Vehicle control device

Abstract

A vehicle control device is provided. Weakening control of a plurality of vehicle control functions is executed in a manner that inhibits a sense of strangeness from being brought to a driver. The vehicle control device (10) includes: a target braking value decision unit (41, 42, 50) that decides a target braking value by performing arbitration processing of input of a plurality of braking request values individually set by a plurality of vehicle control functions possessed by a vehicle (1), and outputs the decided target braking value to a braking device; and a weakening control unit (43) that, when a failure occurs in the vehicle (1), performs weakening control of an in-operation vehicle control function that is a vehicle control function executed when the failure occurs, and sets a weakening rate of the weakening control in accordance with a braking request value set by the in-operation vehicle control function when the failure occurs.

Description

TECHNICAL FIELD

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

[0002] In the past, a vehicle control device having an ACC (Adaptive Cruise Control) function, an LKA (lane keeping assist) function, an override control function that stops the ACC function by an intervening operation of the driver, and a function that, when the LKA function fails, notifies the driver to stop the ACC function and hands over the operation to perform a mitigation control of the ACC function (for example, refer to Patent Literature 1) is known.

[0003] Patent Literature 1: Japanese Patent Application Publication No. 2019-127136

[0004] In recent years, in addition to the above-described ACC function and LKA function, various vehicle control functions for the purpose of reducing the burden on the driver and assisting safe driving have also been put into practical use. Also, in a case where a plurality of brake request values based on these vehicle control functions are simultaneously in operation, a target brake value to the brake device is decided by arbitration of the brake request values.

[0005] Thus, in a case where some failure occurs in a state where a plurality of vehicle control functions are in operation, it is necessary to set the target brake value to the brake device in accordance with the predetermined mitigation operation of each vehicle control function. Also, if the setting of the target brake value is inappropriate, it is possible that a sharp deceleration reduction compared to expectation, an excessive deceleration due to a residual brake command value, a deceleration change that the driver cannot predict due to a change in the reduction rate of the brake command value that is being mitigated, and the like occur due to a decrease in the total value of the mitigation rates, giving the driver a sense of discomfort. SUMMARY

[0006] The present application was completed in view of such a background, and aims to provide a vehicle control device that performs mitigation control of a plurality of vehicle control functions in a manner that suppresses the above-described sense of discomfort to the driver.

[0007] As a means for achieving the above object, a vehicle control device that controls the behavior of a vehicle that is provided with a brake device that generates a braking force corresponding to a prescribed target braking value, the vehicle control device being provided with: a target braking value decision section that performs prescribed arbitration processing on the input of a plurality of braking demand values that are individually set by a plurality of vehicle control functions provided in the vehicle, thereby deciding the target braking value, and outputs the decided target braking value to the brake device; and a weakening control section that, when a failure occurs in the vehicle, performs weakening control of the vehicle control function that is executed when the failure occurs, i.e., an in-operation vehicle control function, sets a weakening rate of the weakening control in accordance with the braking demand value that is set by the in-operation vehicle control function when the failure occurs.

[0008] In the above vehicle control device, the weakening control section can perform processing by the weakening control that reduces the braking demand value that is set by the in-operation vehicle control function when the failure occurs by the weakening rate.

[0009] In the above vehicle control device, the greater the braking demand value that is set by the in-operation vehicle control function when the failure occurs, the greater the weakening rate that the weakening control section sets for the weakening control of the in-operation vehicle control function.

[0010] In the above vehicle control device, the weakening control section sets the weakening rate for a plurality of the vehicle control functions using a common calculation formula that outputs a weakening rate when a braking demand value is input, or a common correspondence map that associates the braking demand value with the weakening rate.

[0011] Effects of Invention

[0012] According to the above vehicle control device, it is possible to perform weakening control of a plurality of vehicle control functions in a manner that suppresses the above-described sense of strangeness for the driver. BRIEF DESCRIPTION OF DRAWINGS

[0013] Figure 1 is a configuration diagram of a vehicle control device and a vehicle equipped with the vehicle control device.

[0014] Figure 2 is a flowchart of weakening control.

[0015] Figure 3 is an explanatory diagram of weakening control when a vehicle failure occurs during the operation of a CMBS function.

[0016] Figure 4is a diagram of the weakening control in the case where a vehicle failure occurs during the operation of the ACC function.

