Vehicle control device

Abstract

The vehicle control unit controls the drive and braking systems to ensure that the actual acceleration matches the target acceleration. The actual acceleration represents the vehicle's actual acceleration, while the target acceleration is the acceleration used to bring the vehicle to a predetermined stop position. Every predetermined time interval, the vehicle control unit acquires the target acceleration. If the change in the difference between the current and previous target acceleration exceeds a threshold change, the vehicle control unit sets the current target acceleration to a value such that the change does not exceed the threshold change. Furthermore, if a predetermined emergency condition requiring greater driving or braking force than usual is met, the vehicle control unit sets the threshold change to a value greater than if the emergency condition is not met.

Description

Technical Field

[0001] The present invention relates to a vehicle control device for driving a vehicle to stop the vehicle at a predetermined target stopping position. Background Technology

[0002] Previously, vehicle control devices were known for driving a vehicle to a target stopping position and stopping the vehicle there. Such vehicle control devices control the vehicle's drive and braking systems so that the actual acceleration of the vehicle matches the "target acceleration used to drive the vehicle to stop at the target stopping position." The drive system provides driving force to the vehicle, and the braking system provides braking force.

[0003] For example, the vehicle control device described in Japanese Patent Application Publication No. 2020-15402 (hereinafter referred to as "the prior art") increases the target acceleration when the vehicle stops due to interference that hinders its movement while traveling towards a target stopping position. Thus, even if the vehicle stops due to interference, the prior art can increase the probability of driving the vehicle to the target stopping position by driving the vehicle in a manner that counteracts the interference. Summary of the Invention

[0004] When at least one of the drive or braking systems exhibits control hysteresis, the time required for the actual acceleration to match the target acceleration becomes longer. Consequently, the target acceleration may increase or decrease abruptly. Repeated abrupt increases or decreases in target acceleration can cause the vehicle to repeatedly accelerate and decelerate rapidly, resulting in vertical vibrations.

[0005] To reduce the possibility of such abrupt increases or decreases in target acceleration, the inventors have researched a vehicle control device with the following configuration: The target acceleration (current target acceleration) is set such that the magnitude of the change in the difference between the current target acceleration and the previously acquired target acceleration (previous target acceleration) does not exceed a threshold change. This configuration is sometimes referred to as a "change limiter".

[0006] Vehicle control units equipped with such variable amplitude limiters may control the drive and braking systems based on a target acceleration that is smaller than the required target acceleration. In this case, the required driving or braking force may not be provided to the vehicle. If the vehicle is not provided with the driving force necessary to counteract the disturbance in the event of a disturbance, the vehicle will stop. If the vehicle is not provided with the braking force necessary to stop at the target stopping position, the vehicle will not be able to stop at the target stopping position.

[0007] The present invention was made to address the aforementioned problems. Specifically, one of the objectives of the present invention is to provide a vehicle control device that, even when there is control lag in at least one of the drive and braking devices, can reduce vehicle vibration under normal conditions and control the drive and braking devices with the required target acceleration when a greater driving or braking force than usual is required.

[0008] The vehicle control device of the present invention (hereinafter also referred to as "the device of the present invention") comprises:

[0009] A drive unit (34a) that provides driving force to the vehicle;

[0010] Braking device (44a) that provides braking force to the vehicle; and

[0011] Control units (20, 30, 40) control the drive and braking devices to ensure that the actual acceleration matches the target acceleration, whereby the actual acceleration represents the actual acceleration of the vehicle, and the target acceleration is the acceleration used to move the vehicle to a predetermined target stopping position.

[0012] The control unit is configured as follows:

[0013] At each predetermined time interval, the target acceleration is obtained (step 325).

[0014] If the magnitude of the change in the difference between the current target acceleration and the previous target acceleration exceeds a threshold change (step 335: "No"), the current target acceleration is set such that the magnitude of the change does not exceed the threshold change (step 355). The current target acceleration is the target acceleration obtained this time, and the previous target acceleration is the target acceleration obtained last time.

[0015] When a predetermined emergency condition is met when a greater driving force or braking force than usual is required (step 515: "Yes", step 535: "Yes", step 545: "Yes"), the threshold change is set to a value greater than that when the emergency condition is not met (step 545: "No", step 555) (step 520, step 550).

[0016] The device of this invention sets the target acceleration to a value such that the magnitude of the change does not exceed a threshold value. Therefore, even if there is control lag in at least one of the drive or braking devices, it can prevent the vehicle from accelerating and decelerating abruptly. As a result, the possibility of vehicle VA vibration can be reduced.

[0017] Furthermore, the device of the present invention can also set the threshold change amount to a larger value than when the emergency condition is not met, even when an emergency condition is met. This allows the target acceleration to vary more significantly than usual when a greater driving or braking force is required. As a result, when a greater driving force is required than usual, the possibility of providing the driving force needed for the vehicle's drive system is increased; and when a greater braking force is required than usual, the possibility of providing the braking force needed for both the drive and braking systems is increased.

