Vehicular control device and vehicular control method

Abstract

The present invention is provided with: a performance information acquisition unit (141) that acquires performance information; a reference output schedule determination unit (145) that determines, without using a drive response delay time and a braking response delay time, an output schedule of a required braking / driving force, which is the braking force required by the braking device and the driving force required by the driving device, in order to decelerate according to a deceleration plan in which an automatic traveling control causes the vehicle to come to a stop at a target stopping position; and a braking / driving force control unit (146) that causes a request for the driving force to the driving device according to the reference output schedule to be performed at a timing earlier than the reference output schedule by an amount corresponding to the drive response delay time acquired by the performance information acquisition unit (141), and causes a request for the braking force to the braking device according to the reference output schedule to be performed at a timing earlier than the reference output schedule by an amount corresponding to the braking response delay time acquired by the performance information acquisition unit (141).

Description

Vehicle control device and vehicle control method CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application is based on Patent Application No. 2023-114029 filed in Japan on July 11, 2023, and the contents of the original application are incorporated by reference in their entirety.

[0002] The present disclosure relates to a vehicle control device and a vehicle control method.

[0003] Patent Document 1 discloses a technology for controlling a vehicle so that the vehicle speed does not exceed a predetermined speed, and for stopping the vehicle when the vehicle reaches a target speed designated by the driver.

[0004] Japanese Patent Application Laid-Open No. 2006-347213

[0005] However, the technology of Patent Document 1 does not take into consideration the response delay time of actuators such as brakes, and therefore the technology of Patent Document 1 may not be able to accurately stop the vehicle at the target stopping position.

[0006] One object of this disclosure is to provide a vehicle control device and a vehicle control method that enable the vehicle to be stopped more accurately at a target stopping position when automatic driving control is performed to stop the vehicle.

[0007] The symbols in parentheses in the claims indicate a correspondence with the specific means described in the embodiments described below as one aspect, and do not limit the technical scope of the present disclosure.

[0008] In order to achieve the above object, the vehicle control device of the present disclosure is a vehicle control device that can be used in a vehicle that performs automatic driving control, and includes a braking / driving force control unit that controls the driving force generated by the vehicle's driving device and the braking force generated by the vehicle's braking device, a performance information acquisition unit that acquires performance information about the vehicle's performance, including a driving response delay time that is the response delay time of the driving device to a power request, and a braking response delay time that is the response delay time of the braking device to a power request, and a performance information acquisition unit that acquires performance information about the vehicle's performance, including a deceleration plan that is performed by automatic driving control until the vehicle stops at a target stopping position, and a deceleration plan that is performed by automatic driving control to request the driving device to decelerate the vehicle in accordance with the deceleration plan. The braking / driving force control unit requests the driving device to output a driving force in accordance with the reference output schedule, which is the output schedule determined by the reference output schedule determination unit, at a timing earlier than the reference output schedule by an amount corresponding to the driving response delay time acquired by the performance information acquisition unit, and requests the braking device to output a braking force in accordance with the reference output schedule at a timing earlier than the reference output schedule by an amount corresponding to the braking response delay time acquired by the performance information acquisition unit.

[0009] In order to achieve the above object, the vehicle control method of the present disclosure is a vehicle control method that can be used in a vehicle that performs automatic driving control, and includes: a braking / driving force control process executed by at least one processor, which controls the driving force generated by the vehicle's driving device and the braking force generated by the vehicle's braking device; a performance information acquisition process which acquires performance information about the vehicle's performance, including a driving response delay time which is the response delay time of the driving device to a power request, and a braking response delay time which is the response delay time of the braking device to a power request; and a deceleration plan which is performed by automatic driving control until the vehicle stops at a target stopping position. The braking / driving force control process includes a reference output schedule determination process for determining an output schedule of a driving force required of the driving device and a requested braking / driving force, which is a braking force required of the braking device, without using a driving response delay time or a braking response delay time, and in the braking / driving force control process, a request for driving force to the driving device in accordance with the reference output schedule, which is the output schedule determined in the reference output schedule determination process, is made at a timing earlier than the reference output schedule by an amount corresponding to the driving response delay time acquired in the performance information acquisition process, and a request for braking force to the braking device in accordance with the reference output schedule is made at a timing earlier than the reference output schedule by an amount corresponding to the braking response delay time acquired in the performance information acquisition process.

[0010] According to the above configuration, when decelerating to stop the vehicle at a target stop position, the request for braking / driving force can be made earlier by an amount corresponding to the response delay time of the braking / driving device than a request for braking / driving force according to a reference output schedule determined without using the driving response delay time and the braking response delay time. The request for driving force to the driving device can be made at a timing earlier than the reference output schedule by an amount corresponding to the driving response delay time. The request for braking force to the braking device can be made at a timing earlier than the reference output schedule by an amount corresponding to the braking response delay time. Therefore, it is possible to minimize the discrepancy between the timing of output of the braking / driving force scheduled in the reference output schedule and the timing of output of the actual braking / driving force. As a result, when automatic driving control is performed to stop the vehicle, it is possible to stop the vehicle at a target stop position with greater accuracy.

[0011] FIG. 1 is a diagram showing an example of a schematic configuration of a vehicle system. FIG. 2 is a diagram showing an example of a schematic configuration of a driving assistance ECU. FIG. 3 is a diagram showing an example of a schematic configuration of a braking / driving control unit. FIG. 4 is a diagram for explaining an example of an overall flow during automatic parking. FIG. 5 is a flowchart showing an example of a control flow during automatic parking in the driving assistance ECU. FIG. 6 is a flowchart showing an example of a flow of processing during stopping in the braking / driving control unit. FIG. 7 is a diagram for explaining changes in braking / driving force toward stopping by the control of the braking / driving control unit. FIG. 8 is a diagram for explaining request generation in a period around the start of deceleration.

[0012] A number of embodiments for the purpose of disclosure will be described with reference to the drawings. For the sake of convenience, parts having the same functions as parts shown in the drawings used in the previous explanations in the number of embodiments will be given the same reference numerals, and their description may be omitted. For parts given the same reference numerals, the explanations in other embodiments may be referred to.

