula to calculate the distance from the current speed to a complete stop at maximum deceleration of . According to this configuration, it is possible to calculate the range in which the vehicle can stop in consideration of the performance of the own vehicle, and to avoid setting a stop candidate point where the vehicle cannot stop beyond the performance of the own vehicle as the target stop point. .

In the present invention, the stop model formula includes at least either the deceleration considering the relative relationship with the following vehicle or the deceleration considering the comfort of the occupants, and the calculated maximum deceleration of the own vehicle, The lower deceleration is used as the deceleration of the own vehicle to specify the range in which the vehicle can be stopped. According to this configuration, it is possible to specify the stop range in consideration of the relative relationship with the following vehicle without making the passenger feel uncomfortable.

ADVANTAGE OF THE INVENTION According to this invention, the stop assistance apparatus which can select and set an appropriate stop point according to the vehicle in motion can be provided.

1 is a block diagram showing a stop assistance device according to an embodiment of the present invention; FIG. FIG. 4 is a diagram showing the relationship between the length of the line-of-sight distance and the possibility of being rear-ended; It is a flow chart which shows stop support control. FIG. 5 is a diagram showing the relationship between points in the process performed by the stop support device during normal driving according to the embodiment of the present invention; It is a figure which shows the relationship between a driving|running|working lane and a road shoulder. FIG. 5 is a schematic diagram showing each point in processing performed by the stop support device when an automatic stop request is generated according to the embodiment of the present invention; It is a figure which shows line-of-sight distance and a stop position.

Embodiments will be described below with reference to the accompanying drawings. For simplification, the same reference numerals are given to the same components in each drawing, and duplicate descriptions are omitted.

First, referring to FIG. 1, the configuration of a stop support device (hereinafter referred to as "device 1") according to an embodiment will be described. FIG. 1 is a block diagram showing the functions of the device 1. As shown in FIG. The device 1 is mounted on a vehicle and assists the stopping of the running vehicle when automatic stopping is required. In this specification, the vehicle on which the device 1 is mounted is referred to as "vehicle 2".

The device 1 includes a camera 11, a navigation device 12, a vehicle speed sensor 13, a wheel speed sensor 14, a following vehicle speed sensor 15, a following vehicle distance sensor 16, an ECU 17 (Electronic Control Unit), It has

The camera 11 captures an image of the outside of the vehicle 2, particularly the front of the vehicle. The camera 11 is installed, for example, near the room mirror. The camera 11 can communicate with the ECU 17 and provides signals corresponding to acquired image data to the ECU 17 at the request of the ECU 17 or actively.

The navigation device 12 provides information to the occupants of the vehicle 2 . The navigation device 12 provides, for example, map information stored inside the navigation device 12 or map information acquired through communication with a server outside the vehicle. The map information includes road shapes and maximum speeds stipulated for each road by law. The map information may also include information on locations where ambulances such as fire stations and hospitals are deployed, and traffic conditions of each road such as congestion and speed of traffic flow. Further, the navigation device 12 has a function of detecting the vehicle position using a GPS (Global Positioning System), self-contained navigation sensors and algorithms, and the like. Further, the navigation device can communicate with the ECU 17, and provides the ECU 17 with the map information and positional information of the own vehicle at the request of the ECU 17 or actively.

The vehicle speed sensor 13 is a sensor that detects the speed of the vehicle. The vehicle speed sensor 13 is capable of communicating with the ECU 17 and transmits to the ECU 17 a signal corresponding to the vehicle speed detected by the ECU 17 at the request of the ECU 17 or actively.

The wheel speed sensor 14 is a sensor that detects the speed of one or all wheels of the vehicle. The wheel speed sensor 14 can communicate with the ECU 17 and sends a signal corresponding to the detected wheel speed to the ECU 17 at the request of the ECU 17 or actively.