[0018] In one technical solution of the device of the present invention,

[0019] The control unit can also be configured to: determine whether the emergency condition is met based on the interference value and the remaining distance, wherein the interference value represents the magnitude of the interference that hinders the vehicle's movement, and the remaining distance represents the remaining distance to the target stopping position (steps 515, 525, 540, and 545).

[0020] If the disturbance value is large, there is a higher probability that a greater driving force will be required for the vehicle to counteract the disturbance. If the remaining distance is short, there is a higher probability that a greater braking force will be required to stop the vehicle at the target stopping position. Since the determination of whether an emergency condition is established is based on such disturbance values ​​and remaining distances, the reliability of determining that an emergency condition is established when a greater driving force or braking force than usual is required can be improved (the reliability of emergency condition determination).

[0021] In the above technical solutions,

[0022] The control unit can also be configured to determine that the emergency condition is met if any one of the following conditions is met: the first condition (step 515), the second condition (step 535), the third condition (step 540), and the fourth condition (step 545).

[0023] The first condition is that the interference value is above a threshold.

[0024] The second condition is that the actual acceleration is above a threshold acceleration set based on the remaining distance.

[0025] The third condition is that the vehicle has passed the target stopping position.

[0026] The fourth condition is that the remaining distance becomes below a predetermined threshold distance.

[0027] Condition 1 is met when there is a high probability that a large driving force is required. Conditions 2 and 4 are met when there is a high probability that a large braking force is required to stop the vehicle at the target stopping position. Condition 3 is met when the target stopping position has been passed. Therefore, for condition 3, since the vehicle needs to be stopped immediately, this condition is met when there is a high probability that a large braking force is required. Since an emergency condition is determined to be met when any of conditions 1 to 4 is met, the reliability of the above-mentioned emergency condition determination can be improved.

[0028] In the above technical solutions,

[0029] The control unit may also be configured such that, when any one of the first to third conditions is met, the threshold change amount is set to a value larger than when the fourth condition is met (step 550) (step 520).

[0030] When any of conditions 1 through 3 is met, the urgency of requiring "large driving or braking force" is higher than when condition 4 is met. Therefore, it is necessary to provide the vehicle with the required driving or braking force as early as possible. Thus, when any of conditions 1 through 3 is met, the threshold change is set to a larger value than when condition 4 is met. This further increases the possibility of further reducing vehicle vibration while simultaneously improving the ability to provide the vehicle with the necessary driving and braking forces.

[0031] Furthermore, in the foregoing description, to aid in understanding the invention, parentheses have been used to add the names and / or reference numerals used in the embodiments described below to the components of the invention corresponding to those embodiments. However, the constituent elements of the invention are not limited to the embodiments specified by the names and / or reference numerals. Other objects, features, and incidental advantages of the invention will be readily understood from the description of embodiments of the invention as illustrated in the following drawings. Attached Figure Description

[0032] The features, advantages, and technical and industrial significance of exemplary embodiments of the present invention will be described below with reference to the accompanying drawings, wherein like reference numerals denote like elements, and wherein:

[0033] Figure 1 This is a schematic diagram of a vehicle control device according to an embodiment of the present invention;

[0034] Figure 2 This is an illustration of emergency conditions;

[0035] Figure 3This is a flowchart representing the automatic parking routine executed by the CPU of the parking ECU;

[0036] Figure 4 This is a flowchart representing the end determination routine executed by the CPU of the parking ECU;

[0037] Figure 5 This is a flowchart representing the threshold change setting routine executed by the CPU of the parking ECU; Detailed Implementation

[0038] <Composition>

[0039] like Figure 1 As shown, the vehicle control device 10 (hereinafter referred to as "this control device 10") according to this embodiment is mounted (applied to) a vehicle VA. This control device 10 includes a parking ECU 20, a drive ECU 30, a brake ECU 40, and a steering ECU 50. These ECUs 20, 30, 40, and 50 are connected to each other via a controller area network (CAN) (not shown) in a manner that enables them to send and receive data.

[0040] ECU is short for Electronic Control Unit, an electronic control circuit that uses a microcomputer, including a CPU, ROM, RAM, and interfaces, as its main components. Sometimes, ECU is also called a "controller" or "control unit." The CPU executes instructions (routes) stored in the memory (ROM) to perform various functions. All or several of the ECUs 20, 30, 40, and 50 mentioned above can also be combined into a single ECU.

[0041] This control device 10 includes multiple cameras 22, multiple sonars 24, an acceleration sensor 26, multiple wheel speed sensors 28, and an automatic parking switch 29. These 22 to 29 are connected to the parking ECU 20 to enable the transmission and reception of data with respect to the parking ECU 20.

[0042] Multiple cameras 22 include a front camera, a rear camera, a left-side camera, and a right-side camera. Each of the multiple cameras 22 generates image data by capturing images of the areas described below at predetermined intervals, and sends this image data to the parking ECU 20. The front camera, rear camera, left-side camera, and right-side camera capture images of the area in front of the vehicle VA, the area behind the vehicle VA, the area to the left of the vehicle VA, and the area to the right of the vehicle VA, respectively.