[0013] (First Embodiment) <Overview of Vehicle System 1> A first embodiment of the present disclosure will now be described with reference to the drawings. The vehicle system 1 shown in FIG. 1 can be used in a vehicle that performs automatic cruise control. Automatic cruise control can also be referred to as automatic driving. As shown in FIG. 1, the vehicle system 1 includes a driving assistance ECU 10, a locator 11, a vehicle state sensor 12, a periphery monitoring sensor 13, a drivetrain ECU 14, a braking system ECU 15, a steering system ECU 16, a user input device 17, and an HCU (Human Machine Interface Control Unit) 18. For example, the driving assistance ECU 10, the locator 11, the vehicle state sensor 12, the periphery monitoring sensor 13, the drivetrain ECU 14, the braking system ECU 15, the steering system ECU 16, and the HCU 18 may be configured to be connected to an in-vehicle LAN (LAN) (see the LAN in FIG. 1 ). Although the vehicle using the vehicle system 1 is not necessarily limited to an automobile, the following description will be given taking the case of using the system in an automobile as an example.

[0014] There can be multiple levels of automated driving (hereinafter referred to as automation levels), as defined by, for example, the SAE. Automation levels are divided, for example, into LV0 to 5 as follows: LV0 is the level at which the driver performs all driving tasks without system intervention. The driving task may also be referred to as a dynamic driving task. Driving tasks include, for example, steering, acceleration / deceleration, and periphery monitoring. LV0 corresponds to so-called manual driving. LV1 is the level at which the system assists with either steering or acceleration / deceleration. LV1 corresponds to so-called driver assistance. LV2 is the level at which the system assists with both steering and acceleration / deceleration. LV2 corresponds to so-called partial driving automation. Note that LV1 and LV2 are also considered to be part of automated driving.

[0015] For example, automated driving at levels 1 to 2 is automated driving in which the driver has a supervisory obligation (hereinafter simply referred to as supervisory obligation) regarding safe driving. In other words, it corresponds to automated driving with a supervisory obligation. The supervisory obligation includes visually monitoring the surroundings. Autonomous driving at levels 1 to 2 can be rephrased as automated driving in which a second task is not permitted. A second task is an act other than driving that is permitted to the driver and is a specific act that is specified in advance. A second task can also be rephrased as a secondary activity, other activity, etc. A second task must not prevent the driver from responding to a request from the automated driving system to take over driving operations. As examples, activities such as watching content such as videos, operating a smartphone, reading, and eating are considered as second tasks.

[0016] Level 3 autonomous driving is a level where the system can perform all driving tasks under certain conditions, with the driver taking over driving operations in an emergency. Level 3 autonomous driving requires the driver to be able to respond quickly when the system requests a driver-takeover. This driver-takeover can also be described as the transfer of the responsibility for monitoring the surroundings from the vehicle's system to the driver. Level 3 corresponds to so-called conditional driving automation. Level 4 autonomous driving is a level where the system can perform all driving tasks except under certain circumstances such as inoperable roads or extreme environments. Level 4 corresponds to so-called high driving automation. Level 5 autonomous driving is a level where the system can perform all driving tasks in any environment. Level 5 corresponds to so-called full driving automation.

[0017] For example, autonomous driving at level 3 or higher is autonomous driving where the driver does not have a monitoring obligation. In other words, it corresponds to autonomous driving without a monitoring obligation. Autonomous driving at level 3 or higher can be rephrased as autonomous driving where a second task is permitted. In the autonomous driving control of this embodiment, the system performs at least acceleration and deceleration. The autonomous driving control of this embodiment may be autonomous driving with a monitoring obligation or autonomous driving without a monitoring obligation. The autonomous driving control of this embodiment is autonomous driving control for automatic parking. In the following, the autonomous driving control of this embodiment will be described assuming that the system performs all driving tasks during automatic parking.

[0018] The locator 11 includes a GNSS (Global Navigation Satellite System) receiver and an inertial sensor. The GNSS receiver receives positioning signals from multiple positioning satellites. The inertial sensor includes, for example, a gyro sensor and an acceleration sensor. The locator 11 sequentially determines the vehicle position of the vehicle (hereinafter referred to as the vehicle position) by combining the positioning signals received by the GNSS receiver with the measurement results of the inertial sensor. The vehicle position may also be determined by using a travel distance calculated from signals sequentially output from a vehicle speed sensor mounted on the vehicle. The vehicle position may be expressed, for example, as the center position of the rear axle of the vehicle, using coordinates on an XY coordinate system with the X and Y axes in a horizontal plane.

[0019] The vehicle condition sensor 12 is a group of sensors for detecting various conditions of the vehicle. The vehicle condition sensor 12 includes a vehicle speed sensor, a steering angle sensor, etc. The vehicle speed sensor detects the speed of the vehicle. The steering angle sensor detects the steering angle, such as the steering angle or turning angle, of the vehicle. The vehicle condition sensor 12 outputs the detected sensing information to an in-vehicle LAN. Note that the sensing information detected by the vehicle condition sensor 12 may be configured to be output to the in-vehicle LAN via an ECU installed in the vehicle.

[0020] The perimeter monitoring sensor 13 monitors the environment surrounding the vehicle. For example, the perimeter monitoring sensor 13 detects obstacles around the vehicle, such as moving objects (e.g., pedestrians, other vehicles), and stationary objects (e.g., fallen objects on the road). The perimeter monitoring sensor 13 also detects road markings (e.g., lane markings) around the vehicle. The perimeter monitoring sensor 13 may be, for example, a perimeter monitoring camera that captures an image of a predetermined area around the vehicle, or a search wave sensor that transmits search waves to a predetermined area around the vehicle. Examples of search wave sensors include millimeter-wave radar, sonar, and LIDAR (Light Detection and Ranging / Laser Imaging Detection and Ranging). The predetermined area may include at least a partial area around the vehicle, including the front, rear, left, and right sides. The perimeter monitoring camera sequentially captures images and outputs them as sensing information to the driving assistance ECU 10. The search wave sensor sequentially outputs scanning results based on received signals obtained when receiving waves reflected by obstacles to the driving assistance ECU 10 as sensing information.