[0017] Explanation of Reference Signs

[0018] 1 vehicle, 5 CAN-BUS, 10 vehicle control device, 20 power source ECU, 21 stall coordination control section, 22 full charge pressurization control section, 30 drive assist ECU, 31 ACC control section, 32 CMBS control section, 40 brake request value management ECU, 41 first brake request value decision section, 42 second brake request value decision section, 43 weakening control section, 50 brake ECU, 51 request value totalizing section, 52 target value decision section, 60 electric servo brake system, 70 brake pedal, 71 brake pedal sensor. DETAILED DESCRIPTION

[0019] [1. Structure of vehicle control device and vehicle]

[0020] Reference Figure 1 The structure of the vehicle control device 10 of the present embodiment and the vehicle 1 equipped with the vehicle control device 10 will be described. The vehicle control device 10 is composed of a brake request value management ECU (Electronic Control Unit) 40 and a brake ECU 50 connected by a CAN (Controller Area Network) -BUS 5.

[0021] The vehicle 1 is equipped with a power source ECU 20 and a drive assist ECU 30 connected to the brake request value management ECU 40 and the brake ECU 50 by the CAN-BUS 5. Further, the vehicle 1 is equipped with an electric servo brake system 60 that outputs a torque generated by an electric actuator to left front brakes 3FL, right front brakes 3FR, left rear brakes 3RL, and right rear brakes 3RR provided to the left front wheel 2FL, the right front wheel 2FR, the left rear wheel 2RL, and the right rear wheel 2RR, respectively, and causes these brakes to operate. The electric servo brake system 60, the left front brakes 3FL, the right front brakes 3FR, the left rear brakes 3RL, and the right rear brakes 3RR constitute a brake device of the present application. Hereinafter, the left front brakes 3FL, the right front brakes 3FR, the left rear brakes 3RL, and the right rear brakes 3RR will be collectively referred to as brakes 3.

[0022] The power source ECU 20, the drive assist ECU 30, the brake request value management ECU 40, and the brake ECU 50 are control units constituted by a processor, a memory, an interface circuit, and the like, which are not shown. The power source ECU 20 functions as a stall coordination control section 21 and a full charge pressurization control section 22 by executing a control program stored in the memory by the processor.

[0023] The stall coordination control section 21 performs stall coordination control to transmit a first brake request value Tr1R_a, which is a brake request value (torque value) for the brake 3, to the brake request value management ECU 40 via the CAN-BUS. The stall coordination control is control for protecting the motor (not shown) in a case where the operation of the accelerator pedal (not shown) and the gradient are balanced during parking of the vehicle 1 on a slope by balancing the drive torque and the gradient, and is switched to control based on the braking of the brake 3.

[0024] The full charge pressurization control section 22 performs full charge pressurization control to transmit a first brake request value Tr1R_b, which is a brake request value (torque value) for the brake 3, to the brake request value management ECU 40 via the CAN-BUS. The full charge pressurization control is control to increase the braking force of the brake 3 in a case where the battery (not shown) mounted on the vehicle 1 is in a full charge state and regenerative braking corresponding to disconnection of the accelerator pedal cannot be performed. The stall coordination function and the full charge pressurization function correspond to the vehicle control function of the present application.

[0025] The drive assist ECU 30 functions as an ACC (Adaptive Cruise Control) control section 31 and a CMBS (Collision Mitigation Brake System) control section 32 by executing a control program stored in the memory. The ACC control section 31 performs ACC control to output a second brake request value Tr2R_a, which is a brake request value (torque value) for the brake 3 for generating a necessary braking force, to the brake request value management ECU 40 via the CAN-BUS 5. The ACC control is control to follow a preceding vehicle while constantly maintaining the inter-vehicle distance from the preceding vehicle.

[0026] The CMBS control section 32 performs CMBS control to output the second brake request value Tr2R_b, which is a brake request value (torque value) for the brake 3 for generating a necessary braking force, to the brake request value management ECU 40 via the CAN-BUS 5. The CMBS control is control to monitor a preceding vehicle by a radar (not shown) provided in the vehicle 1, notify the driver by a warning sound, seat belt retraction, display in an instrument panel, or the like in the case where there is a danger of a rear collision, and operate the brake in the case where it is judged that the rear collision cannot be avoided. The ACC function and the CMBS function correspond to the vehicle control function of the present application.

[0027] The brake request value management ECU 40 functions as the first brake request value decision section 41, the second brake request value decision section 42, and the weakening control section 43 by executing a control program stored in a memory. The first brake request value decision section 41 basically decides the larger one of the torque values of the first brake request values Tr1R_a, Tr1R_b transmitted from the power source ECU 20 as the first brake request value Tr1R to be transmitted to the brake ECU 50.