The following vehicle speed sensor 15 is a sensor that detects the speed of the following vehicle or the relative speed between the own vehicle and the following vehicle. The trailing vehicle speed sensor 15 is capable of communicating with the ECU 17 and sends a signal corresponding to the detected speed of the trailing vehicle to the ECU 17 at the request of the ECU 17 or actively. The following vehicle speed sensor 15 may transmit a signal corresponding to not only the speed of the following vehicle but also the relative speed between the own vehicle and the following vehicle.

The following vehicle distance sensor 16 is a sensor that detects the relative distance between the own vehicle and the following vehicle. The trailing vehicle distance sensor 16 can communicate with the ECU 17, and sends a signal corresponding to the detected relative distance between the own vehicle and the trailing vehicle to the ECU 17 at the request of the ECU 17 or actively.

The information acquired by the vehicle speed sensor 13, the wheel speed sensor 14, the following vehicle speed sensor 15, and the following vehicle distance sensor 16 is used to specify the range in which the own vehicle can stop when an automatic stop request occurs. information. The sensor that acquires the information specifying the range in which the own vehicle can stop is not limited to the sensor shown in FIG. 1, and can be appropriately set by those skilled in the art.

The ECU 17 is a control device that controls equipment by transmitting and receiving signals. A part or all of the ECU 17 is configured by an analog circuit or configured as a digital processor. The ECU 17 has an information acquisition section 171 , a candidate stop point detection section 172 , a storage section 173 , and a target stop point setting section 174 .

Moreover, FIG. 1 shows each functional block of the ECU 17 . However, the software modules incorporated in the analog circuit or digital processor of the ECU 17 do not necessarily have to be divided as shown in FIG. That is, each functional block shown in FIG. 1 may be further divided, or a plurality of functional blocks may be integrated into a single functional block. Further, it is not necessary to integrate each functional block into one ECU as shown in FIG. 1, and functions may be achieved by a plurality of ECUs. A person skilled in the art can change the configuration as appropriate as long as the configuration is capable of executing the processing described later.

The information acquisition unit 171 communicates with the camera 11, the navigation device 12, the vehicle speed sensor 13, the wheel speed sensor 14, the following vehicle speed sensor 15, and the following vehicle distance sensor 16 installed in the vehicle, and acquires various information. do.

The candidate stop point detection unit 172 detects the point at which the possibility of a rear-end collision is the lowest, that is, the point with the longest line-of-sight distance, at predetermined time intervals, and a vehicle slightly in front of that point can stop. A point within the range is set as a stop candidate point at that time. The line-of-sight distance may be calculated, for example, from an image acquired by the camera 11, a sensor that directly measures a physical quantity mounted on the vehicle 2, such as an infrared sensor or an ultrasonic sensor, or information from outside the vehicle, such as periodically Map information from the navigation device 12 that is updated may also be used.

Fig. 2 shows the relationship between line-of-sight distance and rear-end collision probability. The longer the line-of-sight distance, the longer the operation time of the evasive movement after the following vehicle visually recognizes the stopped vehicle, and the lower the possibility of being rear-ended. On the other hand, the shorter the line-of-sight distance, the shorter the avoidance movement operation time after the following vehicle visually recognizes the stopped vehicle, and the greater the possibility of being rear-ended.
For example, if the vehicle is stopped on a curved or undulating road, or if there are obstacles such as walls or roadside trees near the road, the line-of-sight distance at the point where the vehicle is stopped is compared. The target is short, and the possibility of being rear-ended is high. On the other hand, when the vehicle is stopped on a straight road or flat road, or when there are few obstacles near the road, the line of sight at the point where the vehicle is stopped is relatively long, and the possibility of being rear-ended is small. . The road conditions, nearby obstacles, and the like are determined by the ECU 17 from the images acquired by the camera 11 . Information included in the map information, such as road changes such as curves, may be acquired from the navigation device 12 .

The target stop point setting unit 173 sets a plurality of stop candidate points stored in the information storage unit 174, information such as the line-of-sight distance associated therewith, and one stop candidate point that satisfies a predetermined condition described later as a stop point. select.

