Vehicle control device

Abstract

The present invention suppresses overshoot of actual acceleration relative to target acceleration when controlling vehicle acceleration by integral control.　A vehicle control device (10) comprises: an actual acceleration recognition unit (23) that recognizes actual acceleration of a vehicle (1); an integral value calculation unit (24) that calculates a time integral value of the difference between predetermined target acceleration and the actual acceleration; a control instruction value setting unit (26) that sets control instruction values for a drive device (40) of the vehicle (1) on the basis of the time integral value; and an integration processing limiting unit (25) that limits the calculation of the time integral value by the integral value calculation unit (24) so that the time integral value of when a predetermined limiting condition is satisfied is smaller than that of when the limiting condition is not satisfied.

Description

Vehicle control device

[0001] The present invention relates to a vehicle control device.

[0002] Efforts to mitigate or reduce the impact of climate change have been ongoing for some time, and research and development into improving vehicle emissions has been conducted to achieve this. Regarding vehicle driving control related to improving emissions, for example, a vehicle control device is known that performs integral control to change a control command to a controlled object in proportion to a time-integrated value of the deviation in order to eliminate a steady-state deviation between a target acceleration and an actual acceleration (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2018-188015

[0004] In improving vehicle emissions, if the time-integrated value of the deviation between the target acceleration and the actual acceleration increases due to a deterioration in the ability to follow the target acceleration, causing an overshoot of the actual acceleration, the fluctuation of the vehicle's drive torque increases, resulting in a deterioration in emissions. Therefore, an object of the present application is to improve vehicle emissions by suppressing overshoot of the actual acceleration relative to the target acceleration. To solve the above problem, an object of the present application is to provide a vehicle control device that can suppress overshoot of the actual acceleration relative to the target acceleration when controlling the vehicle acceleration using integral control.

[0005] This specification includes the entire contents of Japanese Patent Application No. 2022-139153, filed on September 1, 2022. One aspect of the present invention to achieve the above object is a vehicle control device that includes an actual acceleration recognition unit that recognizes the actual acceleration of a vehicle, an integrated value calculation unit that calculates a time integrated value of the difference between a predetermined target acceleration and the actual acceleration, a control instruction value setting unit that sets a control instruction value for a drive device of the vehicle based on the time integrated value, and an integration processing limiting unit that limits the calculation of the time integrated value by the integrated value calculation unit so that the time integrated value when a predetermined limiting condition is met is smaller than when the limiting condition is not met.

[0006] According to the above-mentioned vehicle control device, when a predetermined restriction condition is met, the calculation of the time integrated value by the integrated value calculation unit is limited, thereby suppressing overshoot of the actual acceleration relative to the target acceleration when controlling the vehicle acceleration by integral control.

[0007] Fig. 1 is a configuration diagram of a vehicle control device and a vehicle equipped with the vehicle control device. Fig. 2 is a processing block diagram of an integration processing suppression unit. Fig. 3 is an explanatory diagram of the effect of limiting the time integration of the difference between the target acceleration and the actual acceleration.

[0008] 1, the configuration of a vehicle control device 10 of the present disclosure will be described. The vehicle control device 10 is mounted on a vehicle 1 and controls the operation of the vehicle 1. The vehicle 1 is, for example, a two-wheeled vehicle, and is equipped with a drive unit 40, a front camera 50, a cruise control switch 51, a throttle sensor 52, a speed sensor 53, and an acceleration sensor 54.

[0009] The drive unit 40 is composed of a drive source such as an engine or electric motor that drives drive wheels (not shown), and a control unit for the drive source. The front camera 50 photographs the area ahead of the vehicle 1 to obtain images of the leading vehicle, etc. The images of the leading vehicle are used to recognize the distance between the vehicle 1 and the leading vehicle, etc. Note that instead of the front camera 50, a distance measuring sensor such as radar may be used to recognize the distance between the vehicle 1 and the leading vehicle. Alternatively, the front camera 50 may be used in combination with a distance measuring sensor such as radar to recognize the distance between the vehicle 1 and the leading vehicle.

[0010] The cruise control switch 51 is a switch for setting either an automatic cruise control, which maintains the vehicle 1 at a set speed, or an adaptive cruise control, which automatically adjusts the vehicle speed to maintain a safe distance from a preceding vehicle, in response to an operation by the driver of the vehicle 1. Hereinafter, the automatic cruise control and adaptive control will be collectively referred to as cruise control.

