Vehicle control system

Abstract

To provide a technique to execute hard protection control suitable for an operation mode.SOLUTION: A vehicle control device executes: first hard protection control based on a component related parameter representing a state or an operating environment of an on-vehicle component when an operation mode is automatic; and second hard protection control offering greater protection for the on-vehicle component than the first hard protection control based on the component related parameter when the operation mode is manual.SELECTED DRAWING: Figure 4

Description

Technical Field

[0001] The present disclosure relates to a vehicle control device used in a vehicle having an automatic driving mode and a manual driving mode.

Background Art

[0002] Conventionally, a technique has been proposed to protect in - vehicle components by controlling so as to limit the output torque when the oil temperature of a vehicle's transmission is high (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, the inventor of the present disclosure has found that the necessity for component protection changes depending on whether the vehicle is running in the manual driving mode or the automatic driving mode. Therefore, it is desirable to perform component protection suitable for the driving mode.

Means for Solving the Problems

[0005] (1) According to one aspect of the present disclosure, a vehicle control device used in a vehicle having an automatic driving mode and a manual driving mode as driving modes is provided. When the driving mode is the automatic driving mode, this vehicle control device executes first hard protection control according to component - related parameters representing the state or operating environment of in - vehicle components. When the driving mode is the manual driving mode, second hard protection control with a higher protection performance for the in - vehicle components than the first hard protection control is executed according to the component - related parameters. According to this vehicle control system, the protection performance of onboard components can be enhanced in manual driving mode compared to automatic driving mode, and the vehicle's driving performance can be enhanced in automatic driving mode compared to manual driving mode. (2) In the above-mentioned vehicle control device, the automatic driving mode may include a manned automatic driving mode and an unmanned automatic driving mode, and the vehicle control device may be configured in the first hardware protection control such that the protection performance of the in-vehicle components is higher in the manned automatic driving mode than in the unmanned automatic driving mode. According to this vehicle control system, the protection performance of onboard components can be enhanced in the manned autonomous driving mode compared to the unmanned autonomous driving mode, and the vehicle's driving performance can be enhanced in the unmanned autonomous driving mode compared to the manned autonomous driving mode. (3) The vehicle control device may be capable of executing the automatic driving mode at multiple automatic driving levels, and the vehicle control device may be configured to provide higher protection performance for the in-vehicle components when the automatic driving level is a first level than when the automatic driving level is a second level which is higher than the first level. This vehicle control system can enhance the protection of onboard components when the autonomous driving level is low, and improve the vehicle's driving performance when the autonomous driving level is high. [Brief explanation of the drawing]

[0006] [Figure 1] An explanatory diagram showing the configuration of the vehicle's power transmission system. [Figure 2] A timing chart illustrating an example of hardware protection control operation. [Figure 3] An explanatory diagram showing examples of automotive components subject to hardware protection control, component-related parameters, and hardware protection limits. [Figure 4] A flowchart illustrating the processing procedure for hard protection control in an embodiment. [Modes for carrying out the invention]

[0007] Figure 1 is an explanatory diagram showing the configuration of the power transmission system of vehicle 100. This vehicle 100 has an automatic driving mode and a manual driving mode as driving modes. Vehicle 100 is equipped with an internal combustion engine 10, a motor drive unit 20, a transmission 30, a differential 40, a plurality of drive wheels 50, and a vehicle control device 80.

[0008] The transmission 30 includes a first clutch 31, an electric motor 32, a lock-up clutch 33, and an automatic transmission 34. The first clutch 31 has the function of disconnecting the connection between the engine 10 and the electric motor 32. The electric motor 32 is driven by the motor drive unit 20 as needed to assist the driving force of the vehicle 100. It is also possible to perform EV (Electric Vehicle) driving using the electric motor 32 with the engine 10 completely disconnected by the first clutch 31. The motor drive unit 20 includes a battery 21 and an inverter 22. The electric motor 32 can also perform regenerative operation. The regenerative power generated by the inverter 22 is used to charge the battery 21.