[0043] Multiple sonars 24 include a front sonar, a rear sonar, a left-side sonar, and a right-side sonar. Each of the multiple sonars 24 transmits sound waves to the areas described below and receives reflected waves caused by objects. Each of the multiple sonars 24 transmits information (i.e., sonar data) related to the transmitted sound waves and the received reflected waves to the parking ECU 20 at predetermined intervals. The front, rear, left-side, and right-side sonars transmit sound waves to the areas in front of the vehicle VA, the areas behind the vehicle VA, the areas to the left of the vehicle VA, and the areas to the right of the vehicle VA, respectively.

[0044] The parking ECU 20 uses image data and sonar data to identify objects around the vehicle VA, and uses image data to identify white lines on the road surface around the vehicle VA.

[0045] Accelerometer 26 measures the actual acceleration G of vehicle VA in the longitudinal direction and generates a detection signal representing the acceleration G. Parking ECU 20 determines the acceleration G of vehicle VA based on the detection signal received from acceleration sensor 26. This acceleration G is sometimes referred to as "actual acceleration".

[0046] Wheel speed sensors 28 are provided for each wheel of the vehicle VA. Each wheel speed sensor 28 generates a wheel pulse signal for each predetermined angle of rotation of the corresponding wheel. The parking ECU 20 counts the number of pulses per unit time of the wheel pulse signals received from each wheel speed sensor 28, and obtains the rotational speed of each wheel based on the number of pulses. Furthermore, the parking ECU 20 obtains the vehicle speed Vs, representing the speed of the vehicle VA, based on the wheel speed of each wheel. As an example, the parking ECU 20 obtains the average wheel speed of the four wheels as the vehicle speed Vs.

[0047] The automatic parking switch 29 is located near the steering wheel 52a of the vehicle. The driver operates the automatic parking switch 29 when they wish to perform automatic parking control. The automatic parking control is as follows: the vehicle VA automatically drives to the target stopping position so that the vehicle VA stops at the target stopping position.

[0048] The drive ECU 30 is connected to the accelerator pedal operation amount sensor 32 and the drive source actuator 34 so that it can send and receive data with respect to the accelerator pedal operation amount sensor 32 and the drive source actuator 34.

[0049] Accelerator pedal operation amount sensor 32 detects accelerator pedal operation amount AP and generates a signal representing the accelerator pedal operation amount AP, which is the amount of operation by the driver on the accelerator pedal 32a. The drive ECU 30 determines the accelerator pedal operation amount AP based on the signal generated by the accelerator pedal operation amount sensor 32.

[0050] The drive source actuator 34 is connected to a drive source (such as an electric motor or internal combustion engine) 34a that generates the driving force supplied to the vehicle VA. Furthermore, the drive source 34a is sometimes also referred to as a "drive unit". The drive ECU 30 controls the drive source actuator 34 to change the operating state of the drive source 34a. Thus, the drive ECU 30 can adjust the driving force supplied to the vehicle VA. The drive ECU 30 controls the drive source actuator 34 such that the greater the demand from the accelerator pedal operation amount AP or the parking ECU 20, the greater the driving force supplied to the vehicle VA.

[0051] The brake ECU 40 is connected to the brake pedal operation sensor 42 and the brake actuator 44 so that it can send and receive data with respect to the brake pedal operation sensor 42 and the brake actuator 44.

[0052] Brake pedal operation amount sensor 42 detects the brake pedal operation amount BP and generates a signal representing the brake pedal operation amount BP, which is the operation amount of brake pedal 42a. Brake ECU 40 determines the brake pedal operation amount BP based on the signal generated by brake pedal operation amount sensor 42.

[0053] Brake actuator 44 is connected to a known hydraulic braking device 44a. Brake ECU 40 controls brake actuator 44 to modify the frictional braking force generated by braking device 44a. Thus, brake ECU 40 can adjust the braking force provided to vehicle VA. Brake ECU 40 controls brake actuator 44 such that the greater the brake pedal operation amount BP or the demand from parking ECU 20, the greater the braking force provided to vehicle VA.

[0054] The steering ECU 50 is connected to the steering angle sensor 52, the steering torque sensor 54, and the steering motor 56.

[0055] The steering angle sensor 52 detects the rotation angle of the steering wheel 52a from the neutral position and uses it as the steering angle θs, generating a signal representing the steering angle θs. The steering ECU 50 determines the steering angle θs based on the signal generated by the steering angle sensor 52.

[0056] The steering torque sensor 54 detects the steering torque Tr and generates a signal representing the steering torque Tr, which represents the torque acting on the steering shaft 54a connected to the steering wheel 52a. The steering ECU 50 determines the steering torque Tr based on the signal generated by the steering torque sensor 54.

[0057] The steering motor 56 generates torque corresponding to the power supplied by the vehicle battery (not shown). The steering ECU 50 controls the direction and magnitude of the power supplied to the steering motor 56. The steering motor 56 is assembled in such a way that the aforementioned torque can be transmitted to the steering mechanism 56a of the vehicle VA. The steering mechanism 56a includes a steering wheel 52a, a steering shaft 54a, and a steering gear mechanism, etc. The torque generated by the steering motor 56 produces steering assist torque, causing the left and right steering wheels to be steered (turned).

