JP2019001283A - vehicle - Google Patents

Abstract

To provide a vehicle capable of smoothly performing operations from deceleration to acceleration without delay while travelling is performed by driving support.SOLUTION: The vehicle includes: an internal combustion engine; a transmission; a recognition unit which recognizes an other vehicle located in front of the vehicle; a support unit which controls support driving of the vehicle so that a relative position with respect to the other vehicle has a predetermined positional relationship and/or constant speed travelling, in which a travelling speed of the vehicle is equal to or lower than a target speed, is performed; and a control unit which controls the internal combustion engine and the transmission gear ratio of the transmission according to support control of the support unit. When the vehicle travels according to the support control, and the support unit predicts or detects that the other vehicle is in a near space closer to the vehicle than a space which satisfies the predetermined positional relationship ahead in a travelling direction of the vehicle, the control unit performs downshift control which increases the transmission gear ratio of the transmission, and when the support unit predicts or detects that the other vehicle is not in the space after the downshift control, the control unit controls the vehicle to be accelerated by driving power from the internal combustion engine.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a vehicle.

  In recent years, various driving support devices have been developed and put into practical use in order to reduce the burden on the driver of the vehicle and avoid accidents. As one of such driving assistance devices, one having an adaptive cruise control function (hereinafter referred to as “ACC function”) is known. In general, it is assumed that the ACC function is used when traveling on a highway where the operation frequency of an accelerator and a brake is relatively low. The driving support device sets a target speed when the driver performs an operation for activating the ACC function, performs constant speed traveling at the target speed when there is no preceding vehicle, and is constant when there is a preceding vehicle. The driving force and braking force of the vehicle are controlled so as to follow the vehicle while maintaining the following inter-vehicle distance (target inter-vehicle distance).

JP 2003-025869 A

  Patent Document 1 includes at least the following traveling control included in the ACC function described above and automatic engine brake control that automatically activates the engine brake by the shift control of the transmission under a traveling condition that requires engine braking. Even if one of the vehicles that can use either one is instructed to perform follow-up driving control, the automatic engine brake control is continued while the inter-vehicle distance is equal to or greater than the target inter-vehicle distance, and the inter-vehicle distance is less than the target inter-vehicle distance. A technique that sometimes stops automatic engine brake control is described. This technology has the idea that the engine brake may be applied until the vehicle-to-vehicle distance reaches the target vehicle-to-vehicle distance during traveling on a downhill road that requires engine braking. According to the technology, follow-up running control is started while driving downhill roads that require engine braking, but if the inter-vehicle distance is greater than or equal to the target inter-vehicle distance, automatic engine brake control will continue, and the downhill road will run. Sudden acceleration that occurs when the automatic engine brake control is deactivated can be prevented.

  In the technique of Patent Document 1 described above, automatic engine brake control by shifting (downshift) of the transmission is operated until the inter-vehicle distance from the preceding vehicle reaches the target inter-vehicle distance when the follow-up running control is operated. However, the control when the preceding vehicle accelerates and the inter-vehicle distance increases thereafter is not considered.

  An object of the present invention is to provide a vehicle that can smoothly perform a driving from deceleration to acceleration performed during driving by driving assistance without delay.

In order to achieve the above object, the invention described in claim 1
An internal combustion engine (for example, an internal combustion engine 101 in an embodiment described later);
A vehicle (for example, a transmission 103 in an embodiment to be described later) that shifts and transmits drive rotation of the internal combustion engine to drive wheels,
A recognizing unit that recognizes another vehicle located in front of the vehicle (for example, a recognizing unit 109 in an embodiment described later);
The vehicle is operated so that the relative position with the other vehicle recognized by the recognition unit is in a predetermined positional relationship and / or the vehicle travels at a constant speed below a target speed. A support unit that performs control to support (for example, a support unit 111 in an embodiment described later);
A control unit (e.g., an ECU 107 in an embodiment described later) for controlling the gear ratio of the internal combustion engine and the transmission according to the support control of the support unit,
The control unit, while the vehicle is traveling according to the support control of the support unit,
Based on the recognition content of the recognition unit, the support unit determines that another vehicle exists in a close space closer to the vehicle than a space satisfying the predetermined positional relationship ahead along the traveling direction of the vehicle. If predicted or detected, downshift control to increase the transmission gear ratio is performed,
After the downshift control, when the support unit predicts or detects that the other vehicle does not exist in the space based on the recognition content of the recognition unit, the vehicle is driven by the power from the internal combustion engine. A vehicle that performs acceleration control.

The invention according to claim 2 is the invention according to claim 1,
The control unit maintains the transmission gear ratio after the downshift control when the vehicle accelerates after the downshift control, or changes the transmission gear ratio after the downshift control. Upshift control is performed to reduce the transmission gear ratio.

The invention according to claim 3 is the invention according to claim 2,
The control unit performs the upshift control after the relative position with the other vehicle becomes the predetermined positional relationship after the downshift control.

The invention according to claim 4 is the invention according to any one of claims 1 to 3,
When the downshift control is performed, the control unit determines a gear ratio of the transmission after the downshift control based on a relative speed between the vehicle and the other vehicle.

The invention according to claim 5 is the invention according to any one of claims 1 to 3,
When the downshift control is performed, the control unit determines a gear ratio of the transmission after the downshift control based on a distance between the vehicle and the other vehicle.

The invention according to claim 6 is the invention according to any one of claims 1 to 5,
The control unit performs the downshift control and performs fuel cut of the internal combustion engine.

The invention according to claim 7 is the invention according to any one of claims 1 to 6,
The recognizing unit detects a movement of the other vehicle related to traveling or a lighting state of a lamp body of the other vehicle,
The control unit performs the downshift control when the support unit predicts or detects that the other vehicle exists in the close space based on the information detected by the recognition unit.

The invention according to claim 8 is the invention according to any one of claims 1 to 7,
The recognizing unit detects a movement of the other vehicle related to traveling or a lighting state of a lamp body of the other vehicle,
The control unit, when the vehicle is traveling at a speed less than the target speed so that the relative position with other vehicles located in the space ahead along the traveling direction is the predetermined positional relationship, When the support unit predicts or detects that the other vehicle does not exist in the space based on the information detected by the recognition unit, the downshift control is performed.