[0021] The drive system ECU 14 and the braking system ECU 15 are electronic control devices that perform acceleration and deceleration control. The drive system ECU 14 controls the drive system of the vehicle. If the vehicle uses an internal combustion engine as a drive source for running, the drive system ECU 14 may be, for example, an engine ECU. If the vehicle uses a motor as a drive source for running, the drive system ECU 14 may be, for example, a power unit control ECU. The drive source for running corresponds to the drive system. The braking system ECU 15 controls the braking system of the vehicle. The braking system ECU 15 may be, for example, a brake ECU. The brake system corresponds to the braking system. The drive system and braking system are collectively referred to as the braking / drive system. The steering system ECU 16 is an electronic control device that performs steering control. The steering system ECU 16 controls the steering system of the vehicle. The steering system ECU 16 may be, for example, a steering ECU. A steering actuator corresponds to the steering system.

[0022] The user input device 17 accepts input from an occupant of the vehicle. The user input device 17 may be an operation device that accepts operation input from the occupant. The operation device may be a mechanical switch or a touch switch integrated with a display device. Note that the user input device 17 is not limited to an operation device that accepts operation input, as long as it is a device that accepts input from the occupant. For example, the user input device 17 may be a voice input device that accepts voice commands from the occupant. The user input device 17 also includes an auto-parking activation switch (hereinafter referred to as an AP switch). The AP switch is a switch that activates the automatic parking function of the driving assistance ECU 10.

[0023] The HCU 18 is mainly composed of a computer equipped with a processor, volatile memory, non-volatile memory, I / O, and a bus connecting these. The HCU 18 executes control programs stored in the non-volatile memory to perform various processes related to interactions between the occupant and the vehicle's systems. The HCU 17 acquires information input by the occupant via the user input device 17.

[0024] The driving assistance ECU 10 is mainly configured with a computer including, for example, a processor, a volatile memory, a non-volatile memory, an I / O, and a bus connecting these. The driving assistance ECU 10 executes a control program stored in the non-volatile memory to perform processing related to automatic parking. The configuration of the driving assistance ECU 10 will be described in detail below.

[0025] <General Configuration of Driving Assistance ECU 10> Next, the general configuration of the driving assistance ECU 10 will be described with reference to Fig. 2. As shown in Fig. 2, the driving assistance ECU 10 includes, as functional blocks, an environment recognition unit 101, a parking position determination unit 102, a route determination unit 103, a braking / driving control unit 104, and a steering control unit 105. Note that some or all of the functions executed by the driving assistance ECU 10 may be configured as hardware using one or more ICs or the like. Furthermore, some or all of the functional blocks included in the driving assistance ECU 10 may be realized by a combination of software execution by a processor and hardware components.

[0026] The environment recognition unit 101 recognizes the driving environment of the vehicle from sensing information acquired from the perimeter monitoring sensor 13. The environment recognition unit 101 recognizes the position, shape, and movement state of objects around the vehicle using the sensing information from the perimeter monitoring sensor 13, and generates a virtual space that reproduces the actual driving environment. The environment recognition unit 101 may also recognize the position of lane lines around the vehicle. The environment recognition unit 101 detects a parking space from the recognized driving environment. A parking space is an empty space in which the vehicle can be parked. The environment recognition unit 101 may determine whether a space is empty or not based on the size of the vehicle. As an example, the environment recognition unit 101 may detect an empty space sandwiched between or adjacent to an obstacle as a parking space. The environment recognition unit 101 may also detect an empty space sandwiched between parking lane lines as a parking space.

[0027] The parking position determination unit 102 determines a target parking position for parking the vehicle in a parking space detected by the environment recognition unit 101. The target parking position may be determined so that the vehicle fits into the parking space. This target parking position corresponds to the target stopping position. The parking position determination unit 102 may determine the parking space according to input received by the user input device 17. In other words, the parking space may be determined to be a parking space selected by the occupant from among candidate parking spaces.

[0028] The route determination unit 103 determines, as a route, a target trajectory along which the vehicle should travel to the target parking position determined by the parking position determination unit 102 while avoiding obstacles. This route will be referred to as a planned route hereinafter. The route determination unit 103 may successively re-determine the target trajectory in order to respond to changes in the situation.

[0029] The braking / driving control unit 104 determines a target vehicle speed and a target acceleration for moving the host vehicle along the planned route determined by the route determination unit 103. For example, the target vehicle speed while the host vehicle is traveling may be a constant speed. Furthermore, the target vehicle speed and target acceleration when the host vehicle is parked at the target parking position may be determined to decrease, for example, in accordance with the sensory index. The sensory index here refers to an index of a speed change that is comfortable for the occupants and is preset through experiments, simulations, or the like. For example, the braking / driving control unit 104 determines a plan for changes in the target vehicle speed and target acceleration from the timing at which deceleration begins in the automatic driving control to stop the vehicle at the target parking position until the vehicle is stopped. Hereinafter, this plan will be referred to as a deceleration plan. Furthermore, the timing at which deceleration begins in the automatic driving control to stop the vehicle at the target parking position will be referred to as the stopping deceleration start timing. To stop the vehicle at the target parking position by changing the target vehicle speed and target acceleration in accordance with the sensory index, the stopping deceleration start timing is determined depending on the vehicle speed. The braking / driving control unit 104 may determine the deceleration plan depending on this stopping deceleration start timing.

[0030] The braking / driving control unit 104 determines braking / driving forces that will produce the determined target vehicle speed and target acceleration. Braking / driving forces are a collective expression of power such as braking force and driving force. Braking / driving forces indicate at least one of braking force and driving force. Braking force and driving force may be expressed in units of N (Newton), for example. Braking force is a negative value, and driving force is a positive value. The braking / driving control unit 104 instructs the drive system ECU 14 and the brake system ECU 15 to generate the determined braking / driving forces. This controls the driving force generated from the driving source and the braking force generated from the brake device. The braking / driving control unit 104 determines and controls the braking / driving forces when the host vehicle starts from a stopped state. The braking / driving control unit 104 determines and controls the braking / driving forces while the host vehicle is traveling after starting. The braking / driving control unit 104 determines and controls the braking / driving forces when the host vehicle is stopped. The process performed by the braking / driving control unit 104 to stop the vehicle at the target parking position will be described in detail below. The process to stop the vehicle at the target parking position will be referred to as the "vehicle stopping process" below. Note that the vehicle is traveling at a constant speed under automatic driving control before transitioning to the vehicle stopping process.