[0058] The steering ECU 50 normally uses the steering motor 56 to generate steering assist torque corresponding to the steering torque Tr. Furthermore, when the steering ECU 50 receives a steering command including a target steering angle from the parking ECU 20, it controls the steering motor 56 to make the steering angle θs consistent with the target steering angle included in the received steering command, thereby automatically turning the steering wheel.

[0059] (Job Summary)

[0060] This control device 10 performs automatic parking control. During the execution of automatic parking control, each time a predetermined time has elapsed, this control device 10 acquires the target acceleration Gtgt for the vehicle VA to travel along the "travel path to the target stopping position" and stop at the target stopping position. This control device 10 obtains the change ΔGtgt by subtracting the previous target acceleration Gtgt' from the current target acceleration Gtgt. The current target acceleration Gtgt is the target acceleration Gtgt acquired at the current time point (acquired this time). The previous target acceleration Gtgt' is the target acceleration Gtgt acquired a predetermined time ago from the current time point (previously acquired).

[0061] The control device 10 sets the target acceleration Gtgt in such a way that the magnitude of the change ΔGtgt (|ΔGtgt|) does not exceed the threshold change ΔGth, and sends acceleration and deceleration commands containing the target acceleration Gtgt to the drive ECU 30 and the brake ECU 40.

[0062] The drive ECU 30 and brake ECU 40 control the drive source 34a and brake device 44a respectively via the drive source actuator 34 and brake actuator 44, so that the acceleration G is consistent with the target acceleration Gtgt contained in the acceleration / deceleration command. When the target acceleration Gtgt is greater than 0, the drive ECU 30 and brake ECU 40 control the drive source 34a and brake device 44a respectively to accelerate the vehicle VA (i.e., provide driving force to the vehicle VA). When the target acceleration Gtgt is less than 0, the drive ECU 30 and brake ECU 40 control the drive source 34a and brake device 44a respectively to decelerate the vehicle VA (i.e., provide braking force to the vehicle VA).

[0063] The control device 10 determines a predetermined emergency condition that occurs when a greater driving or braking force than usual is required (refer to...). Figure 2 (This will be described later.) Whether the emergency condition is met. If the emergency condition is not met, the control device 10 sets the threshold change ΔGth to the normal threshold Gnth. Conversely, if the emergency condition is met, the control device 10 sets the threshold change ΔGth to the emergency threshold Gkth. The emergency threshold Gkth is set to a value larger than the normal threshold Gnth.

[0064] When an emergency condition is met, the control device 10 increases the threshold change ΔGth compared to when the emergency condition is not met. Therefore, the control device 10 can reduce the likelihood of vehicle VA vibration caused by repeated sharp increases and decreases in the target acceleration Gtgt under normal conditions. Furthermore, when a greater driving or braking force than usual is required, the control device 10 can control the drive source 34a and braking device 44a with the required target acceleration. This increases the likelihood that the vehicle VA can reach the target stopping position even when interference hinders its movement, and increases the likelihood of accurately stopping the vehicle VA at the target stopping position.

[0065] (Emergency Conditions)

[0066] Reference Figure 2 Emergency conditions are explained. This control device 10 determines that an emergency condition has been met if any of the following conditions 1 to 4 are met.

[0067] <Condition 1>

[0068] When the interference value Dv is above the threshold Dvth, the control device 10 determines that the first condition is met. The interference value Dv represents the magnitude of the interference that hinders the driving of vehicle VA.

[0069] The control device 10 obtains the disturbance value Dv by subtracting the acceleration G from the target acceleration Gtgt. The larger the disturbance value Dv, the greater the disturbance.

[0070] For example, in such Figure 2 When the front wheel of vehicle VA contacts the step as shown, the movement of vehicle VA is hindered by the step, and vehicle VA cannot accelerate. Therefore, the aforementioned disturbance value Dv is larger than usual, and the probability of condition 1 being true increases. Condition 1 is a condition that is true when a greater driving force than usual is required.

[0071] <Second condition>

[0072] The control device 10 determines that the second condition is met when the acceleration G is a threshold acceleration Gth set based on the remaining distance D, which represents the remaining distance to the target stopping position. As an example, the threshold acceleration Gth is set such that it decreases from a value greater than 0 as the remaining distance D shortens. To explain this example in more detail, the threshold acceleration Gth is pre-set to a value such that when the remaining distance D becomes "0" (i.e., when the vehicle VA reaches the target stopping position), the acceleration G becomes "0". Therefore, if the acceleration G is greater than or equal to the threshold acceleration Gth, it is possible that the acceleration G will not become "0" when the vehicle VA reaches the target stopping position, and the vehicle VA may not be able to stop. Thus, the second condition is met when a greater braking force than usual is required.