[0011] The throttle sensor 52 detects the opening degree of a throttle grip (not shown) in response to the operation of the driver of the vehicle 1. The speed sensor 53 recognizes the speed (traveling speed) of the vehicle 1. The acceleration sensor 54 recognizes the acceleration (traveling acceleration) of the vehicle 1.

[0012] The vehicle control device 10 is a control unit including a processor 20, a memory 30, etc., and a program 31 for controlling the vehicle control device 10 is stored in the memory 30. The processor 20 reads and executes the program 31 to function as an actual speed recognition unit 21, a target acceleration setting unit 22, an actual acceleration recognition unit 23, an integrated value calculation unit 24, an integrated processing limiting unit 25, and a control instruction value setting unit 26.

[0013] The actual speed recognition unit 21 recognizes the speed of the vehicle 1 (hereinafter referred to as the actual speed V_r) based on the speed detection signal output from the speed sensor 53. When the cruise control is set by the cruise control switch, the target acceleration setting unit 22 sets the target acceleration AC_c so as to reduce the difference between the set speed V_ctr by the cruise control and the actual speed V_r.

[0014] The actual acceleration recognition unit 23 recognizes the acceleration of the vehicle 1 (hereinafter referred to as actual acceleration AC_r) based on the acceleration detection signal output from the acceleration sensor 54. The integrated value calculation unit 24 calculates a time integrated value, which is the integrated value per predetermined time of the difference ΔAC (ΔAC = AC_c - AC_r) between the target acceleration AC_c and the actual acceleration AC_r.

[0015] The integration processing limiting unit 25 stops the calculation of the integration value by the integration value calculating unit 24 when the following limiting conditions, which satisfy the first and second conditions, are met: First condition: Regarding the magnitude (|ΔAC|) of the difference ΔAC between the target acceleration AC_c and the actual acceleration AC_r, ΔAC_Th<|ΔAC| (ΔAC_Th is an acceleration difference determination value) is met. Second condition: Regarding the difference ΔJK between the target jerk JK_c, which is the differential value of the target acceleration AC_c, and the actual jerk JK_r, which is the differential value of the actual acceleration AC_r, when ΔJK≧0, ΔJK_Th<ΔJK (ΔJK_Th is a jerk difference determination value), and when ΔJK<0, ΔJK<-ΔJK_Th is met.

[0016] The control instruction value setting unit 26 calculates a torque instruction value Tr_c, which is a control instruction value for the drive device 40, using the following equation (1), and outputs the calculated torque instruction value to the drive device 40. The third term (integral term) of equation (1) is the time-integrated value of the difference ΔAC between the target acceleration AC_c and the actual acceleration AC_r, calculated by the integrated value calculation unit 24. where Tr_f(t): feedforward term at sampling time t, Tr_c(t): torque command value at sampling time t, Kp: proportional gain, ΔAC(t): acceleration difference at sampling time t, Ki: integral gain, ts: start point of the integration period of ΔAC. The feedforward term, which is the first term in the above formula (1), is calculated, for example, by the following formula (2). where Tr_f(t): feedforward term at sampling time t, M: gain, AC_c(t): target acceleration at sampling time t. The running resistance is set according to the running conditions of the vehicle 1 (such as the gradient of the road). The gear specifications are set according to the selection conditions of the transmission gear in the vehicle 1. Note that a differential term Kd·dΔAC(t) / dt (Kd is a differential gain) may be added to the above equation (1).

[0017] 2, the configuration of the integration processing limiting unit 25 will be described. When cruise control is set by the cruise control switch 51, the integration processing limiting unit 25 executes processing to stop integration by the integration value calculation unit 24 based on the target acceleration AC_c and the actual acceleration AC_r.

[0018] The integration processing limiting unit 25 calculates the difference ΔAC between the target acceleration AC_c and the actual acceleration AC_r using the first subtraction unit 100. When the difference ΔAC is equal to or greater than 0, the integration processing limiting unit 25 determines whether the difference ΔAC is greater than the acceleration difference determination value ΔAC_Th using the first comparison unit 101. When the difference ΔAC is greater than the acceleration difference determination value ΔAC_Th, the first comparison unit 101 inputs "1" to the first AND unit 120, and when the difference ΔAC is equal to or less than the acceleration difference determination value ΔAC_Th, the first comparison unit 101 inputs "0" to the first AND unit 120.