[0009] The lock-up clutch 33 can maintain a slip state between the engine 10 and the automatic transmission 34. The slip control of the lock-up clutch 33 allows for adjustment of the engagement force by external forces such as hydraulic pressure. The output shaft of the automatic transmission 34 is connected to the differential 40. Note that the configuration of the transmission 30 shown in Figure 1 is an example, and other configurations are also possible.

[0010] Each of the drive wheels 50 is equipped with a wheel speed sensor 70. The accelerator pedal 61 is equipped with an accelerator position sensor 71 that measures the accelerator position ACC. The brake pedal 62 is equipped with a brake pedal sensor 72 that measures the amount of depression BRA of the brake pedal 62. The shift lever 63 is equipped with a shift position sensor 73 that measures the shift position LP. The engine 10 is equipped with a water temperature sensor 74 that measures its coolant temperature Tw and an intake air temperature sensor 75 that measures the intake air temperature Ta. The transmission 30 is equipped with an oil temperature sensor 76 that measures the oil temperature To of its hydraulic circuit and a clutch temperature sensor 77 that measures the clutch temperature Tc of the lock-up clutch 33. The battery 21 is equipped with a battery temperature sensor 78 that measures the battery temperature Tb. The electric motor 32 is equipped with a motor temperature sensor 79 that measures the motor temperature Tm. The measured values ​​from the various sensors 70 to 79 are input to the vehicle control device 80.

[0011] The vehicle control device 80 comprises a vehicle control unit 81, an automatic driving control unit 82, a driving mode setting unit 83, and a hardware protection control unit 84. The vehicle control device 80 can be configured using one or more ECUs (Electronic Control Units). The ECU has a processor, RAM, and ROM, and a computer program is stored in the ROM. The functions of each unit 81 to 84 can be realized by the processor executing a computer program stored in a non-volatile storage medium. In addition, some of the functions of each unit 81 to 84 may be realized by hardware circuits.

[0012] The vehicle control unit 81 performs various controls for the operation of the vehicle 100, such as drive control, brake control, and steering angle control. The vehicle control unit 81 is used in both automatic and manual driving modes.

[0013] The automatic driving control unit 82 performs automatic driving of the vehicle 100. Specifically, the automatic driving control unit 82 transmits a drive force command value indicating the driving force of the drive unit (engine or motor), a brake command value indicating the operating state of the brake mechanism, and a steering angle command value indicating the steering angle of the wheels to the vehicle control unit 81. The vehicle control unit 81 performs control of each controlled mechanism according to the given command values.

[0014] In this disclosure, "autonomous driving" means driving in which at least a portion of the drive control, brake control, and steering angle control are performed automatically. In other words, the term "autonomous driving" includes autonomous driving from Level 1 to Level 5. Autonomous driving at Levels 1 and 2 requires driver supervision and is therefore called "manned autonomous driving." Manned autonomous driving includes driving using Adaptive Cruise Control and Lane Keep Assist System. Autonomous driving at Levels 3, 4, and 5 does not require driver supervision and is therefore called "unmanned autonomous driving." In unmanned autonomous driving, the operating state of the drive unit, the operating state of the brake mechanism, and the steering angle of the wheels are determined automatically. "Manual driving" means driving in which the driver operates the accelerator pedal for drive unit control, the brake pedal for brake control, and the steering wheel for steering angle control.

[0015] The driving mode setting unit 83 switches the driving mode of the vehicle 100 between manual driving mode and automatic driving mode. In automatic driving mode, the level of automatic driving to be performed is also set. The driving mode can be switched, for example, by the occupant selecting from the options displayed on the display. Alternatively, the system may receive the driving mode switch from an external device via wireless communication.

[0016] The hard protection control unit 84 executes hard protection control for in-vehicle components. The hard protection control is control performed to protect in-vehicle components and can also be referred to as "component protection control". In this embodiment, in particular, protection control for components of the power transmission system is executed.