[0031] The steering control unit 105 determines a target steering angle for moving the host vehicle along the planned route determined by the route determination unit 103. For example, it may determine a target steering angle at a point located a response distance ahead of the host vehicle's position on the planned route. The response distance in this case may be the distance the host vehicle is estimated to travel during the steering control response delay time. The target steering angle is uniquely determined from the curvature of the planned route at the target point. The relationship between the curvature of the planned route and the target steering angle may be determined in advance through testing or the like. The steering control unit 105 instructs the steering system ECU 16 to achieve the determined target steering angle. This controls the steering actuator to automatically change the steering angle of the host vehicle.

[0032] <General Configuration of Brake / Drive Control Unit 104> Next, the general configuration of the brake / drive control unit 104 related to processing when the vehicle is stopped will be described using Figure 3. As shown in Figure 3, the brake / drive control unit 104 includes, as functional blocks, a performance information acquisition unit 141, a driving-related information acquisition unit 142, a reference threshold value determination unit 143, a correction threshold value determination unit 144, a reference output schedule determination unit 145, and a brake / drive force control unit 146 when the vehicle is stopped. This brake / drive control unit 104 corresponds to a vehicle control device. Furthermore, the execution of processing by a computer of each functional block of the brake / drive control unit 104 corresponds to the execution of a vehicle control method.

[0033] The performance information acquisition unit 141 acquires performance information about the performance of the host vehicle. The performance information may be information about the performance of actuators such as the braking system and drive system of the host vehicle. The braking system and drive system will hereinafter be collectively referred to as actuators. The performance information may be stored in advance in a non-volatile memory of the driving assistance ECU 10 and acquired by the performance information acquisition unit 141. The performance information may be stored in a non-volatile memory other than the driving assistance ECU 10. The performance information includes a driving response delay time and a braking response delay time. The processing by the performance information acquisition unit 141 corresponds to the performance information acquisition step. The driving response delay time is the response delay time of the drive system in response to a power request. This power may be taken as driving force. The braking response delay time is the response delay time of the braking system in response to a power request. This power may be taken as braking force. The performance information may include information other than that described above.

[0034] The driving-related information acquisition unit 142 acquires driving-related information related to the driving of the vehicle. The driving-related information includes the current vehicle speed, vehicle position, planned route, and target parking position of the vehicle. The vehicle speed may be acquired from a vehicle speed sensor in the vehicle state sensors 12. The vehicle position may be acquired from the locator 11. The planned route may be acquired from the planned route determined by the route determination unit 103. The target parking position may be acquired from the target parking position determined by the parking position determination unit 102.

[0035] The reference threshold determination unit 143 determines a reference threshold that serves as a transition condition for deceleration control to stop the vehicle at the target parking position. The reference threshold is a value of the remaining distance from the host vehicle to the target parking position at which the host vehicle should start decelerating. The remaining distance from the host vehicle to the target parking position is called the remaining parking distance. The reference threshold is determined without using the driving response delay time or the braking response delay time. In other words, the reference threshold is a theoretical value that does not take into account the driving response delay time or the braking response delay time. The reference threshold determination unit 143 determines the reference threshold according to the remaining parking distance and the current vehicle speed. The reference threshold determination unit 143 may identify the remaining parking distance from the host vehicle position, planned route, and target parking position acquired by the driving-related information acquisition unit 142. The reference threshold determination unit 143 may identify the current vehicle speed acquired by the driving-related information acquisition unit 142 as the current vehicle speed. The reference threshold determination unit 143 may determine the reference threshold, for example, as follows. First, the timing to start deceleration for stopping is determined based on the current vehicle speed, as described above. Then, the remaining parking distance at the position corresponding to the timing to start deceleration for stopping can be determined as the reference threshold value.

[0036] The corrected threshold determination unit 144 determines a driving-side threshold by correcting the reference threshold for the driving device to be longer by an amount corresponding to the driving response delay time. The driving response delay time acquired by the performance information acquisition unit 141 is used. The reference threshold is determined by the reference threshold determination unit 143. The corrected threshold determination unit 144 may set, as the driving-side threshold, a value obtained by correcting the reference threshold to be longer by an amount corresponding to the distance traveled at the current vehicle speed during the driving response delay time. The corrected threshold determination unit 144 determines a braking-side threshold by correcting the reference threshold for the braking device to be longer by an amount corresponding to the braking response delay time. The braking response delay time acquired by the performance information acquisition unit 141 is used. The corrected threshold determination unit 144 may set, as the braking-side threshold, a value obtained by correcting the reference threshold to be longer by an amount corresponding to the distance traveled at the current vehicle speed during the braking response delay time.

[0037] The reference output schedule determination unit 145 determines the output schedule of the required braking / driving force for deceleration in accordance with the deceleration plan without using the driving response delay time or the braking response delay time. In other words, the reference output schedule determination unit 145 determines the output schedule of the required braking / driving force assuming that the driving response delay time and the braking response delay time are zero. As described above, the deceleration plan is a vehicle behavior plan, such as changes in the target vehicle speed and target acceleration, performed by automatic driving control until the vehicle is stopped at the target parking position. The required braking / driving force collectively represents the driving force required of the driving device and the braking force required of the braking device. The processing by the reference output schedule determination unit 145 corresponds to the reference output schedule determination step. Note that, if the deceleration plan is changed, the reference output schedule determination unit 145 may also change the output schedule of the required braking / driving force accordingly. The reference output schedule determination unit 145 may sequentially perform feedback correction of the reference output schedule so as to reduce the difference between the braking / driving force requested by the braking / driving force control unit 146 (described later) and the actually generated braking / driving force.