  According to the invention of claim 1, when traveling according to the support control of the support unit, when another vehicle seems to be able to interrupt in front of the traveling direction of the host vehicle at a lower speed than the traveling speed of the host vehicle. Deceleration is performed by downshift control, and then acceleration is performed to travel following the other vehicle. Further, during follow-up running according to the support control of the support unit, when another vehicle traveling ahead is likely to decelerate, the vehicle is decelerated by performing downshift control, and thereafter, acceleration following the other vehicle is performed. In this way, driving from deceleration to acceleration performed during driving by driving assistance can be performed smoothly and without delay.

  According to the second aspect of the present invention, when another vehicle that has entered the front in the traveling direction of the host vehicle has accelerated, or has accelerated after the other vehicle that the host vehicle follows has decelerated, the other vehicle When the host vehicle accelerates in order to follow this vehicle, the acceleration can be continued while performing the upshift control by performing the acceleration while maintaining the downshifted gear. As a result, smooth acceleration without delay from deceleration during follow-up traveling is possible, and other vehicles can be followed quickly.

  According to the third aspect of the present invention, when accelerating and following another vehicle that has interrupted forward along the traveling direction of the host vehicle, the relative position with the other vehicle has a predetermined positional relationship. After that, upshift control is performed. As a result, smooth acceleration from deceleration during follow-up running is possible, and other vehicles can be smoothly followed.

  When the relative speed with another vehicle is large, a large deceleration is required, whereas when the relative speed is small, a large deceleration is not necessary. For this reason, if the gear ratio of the transmission during downshift control is changed more than necessary even though the relative speed is small, an unnecessarily large deceleration occurs, and passenger comfort is impaired by the sense of deceleration. However, according to the invention of claim 4, since the transmission gear ratio after the downshift control is determined based on the relative speed, it is possible to achieve both deceleration and passenger comfort.

  A large deceleration is required when the distance to another vehicle is short, whereas a large deceleration is not necessary when the distance is long. For this reason, if the transmission gear ratio during downshift control is changed more than necessary even though the distance is long, an unnecessarily large deceleration occurs, and passenger comfort is impaired by the sense of deceleration. However, according to the invention of claim 5, since the gear ratio of the transmission after the downshift control is determined based on the distance to the other vehicle, both deceleration and passenger comfort are achieved. be able to.

  According to the sixth aspect of the present invention, it is possible to perform deceleration using the engine brake effectively by performing fuel cut of the internal combustion engine during downshift control.

  According to the seventh aspect of the present invention, during traveling according to the support control of the support unit, a situation in which another vehicle is likely to interrupt at a lower speed than the traveling speed of the host vehicle in front of the traveling direction of the host vehicle. When it is detected from the movement of another vehicle related to traveling or the lighting state of the lamp of another vehicle, downshift control is performed. For this reason, even when a large deceleration is necessary because another vehicle has actually interrupted at a low speed forward along the traveling direction of the host vehicle, the vehicle can be quickly decelerated. Further, during the follow-up running according to the support control of the support unit, a situation in which the other vehicle running ahead is likely to decelerate is detected from the movement of the other vehicle related to the running or the lighting state of the lamp of the other vehicle. In this case, downshift control is performed. For this reason, even when another vehicle is actually decelerated and a large deceleration is required, it is possible to quickly decelerate.

  According to the invention of claim 8, during the follow-up traveling according to the support control of the support unit, the other vehicle traveling forward along the traveling direction of the host vehicle has a predetermined positional relationship ahead along the traveling direction. Downshift control is performed when a situation that does not exist in the filled space is detected. For this reason, when other vehicles no longer exist in the said space, the quick acceleration to a target speed can be performed smoothly and without delay.

It is a block diagram which shows the internal structure of the vehicle of one Embodiment. It is a figure which shows the example of the relative position of the other vehicle in which the relative position with the own vehicle has a predetermined positional relationship, and the own vehicle. 2 is a timing chart in the case where control is performed to change the vehicle speed VP, the transmission gear ratio, and the like according to the movement of another vehicle while the vehicle shown in FIG. 2 is a timing chart in the case where control is performed to change the vehicle speed VP, the transmission gear ratio, and the like according to the movement of another vehicle while the vehicle shown in FIG. (A) When the host vehicle is traveling at a constant speed in the travel lane that is the main road of the highway, the other vehicle joins the travel lane from the rampway in front of the host vehicle at a lower speed than the host vehicle. The situation, (b) a second situation in which the vehicle follows the accelerated preceding vehicle after joining the main road, and (c) the preceding vehicle traveling on the main road followed by the host vehicle leaves the rampway. It is a figure which shows a 3rd condition. 2 is a timing chart in a case where control is performed to change the vehicle speed VP, the transmission gear ratio, and the like according to the movement of the host vehicle with respect to another vehicle while the vehicle shown in FIG. 2 is a timing chart in a case where control is performed to change the vehicle speed VP, the transmission gear ratio, and the like according to the movement of the host vehicle with respect to another vehicle while the vehicle shown in FIG. (A) Fourth situation in which the host vehicle traveling at a constant speed on the overtaking lane, which is the main road of the expressway, joins the traveling lane behind the other vehicle traveling on the traveling lane at a higher speed than the other vehicle And (b) a fifth situation in which the vehicle follows a preceding vehicle that has accelerated after merging into the traveling lane, and (c) a sixth situation in which the host vehicle that follows the preceding vehicle in the traveling lane changes to a passing lane. FIG. It is a flowchart which shows the flow of the process according to the motion of the other vehicle in which the own vehicle is drive | working at constant speed. It is a flowchart which shows the flow of the process according to the motion of the other vehicle in which the own vehicle is drive | working at constant speed. It is a flowchart which shows the flow of a process at the time of the own vehicle shifting from a constant speed driving | running | working to a follow-up driving | running | working. It is a flowchart which shows the flow of a process at the time of the own vehicle shifting from a constant speed driving | running | working to a follow-up driving | running | working. It is a flowchart which shows the flow of a process at the time of the own vehicle shifting from follow driving | running | working to constant speed driving | running | working.