[0019] On the other hand, when the difference ΔAC is less than 0, the integration processing limiting unit 25 determines whether or not the difference ΔAC is smaller than the acceleration determination value −ΔAC_Th using the second comparing unit 102. When the difference ΔAC is smaller than the acceleration determination value −ΔAC_Th, the second comparing unit 102 inputs “1” to the second AND unit 121, and when the difference ΔAC is equal to or greater than the acceleration difference determination value −ΔAC_Th, the second comparing unit 102 inputs “0” to the second AND unit 121. In this way, the first subtracting unit 100, the first comparing unit 101, and the second comparing unit 102 determine whether or not the first condition is met.

[0020] Furthermore, the integration processing limiting unit 25 calculates a target jerk JK_c, which is a derivative of the target acceleration AC_c, using the target acceleration jerk calculation unit 103, and calculates an actual jerk JK_r, which is a derivative of the actual acceleration AC_r, using the actual acceleration jerk calculation unit 113. Then, the integration processing limiting unit 25 calculates a difference ΔJK between the target jerk JK_c and the actual jerk JK_r using the second subtraction unit 110.

[0021] When the difference ΔJK is equal to or greater than 0, the integration processing limiting unit 25 determines whether the difference ΔJK is greater than the jerk determination value ΔJK_Th using the third comparing unit 111. When the difference ΔJK is greater than the jerk determination value ΔJK_Th, the third comparing unit 111 inputs "1" to the first AND unit 120, and when the difference ΔJK is equal to or less than the jerk determination value ΔJK_Th, the third comparing unit 111 inputs "0" to the first AND unit 120.

[0022] On the other hand, when the difference ΔJK is less than 0, the integration processing limiting unit 25 determines whether the difference ΔJK is smaller than the jerk determination value −ΔJK_Th using the fourth comparing unit 112. When the difference ΔJK is smaller than −ΔJK_Th, the fourth comparing unit 112 inputs “1” to the second logical product unit 121, and when the difference ΔJK is equal to or greater than −ΔJK_Th, the fourth comparing unit 112 inputs “0” to the second logical product unit 121. In this way, the target acceleration jerk calculating unit 103, the actual acceleration jerk calculating unit 113, the second subtracting unit 110, the third comparing unit 111, and the fourth comparing unit 112 determine whether the second condition is met.

[0023] The outputs of the first AND unit 120 and the second AND unit 121 are input to the OR unit 122. When the output of the OR unit 122 is "1", the integration process limiting unit 25 outputs an integration stop flag IFB_NG that instructs the integration value calculation unit 24 to stop integrating the acceleration difference ΔAC. While the integration stop flag IFB_NG is being output, the integration value calculation unit 24 stops integrating the acceleration difference ΔAC. By stopping the integration of the acceleration difference ΔAC by the integration value calculation unit 24, an increase in the third term (integral term) of the above equation (1) stops, and the torque command value Tr_c is prevented from becoming excessively large.

[0024] The output of the OR unit 122 becomes "1" when the above-mentioned restrictive condition is met, i.e., when the output of the first comparing unit 101 is "1" and the output of the third comparing unit 111 is "1", or when the output of the second comparing unit 102 is "1" and the output of the fourth comparing unit 112 is "1".

[0025] 3. Effect of Suppressing Integration by Integration Value Calculation Unit] The effect of providing an integration process limiting unit 25 and stopping integration of the acceleration difference ΔAC by the integration value calculation unit 24 will be described with reference to Fig. 3. Fig. 3 is an explanatory diagram showing a comparison graph between the actual speed V_r of the vehicle 1 and the set speed V_ctr by cruise control, a comparison graph between the target acceleration AC_c and the actual acceleration AC_r, and a graph of the integral value Itr of the third term of the above equation (1), all on a common time axis t.

[0026] FIG. 3 shows a situation in which cruise control is set by the cruise control switch 51 at time t1, cruise control is initiated, the cruise control is interrupted by throttle operation by the driver from time t3 to time t4, and cruise control is resumed from time t4.

[0027] The target acceleration setting unit 22 sets the target acceleration AC_c so as to reduce the difference between the speed V_ctr set by the cruise control and the actual speed V_r of the vehicle 1. Then, the control command value setting unit 26 outputs the torque command value Tr_c calculated based on the difference ΔAC between the target acceleration AC_c and the actual acceleration AC_r using the above equation (1) to the drive unit 40. This executes control to reduce the difference between the speed V_ctr set by the cruise control and the actual speed V_r.