[0073] Furthermore, the remaining distance D is obtained as follows. Based on image data and sonar data, the control device 10 obtains the distance traveled by the vehicle VA along the travel route from the current position of the vehicle VA to the target stopping position after a predetermined time interval, and uses this distance as the remaining distance D. However, sometimes, for example, a three-dimensional object exists between the camera 22 and the target stopping position, and the image data does not include the target stopping position. In this case, the remaining distance D cannot be obtained based on the image data and sonar data. In such cases, the control device 10 determines the measured distance Dm, which is the actual distance the vehicle VA has moved since the last time the remaining distance D was obtained, based on wheel pulse signals from the wheel speed sensor 28, and subtracts the measured distance Dm from the last remaining distance D to obtain the remaining distance D.

[0074] <Condition 3>

[0075] The control device 10 determines that the third condition is met if, based on the remaining distance D, the vehicle VA will not stop even after reaching the target stopping position. More specifically, the control device 10 determines that the third condition is met when the vehicle speed Vs is not zero even when the remaining distance D is zero. When the third condition is met, the vehicle VA needs to stop immediately. Therefore, the third condition is a condition that is met when a greater braking force than usual is required.

[0076] <Condition 4>

[0077] When the remaining distance D is less than or equal to a threshold distance Dth, the control device 10 determines that condition 4 is met. When the remaining distance D is less than or equal to the threshold distance Dth, the vehicle VA is relatively close to the target stopping position, requiring a rapid deceleration to bring the vehicle VA to a stop at the target stopping position. Therefore, condition 4 is met when a greater braking force than usual is required.

[0078] Here, a first emergency threshold Gkth1 and a second emergency threshold Gkth2 are prepared as the emergency threshold Gkth. The first emergency threshold Gkth1 is set to a value larger than the second emergency threshold Gkth2. Among the normal threshold Gnth, the first emergency threshold Gkth1, and the second emergency threshold Gkth2, the normal threshold Gnth is the smallest, and the first emergency threshold Gkth1 is the largest.

[0079] If any one of the conditions 1 to 3 is met, the control device 10 sets the threshold change ΔGth to the first emergency threshold Gkth1.

[0080] If the fourth condition is met, the control device 10 sets the threshold change ΔGth to the second emergency threshold Gkth2.

[0081] When any of conditions 1 through 3 is met, the urgency requiring "large driving or braking force" is higher than when condition 4 is met. Therefore, it is necessary to provide the vehicle with the required driving or braking force as quickly as possible. Thus, when any of conditions 1 through 3 is met, compared to when condition 4 is met, the threshold change ΔGth is set to "the first emergency threshold Gkth1, which is larger than the second emergency threshold Gkth2".

[0082] If none of the conditions 1 to 4 are met, i.e., if the emergency condition is not met, the control device 10 sets the threshold change ΔGth to the normal threshold Gnth.

[0083] Based on the above, the control device 10 determines whether any of the first to fourth conditions (i.e., emergency conditions) are met based on the interference value Dv and the remaining distance D. If an emergency condition is met, a threshold change ΔGth is set that is larger than the threshold change ΔGth if the emergency condition is not met.

[0084] (Specific tasks)

[0085] <Automatic Parking Routine>

[0086] The CPU of the parking ECU20 (hereinafter referred to as "CPU" unless otherwise stated) executes its functions every predetermined time interval. Figure 3 The automatic parking routine is represented by a flowchart.

[0087] Therefore, when the scheduled time is reached, the CPU starts from... Figure 3 Step 300 begins processing, proceeding to step 305, where it is determined whether the value of the execution flag Xexe is "0".

[0088] The value of the execution flag Xexe is set to "1" when automatic parking control is enabled and to "0" when automatic parking control is disabled. Furthermore, the value of the execution flag Xexe is set to "0" in the initialization routine. The initialization routine is executed by the CPU when the ignition switch (not shown) changes from the off position to the on position.

[0089] If the value of the execution flag Xexe is "0", the CPU determines "yes" in step 305 and proceeds to step 310. In step 310, the CPU determines whether the driver has operated the automatic parking switch 29.

[0090] If the driver does not operate the automatic parking switch 29, the CPU determines "no" in step 310, proceeds to step 395, and temporarily terminates this routine.

[0091] On the other hand, if the driver operates the automatic parking switch 29, the CPU determines "yes" in step 310 and executes steps 315 to 335 in sequence.

[0092] Step 315: The CPU sets the value of the execution flag Xexe to "1" and sets the threshold change ΔGth to the normal threshold Gnth.

[0093] Step 320: The CPU sets the target stop position.

[0094] In detail, the CPU searches for parking spaces for the vehicle VA based on image and sonar data, and displays the relationship between the nearest space to the vehicle VA's current position and the vehicle VA's position on the screen. If the driver agrees to park the vehicle VA in that space, they press a confirmation button (not shown). Once the driver presses the confirmation button, the CPU sets the aforementioned space as the target stopping position.

[0095] Furthermore, the process of setting the target stopping position includes various methods, not limited to the examples mentioned above. For instance, the driver could determine the target stopping position based on an image of the vehicle's VA displayed on a monitor, and the CPU could set the position determined by the driver as the target stopping position.

[0096] Step 325: The CPU obtains the target acceleration Gtgt (the target acceleration Gtgt in this case).