[0038] The braking / driving force control unit 146 controls the driving force generated by the driving system of the vehicle and the braking force generated by the braking system of the vehicle. The braking / driving force control unit 146 controls the driving force generated by the driving system by issuing instructions to the driving system ECU 14. The braking / driving force control unit 146 controls the braking force generated by the braking system by issuing instructions to the braking system ECU 15. The braking / driving force control unit 146 requests the driving system to provide driving force in accordance with the reference output schedule at a timing earlier than the reference output schedule by an amount corresponding to the driving response delay time. In other words, the driving force request is changed in the same manner as the reference output schedule, but with a phase shifted by an amount corresponding to the driving response delay time. The braking / driving force control unit 146 requests the braking system to provide braking force in accordance with the reference output schedule at a timing earlier than the reference output schedule by an amount corresponding to the braking response delay time. In other words, the braking / driving force control unit 146 requests the braking system to provide braking force in accordance with the reference output schedule at a timing earlier than the reference output schedule by an amount corresponding to the braking response delay time. In other words, the braking force request is changed in the same manner as the reference output schedule, but with a phase shifted by an amount corresponding to the braking response delay time. The reference output schedule uses the output schedule determined by the reference output schedule determination unit 145. The driving response delay time uses the driving response delay time acquired by the performance information acquisition unit 141. The braking response delay time uses the braking response delay time acquired by the performance information acquisition unit 141. The timing to advance may be time or position. If it is time, it is sufficient to advance the time in the reference output schedule at which a certain output is required by the response delay time. The driving response delay time and braking response delay time are collectively expressed as response delay time. If it is position, it is sufficient to advance the position in the reference output schedule by the distance traveled during the response time at the current vehicle speed. The processing in the braking / driving force control unit 146 corresponds to the braking / driving force control process.

[0039] With the above configuration, it is possible to request driving force from the drive device at a timing earlier than the reference output schedule by an amount corresponding to the driving response delay time. Furthermore, it is possible to request braking force from the brake device at a timing earlier than the reference output schedule by an amount corresponding to the braking response delay time. Therefore, it is possible to minimize the discrepancy between the timing of output of the braking / driving force scheduled in the reference output schedule and the timing of output of the actual braking / driving force. As a result, when automatic driving control is performed to stop the vehicle, it is possible to stop the vehicle at a target stopping position with greater accuracy.

[0040] It is preferable that the braking / driving force control unit 146 requests the drive device to apply driving force at a timing earlier than the reference output schedule, starting from the start of deceleration in the deceleration plan. It is also preferable that the braking / driving force control unit 146 requests the brake device to apply braking force at a timing earlier than the reference output schedule, starting from the start of deceleration in the deceleration plan. This makes it possible to minimize the discrepancy between the timing of output of the braking / driving force scheduled in the reference output schedule and the timing of the actual output of the braking / driving force, starting from the start of deceleration for parking. Therefore, it is possible to stop the vehicle at the target parking position with more precision by decelerating in accordance with the deceleration plan, with less discomfort for the occupants. Therefore, it is possible to stop the vehicle at the target parking position with more precision, while further minimizing discomfort for the occupants.

[0041] The braking / driving force control unit 146 may request the braking / driving force at a timing earlier than the reference output schedule, from the start of deceleration in the deceleration plan, as follows: When the remaining parking distance reaches the driving-side threshold, the braking / driving force control unit 146 may start requesting the driving force scheduled in the reference output schedule as the driving force at the start of deceleration. The driving-side threshold is determined by the correction threshold determination unit 144. When the remaining parking distance reaches the braking-side threshold, the braking / driving force control unit 146 may start requesting the braking force scheduled in the reference output schedule as the braking force at the start of deceleration. The braking-side threshold is also determined by the correction threshold determination unit 144. With the above configuration, it is possible to more easily request the driving force from the drive device at a timing earlier than the reference output schedule, from the start of deceleration in the deceleration plan.

[0042] The braking / driving force control unit 146 may sequentially request driving force from the drive device in the following manner, for example. The braking / driving force control unit 146 may merge a requested driving force value at a timing earlier than the reference output schedule with a requested driving force value in accordance with the reference output schedule at that timing, and then have the drive device request the resulting value. Hereinafter, the requested driving force value in accordance with the reference output schedule is referred to as a reference driving force requested value. The requested driving force value at a timing earlier than the reference output schedule is referred to as a phase-compensated driving request value. The merging process may involve adding the difference between the reference driving force requested value at the same timing and the phase-compensated driving request value. Furthermore, the braking / driving force control unit 146 may sequentially request braking force from the brake device in the following manner, for example. The braking / driving force control unit 146 may merge a requested braking force value at a timing earlier than the reference output schedule with a requested braking force in accordance with the reference output schedule at that timing, and then have the brake device request the resulting value. Hereinafter, the requested braking force value in accordance with the reference output schedule is referred to as a reference braking request value. The braking force requirement value at a timing earlier than the reference output schedule is called a phase compensation braking requirement value. In the merge process, the difference between the phase compensation braking requirement value and the reference braking requirement value at the same timing is added.

[0043] <Flow of Automatic Parking> Here, an example of the overall flow of automatic parking will be described using Figure 4. HV in Figure 4 indicates the vehicle. PS in Figure 4 indicates the parking space. TPP in Figure 4 indicates the target parking position. A, B, C, and D in Figure 4 indicate the steps of automatic parking.

[0044] As shown in FIG. 4 , automatic parking starts, for example, from a stopped state near a parking space. The stopping may be performed, for example, by a driver of the host vehicle manually driving the vehicle. That is, the stopping may be performed by the driver operating the brakes. The stopping may also be performed by a system that automatically drives the vehicle. When automatic parking starts, the host vehicle HV is moved forward to adjust the vehicle attitude (see A in FIG. 4 ). In adjusting the vehicle attitude, the host vehicle HV is moved forward while turning so that the vehicle attitude allows it to enter the parking space PS in reverse. Next, the host vehicle HV is moved backward into the parking space PS (see B in FIG. 4 ). After that, the host vehicle HV is moved forward to turn around and align its position with the target parking position TPP (see C in FIG. 4 ). Finally, the host vehicle HV is moved backward to align its position with the target parking position TPP (see D in FIG. 4 ).