The information storage unit 174 temporarily stores the acquired information or the information of the detected stop candidate point and the line-of-sight distance at the stop candidate point. The information storage unit 174 is configured by, for example, a non-volatile memory, and can write and read information by the information acquisition unit 171, the candidate stop point detection unit 172, and the target stop point setting unit 173. Used.

Next, the processing of the stop assistance device 1 will be described with reference to FIGS. 3, 4, 5 and 6. FIG. FIG. 3 is a flow chart of processing that is always executed by the ECU 17 while the vehicle is running, and this processing is repeatedly executed at predetermined intervals while the vehicle is running. FIG. 4 is a diagram showing the relationship of each point in the processing performed by the stop support device 1 during normal running. FIG. 5 is a diagram showing the relationship between the driving lane and the road shoulder. FIG. 6 is a diagram showing the relationship between points in the process performed by the stop support device 1 when an automatic stop request is issued.

First, in step S1 of FIG. 3, the ECU 17 receives information from the navigation device 12, the camera 11, the vehicle speed sensor 13, the wheel speed sensor 14, the following vehicle speed sensor 15, and the following vehicle distance sensor 16. Acquired at predetermined intervals. Specifically, for example, when the vehicle passes point A in FIG. 4 at a predetermined time, the ECU 17 acquires image data captured by the camera 11, vehicle position information from the navigation device 12, map information, and the like. The predetermined interval for acquiring information is a condition appropriately set by a person skilled in the art according to the processing capacity of the ECU 17 and the actual driving situation, and is, for example, a time interval such as 0.01 seconds or a travel distance interval such as 1 meter. .

In step S2 of FIG. 3, the ECU 17 calculates the distance to the farthest point of the visible road at the current position as the line-of-sight distance. For example, the ECU 17 sets the current position of the host vehicle in FIG. Then, the distance from the farthest point EPA is calculated as the line-of-sight distance a. The method of identifying the "extreme end" of the white line is, for example, whether the ECU 17 has the number of pixels corresponding to the size at which a person with a visual acuity of 1.0 can distinguish the white line (width 15 cm) from the image acquired by the camera 11. Detect whether or not the number of pixels is insufficient, and assume that the point just before the number of pixels is insufficient is the "farthest point". The line-of-sight distance a may be calculated from the image acquired by the camera 11 as described above, or may be obtained from a sensor that directly measures a physical quantity mounted on the vehicle 2, such as an infrared sensor or an ultrasonic sensor, or information from outside the vehicle, such as navigation Map information from device 12 may be used. Further, the reference to be visible is not limited to the outer white line, and may be the entire road or a portion thereof.

Here, definitions of the driving lane 41 and the road shoulder 43 will be explained. As shown in FIG. 5 , the road 4 includes a travel lane 41 on which the vehicle travels, an outside line 42 of the travel lane 41 , and a shoulder 43 that is a space outside the outside line 42 . Note that the road shoulder 43 is not shown in FIGS. 4, 6 and 7 in order to simplify the display.

In step S3 of FIG. 3, the ECU 17 detects a range slightly before the calculated furthest point EPA as a candidate stop point SPA. The candidate stop point SPA is a range in which one vehicle can be stopped at, for example, the farthest point EPA in the traveling direction of the road. Including some.

At step S4 in FIG. 3, the ECU 17 stores information such as the current position of the vehicle, the line-of-sight distance at the current position of the vehicle, and candidate stop points. For example, the ECU 17 associates the stop candidate point SPA detected when passing the current position point A in FIG. At that time, information such as the legal maximum speed at point A and the frictional force between the wheels and the road surface may be stored in association with each other.

In step S5 of FIG. 3, when the ECU 17 receives a request to stop the own vehicle, the process proceeds to step S6 of FIG. For example, when the vehicle 2 detects that the driver is in poor physical condition and cannot continue normal driving, or when the driver voluntarily presses the automatic stop button, the own vehicle stops. It judges that it is necessary to stop the vehicle automatically, and issues an automatic stop request to the ECU 17. - 特許庁On the other hand, the ECU 17 acquires information from step S1 at predetermined time intervals when there is no request to stop the own vehicle.