[0097] The details of the processing of the target acceleration Gtgt are described in Japanese Patent Application Publication No. 2020-15402, and will be briefly explained here.

[0098] First, a position-velocity feedback term (position-velocity FB term) is added to the acceleration feedforward term (acceleration FF term) to obtain the first target acceleration. Then, an acceleration feedback term (acceleration FB term) is added to the first target acceleration to obtain the second target acceleration. Finally, a disturbance feedforward term (disturbance FF term) is added to the second target acceleration to obtain the final target acceleration.

[0099] <Acceleration FF Item>

[0100] As the acceleration FF term, the acceleration used is the acceleration that causes the vehicle VA to travel along the travel path from the current position of the vehicle VA to the target stopping position.

[0101] <Position and Speed ​​FB Item>

[0102] The position-speed (FB) term is a feedback term used to ensure that the actual vehicle speed Vs and the vehicle VA position are consistent with the target vehicle speed and target stopping position. The position-speed (FB) term is obtained by proportionally controlling the difference between the target vehicle speed and target stopping position and the current position of vehicle speed Vs and vehicle VA.

[0103] <Acceleration FB item>

[0104] The acceleration FB term is a feedback term used to ensure that the acceleration G matches the target acceleration Gtgt. The acceleration FB term is obtained through proportional-integral control of the difference between the target acceleration Gtgt and the acceleration G.

[0105] <Interference FF Item>

[0106] The interference FF term is a feedforward term used to correct for the effects of interference. It is obtained by adding the observable interference FF term and the unknown interference FF term. For example, the observable interference FF term is obtained based on the road slope obtained from the acceleration G. The unknown interference FF term is obtained based on the aforementioned interference value Dv.

[0107] Furthermore, the method for obtaining the target acceleration Gtgt is not limited to the methods described above.

[0108] Step 330: The CPU obtains the change ΔGtgt by subtracting the previous target acceleration Gtgt' from the current target acceleration Gtgt.

[0109] Step 335: The CPU determines whether the magnitude of the change ΔGtgt (|ΔGtgt|) is below the threshold change ΔGth.

[0110] If the magnitude of the change ΔGtgt is below the threshold change ΔGth, the CPU determines "yes" in step 335 and executes steps 340 to 350 sequentially.

[0111] Step 340: The CPU obtains the target steering angle θtgt for the vehicle VA to travel along the driving route.

[0112] Step 345: The CPU sends acceleration / deceleration commands containing the target acceleration Gtgt to the drive ECU30 and brake ECU40, and sends steering commands containing the target steering angle θtgt to the steering ECU50.

[0113] Step 350: The CPU stores the current target acceleration Gtgt as the previous target acceleration Gtgt' in RAM.

[0114] Then, the CPU proceeds to step 395, temporarily terminating this routine.

[0115] When the CPU reaches step 335, if the magnitude of the change ΔGtgt is greater than the threshold change ΔGth, the CPU determines "No" in step 335 and proceeds to step 355. In step 355, the CPU sets the target acceleration Gtgt to a value that makes the magnitude of the change ΔGtgt smaller than the threshold change ΔGth.

[0116] In detail, when the change ΔGtgt is "0" or higher (i.e., when the current target acceleration Gtgt is greater than the previous target acceleration Gtgt'), the CPU sets the current target acceleration Gtgt to "the value obtained by adding the previous target acceleration Gtgt' to the threshold change ΔGth".

[0117] In contrast, when the change ΔGtgt is less than "0" (i.e., when the current target acceleration Gtgt is less than the previous target acceleration Gtgt'), the CPU sets the current target acceleration Gtgt to "the value obtained by subtracting the threshold change ΔGth from the previous target acceleration Gtgt'".

[0118] After executing step 355, the CPU executes steps 340 to 350, then proceeds to step 395, temporarily ending this routine.

[0119] On the other hand, when the CPU enters step 305, if the value of the execution flag Xexe is "1", the CPU determines "no" in step 305 and enters step 325.

[0120] <End of decision routine>

[0121] The CPU executes [the command] every time a predetermined time elapses. Figure 4 The termination determination routine is represented by a flowchart.

[0122] Therefore, when the scheduled time is reached, the CPU starts from... Figure 4 Step 400 begins processing, proceeding to step 405, where it is determined whether the value of the execution flag Xexe is "1".

[0123] If the value of the execution flag Xexe is "0", the CPU determines "No" in step 405, proceeds to step 495, and temporarily terminates this routine.

[0124] Conversely, if the value of the execution flag Xexe is "1", the CPU determines "yes" in step 405 and proceeds to step 410. In step 410, the CPU determines whether the value of the flag Xovr is "0".

[0125] The value of the Xovr flag is set to "1" if the vehicle VA has reached the target stopping position but has not stopped. The value of the Xovr flag is set to "0" if the vehicle VA has passed the target stopping position and stopped. Furthermore, the value of the Xovr flag is set to "0" in the initialization routine.

[0126] If the value of the Xovr flag is "0", the CPU determines "yes" in step 410 and proceeds to step 415. In step 415, the CPU determines whether the vehicle VA has reached the target stopping position.