[0045] Next, an example of the control flow during automatic parking by the driving assistance ECU 10 will be described using the flowchart in Figure 5. In the example of Figure 5, a case where the occupant needs to apply the brakes to maintain the vehicle stopped before starting will be described. The flowchart in Figure 5 may be configured to start when, for example, the AP switch is turned on while the vehicle is stopped near a parking space. For convenience, a description of steering control will be omitted here, and only braking / driving force control will be described.

[0046] First, in step S1, the parking position determination unit 102 accepts the selection of a parking space where the vehicle will be parked. The parking position determination unit 102 may determine the parking space in response to input received from the occupant via the user input device 17. As an example, the occupant may select a parking space from candidate parking spaces displayed on the display of the vehicle. In step S2, the parking position determination unit 102 determines the target parking position to be the parking space selected in S1.

[0047] In step S3, if the brake operation by the occupant is released (YES in S3), the process proceeds to step S5. On the other hand, if the brake operation by the occupant is not released (NO in S3), the process proceeds to step S4. Whether the brake operation has been released can be determined by the driving assistance ECU 10 from sensing information of the brake sensor. For example, the timing at which the brake operation is released can be set as the timing at which control for starting the host vehicle can be started.

[0048] In step S4, braking / driving control unit 104 performs braking / driving force control for vehicle stop maintenance. Then, the process returns to step S3 and repeats. In the braking / driving force control for vehicle stop maintenance, braking / driving control unit 104 generates braking / driving force that is insufficient to maintain the vehicle stop by braking operation alone. In other words, braking / driving force is generated by an amount that is insufficient to maintain the vehicle stop by the braking force required by braking operation.

[0049] In step S5, the route determination unit 103 determines a route for automatic parking to the target parking position determined in S2. The route determination unit 103 may successively re-determine the target trajectory to respond to changes in the situation. In step S6, the braking / driving control unit 104 determines a target vehicle speed and a target acceleration for moving the host vehicle along the route determined in S5. In step S7, the braking / driving control unit 104 determines a required braking / driving force that will produce the target vehicle speed and target acceleration determined in S6.

[0050] In step S8, the braking / driving control unit 104 performs control to generate the required braking / driving force determined in step S7. In step S9, if the vehicle has reached the target parking position (YES in S9), the flow ends. On the other hand, if the vehicle has not reached the target parking position (NO in S9), the flow returns to step S5 and the process is repeated.

[0051] <Processing by braking / driving control unit 104 when vehicle is stopped> Next, an example of the flow of processing by braking / driving control unit 104 when vehicle is stopped will be described using the flowchart in Fig. 6. Fig. 6 describes an example in which the host vehicle performs automatic parking. The flowchart in Fig. 6 may be configured to start when the host vehicle performing automatic parking is within a specified distance to the target parking position. The specified distance is set to a distance longer than the remaining parking distance at which deceleration will begin in the deceleration plan.

[0052] First, in step S101, the reference threshold value determination unit 143 determines a reference threshold value that is a transition condition for deceleration control to stop the vehicle at the target parking position. When the remaining parking distance reaches the reference threshold value, the reference condition described below is satisfied.

[0053] In step S102, the correction threshold determination unit 144 determines a drive-side threshold and a brake-side threshold. Hereinafter, the drive-side threshold and the brake-side threshold will be collectively referred to as the correction thresholds. As described above, the drive-side threshold is a value obtained by correcting the reference threshold for the drive unit to be longer by an amount corresponding to the drive response delay time. As described above, the brake-side threshold is a value obtained by correcting the reference threshold for the brake unit to be longer by an amount corresponding to the brake response delay time. Hereinafter, the drive unit or the brake unit with the longer response delay time will be referred to as the large delay side. On the other hand, the drive unit or the brake unit with the shorter response delay time will be referred to as the small delay side. When the remaining parking distance reaches the large delay side correction threshold, it means that the large delay side condition, described below, is met. Also, when the remaining parking distance reaches the small delay side correction threshold, it means that the small delay side condition, described below, is met.

[0054] In step S103, if the condition for large delay is met (YES in S103), the process proceeds to step S104. On the other hand, if the condition for large delay is not met (NO in S103), the process returns to S101 and is repeated. Whether the condition for large delay is met can be determined by braking / driving force control unit 146.

[0055] In step S104, if the condition for the small delay side is met (YES in S104), the process proceeds to step S106. On the other hand, if the condition for the small delay side is not met (NO in S104), the process proceeds to S105. Whether the condition for the small delay side is met can be determined by braking / driving force control unit 146. In step S105, requested braking / driving force values ​​are generated only for the large delay side of the drive system and braking system. In other words, the requested value for the large delay side in accordance with the reference output schedule is started to be generated earlier than the reference output schedule by the response delay time of the large delay side.

[0056] In step S106, if the reference condition is met (YES in S106), the process proceeds to step S108. On the other hand, if the reference condition is not met (NO in S106), the process proceeds to step S107. Whether the reference condition is met can be determined by braking / driving force control unit 146. In step S107, a braking / driving force request value is also generated for the small-delay side. That is, the request value for the small-delay side in accordance with the reference output schedule is started to be generated earlier than the reference output schedule by the response delay time of the small-delay side. In S107, the request value for the large-delay side, which has already been generated, is also generated. Here, the request values ​​for the small-delay side and the large-delay side are generated with timing shifted from the reference output schedule by the phase shift in the response delay time between the large-delay side and the small-delay side.

[0057] In step S108, required values ​​of braking and braking forces for decelerating at the target stopping position are generated. In S108, required values ​​of driving force and braking force are generated in accordance with the reference output schedule. In S108, the above-mentioned merging process is performed, which also takes into account the required values ​​for the large delay side and the small delay side, which have already been generated and whose timing is earlier than the reference output schedule, and the required values ​​of driving force and braking force are generated.

[0058] In step S109, the braking / driving device is requested to output the required value generated in step S105, S107, or S108. In step S110, if the vehicle has reached the target parking position (YES in S110), the flow ends. On the other hand, if the vehicle has not reached the target parking position (NO in S110), the flow returns to S101 and the process is repeated.