In step S6 of FIG. 3, the ECU 17 identifies the range in which the vehicle can be stopped from the current location of the vehicle based on the acquired information and a preset vehicle stop model formula. Specifically, predetermined conditions and formulas are set in the stop model formula, and with the acquired information as input, the stop model formula is calculated using the predetermined conditions and formulas to specify the range in which the vehicle can be stopped. For example, the stop model formula calculates the distance required for the vehicle to come to a complete stop from the current location based on the road surface friction coefficient calculated using information on wheel speed and vehicle speed obtained from sensors and the maximum deceleration of the vehicle. Then, the range ahead of the point corresponding to the calculated distance required for stopping is specified as the range in which the vehicle can be stopped.

Therefore, as shown in FIG. 6, when the host vehicle is requested to stop at point X, the stopping distance required for the host vehicle to decelerate at the maximum deceleration and stop is DX. The range ahead of the point corresponding to DX is the stopable range DPX.

The above is an example of a stop model formula that considers only the maximum deceleration of the own vehicle, but the stop model formula may be set by considering additional conditions, such as the relative speed and distance to the following vehicle. When using a stop model formula that calculates by adding the relative relationship between , the lower one may be used as the deceleration of the own vehicle to calculate the stopping distance, and the range in which the vehicle can be stopped may be specified.

In addition to deceleration conditions that consider the relative relationship with the following vehicle, for example, deceleration conditions that do not cause discomfort to the occupants (e.g., 0.3 G or less), etc. A legal condition such as the assumption that the vehicle will run at a high speed may be taken as one condition, or a plurality of these conditions may be combined.

The information corresponding to each condition may be obtained from each sensor and the navigation device 12 installed in the vehicle 2 shown in FIG. You may use the information provided by A person skilled in the art can appropriately set the conditions used for the calculation of the stop model formula and the acquisition method of the information corresponding to the conditions.

At step S7 in FIG. 3, the ECU 17 selects and sets a stop candidate point with the smallest possibility of being rear-ended as a target stop point within the range where the own vehicle can stop specified from step S6 in FIG. For example, when the vehicle is requested to automatically stop at point X in FIG. stop candidate points SPC (stop candidate points detected when the vehicle passes point C) and SPD (stop candidate points detected when the vehicle reaches point D) that exist within the range of DPX. A stop candidate point SPC with the lowest possibility of being rear-ended is selected and set as a target stop point from among the stop candidate points detected during the passage of time. Before selecting and setting the target stop point, confirmation may be made with the passenger.

According to the above-described embodiment, it is possible to select and set a location with the lowest possibility of being rear-ended as a target stop point in consideration of actual road conditions.

Next, the relationship between the line-of-sight distance and the stop position will be described with reference to FIG. When the own vehicle passes the E point, the stop candidate point SPE at the E point is detected. When the own vehicle passes the F point, the stop candidate point SPF at the F point is detected. The shape of the road and surrounding obstacles affect the line-of-sight distance. longer than the distance f. A stop point can be set from a plurality of stop candidate points stored in the information storage unit 173 during past travel, and when a stop request is generated, the vehicle can be stopped at a point with the lowest possibility of being rear-ended.

Next, the operation of the stop assist system of this embodiment will be described.
The vehicle stop support device 2 includes an information acquisition unit 171 that acquires information about the own vehicle and external environment information while the vehicle is running, and based on the acquired information, the vehicle position at the time the information is acquired is used as an observation point to detect the collision. A stop candidate point detection unit 172 that detects the stop candidate point with the lowest possibility, an information storage unit 174 that stores the acquired information, the observation point, and the stop candidate point in association with each other, and a stop request. In this case, a range in which the vehicle can be stopped is specified by referring to the information of the own vehicle and the external environment information at the time when the stop request is generated, and the stop candidate points are selected from among the plurality of candidate stop points stored in the information storage unit 174. A target stop point setting unit 173 that selects and sets a stop candidate point within the possible range and having the smallest possibility of being rear-ended as a target stop point.