[0028] The second brake request value decision section 42 basically decides the larger one of the torque values of the second brake request values Tr2R_a, Tr2R_b transmitted from the drive assist ECU 30 as the second brake request value Tr2R to be transmitted to the brake ECU 50.

[0029] When a failure of the vehicle 1 occurs due to a communication failure or the like with the power source ECU 20 while the stall coordination control is being executed by the stall coordination control section 21, the weakening control section 43 executes weakening control of the stall coordination function to execute weakening control to output the weakened first brake request value Tr1R_ad to the first brake request value decision section 41. The weakening control section 43 gradually reduces the weakened first brake request value Tr1R_ad to zero at a prescribed weakening rate to hand over the brake operation to the driver, the details of which will be described later. The first brake request value decision section 41 executes the process of deciding the first brake request value Tr1R by replacing the first brake request value Tr1R_a with the weakened first brake request value Tr1R_ad when the weakened first brake request value Tr1R_ad is input.

[0030] Likewise, when a failure of the vehicle 1 is recognized due to a communication failure or the like with the power source ECU 20 while the full charge pressurization control section 22 is executing the full charge pressurization control, the weakening control section 43 executes weakening control of the full charge pressurization function, and executes weakening control that outputs a weakened first brake request value Tr1R_bd to the first brake request value decision section 41. The weakening control section 43 gradually reduces the weakened first brake request value Tr1R_bd to zero at a prescribed weakening rate, thereby handing over the brake operation to the driver, the details of which will be described later. The first brake request value decision section 41 executes processing to decide the first brake request value Tr1R by replacing the first brake request value Tr1R_b with the weakened first brake request value Tr1R_bd when the weakened first brake request value Tr1R_bd is input.

[0031] In addition, when a failure of the vehicle 1 is recognized due to a communication failure or the like with the drive assist ECU 30 while the ACC control section 31 is executing ACC control, the weakening control section 43 executes weakening control of the ACC function, and executes weakening control that outputs a weakened second brake request value Tr2R_ad to the second brake request value decision section 42. The weakening control section 43 gradually reduces the weakened second brake request value Tr2R_ad to zero at a prescribed weakening rate, thereby handing over the brake operation to the driver, the details of which will be described later. The second brake request value decision section 42 executes processing to decide the second brake request value Tr2R by replacing the second brake request value Tr2R_a with the weakened second brake request value Tr2R_ad when the weakened second brake request value Tr2R_ad is input.

[0032] Likewise, when a failure of the vehicle 1 is recognized due to a communication failure or the like with the drive assist ECU 30 while the CMBS control section 32 is executing CMBS control, the weakening control section 43 executes weakening control of the CMBS function, and executes weakening control that outputs a weakened second brake request value Tr2R_bd to the second brake request value decision section 42. The weakening control section 43 gradually reduces the weakened second brake request value Tr2R_bd to zero at a prescribed weakening rate, thereby handing over the brake operation to the driver, the details of which will be described later. The second brake request value decision section 42 executes processing to decide the second brake request value Tr2R by replacing the second brake request value Tr2R_b with the weakened second brake request value Tr2R_bd when the weakened second brake request value Tr2R_bd is input.

[0033] The brake ECU 50 functions as a demand value aggregation unit 51 and a target value determination unit 52 by executing a control program stored in memory using a processor. The brake ECU 50 receives an operating brake demand value (torque value) TrS corresponding to the amount of brake pedal 70 operation detected by the brake pedal sensor 71. The demand value aggregation unit 51 adds the first brake demand value Tr1R sent from the brake demand value management ECU 40 to the operating brake demand value TrS to calculate the total brake demand value TrA.

[0034] The target value determination unit 52 determines the larger torque value between the second braking requirement value Tr2R and the total braking requirement value TrA sent from the braking requirement value management ECU 40 as the target braking value TrC. Then, the braking ECU 50 outputs the target braking value TrC to the electric servo braking system 60. The electric servo braking system 60 brakes the vehicle 1 by actuating the electric actuator with the torque indicated by the target braking value TrC, thereby actuating the brake 3. The first braking requirement value determination unit 41, the second braking requirement value determination unit 42, the requirement value aggregation unit 51, and the target value determination unit 52 constitute the target braking value determination unit of the present invention.