  Hereinafter, an embodiment of a vehicle according to the present invention will be described with reference to the drawings.

  FIG. 1 is a block diagram illustrating an internal configuration of a vehicle according to an embodiment. In FIG. 1, a thick solid line indicates mechanical connection, and a thin solid line arrow indicates a control signal or a detection signal.

  The vehicle shown in FIG. 1 includes an internal combustion engine (ENG) 101, a transmission (T / M) 103, a vehicle speed sensor 105, a brake BRK, an ECU 107, a recognition unit 109, and a support unit 111. In the vehicle, the power output from the internal combustion engine 101 is transmitted to the drive wheels DW via the transmission 103, the differential gear 8 and the axle 9.

  Hereafter, each component which the vehicle of FIG. 1 has is demonstrated.

  The internal combustion engine 101 outputs power for running the vehicle. The rotation shaft of the internal combustion engine 101 is connected to the input shaft of the transmission 103.

  The transmission 103 shifts the drive rotation of the internal combustion engine 101 at a predetermined gear ratio and transmits it to the drive wheels DW. The transmission ratio of the transmission 103 is changed according to an instruction from the ECU 107. The transmission 103 includes a clutch CL that connects and disconnects a power transmission path between the internal combustion engine 101 and the drive wheels DW. The transmission 103 may be a transmission in which a plurality of different speed ratios are set in stages, or may be a continuously variable transmission capable of continuously changing the speed ratio.

  The vehicle speed sensor 105 detects the traveling speed (vehicle speed VP) of the vehicle. A signal indicating the vehicle speed VP detected by the vehicle speed sensor 105 is sent to the ECU 107.

  The brake BRK is a mechanical brake. That is, the brake BRK brakes the vehicle with hydraulic pressure or the like controlled according to the operation of the brake pedal by the driver of the vehicle.

  The recognition unit 109 is a radar unit such as an infrared laser radar or a millimeter wave radar, an imaging unit such as a stereo camera or a monocular camera, or another vehicle positioned in front of the host vehicle by using the radar unit and the imaging unit in combination. Recognize The recognition unit 109 detects the movement of another vehicle located in front of the host vehicle from the information obtained by the radar unit or the imaging unit, and the lighting state of a lamp body such as a brake lamp or a direction indicator of the other vehicle Is detected.

  The support unit 111 performs so-called adaptive cruise control to support driving of the host vehicle. The support unit 111 selectively switches between constant speed traveling control and inter-vehicle distance control according to the vehicle exterior situation recognized by the recognition unit 109. When there is no preceding vehicle, the support unit 111 performs constant speed traveling control, and the vehicle performs constant speed traveling at a target speed or less by the control. The difference between the vehicle speed and the target speed during constant speed traveling is less than or equal to a predetermined value. On the other hand, when there is a preceding vehicle, the support unit 111 performs inter-vehicle distance control, and the control causes the vehicle to follow and maintain a constant inter-vehicle distance (target inter-vehicle distance). In the following description, both the constant speed traveling control performed by the support unit 111 and the inter-vehicle distance control are collectively referred to as “ACC”.

  In addition, the “preceding vehicle” in the above description is located in front of the host vehicle recognized by the recognition unit, and the relative position with the host vehicle is predicted to have a predetermined positional relationship or the predetermined positional relationship. Other vehicles. As shown in FIG. 2, the other vehicle B and the own vehicle A having a predetermined positional relationship with the own vehicle travel in the same or adjacent lanes with the inter-vehicle distance d being substantially constant. . As a result, the relative position of the host vehicle A with the other vehicle B becomes a “predetermined positional relationship”.

  The ECU 107 is obtained from the accelerator pedal opening (AP opening) according to the accelerator pedal operation by the driver of the vehicle, the brake pedal pressing force (BRK pressing force) according to the operation of the brake pedal by the driver, and the vehicle speed sensor 105. Based on the vehicle speed VP and the like, operation control of the internal combustion engine 101, shift control in the transmission 103, control of the brake BRK, and the like are performed. Further, if the switch ACC_SW for enabling the ACC by the support unit 111 is in an ON state, the ECU 107 does not operate the accelerator pedal by the driver, and according to the control contents of the ACC by the support unit 111, the ECU 107 Operation control, shift control in the transmission 103, control of the brake BRK, and the like are performed. The switch ACC_SW is turned on by being operated by the driver while the vehicle is traveling.

(Driving control according to the movement of other vehicles when ACC is effective)
Hereinafter, control of the internal combustion engine 101 and the transmission 103 in the host vehicle according to the movement of another vehicle recognized by the recognition unit 109 when the ACC is valid will be described. 3 and 4 are timing charts when the vehicle shown in FIG. 1 is controlled to change the vehicle speed VP and the gear ratio of the transmission 103 in accordance with the movement of other vehicles while the vehicle is running at ACC. . In the example shown in FIG. 3, when the host vehicle is traveling at a constant speed in the travel lane that is the main road of the highway, another vehicle moves from the rampway to the front of the host vehicle at a lower speed than the host vehicle. An example shown in FIG. 4 includes a first situation (FIG. 5 (a)) that merges and a second situation (FIG. 5 (b)) that travels following a preceding vehicle that has accelerated after joining the main road. Includes a third situation (FIG. 5C) in which the preceding vehicle traveling on the main road followed by the host vehicle leaves the rampway. In the example shown in FIGS. 3 and 4, the transmission 103 is a stepped automatic transmission.