[0059] <Changes in braking / driving force for stopping the vehicle under control of braking / driving control unit 104> Next, using the graph in FIG. 7, changes in braking / driving force for stopping the vehicle at a target parking position under control of braking / driving control unit 104 will be described. In FIG. 7, an example will be described in which the drive system is on the small delay side and the braking system is on the large delay side. The horizontal axis of the graph in FIG. 7 represents time. Po in FIG. 7 represents the change in the position of the host vehicle over time. TPP in FIG. 7 represents the target parking position. VS in FIG. 7 represents the change in the speed of the host vehicle over time. DP in FIG. 7 represents the change in the driving force of the host vehicle over time. BP in FIG. 7 represents the change in the braking force of the host vehicle over time. The solid line in FIG. 7 represents the actual value, and the dashed line represents the required value. CSS in FIG. 7 represents the period during which constant speed traveling is performed. DS in FIG. 7 represents the period during which deceleration is performed. Here, changes in braking / driving force during this period of deceleration will be described. It is assumed that deceleration is performed according to a deceleration plan. ST in FIG. 7 represents the period after stopping. A in FIG. 7 shows the period around the start of deceleration.

[0060] As shown in FIG. 7 , deceleration is achieved by increasing the braking force. Note that the braking force increases as the negative value increases. During deceleration, not only braking force but also driving force is required. This allows the braking force to be adjusted by the driving force. Referring to FIG. 8 , the generation of a request during the period around the start of deceleration, indicated by A in FIG. 7 , will be described. The horizontal axis of the graph in FIG. 8 represents time. Ac in FIG. 8 represents the change in acceleration required of the host vehicle over time. Since the acceleration is a negative value in FIG. 8 , this corresponds to the so-called deceleration. TRC in FIG. 8 is the ideal request value assuming no response delay. DRC in FIG. 8 is the request value advanced by the driving response delay. BRC in FIG. 8 is the request value advanced by the braking response delay. As shown in FIG. 8 , the request value is generated earlier by the response delay. This allows the braking / driving device to accurately track the request value. This reduces the discrepancy between the request value and the actual value immediately before stopping, improving the accuracy of the stopping position.

[0061] Second Embodiment In the first embodiment, the driving environment of the vehicle is recognized by the driving assistance ECU 10, but this is not necessarily limited to this. For example, the driving environment of the vehicle may be recognized by an ECU other than the driving assistance ECU 10. In this case, the driving assistance ECU 10 may acquire information about the driving environment recognized by an ECU other than the driving assistance ECU 10.

[0062] (Embodiment 3) In the first embodiment, the control of the braking / driving force when the vehicle is stopped toward a target parking position in automatic parking has been described, but this is not necessarily limited to this. For example, similar control may be performed for the control of the braking / driving force when the vehicle is stopped toward a target stopping position that is not limited to automatic parking. In this case, the target stopping position may be a planned point where the host vehicle is to be stopped in the travel plan of the automatic travel control.

[0063] (Disclosed Technical Ideas) This specification discloses multiple technical ideas described in the following multiple clauses. Some clauses may be described in a multiple dependent form, with the subsequent clause alternatively referring to the preceding clause. Furthermore, some clauses may be described in a multiple dependent form, referring to another multiple dependent clause. These multiple dependent clauses define multiple technical ideas.

[0064] (Technical Idea 1) A vehicle control device that can be used in a vehicle that performs automatic driving control, comprising: a braking / driving force control unit (146) that controls a driving force generated by a driving device of the vehicle and a braking force generated by a braking device of the vehicle; a performance information acquisition unit (141) that acquires performance information about the performance of the vehicle, including a driving response delay time that is a response delay time of the driving device to a power request, and a braking response delay time that is a response delay time of the braking device to a power request; and a reference output schedule determination unit (145) that determines an output schedule of a driving force requested of the driving device and a requested braking / driving force that is a braking force requested of the braking device, without using the driving response delay time and the braking response delay time, in order to decelerate in accordance with a deceleration plan performed by automatic driving control until the vehicle stops at a target stopping position, The braking / driving force control unit requests the drive device for driving force in accordance with a reference output schedule, which is an output schedule determined by the reference output schedule determination unit, at a timing earlier than the reference output schedule by an amount corresponding to the driving response delay time acquired by the performance information acquisition unit, and requests the brake device for braking force in accordance with the reference output schedule at a timing earlier than the reference output schedule by an amount corresponding to the braking response delay time acquired by the performance information acquisition unit.

[0065] (Technical Idea 2) A vehicle control device according to Technical Idea 1, wherein the braking / driving force control unit requests the drive device for driving force in accordance with the reference output schedule from the start of deceleration in the deceleration plan at a timing earlier than the reference output schedule by an amount corresponding to the driving response delay time, and requests the brake device for braking force in accordance with the reference output schedule at a timing earlier than the reference output schedule by an amount corresponding to the braking response delay time.

[0066] (Technical Idea 3) The vehicle control device according to Technical Idea 2 includes a reference threshold value determination unit (143) that determines a reference threshold value, which is the value of the remaining distance at which the vehicle should start decelerating, in accordance with the remaining distance from the vehicle to the target stopping position and the vehicle speed of the vehicle, without using the driving response delay time and the braking response delay time; and a corrected threshold value determination unit (144) that determines a driving side threshold value for the driving device by correcting the reference threshold value to be longer by an amount corresponding to the driving response delay time acquired by the performance information acquisition unit, and determines a braking side threshold value for the braking device by correcting the reference threshold value to be longer by an amount corresponding to the braking response delay time acquired by the performance information acquisition unit, The braking / driving force control unit starts requesting the driving force planned in the standard output schedule as the driving force at the start of deceleration when the remaining distance reaches the driving side threshold determined by the correction threshold determination unit, and starts requesting the braking force planned in the standard output schedule as the braking force at the start of deceleration when the remaining distance reaches the braking side threshold determined by the correction threshold determination unit.

[0067] (Technical Idea 4) A vehicle control device according to any one of Technical Ideas 1 to 3, which can be used in a vehicle that performs automatic driving control for automatic parking, wherein the braking / driving force control unit, when decelerating to stop at a target stopping position during automatic parking, requests a driving force from the drive device in accordance with a reference output schedule, which is an output schedule determined by the reference output schedule determination unit, at a timing earlier than the reference output schedule by an amount corresponding to the driving response delay time acquired by the performance information acquisition unit, and requests a braking force from the brake device in accordance with the reference output schedule at a timing earlier than the reference output schedule by an amount corresponding to the braking response delay time acquired by the performance information acquisition unit.