[0035] [2. Weakening Control Processing]

[0036] according to Figure 2 The flowchart shown illustrates the weakening control process performed by the weakening control unit 43. Figure 2 In step S1, the weakening control unit 43 determines whether a vehicle control function is being executed, and if so, proceeds to step S2. In this embodiment, the vehicle control functions are the aforementioned stop-start coordination, full charge pressurization, ACC, and CMBS.

[0037] In step S2, the weakening control unit 43 determines whether vehicle 1 has malfunctioned, and if vehicle 1 has malfunctioned, proceeds to step S3. Malfunctions of vehicle 1 include poor CAN-BUS communication, malfunctions of electrical auxiliary equipment such as cameras and radar, etc. In step S3, the weakening control unit 43 performs the processing steps S31 to S34 for each vehicle control function currently being executed.

[0038] In step S31, the weakening control unit 43 sets the weakening rate when weakening the vehicle control function based on the previously identified braking requirement value. The weakening rate can be set by the speed at which the deceleration G of vehicle 1 decreases, or by the speed at which the braking requirement value decreases. For any vehicle notification function, the weakening control unit 43 uses a common corresponding mapping 100 to set the weakening rate.

[0039] The correspondence map 100 is a map in which the horizontal axis is set as the brake request value TRr and the vertical axis is set as the degradation rate DR, and the greater the brake request value TRr, the greater the degradation rate DR is set. In this way, by using the common correspondence map 100 to set the degradation rate when each vehicle control function is degraded, the design man-hours of the calculation process of the degradation rate can be reduced. Further, instead of the correspondence map, a common calculation formula for the input of the brake request value can be used to set the degradation rate of each vehicle control function, and with this calculation formula, the greater the brake request value, the greater the degradation rate output by the calculation formula is set.

[0040] Through the processing cycle of the following step S32 and step S33, the degradation control portion 43 gradually reduces the degradation control request value in step S32 according to the degradation rate until the degradation control request value becomes zero in step S33. For example, in the case of degrading the ACC function, the degradation control portion 43 gradually reduces the degradation second brake request value TrR bd according to the degradation rate. Thereby, the second brake request value Tr2R transmitted from the brake request management ECU 40 to the brake ECU 50 is gradually reduced. Further, the target brake value TrC output from the brake ECU 50 to the electric servo brake system 60 is reduced, and the operation of the brake is handed over to the driver.

[0041] [3. Reduction of deceleration G based on degradation control]

[0042] With reference to Figure 3 , Figure 4 , the change in the deceleration G of the vehicle 1 when the degradation control by the degradation control portion 43 is executed will be described.

[0043] Figure 3 A case where a failure occurs at tl in a state where the vehicle 1 is decelerated at 0.9G by executing the CMBS function-based brake will be described. The degradation control portion 43 sets the degradation rate corresponding to the second brake request value Tr2R_b corresponding to the 0.9G recognized until tl, and outputs the degradation second brake request value Tr2R bd while reducing it according to the degradation rate to the second brake request value decision portion 42. Thereby, in a situation where the deceleration G of the vehicle 1 is rapidly reduced to zero and the brake is required, the operation of the brake can be rapidly handed over to the driver.

[0044] Next, Figure 4A case where a failure occurs at t2 in a state where 0.2 G of deceleration G is generated in the vehicle 1 by performing braking based on the ACC function is indicated. In this case, the weakening control section 43 sets the weakening rate based on the second brake request value Tr2R_a corresponding to 0.2 G recognized until t2, and outputs the second brake request value Tr2R_ad to the second brake request value decision section 42 while decreasing at the weakening rate. Thereby, the deceleration G generated in the vehicle 1 is slowly reduced to zero, and it is possible to suppress the feeling of strangeness caused by a sudden change in deceleration G from being given to the driver.

[0045] [3. Other Embodiments]

[0046] In the above-described embodiments, the brake request value is torque, but as long as it is a physical quantity that determines deceleration, it can be, for example, a brake force acting on the vehicle, a wheel torque, a vehicle body deceleration, or the like.

[0047] In the above-described embodiments, the electric servo brake system 60 is shown as the brake device, but it can also be a brake device that causes the brake 3 to act by hydraulic pressure. In the case of targeting a brake device that causes the brake 3 to act by hydraulic pressure, the brake request value is not a request value based on torque but based on hydraulic pressure. In addition, the target brake value output from the brake ECU 50 to the brake device also becomes an indication value of hydraulic pressure.