  In the first situation shown in FIG. 3 (FIG. 5A), the recognition unit 109 of the host vehicle traveling at a constant speed in the traveling lane recognizes another vehicle traveling on the rampway (time t10) and assisting. Based on the movement of the other vehicle detected by the recognition unit 109, the unit 111 predicts that another vehicle will join the front lane of the vehicle from the rampway (time t11). In the example shown in FIG. 3, since the traveling speed of the other vehicle that is predicted to join is slower than that of the own vehicle, the assisting unit 111 determines that when the other vehicle joins the traveling lane as it is, the own vehicle It is predicted that the other vehicle exists in a close space closer to the host vehicle than a space satisfying the above-described predetermined positional relationship in front of the vehicle in the traveling direction. In this case, since the inter-vehicle distance between the other vehicle that joins the traveling lane and the own vehicle becomes shorter than the target inter-vehicle distance dt during the follow-up traveling, the own vehicle is highly likely to be braked. Therefore, the ECU 107 performs downshift control for increasing the gear ratio of the transmission 103 (decreasing the gear position), and the transmission 103 is shifted down from, for example, 10 gears to 9 gears. The ECU 107 performs downshift control and also performs fuel cut (fuel cut) of the internal combustion engine 101.

  Thereafter, the support unit 111 determines that another vehicle has started merging from the ramp way to the travel lane based on the movement of the other vehicle detected by the recognition unit 109 (time t12), and the vehicle speed VP. The ECU 107 performs downshift control so as to match the traveling speed of the other vehicle, and the transmission 103 shifts down from, for example, 9th to 7th. The ECU 107 determines the number of steps of the transmission 103 after the downshift control (seven steps in the example of FIG. 3) as a relative vehicle speed ΔVP (= vehicle speed VP−other vehicle's relative speed between the host vehicle and the other vehicle). Travel speed) or a distance between the host vehicle and another vehicle. In the example shown in FIG. 3, the relative vehicle speed ΔVP does not become zero even when the transmission 103 is shifted down to seven stages. Therefore, the relative vehicle speed ΔVP is reduced to zero by the mechanical braking force using the brake BRK. In the example shown in FIG. 3, since the rotational speed of the internal combustion engine 101 after the transmission 103 is shifted down to the seventh stage is a high rotation state equal to or higher than the threshold value, the gear shift is not further shifted down. Since the fuel cut of the internal combustion engine 101 is also performed, the relative vehicle speed ΔVP is reduced to 0 by applying a mechanical braking force using the brake BRK.

  Next, in the second situation shown in FIG. 3 (FIG. 5B), both the own vehicle and the other vehicle travel on the same traveling lane, and the inter-vehicle distance between the other vehicle and the own vehicle is the following traveling time. After the target inter-vehicle distance dt is reached, that is, after the relative position between the own vehicle and the other vehicle becomes the above-described predetermined relationship, the other vehicle moves forward along the traveling direction of the own vehicle. When the support unit 111 predicts or detects that the vehicle does not exist in the space satisfying the predetermined positional relationship (time t13), the ECU 107 determines that the relative position with respect to other vehicles is a predetermined position according to the follow-up traveling control by the support unit 111. In order to satisfy the positional relationship, control is performed in which the host vehicle is accelerated by the power from the internal combustion engine 101. When the acceleration control is performed, the ECU 107 performs upshift control in which the speed ratio of the transmission 103 is reduced stepwise from the speed ratio after the downshift control. In the example shown in FIG. 3, the vehicle speed VP increases by increasing the output of the internal combustion engine 101 while shifting the transmission 103 stepwise from 7 to 10 at regular time intervals.

  Next, in the third situation shown in FIG. 4 (FIG. 5 (c)), when the host vehicle and the other vehicle travel on the same traveling lane, and the host vehicle travels following the other vehicle, Based on the movement of the other vehicle detected by the recognizing unit 109, the other vehicle leaves the driving lane to the rampway, and satisfies the predetermined positional relationship described above ahead along the traveling direction of the host vehicle. When the support unit 111 predicts or detects that the space no longer exists (time t14), the ECU 107 performs downshift control, and the transmission 103 is shifted down stepwise from, for example, 10 steps to 8 steps. The ECU 107 sets the gear ratio of the transmission 103 after the downshift control to be larger (the number of steps is smaller) as the difference between the vehicle speed VP at this time and the target speed during constant speed traveling is larger.

  Thereafter, when the other vehicle leaves the driving lane on the rampway and the relative position between the host vehicle and the other vehicle does not satisfy the predetermined relationship described above (time t15), the ECU 107 determines that the support unit 111 In accordance with the high-speed driving control, the vehicle is accelerated to the target vehicle speed by the power from the internal combustion engine 101. When the acceleration control is performed, the ECU 107 performs upshift control in which the speed ratio of the transmission 103 is reduced stepwise from the speed ratio after the downshift control. In the example shown in FIG. 4, the vehicle speed VP is increased by increasing the output of the internal combustion engine 101 while shifting the transmission 103 from 8 to 10 stepwise.

(Driving control according to the movement of the vehicle when ACC is effective)
Hereinafter, control of the internal combustion engine 101 and the transmission 103 in the own vehicle based on the contents recognized by the recognition unit 109 according to the movement of the own vehicle with respect to another vehicle when the ACC is valid will be described. FIGS. 6 and 7 are timings when the vehicle shown in FIG. 1 performs control to change the vehicle speed VP and the gear ratio of the transmission 103 in accordance with the movement of the host vehicle with respect to other vehicles while the vehicle is running at ACC It is a chart. In the example shown in FIG. 6, a host vehicle that travels at a constant speed on an overtaking lane, which is a main roadway of an expressway, is behind the other vehicle traveling on the traveling lane by the driver's operation. A fourth situation (FIG. 8 (a)) that merges at high speed and a fifth situation (FIG. 8 (b)) that travels following a preceding vehicle that has accelerated after joining the traveling lane are included. The example shown includes a sixth situation (FIG. 8C) in which the own vehicle that travels following the preceding vehicle in the traveling lane changes the lane to the passing lane by the driver's operation. In the example shown in FIGS. 6 and 7, the transmission 103 is a stepped automatic transmission.