[0127] If the vehicle VA fails to reach the target stopping position, the CPU determines "no" in step 415, proceeds to step 495, and temporarily terminates this routine.

[0128] Conversely, if vehicle VA reaches the target stopping position, the CPU determines "yes" in step 415 and proceeds to step 420. In step 420, the CPU determines whether vehicle VA has stopped, i.e., whether the vehicle speed Vs is "0".

[0129] If the vehicle VA has stopped, the CPU determines "yes" in step 420 and executes steps 425 and 430 in sequence.

[0130] Step 425: The CPU sets the value of the execution flag Xexe to "0".

[0131] Step 430: The CPU determines whether the value of the pass flag Xovr is "1".

[0132] If the value of the Xovr flag is "0", the CPU determines "No" in step 430 and proceeds to step 435. In step 435, the CPU activates a parking brake actuator (not shown) and changes the gear to parking. When the parking brake actuator is activated, it provides friction braking force to the wheels, and the gear is changed to parking, thereby maintaining the vehicle VA in a stopped state.

[0133] Then, the CPU proceeds to step 495, temporarily terminating this routine.

[0134] On the other hand, if vehicle VA has reached the target stopping position but has not stopped, the CPU determines "no" in step 420 and proceeds to step 440. In step 440, the CPU sets the value of the flag Xovr to "1". Then, the CPU proceeds to step 495, temporarily ending this routine.

[0135] When the value of the pass flag Xovr is set to "1" and the CPU executes this routine and enters step 410, the CPU determines "No" in step 410 and proceeds to step 420. If the vehicle VA passes the target stopping position but does not stop, the CPU determines "No" in step 420, proceeds to step 440, and sets the value of the pass flag Xovr to "1". Then, the CPU proceeds to step 495, temporarily terminating this routine.

[0136] Conversely, after vehicle VA passes the target stopping position and stops, the CPU determines "yes" in step 420 and sets the execution flag Xexe to "0" in step 425. Then, the CPU determines "yes" in step 430, proceeds to step 445, sets the passing flag Xovr to "0", and executes step 435. Then, the CPU proceeds to step 495, temporarily terminating this routine.

[0137] <Threshold Change Setting Routine>

[0138] The CPU executes [the command] every time a predetermined time elapses. Figure 5 The flowchart represents the threshold change setting routine.

[0139] Therefore, when the scheduled time is reached, the CPU starts from... Figure 5 Step 500 begins processing, proceeding to step 505, where it is determined whether the value of the execution flag Xexe is "1".

[0140] If the value of the execution flag Xexe is "0", the CPU determines "No" in step 505, proceeds to step 595, and temporarily terminates this routine.

[0141] In contrast, if the value of the execution flag Xexe is "1", the CPU determines "yes" in step 505 and executes steps 510 and 515 in sequence.

[0142] Step 510: The CPU obtains the disturbance value Dv by subtracting the acceleration G from the most recently acquired target acceleration Gtgt.

[0143] Step 515: The CPU determines whether the first condition is met (i.e., whether the interference value Dv is above the threshold Dvth).

[0144] If the first condition is met (the interference value Dv is above the threshold Dvth), the CPU determines "yes" in step 515 and proceeds to step 520. In step 520, the CPU sets the threshold change ΔGth to the first emergency threshold Gkth1. Then, the CPU proceeds to step 595, temporarily ending this routine.

[0145] In contrast, if the first condition is not met (if the interference value Dv is less than the threshold Dvth), the CPU determines "no" in step 515 and executes steps 525 to 535 in sequence.

[0146] Step 525: The CPU obtains the remaining distance D as described above.

[0147] Step 530: The CPU obtains the threshold acceleration Gth corresponding to the remaining distance D.

[0148] Step 535: The CPU determines whether the second condition is met (whether the acceleration G is above the threshold acceleration Gth).

[0149] If the second condition is met (acceleration G is greater than or equal to the threshold acceleration Gth), the CPU determines "yes" in step 535, proceeds to step 520, and sets the threshold change ΔGth to the first emergency threshold Gkth1. Then, the CPU proceeds to step 595 and temporarily terminates this routine.

[0150] Conversely, if the second condition is not met (acceleration G is less than the threshold acceleration Gth), the CPU determines "No" in step 535 and proceeds to step 540. In step 540, the CPU determines whether the third condition is met (by checking whether the value of the flag Xovr is set to "1"). As described above, if the vehicle VA is at the target stopping position but has not stopped (i.e., the vehicle VA has passed the target stopping position), the value of the flag Xovr is set to "1".

[0151] If condition 3 is met (by setting the value of flag Xovr to "1"), the CPU determines "yes" in step 540 and proceeds to step 520, setting the threshold change ΔGth to the first emergency threshold Gkth1. Then, the CPU proceeds to step 595, temporarily ending the current routine.

[0152] Conversely, if the third condition is not met (by setting the value of the flag Xovr to "0"), the CPU determines "No" in step 540 and proceeds to step 545. In step 545, the CPU determines whether the fourth condition is met (whether the remaining distance D is below the threshold distance Dth).