[0048] In the above-described embodiments, the stall coordination function, the full charge pressurization function, the ACC function, and the CMBS function are exemplified as the vehicle control functions of the application, but as for other vehicle control functions, as long as they are functions accompanied by braking, the effects of the vehicle control device of the application can be obtained.

[0049] Further, in order to easily understand the application, Figure 1 The schematic diagram showing the structure of the vehicle 1 and the vehicle control device 10 is distinguished according to the main processing content, and the structure of the vehicle control device 10 can also be constituted by other distinguishing methods. In addition, the processing of each structural element can be performed by one hardware unit or by a plurality of hardware units. In addition, Figure 4 The processing of each structural element shown can be performed by one program or by a plurality of programs.

[0050] [4. Structure Supported by the Above-Described Embodiments]

[0051] The above-described embodiments are specific examples of the following structure.

[0052] A vehicle control device controls an operation of a vehicle that has a brake device that generates a braking force corresponding to a prescribed target braking value, the vehicle control device including: a target braking value decision section that decides a target braking value by performing arbitration processing on inputs of a plurality of braking request values that are individually set by a plurality of vehicle control functions possessed by the vehicle, and outputs the decided target braking value to the brake device; and a weakening control section that performs weakening control of an in-operation vehicle control function that is a vehicle control function executed when a failure occurs in the vehicle, and sets a weakening rate of the weakening control in accordance with the braking request value set by the in-operation vehicle control function when the failure occurs.

[0053] According to the vehicle control device of Structure 1, weakening control of a plurality of vehicle control functions can be performed while suppressing a sense of strangeness to the driver.

[0054] (Structure 2) The vehicle control device according to Structure 1, wherein the weakening control section performs, by the weakening control, processing that reduces the braking request value set by the in-operation vehicle control function when the failure occurs by the weakening rate.

[0055] According to the vehicle control device of Structure 2, by reducing the braking request value set by the in-operation vehicle control function by the weakening rate, the target braking value to the brake device can be reduced to weaken the in-operation vehicle control function.

[0056] (Structure 3) The vehicle control device according to Structure 1 or Structure 2, wherein the greater the braking request value set by the in-operation vehicle control function when the failure occurs, the greater the weakening rate of the weakening control of the in-operation vehicle control function that the weakening control section sets.

[0057] According to the vehicle control device of Structure 3, when a failure occurs, the withdrawal rate can be set in a manner that does not cause a sense of strangeness to the driver, in correspondence with the braking request value set by the in-operation vehicle control function.

[0058] (Structure 4) The vehicle control device according to any one of Structures 1 to 3, wherein the weakening control section sets the weakening rate for the plurality of vehicle control functions using a common calculation formula that outputs a weakening rate when a braking request value is input, or a common correspondence map that associates the braking request value with the weakening rate.

[0059] According to the vehicle control device according to Structure 4, the weakening rate is set using a common calculation formula or a corresponding map for a plurality of vehicle control functions, so it is not necessary to separately prepare logic for determining the retreat rate for each vehicle control function. Therefore, it is possible to reduce the design man-hours for the process of setting the weakening rate.

Claims

1. A vehicle control device for controlling the movement of a vehicle, the vehicle having a braking device that generates a braking force corresponding to a predetermined target braking value, the vehicle control device comprising: The target braking value determination unit performs prescribed arbitration processing on multiple braking requirement values ​​individually set by multiple vehicle control functions of the vehicle, thereby determining the target braking value, and outputs the determined target braking value to the braking device; and The weakening control unit performs weakening control of the vehicle control function executed at the time of the vehicle malfunction, namely the vehicle control function in operation, when the malfunction occurs. The weakening rate of the weakening control is set based on the braking requirement value set by the vehicle control function in operation when the malfunction occurs. The weakening control unit determines whether the vehicle has malfunctioned. For each vehicle control function that was being executed when the malfunction occurred, the larger the braking requirement value identified up to the time of the malfunction, the larger the weakening rate of the weakening control for the vehicle control function in operation will be.

2. The vehicle control device according to claim 1, wherein, The weakening control unit performs the following processing through the weakening control: reducing the braking requirement value set by the vehicle control function during operation according to the weakening rate when the fault occurs.

3. The vehicle control device according to claim 1 or 2, wherein, The weakening control unit uses a common calculation formula or a common corresponding mapping to set the weakening rate for multiple vehicle control functions. Regarding the common calculation formula, if a braking requirement value is input, the weakening rate will be output. The common corresponding mapping associates the braking requirement value with the weakening rate.

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