  In the fourth situation shown in FIG. 6 (FIG. 8A), the recognition unit 109 of the host vehicle traveling at a constant speed in the overtaking lane recognizes another vehicle traveling in the traveling lane (time t20). The support unit 111 predicts that the own vehicle will merge from the overtaking lane to the traveling lane behind the other vehicle by the driver's operation based on the change in the relative position with the other vehicle detected by the recognition unit 109. (Time t21). In the example shown in FIG. 6, since the traveling speed of the host vehicle is faster than other vehicles, the support unit 111 moves forward along the traveling direction of the host vehicle when the host vehicle joins the traveling lane as it is. It is predicted that the other vehicle exists in a close space closer to the host vehicle than the space satisfying the predetermined positional relationship described above. In this case, since the inter-vehicle distance between the host vehicle that joins the travel lane and the other vehicle is shorter than the target inter-vehicle distance dt during the follow-up travel, the host vehicle is highly likely to be braked. Therefore, the ECU 107 performs downshift control for increasing the gear ratio of the transmission 103 (decreasing the gear position), and the transmission 103 is shifted down from, for example, 10 gears to 9 gears. The ECU 107 performs downshift control and also performs fuel cut (fuel cut) of the internal combustion engine 101.

  Thereafter, the support unit 111 determines that the own vehicle has started to merge from the overtaking lane to the traveling lane based on a change in relative position with the other vehicle detected by the recognition unit 109 (time t22). Then, in order to match the vehicle speed VP with the traveling speed of the other vehicle, the ECU 107 performs downshift control, and the transmission 103 is downshifted stepwise from 9 to 7, for example. The ECU 107 determines the number of stages of the transmission 103 after the downshift control (seven stages in the example of FIG. 6) as a relative vehicle speed ΔVP (= vehicle speed VP−the speed of the other vehicle) that is the relative speed between the host vehicle and the other vehicle. Travel speed) or a distance between the host vehicle and another vehicle. In the example shown in FIG. 6, the relative vehicle speed ΔVP does not become 0 even when the transmission 103 is shifted down to 7 stages. Therefore, the relative vehicle speed ΔVP is reduced to 0 by the mechanical braking force using the brake BRK. In the example shown in FIG. 6, since the number of revolutions of the internal combustion engine 101 after the transmission 103 is shifted down to seven stages is a high revolution state that is equal to or higher than a threshold value, the gears are not further downshifted. Since the fuel cut of the internal combustion engine 101 is also performed, the relative vehicle speed ΔVP is reduced to 0 by applying a mechanical braking force using the brake BRK.

  Next, in the fifth situation shown in FIG. 6 (FIG. 8B), the host vehicle and the other vehicle travel on the same lane, and the inter-vehicle distance between the other vehicle and the host vehicle is the same as in the following travel. After the target inter-vehicle distance dt is reached, that is, after the relative position between the own vehicle and the other vehicle becomes the above-described predetermined relationship, the other vehicle moves forward along the traveling direction of the own vehicle. When the support unit 111 predicts or detects that the vehicle does not exist in the space that satisfies the predetermined positional relationship (time t23), the ECU 107 determines that the relative position with respect to another vehicle is a predetermined position according to the follow-up traveling control by the support unit 111. In order to satisfy the positional relationship, control is performed in which the host vehicle is accelerated by the power from the internal combustion engine 101. When the acceleration control is performed, the ECU 107 performs upshift control in which the speed ratio of the transmission 103 is reduced stepwise from the speed ratio after the downshift control. In the example shown in FIG. 6, the vehicle speed VP is increased by increasing the output of the internal combustion engine 101 while shifting the transmission 103 from 7 to 10 stepwise at regular time intervals.

  Next, in the sixth situation shown in FIG. 7 (FIG. 8C), when the host vehicle and the other vehicle travel on the same travel lane, and the host vehicle travels following the other vehicle, Based on the change in the relative position with the other vehicle detected by the recognition unit 109, the vehicle changes its lane to the overtaking lane by the driver's operation, and the above description along the traveling direction of the host vehicle When the support unit 111 predicts or detects that it does not exist in the space that satisfies the predetermined positional relationship (time t24), the ECU 107 performs downshift control, and the transmission 103 is stepped from, for example, 10 steps to 8 steps. Shift down. The ECU 107 sets the gear ratio of the transmission 103 after the downshift control to be larger (the number of steps is smaller) as the difference between the vehicle speed VP at this time and the target speed during constant speed traveling is larger.

  After that, when the lane change of the host vehicle to the overtaking lane is completed and the relative position between the host vehicle and the other vehicle is not in the predetermined relationship described above (time t25), the ECU 107 performs the constant speed by the support unit 111. In accordance with the travel control, the vehicle is accelerated to the target vehicle speed by the power from the internal combustion engine 101. When the acceleration control is performed, the ECU 107 performs upshift control in which the speed ratio of the transmission 103 is reduced stepwise from the speed ratio after the downshift control. In the example shown in FIG. 7, the vehicle speed VP is increased by increasing the output of the internal combustion engine 101 while shifting up the transmission 103 from 8 to 10 stepwise.

  Next, processing performed by the support unit 111 and the ECU 107 according to the movement of another vehicle or the host vehicle when ACC is valid will be described in detail with reference to FIGS. 9 to 13. The flowcharts of FIGS. 9 and 10 are the flow of processing according to the movement of the other vehicle in which the host vehicle is traveling at a constant speed, and the flowcharts of FIGS. The flowchart of FIG. 13 is a process flow when the host vehicle shifts from the follow-up running to the constant speed running. In the flowcharts of FIGS. 9 to 13, the own vehicle is referred to as “own vehicle”, and the other vehicle is referred to as “other vehicle”.

  First, a process according to the movement of another vehicle in which the host vehicle is traveling at a constant speed will be described. As shown in FIG. 9, the support unit 111 determines whether there is another vehicle on another lane such as a rampway based on the information recognized by the recognition unit 109 (step S101). If NO exists, the process proceeds to step S103, and if present, the process proceeds to step S105. In step S103, the ECU 107 controls the operation of the internal combustion engine 101 so that the gear stage of the transmission 103 is maintained at the current stage and the vehicle speed VP is maintained. In step S105, the support unit 111 determines whether another vehicle has started a merging operation to the own lane on which the own vehicle is traveling or whether the own vehicle has started a merging operation to another lane on which the other vehicle is traveling. If the joining operation has not been started, the process proceeds to step S107. If the joining operation has been started, the process proceeds to step S121.