[0068] The present disclosure is not limited to the above-described embodiments, and various modifications are possible within the scope of the claims. Embodiments obtained by appropriately combining the technical means disclosed in different embodiments are also within the technical scope of the present disclosure. Furthermore, the control unit and method described in the present disclosure may be implemented by a special-purpose computer comprising a processor programmed to execute one or more functions embodied in a computer program. Alternatively, the apparatus and method described in the present disclosure may be implemented by a special-purpose hardware logic circuit. Alternatively, the apparatus and method described in the present disclosure may be implemented by one or more special-purpose computers configured by combining a processor executing a computer program with one or more hardware logic circuits. Furthermore, the computer program may be stored as instructions executed by a computer on a computer-readable non-transitory tangible recording medium.

Claims

1. A vehicle control device that can be used in vehicles that perform automatic driving control, A braking and driving force control unit (146) controls the driving force generated from the vehicle's drive system and the braking force generated from the vehicle's braking system. A performance information acquisition unit (141) acquires performance information about the vehicle's performance, including a drive response delay time, which is the response delay time of the drive unit to a power request, and a brake response delay time, which is the response delay time of the brake unit to a power request. The system includes a reference output schedule determination unit (145) that determines the planned output of the required braking force, which is the driving force required by the drive unit and the braking force required by the brake unit, without using the driving response delay time and the braking response delay time, in order to perform deceleration in accordance with a deceleration plan that is performed by automatic driving control until stopping at the target stopping position. The braking force control unit causes the drive unit to request driving force in accordance with the reference output schedule determined by the reference output schedule determination unit, at a timing earlier than the reference output schedule by an amount corresponding to the drive response delay time acquired by the performance information acquisition unit, and also causes the brake unit to request braking force in accordance with the reference output schedule, at a timing earlier than the reference output schedule by an amount corresponding to the brake response delay time acquired by the performance information acquisition unit. A reference threshold determination unit (143) determines a reference threshold value, which is the value of the remaining distance at which the vehicle should begin to decelerate, without using the drive response delay time and the brake response delay time, according to the remaining distance from the vehicle to the target stopping position and the vehicle speed of the vehicle, The system further includes a correction threshold determination unit (144) which determines a drive-side threshold obtained by correcting the reference threshold for the drive device to be longer by the amount corresponding to the drive response delay time obtained by the performance information acquisition unit, and a correction threshold determination unit (144) which determines a braking-side threshold obtained by correcting the reference threshold for the braking device to be longer by the amount corresponding to the braking response delay time obtained by the performance information acquisition unit, The braking and driving force control unit initiates a request for the driving force scheduled in the reference output as the driving force at the start of deceleration when the remaining distance reaches the driving-side threshold determined by the correction threshold determination unit, while the vehicle control device initiates a request for the braking force scheduled in the reference output as the braking force at the start of deceleration when the remaining distance reaches the braking-side threshold determined by the correction threshold determination unit.

2. A vehicle control device according to claim 1, The braking and driving force control unit causes the drive unit to request driving force in accordance with the reference output schedule from the start of deceleration in the deceleration plan, at a timing earlier than the reference output schedule by a amount corresponding to the drive response delay time, and also causes the brake unit to request braking force in accordance with the reference output schedule, at a timing earlier than the reference output schedule by a amount corresponding to the brake response delay time.

3. A vehicle control device according to claim 1 or 2, It can be used in vehicles that perform automatic driving control for automatic parking. The aforementioned braking and driving force control unit, when decelerating towards stopping at a target stopping position during automatic parking, causes the drive unit to request driving force in accordance with the reference output schedule determined by the reference output schedule determination unit, at a timing earlier than the reference output schedule by an amount corresponding to the drive response delay time acquired by the performance information acquisition unit, and also causes the brake unit to request braking force in accordance with the reference output schedule, at a timing earlier than the reference output schedule by an amount corresponding to the brake response delay time acquired by the performance information acquisition unit.

4. A vehicle control method that can be used in vehicles that perform automatic driving control, Run by at least one processor, A braking force control process for controlling the driving force generated from the vehicle's drive system and the braking force generated from the vehicle's braking system, A performance information acquisition step for acquiring performance information about the vehicle's performance, including a drive response delay time, which is the response delay time of the drive unit to a power request, and a brake response delay time, which is the response delay time of the brake unit to a power request; The process includes a reference output schedule determination step, which determines the planned output of the required braking force, which is the driving force required for the drive unit and the braking force required for the brake unit, without using the driving response delay time and the braking response delay time, in order to perform deceleration in accordance with a deceleration plan that is performed by automatic driving control until stopping at the target stopping position. In the braking force control process, a request for driving force to the drive unit in accordance with the reference output schedule determined in the reference output schedule determination process is made earlier than the reference output schedule by an amount corresponding to the drive response delay time acquired in the performance information acquisition process, and a request for braking force to the braking unit in accordance with the reference output schedule is made earlier than the reference output schedule by an amount corresponding to the braking response delay time acquired in the performance information acquisition process. A reference threshold determination step, in which a reference threshold is determined, which is the value of the remaining distance at which the vehicle should begin to decelerate, without using the drive response delay time and the brake response delay time, based on the remaining distance from the vehicle to the target stopping position and the vehicle speed of the vehicle, The process further includes determining a drive-side threshold obtained by correcting the reference threshold for the drive device to be longer by an amount corresponding to the drive response delay time obtained in the performance information acquisition step, and determining a braking-side threshold obtained by correcting the reference threshold for the braking device to be longer by an amount corresponding to the braking response delay time obtained in the performance information acquisition step, A vehicle control method comprising the braking and driving force control step, wherein when the remaining distance reaches the driving-side threshold determined in the correction threshold determination step, a request for the driving force planned in the reference output schedule is initiated as the driving force at the start of deceleration, and when the remaining distance reaches the braking-side threshold determined in the correction threshold determination step, a request for the braking force planned in the reference output schedule is initiated as the braking force at the start of deceleration.