[0153] If condition 4 is met (the remaining distance D is below the threshold distance Dth), the CPU determines "yes" in step 545 and proceeds to step 550. In step 550, the CPU sets the threshold change ΔGth to the second emergency threshold Gkth2. Then, the CPU proceeds to step 595, temporarily ending this routine.

[0154] If condition 4 is not met (the remaining distance D is longer than the threshold distance Dth), the CPU determines that the emergency condition is not met. In this case, the CPU determines "No" in step 545, proceeds to step 555, and sets the threshold change ΔGth to the normal threshold Gnth. Then, the CPU proceeds to step 595 and temporarily terminates this routine.

[0155] As explained above, the control device 10 sets the target acceleration Gtgt to "make the change ΔGtgt not exceed the threshold change ΔGth value", thus preventing the acceleration G from increasing or decreasing abruptly. Therefore, even if there is control lag in at least one of the drive source 34a and the braking device 44a, it can prevent the vehicle VA from accelerating and decelerating abruptly, and can reduce the possibility of vehicle VA vibration.

[0156] Furthermore, when an emergency condition is met, the control device 10 sets the threshold change ΔGth to a larger value than when the emergency condition is not met (either a first emergency threshold Gkth1 or a second emergency threshold Gkth2). An emergency condition is met when a greater driving force or braking force than normally is required. When a greater driving force is required than normally, the likelihood of the drive source 34a providing the necessary driving force to the vehicle VA is increased; when a greater braking force is required than normally, the likelihood of the drive source 34a and the braking device 44a providing the necessary braking force to the vehicle VA is increased.

[0157] This invention is not limited to the above-described embodiments, and various modifications can be adopted within the scope of this invention.

[0158] (First variation)

[0159] The vehicle control device 10 involved in the first modification can also obtain the remaining distance D by subtracting "the measured distance Dm that the vehicle VA has actually moved from the last time to the current time point" from the remaining distance D obtained last time, regardless of whether the image data contains the target stopping position.

[0160] (Second variation)

[0161] Automatic parking control can also be performed when the vehicle VA is not occupied by a driver (the driver has exited the vehicle VA). Such automatic parking control as remote automatic parking control is known, for example, as described in Japanese Patent Application Publication No. 2020-104529. Furthermore, this control device 10 can be applied to control the vehicle VA to move and stop at a target stopping position. For example, this control device 10 can also be applied to automatic exit control that automatically exits a parked vehicle VA.

[0162] (3rd variation)

[0163] The threshold distance Dth used to determine whether the fourth condition is met can also be set based on the relationship between the predetermined stopping acceleration Gst for the vehicle VA to stop at the target stopping position and the remaining distance D.

[0164] The time taken until vehicle VA comes to a stop is represented by the following equation (1).

[0165] t=Vsp / Gst···Equation (1)

[0166] In equation (1), “Vsp” represents the current vehicle speed Vs.

[0167] Furthermore, the distance D traveled by vehicle VA during the period t seconds is represented by the following equation (2).

[0168]

[0169] When equation (1) is substituted into equation (2), the relationship between the stopping acceleration Gst and the remaining distance D is expressed by the following equation (3).

[0170]

[0171] The third variation involves a vehicle control device 10 that calculates the remaining distance D by applying the current vehicle speed Vs to "Vsp" in the above equation (3). Furthermore, the vehicle control device 10 sets this remaining distance D as a threshold distance Dth.

[0172] (4th variation)

[0173] The vehicle control unit 10 can be installed in vehicles such as engine vehicles, hybrid electric vehicles (HEV), plug-in hybrid electric vehicles (PHEV), fuel cell electric vehicles (FCEV), and battery electric vehicles (BEV).

Claims

1. A vehicle control device, comprising: A drive unit that provides driving force to a vehicle; Braking device that provides braking force to the vehicle; and A control unit controls the drive and braking systems to ensure that the actual acceleration matches the target acceleration, where the actual acceleration represents the vehicle's actual acceleration. The target acceleration is the acceleration used to move the vehicle so that it stops at a predetermined target stopping position. The control unit The target acceleration is obtained after each predetermined time interval. If the change in the difference between the current target acceleration and the previous target acceleration exceeds a threshold change, the current target acceleration is set such that the change does not exceed the threshold change. The current target acceleration is the target acceleration obtained this time, and the previous target acceleration is the target acceleration obtained previously. If a predetermined emergency condition requiring a greater driving force or braking force than usual is met, the threshold change amount is set to a value greater than if the emergency condition is not met. The control unit determines whether the emergency condition is met based on the interference value and the remaining distance. The interference value represents the magnitude of the interference that hinders the vehicle's movement, and the remaining distance represents the distance remaining to the target stopping position. If any one of the first, second, third, and fourth conditions is met, the control unit determines that the emergency condition has been met. The first condition is that the interference value is above a threshold. The second condition is that the actual acceleration is above a threshold acceleration set based on the remaining distance. The third condition is that the vehicle has passed the target stopping position. The fourth condition is that the remaining distance becomes below a predetermined threshold distance. When any one of the first to third conditions is met, the control unit sets the threshold change to a value greater than when the fourth condition is met.

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