  In step S107, the support unit 111 determines whether another vehicle is likely to join the own lane on which the host vehicle is traveling, or is likely to join the other lane on which the other vehicle is traveling. If it is determined that there is not, the process proceeds to step S103. Note that whether or not another vehicle or the host vehicle is likely to join is determined based on the distance between the host vehicle and the other vehicle. The support unit 111 determines that a merge is likely to occur when the distance becomes shorter.

  In step S109, the support unit 111 determines whether or not the traveling speed of the other vehicle is slower than that of the host vehicle. If it is not late, the process proceeds to step S111. If it is late, the process proceeds to step S113. In step S111, the support unit 111 determines whether or not the traveling speed of the other vehicle is faster than that of the host vehicle. If not faster, the process proceeds to step S103. If faster, the process proceeds to step S151 shown in FIG. The case where the traveling speed of the other vehicle is neither slow nor fast is the case where the traveling speed of the other vehicle matches the vehicle speed VP of the host vehicle.

  In step S113, the support unit 111 determines whether or not it is likely to catch up with another vehicle that is slower than the own vehicle because the deceleration is not sufficient only by performing the fuel cut (F / C) of the internal combustion engine 101. If it is not likely to catch up with the other vehicle, the process proceeds to step S115, and if it is likely to catch up, the process proceeds to step S117. The support unit 111 determines that the host vehicle is likely to catch up with another vehicle if the difference between the traveling speeds of the host vehicle and the other vehicle is greater than or equal to a predetermined value, and determines that the host vehicle is not likely to catch up if the difference is less than the predetermined value. In step S115, the ECU 107 controls the operation of the internal combustion engine 101 so that the gear stage of the transmission 103 is maintained at the current stage and the vehicle speed VP is maintained or slowed down. On the other hand, in step S117, the ECU 107 performs downshift control for increasing the gear ratio of the transmission 103 (decreasing the gear position), and controls the operation of the internal combustion engine 101 so as to maintain the vehicle speed VP or to reduce the speed slowly.

  In step S121, the support unit 111 determines whether or not the traveling speed of the other vehicle that has started the merging operation is slower than that of the host vehicle. If not slower, the process proceeds to step S123. If slower, the process proceeds to step S127. In step S123, the support unit 111 determines whether or not the traveling speed of the other vehicle that has started the merging operation is faster than the own vehicle. If not, the process proceeds to step S125, and if it is faster, the step illustrated in FIG. The process proceeds to S151. In step S125, the ECU 107 controls the operation of the internal combustion engine 101 so that the gear stage of the transmission 103 is maintained at the current stage and the vehicle speed VP is maintained.

  In step S127, the support unit 111 determines whether or not the fuel cut (F / C) of the internal combustion engine 101 is insufficient to slow down the vehicle and catch up with another vehicle that is slower than the host vehicle. If it is not likely to catch up with the other vehicle, the process proceeds to step S129, and if it is likely to catch up, the process proceeds to step S131. In step S129, the ECU 107 maintains the gear stage of the transmission 103 at the current stage and performs fuel cut of the internal combustion engine 101. As a result, the host vehicle decelerates.

  In step S131, the support unit 111 determines whether or not the condition that the gear stage of the transmission 103 is the lowest stage or the high speed state where the rotational speed of the internal combustion engine 101 is equal to or higher than a threshold value is satisfied. If the condition is not satisfied, the process proceeds to step S133. If satisfied, the process proceeds to step S135. In step S133, the ECU 107 performs downshift control of the transmission 103 and performs fuel cut of the internal combustion engine 101. As a result, the host vehicle decelerates. On the other hand, in step S135, the ECU 107 controls the transmission 103 so that the gear stage of the transmission 103 is maintained, the fuel cut of the internal combustion engine 101 is performed, and the brake BRK is operated. As a result, the host vehicle decelerates.

  In step S <b> 151 shown in FIG. 10, which proceeds when it is determined in step S <b> 111 and step S <b> 123 in FIG. 9 that the traveling speed of the other vehicle is faster than the own vehicle, the support unit 111 travels between the other vehicle and the own vehicle. Based on the difference in speed, it is determined whether the acceleration at the current gear position of the transmission 103 does not provide the acceleration force required to follow another vehicle, and the speed cannot be adjusted within a certain time. To do. That is, the support unit 111 determines whether the vehicle speed difference with other vehicles is equal to or greater than a predetermined value Δth (vehicle speed difference ≧ Δth). If the vehicle speed difference <Δth, the process proceeds to step S153, and if the vehicle speed difference ≧ Δth. If so, the process proceeds to step S155. In step S153, the ECU 107 maintains the gear stage of the transmission 103 at the current stage, and controls the operation of the internal combustion engine 101 so that the host vehicle accelerates.

  In step S155, the support unit 111 determines whether or not the condition that the speed of the transmission 103 is the lowest speed or the high speed state where the rotational speed of the internal combustion engine 101 is equal to or higher than a threshold is satisfied. If the condition is not satisfied, the process proceeds to step S157. If the condition is satisfied, the process proceeds to step S159. In step S157, the ECU 107 performs downshift control of the transmission 103 and controls the operation of the internal combustion engine 101 so that the host vehicle is accelerated. On the other hand, in step S159, the ECU 107 controls the operation of the internal combustion engine 101 so that the speed of the transmission 103 is maintained at the current speed and the host vehicle is accelerated.

  Next, processing when the host vehicle shifts from constant speed traveling to follow-up traveling will be described. As shown in FIG. 11, the support unit 111 determines whether the traveling speed of another vehicle that the host vehicle is to follow is slower than the host vehicle (step S201), and if not, the process proceeds to step S203. If it is late, the process proceeds to step S127 shown in FIG. In step S203, the support unit 111 determines whether the traveling speed of another vehicle that the host vehicle is to follow is faster than the host vehicle. If not, the process proceeds to step S205. It progresses to step S221 shown. The case where the traveling speed of the other vehicle is neither slow nor fast is the case where the traveling speed of the other vehicle matches the vehicle speed VP of the host vehicle.