[0028] With the cruise control set, from t3 to t4 when the driver of the vehicle 1 is operating the throttle, the control instruction value setting unit 26 sets the torque instruction value Tr_c for the drive device 40 in accordance with the throttle opening detected by the throttle sensor 52. As a result, the vehicle 1 accelerates in accordance with the throttle operation by the driver, and the speed of the vehicle 1 increases.

[0029] As described above, when the difference ΔAC between the target acceleration AC_c and the actual acceleration AC_r becomes large and the difference ΔJK between the target jerk JK_c and the actual jerk JK_r becomes large and the above-mentioned limiting condition is met, the integration process limiting unit 25 stops the integration of the difference ΔAC by the integration value calculating unit 24. This prevents the value of the third term (integral term) in the above equation (1) from changing excessively in response to a sudden increase or decrease in the actual acceleration AC_r.

[0030] Therefore, cruise control is set at t1, and at ST1 around t2 when the difference ΔAC between the target acceleration AC_c and the actual acceleration AC_r approaches zero, the occurrence of an overshoot (including an undershoot in the negative direction) of the actual acceleration AC_r relative to the target acceleration AC_c is suppressed.

[0031] Similarly, at time t4, the driver's throttle operation ends, cruise control resumes, and the difference ΔAC between the target acceleration AC_c and the actual acceleration AC_r approaches zero at time ST2, where overshoot (including undershoot in the negative direction) of the actual acceleration AC_r relative to the target acceleration AC_c is suppressed. In this way, by suppressing overshoot of the actual acceleration AC_r relative to the target acceleration AC_c, sudden fluctuations in the acceleration / deceleration of the vehicle 1 can be reduced, thereby improving the emissions performance of the vehicle 1.

[0032] 4. Other Embodiments In the above embodiment, a two-wheeled vehicle was shown as the vehicle 1, but the vehicle control device of the present disclosure can also be applied to other types of vehicles, such as three-wheeled vehicles and four-wheeled vehicles.

[0033] In the above embodiment, a case has been described in which the difference ΔAC between the target acceleration AC_c and the actual acceleration AC_r is reduced by control using cruise control, but the control using the vehicle control device of the present disclosure can also be applied to other types of control as long as control is performed to reduce the difference ΔAC between the target acceleration AC_c and the actual acceleration AC_r.

[0034] In the above embodiment, when the above-mentioned limiting condition is satisfied, the integration process limiting unit 25 stops the integration of ΔAC by the integration value calculation unit 24, thereby limiting the integration of ΔAC by the integration value calculation unit 24 and making the time integrated value of the third term in the above equation (1) smaller than when the above-mentioned limiting condition is not satisfied. In another embodiment, the time integrated value of the third term in the above equation (1) may be reduced by another method, such as reducing the integral gain Ki in the above equation (1).

[0035] In the above embodiment, the first and second conditions are exemplified as the restrictive conditions of the present disclosure. In another embodiment, only the first condition, ΔAC_Th<|ΔAC|, may be the restrictive condition. Alternatively, only the second condition, ΔJK_Th<|ΔJK|, may be the restrictive condition.

[0036] 1 and 2 are schematic diagrams showing the functional configuration of the vehicle control device 10 divided by main processing content to facilitate understanding of the invention of the present disclosure, but the configuration of the vehicle control device 10 may be divided by other categories. Furthermore, the processing of each component may be executed by one hardware unit or multiple hardware units. Furthermore, the processing by each component of the vehicle control device 10 shown in FIGS. 1 and 2 may be executed by one program or multiple programs.

[0037] 5. Configurations Supported by the Above-described Embodiments The above-described embodiments are specific examples of the following configurations.

[0038] (Configuration 1) A vehicle control device comprising: an actual acceleration recognition unit that recognizes the actual acceleration of a vehicle; an integrated value calculation unit that calculates a time integrated value of the difference between a predetermined target acceleration and the actual acceleration; a control instruction value setting unit that sets a control instruction value for a drive device of the vehicle based on the time integrated value; and an integration processing limiting unit that limits calculation of the time integrated value by the integrated value calculation unit so that the time integrated value when a predetermined restriction condition is met is smaller than when the restriction condition is not met. According to the vehicle control device of Configuration 1, when the predetermined restriction condition is met, by limiting the calculation of the time integrated value by the integrated value calculation unit to reduce the control instruction value, it is possible to suppress overshoot of the actual acceleration relative to the target acceleration when controlling the acceleration of the vehicle by integral control.