According to this configuration, considering external environment information that is not reflected in map information such as a navigation device, the possibility of being rear-ended at each point within the section or time zone that the vehicle has traveled in the past is maximized. By setting a stop candidate point with the smallest possibility of being rear-ended from the small stop candidate points as the target stop point, the vehicle can be stopped according to the actual road environment.

The stop candidate point detection unit 172 sets the distance from the observation point at the time when the information is acquired to the farthest point where the driving lane can be visually recognized as the line of sight distance, and determines the distance from the farthest point to the driving lane or road shoulder in the vicinity of the near side from the farthest point. Detect a point as a candidate stop point. According to this configuration, it is possible to detect, as a stop candidate point, the point with the longest line-of-sight distance, that is, the point with the lowest possibility of being rear-ended at the time when the information is acquired.

The target stop point setting unit 174 has a stop model formula for specifying a range in which the own vehicle can be stopped based on the information acquired by the information acquisition unit 171. Contains formulas for calculating the distance from the current speed to a complete stop in deceleration. According to this configuration, it is possible to calculate the range in which the vehicle can stop in consideration of the performance of the own vehicle, and to avoid setting a stop candidate point where the vehicle cannot stop beyond the performance of the own vehicle as the target stop point. .

The above-mentioned stop model formula is based on at least the deceleration that takes into account the relative relationship with the following vehicle or the deceleration that takes into account the comfort of the occupants, and the maximum deceleration of the own vehicle, whichever has the lower deceleration. Specify the range in which the vehicle can be stopped as the deceleration of the According to this configuration, it is possible to specify a stop range in which the relative relationship with the following vehicle is taken into consideration without making the occupant feel uncomfortable.

1 stop assist device 2 vehicle 4 road 11 camera 12 navigation device 17 ECU (Electronic Control Unit)
171 Information acquisition unit 172 Candidate stop point detection unit 173 Information storage unit 174 Target stop point setting unit SPA Candidate stop point at point A EPA Farthest point at point A DX Distance required to stop at point X DPX Range in which the vehicle can stop at point X

Claims (4)

An information acquisition unit that acquires information about the own vehicle and external environment information while the vehicle is running, and based on the information acquired by the information acquisition unit , the possibility of a rear-end collision is determined using the position of the vehicle at the time the information is acquired as an observation point. a candidate stop point detection unit that detects the smallest candidate stop point;
an information storage unit that associates and stores the information acquired by the information acquisition unit , the observation point, and the candidate stop point;
When there is a request to stop, a range in which the vehicle can be stopped is specified by referring to the information of the own vehicle and the external environment information at the time when the request to stop is made, and the range in which the vehicle can be stopped is selected from the plurality of candidate stop points stored in the information storage unit. and a target stop point setting unit that selects and sets, as a target stop point, a stop candidate point that is within the range where the vehicle can be stopped and has the lowest possibility of being rear-ended. The candidate stop point detection unit sets the distance from the observation point at the time when the information acquisition unit acquires the information to the farthest point where the driving lane can be visually recognized as a line of sight distance, and the driving lane near the front side from the farthest point. Alternatively, the stop support device according to claim 1, wherein a point on the shoulder of the road is detected as a stop candidate point. The target stop point setting unit has a stop model formula for specifying a range in which the vehicle can stop based on the information acquired by the information acquisition unit. 3. The stop assist device according to claim 1, which includes a formula for calculating a distance from the current speed to a complete stop in terms of speed. The above-mentioned stop model formula is based on at least the deceleration that takes into account the relative relationship with the following vehicle or the deceleration that takes into account the comfort of the occupants, and the maximum deceleration of the own vehicle, whichever has the lower deceleration. 4. The stop support device according to claim 3, wherein the stop support device specifies the range in which the vehicle can be stopped as the deceleration of the vehicle.

Images