  In step S205, the support unit 111 determines whether or not a predetermined time has elapsed since the traveling speed of the other vehicle coincides with the vehicle speed VP. If the predetermined time has not elapsed, the process proceeds to step S207. If the fixed time has elapsed, the process proceeds to step S209. In step S207, the ECU 107 controls the operation of the internal combustion engine 101 so as to follow the other vehicle while maintaining the gear stage of the transmission 103 at the current stage.

  In step S209, the support unit 111 determines whether or not the shift stage of the transmission 103 is the final target stage. If it is not the final target stage, the process proceeds to step S211. If it is the final target stage, the process proceeds to step S217. Note that the final target stage is a shift stage according to the vehicle speed VP based on a shift map or the like. In step S211, the support unit 111 determines whether or not a certain time has elapsed since the previous upshift. If the certain time has not elapsed, the process proceeds to step S213, and if the certain time has elapsed, the step 111 is performed. The process proceeds to S215. In step S213, the ECU 107 controls the operation of the internal combustion engine 101 so as to follow the other vehicle while the gear stage of the transmission 103 remains the current stage. In step S215, the ECU 107 performs upshift control to reduce the gear ratio of the transmission 103 (increase the gear position) and control the operation of the internal combustion engine 101 so as to follow the other vehicle. In step S217, the ECU 107 controls the operation of the internal combustion engine 101 so as to follow the other vehicle while the speed stage of the transmission 103 remains the current stage.

  In step S203 shown in FIG. 12 which proceeds when it is determined in step S203 in FIG. 11 that the traveling speed of the other vehicle is faster than that of the own vehicle, the support unit 111 travels the other vehicle scheduled to be followed by the own vehicle. It is determined whether or not the speed is equal to or lower than the target vehicle speed when the host vehicle is traveling at a constant speed. If the speed is higher than the target vehicle speed, the process proceeds to step S223. In step S223, the ECU 107 controls the operation of the internal combustion engine 101 so that the speed of the transmission 103 is maintained at the current speed and the host vehicle travels at the target vehicle speed during constant speed travel.

  In step S225, the support unit 111 determines whether it is possible to follow the acceleration of the other vehicle by the acceleration at the current gear position of the transmission 103. If it can be followed by the current acceleration, the process proceeds to step S227. If no follow-up is possible at the current stage of acceleration, the process proceeds to step S229. In step S227, the ECU 107 maintains the gear stage of the transmission 103 at the current stage and controls the operation of the internal combustion engine 101 so as to follow the other vehicle. In step S119, the ECU 107 performs upshift control of the transmission 103, and controls the operation of the internal combustion engine 101 so as to follow the other vehicle.

  Next, a process when the host vehicle shifts from the following traveling to the constant speed traveling will be described. As shown in FIG. 13, the support unit 111 has no other vehicle traveling ahead of the host vehicle in a space that satisfies the above-described predetermined positional relationship in front of the host vehicle along the traveling direction. (Step S301), if it exists, the process proceeds to step S303, and if it does not exist, the process proceeds to step S321. In step S303, it is determined whether or not another vehicle is likely to exist in the space. If it is determined that the vehicle does not exist, the process proceeds to step S305. Advances to step S307.

  In step S305, the ECU 107 controls the operation of the internal combustion engine 101 so as to follow the other vehicle while maintaining the gear stage of the transmission 103 at the current stage. In step S307, the support unit 111 determines whether or not the difference between the current vehicle speed VP of the subject vehicle that is running following and the target vehicle speed during constant speed traveling is greater than or equal to a threshold value. If it is less than the value, the process proceeds to step S305, and if it is greater than or equal to the threshold value, the process proceeds to step S309. In step S309, the support unit 111 determines whether the gear stage of the transmission 103 matches the final target stage corresponding to the vehicle speed VP based on the shift map or the like, or the internal combustion engine 101 is in a high speed state where the rotational speed is equal to or higher than a threshold value. It is determined whether or not a certain condition is satisfied. If the condition is not satisfied, the process proceeds to step S305. If satisfied, the process proceeds to step S311. In step S311, the ECU 107 performs downshift control of the transmission 103 and controls the operation of the internal combustion engine 101 so as to follow the other vehicle.

  In step S321, the support unit 111 determines whether or not the current vehicle speed VP of the subject vehicle that is following the vehicle is approaching the target vehicle speed during constant speed travel. If the vehicle speed VP is not close to the target vehicle speed, step S323 If the process approaches, the process proceeds to step S331. In step S323, the support unit 111 determines whether or not the difference between the vehicle speed VP and the target vehicle speed is greater than or equal to a threshold value. If the difference is less than the threshold value, the process proceeds to step S325 and exceeds the threshold value. If so, the process proceeds to step S327. In step S325, the ECU 107 controls the operation of the internal combustion engine 101 so as to accelerate to the target vehicle speed at the time of constant speed running while the gear stage of the transmission 103 remains the current stage. In step S327, the support unit 111 determines whether or not the gear position of the transmission 103 matches the final target speed corresponding to the vehicle speed VP based on the shift map or the like. If not, the process proceeds to step S325. If so, the process proceeds to step S329. In step S329, the ECU 107 controls the operation of the internal combustion engine 101 so as to accelerate to the target vehicle speed during constant speed running while the speed stage of the transmission 103 remains the speed stage after the downshift control.

  In step S331, the support unit 111 determines whether or not a predetermined time has elapsed since the previous upshift. If the predetermined time has not elapsed, the process proceeds to step S333, and if the predetermined time has elapsed, the process proceeds to step S335. In step S335, the support unit 111 determines whether or not the shift speed of the transmission 103 matches the final target speed corresponding to the vehicle speed VP based on the shift map or the like. If they match, the process proceeds to step S333 and must match. If so, the process proceeds to step S337. In step S333, the ECU 107 controls the operation of the internal combustion engine 101 so that the transmission 103 travels at the target vehicle speed during constant speed travel while the speed stage of the transmission 103 remains the current stage. In step S337, the ECU 107 performs upshift control of the transmission 103, and controls the operation of the internal combustion engine 101 to travel at the target vehicle speed during constant speed travel.