[0039] (Configuration 2) The vehicle control device according to Configuration 1, wherein the integration processing limiting unit limits the calculation processing of the time integrated value by the integration value calculation unit by stopping the calculation of the time integrated value by the integration value calculation unit when the limiting condition is satisfied. According to the vehicle control device of Configuration 2, the control instruction value when the limiting condition is satisfied can be reduced by the relatively simple processing of stopping the calculation of the time integrated value by the integration value calculation unit.

[0040] (Configuration 3) The vehicle control device according to Configuration 1 or 2, wherein the limiting condition is that the difference between the target jerk, which is a derivative of the target acceleration, and the actual jerk, which is a derivative of the actual acceleration, is greater than a predetermined jerk difference determination value. According to the vehicle control device of Configuration 3, when the difference between the target jerk and the actual jerk becomes greater than the jerk difference determination value and the time-integrated value of the difference between the target acceleration and the actual acceleration is likely to become large, the calculation of the time-integrated value by the integration value calculation unit can be limited, thereby suppressing overshoot of the actual acceleration relative to the target acceleration.

[0041] (Configuration 4) The vehicle control device according to any one of Configurations 1 to 3, wherein the limiting condition is that the difference between the target acceleration and the actual acceleration is greater than a predetermined acceleration difference determination value. According to the vehicle control device of Configuration 4, when the difference between the target acceleration and the actual acceleration becomes greater than the acceleration difference determination value and the time integrated value calculated by the integrated value calculation unit becomes large, the calculation of the time integrated value by the integrated value calculation unit can be limited to suppress overshoot of the actual acceleration relative to the target acceleration.

[0042] The vehicle control device of the present disclosure can be used to suppress overshoot of actual acceleration relative to target acceleration when controlling the acceleration of the vehicle through integral control.

[0043] 1...vehicle, 10...vehicle, 20...processor, 21...actual speed recognition unit, 22...target acceleration setting unit, 23...actual acceleration recognition unit, 24...accumulation value calculation unit, 25...accumulation processing limiting unit, 26...control instruction value setting unit, 30...memory, 31...program, 40...drive device, 50...front camera, 51...cruise control switch, 52...throttle sensor, 53...speed sensor, 54...acceleration sensor.

Claims

1. An actual acceleration recognition unit (23) that recognizes an actual acceleration of a vehicle; an integrated value calculation unit (24) that calculates a time integrated value of a difference between a predetermined target acceleration and the actual acceleration; a control instruction value setting unit (26) that sets a control instruction value for a drive device of the vehicle based on the time integrated value; an integration processing limiting unit (25) that limits the calculation of the time integration value by the integration value calculation unit so that the time integration value when a predetermined limiting condition is satisfied is smaller than the time integration value when the limiting condition is not satisfied; Equipped with The limiting condition is that a difference between a target jerk, which is a differential value of the target acceleration, and an actual jerk, which is a differential value of the actual acceleration, is greater than a predetermined jerk difference determination value. Vehicle control device.

2. The integration process limiting unit limits the calculation of the time integration value by the integration value calculation unit by stopping the calculation of the time integration value by the integration value calculation unit when the limiting condition is satisfied. The vehicle control device according to claim 1.

3. An actual acceleration recognition unit (23) that recognizes an actual acceleration of a vehicle; an integrated value calculation unit (24) that calculates a time integrated value of a difference between a predetermined target acceleration and the actual acceleration; a control instruction value setting unit (26) that sets a control instruction value for a drive device of the vehicle based on the time integrated value; an integration processing limiting unit (25) that limits the calculation of the time integration value by the integration value calculation unit so that the time integration value when a predetermined limiting condition is satisfied is smaller than the time integration value when the limiting condition is not satisfied; Equipped with The limiting condition is that the difference between the target acceleration and the actual acceleration is greater than a predetermined acceleration difference determination value. Vehicle control device.

4. The integration process limiting unit limits the calculation of the time integration value by the integration value calculation unit by stopping the calculation of the time integration value by the integration value calculation unit when the limiting condition is satisfied. The vehicle control device according to claim 3.