  As described above, according to the present embodiment, when traveling at a constant speed, if another vehicle is likely to interrupt the front of the host vehicle at a low speed, the vehicle is decelerated by performing a downshift control, and then the other vehicle. Accelerate to travel following. Also, during follow-up running according to the support control of the support unit 111, even when another vehicle traveling ahead is likely to decelerate, the vehicle is decelerated by performing downshift control, and thereafter, acceleration following the other vehicle is performed. Also good. Thus, when the host vehicle also accelerates to follow another vehicle, the acceleration can be continued while performing the upshift control by performing the acceleration while maintaining the downshifted gear. As a result, smooth acceleration without delay from deceleration during follow-up traveling is possible, and other vehicles can be followed quickly.

  In addition, when accelerating and following another vehicle that has entered the front of the host vehicle while traveling at a constant speed, the upshift control is performed after the relative position with the other vehicle reaches a predetermined positional relationship. . As a result, smooth acceleration from deceleration during follow-up running is possible, and other vehicles can be smoothly followed.

  Further, when the relative speed with other vehicles is large, a large deceleration is required, whereas when the relative speed is small, a large deceleration is not necessary. For this reason, if the gear ratio of the transmission during downshift control is changed more than necessary even though the relative speed is small, an unnecessarily large deceleration occurs, and passenger comfort is impaired by the sense of deceleration. In the present embodiment, the speed ratio of the transmission after downshift control is determined based on the relative speed, so that both deceleration and passenger comfort can be achieved.

  Further, a large deceleration is required when the distance to another vehicle is short, whereas a large deceleration is not necessary when the distance is long. For this reason, if the transmission gear ratio during downshift control is changed more than necessary even though the distance is long, an unnecessarily large deceleration occurs, and passenger comfort is impaired by the sense of deceleration. In the present embodiment, the transmission gear ratio after downshift control is determined based on the distance to another vehicle, so that both deceleration and passenger comfort can be achieved.

  Further, by performing fuel cut of the internal combustion engine during downshift control, it is possible to perform deceleration using engine braking effectively.

  In addition, if a situation in which another vehicle is likely to interrupt the front of the host vehicle at a low speed during constant speed traveling is detected from the movement of another vehicle related to traveling or the lighting state of another vehicle's lamp, Shift control is performed. For this reason, even when a large deceleration is necessary because another vehicle has actually interrupted at a low speed forward along the traveling direction of the host vehicle, the vehicle can be quickly decelerated. In addition, when a situation in which another vehicle traveling ahead is likely to decelerate during the following traveling is detected from the movement of the other vehicle related to traveling or the lighting state of the lamp body of the other vehicle, downshift control is performed. Do. For this reason, even when another vehicle is actually decelerated and a large deceleration is required, it is possible to quickly decelerate.

  Also, if it is detected that there is no other vehicle traveling ahead of the host vehicle in a space that satisfies the predetermined positional relationship ahead of the host vehicle along the traveling direction of the host vehicle, a downshift is performed. By performing the control, the subsequent quick acceleration to the target speed can be performed smoothly and without delay.

  In addition, this invention is not limited to embodiment mentioned above, A deformation | transformation, improvement, etc. are possible suitably.

101 Internal combustion engine 103 Transmission 105 Vehicle speed sensor 107 ECU
109 Recognizing unit 111 Supporting unit 8 Differential gear 9 Axle BRK Brake DW Drive wheel

Claims (8)

An internal combustion engine;
A transmission that shifts and transmits drive rotation of the internal combustion engine to drive wheels,
A recognition unit for recognizing another vehicle located in front of the vehicle;
The vehicle is operated so that the relative position with the other vehicle recognized by the recognition unit is in a predetermined positional relationship and / or the vehicle travels at a constant speed below a target speed. A support unit that performs control to support;
A control unit for controlling a gear ratio of the internal combustion engine and the transmission according to the support control of the support unit,
The control unit, while the vehicle is traveling according to the support control of the support unit,
Based on the recognition content of the recognition unit, the support unit determines that another vehicle exists in a close space closer to the vehicle than a space satisfying the predetermined positional relationship ahead along the traveling direction of the vehicle. If predicted or detected, downshift control to increase the transmission gear ratio is performed,
After the downshift control, when the support unit predicts or detects that the other vehicle does not exist in the space based on the recognition content of the recognition unit, the vehicle is driven by the power from the internal combustion engine. A vehicle that performs acceleration control. The vehicle according to claim 1,
The control unit maintains the transmission gear ratio after the downshift control when the vehicle accelerates after the downshift control, or changes the transmission gear ratio after the downshift control. A vehicle that performs upshift control for reducing the transmission gear ratio. The vehicle according to claim 2,
The said control part is a vehicle which performs the said upshift control after the relative position with respect to the said other vehicle becomes the said predetermined positional relationship after the said downshift control. The vehicle according to any one of claims 1 to 3,
The control unit, when performing the downshift control, determines a gear ratio of the transmission after the downshift control based on a relative speed between the vehicle and the other vehicle. The vehicle according to any one of claims 1 to 3,
The control unit, when performing the downshift control, determines a gear ratio of the transmission after the downshift control based on a distance between the vehicle and the other vehicle. The vehicle according to any one of claims 1 to 5,
The said control part is a vehicle which performs the fuel cut of the said internal combustion engine while performing the said downshift control. The vehicle according to any one of claims 1 to 6,
The recognizing unit detects a movement of the other vehicle related to traveling or a lighting state of a lamp body of the other vehicle,
The control unit performs the downshift control when the support unit predicts or detects that the other vehicle exists in the close space based on information detected by the recognition unit. The vehicle according to any one of claims 1 to 7,
The recognizing unit detects a movement of the other vehicle related to traveling or a lighting state of a lamp body of the other vehicle,
The control unit, when the vehicle is traveling at a speed less than the target speed so that the relative position with other vehicles located in the space ahead along the traveling direction is the predetermined positional relationship, A vehicle that performs the downshift control when the support unit predicts or detects that the other vehicle no longer exists in the space based on information detected by the recognition unit.

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