[0017] Figure 2 is a timing chart showing an operation example of the hard protection control. In Figure 2, examples of changes in the component-related parameter Tp and the hard protection limit value Lim are shown. The component-related parameter Tp is a parameter representing the state or operating environment of the in-vehicle component to be protected. A typical example of the component-related parameter Tp is the temperature of the in-vehicle component. The hard protection limit value Lim is a characteristic value restricted for hard protection and is, for example, output or torque.

[0018] The component-related parameter Tp is set with a first threshold value T1 for determining the start timing of hard protection and a second threshold value T2 for determining the end timing of hard protection. The second threshold value T2 is set to a value smaller than the first threshold value T1.

[0019] The hard protection limit value Lim is set with a normal limit value Lim1 when the hard protection control is not executed and a protection enhancement limit value Lim2 when the hard protection control is executed. The protection enhancement limit value Lim2 is set to a value lower than the normal limit value Lim1.

[0020] Before time t1, since the component-related parameter Tp is less than the first threshold value T1, the normal limit value Lim1 is applied. At time t1, when the component-related parameter Tp becomes greater than or equal to the first threshold value T1, the hard protection control is started at time t2 after a preset delay time Δt, and the protection enhancement limit value Lim2 is applied as the hard protection limit value. However, if the component-related parameter Tp becomes less than or equal to the second threshold value T2 during the delay time Δt, the hard protection control is not started and the normal limit value Lim1 is maintained.

[0021] During the period from time t2 to time t3, since the component-related parameter Tp is maintained at or above the second threshold value T2, the enhanced protection limit value Lim2 is applied. After time t3, since the component-related parameter Tp becomes less than the second threshold value T2, the hard protection control ends and the normal limit value Lim1 is applied. According to such hard protection control, it is possible to prevent problems such as failures in in-vehicle components.

[0022] FIG. 3 is an explanatory diagram showing an example of an in-vehicle component to be subjected to hard protection control, a component-related parameter Tp, and a hard protection limit value. Examples of in-vehicle components to be subjected to hard protection control include, for example, an engine 10, a clutch 33, an automatic transmission 34, an electric motor 32, a battery 21, and the like. As the component-related parameter Tp of the engine 10, the intake air temperature Ta or the outside air temperature, and the case of using the coolant water temperature Tw can be considered. The intake air temperature Ta or the outside air temperature is a parameter indicating the operating environment of the engine 10. The coolant water temperature Tw is a parameter indicating the state of the engine 10. In the example of FIG. 3, the component-related parameter Tp of in-vehicle components other than the engine 10 is a parameter indicating the state of each in-vehicle component. The hard protection limit value is the respective output for the engine 10, the electric motor 32, and the battery 21, and is torque for the clutch 33 and the automatic transmission 34. Note that the hard protection control may be applied to only some of these in-vehicle components. Also, in-vehicle components other than these may be the subject of hard protection control.

[0023] FIG. 4 is a flowchart showing the processing procedure of the hard protection control in the embodiment. The processing in FIG. 4 is preferably executed periodically at regular intervals. In this embodiment, the following three types of hard protection controls are used. <Hard protection priority control> Among the three types of hard protection controls, the control with the highest hard protection performance and the lowest running performance. <Hard protection / running performance compatible control> Among the three types of hard protection, the control with intermediate performance in terms of hard protection performance and running performance, respectively. <Running performance priority control> Among the three types of hard protection controls, the control with the highest running performance and the lowest hard protection performance.

[0024] In step S10, the hardware protection control unit 84 determines whether the current driving mode of the vehicle 100 is automatic driving mode or manual driving mode. If it is manual driving mode, the process proceeds to step S30, where the hardware protection control unit 84 executes hardware protection priority control.

[0025] If the current driving mode is automatic driving mode, the process proceeds to step S20, where the hardware protection control unit 84 determines whether it is unmanned automatic driving mode or manned automatic driving mode. As mentioned above, unmanned automatic driving mode is level 3 to 5 automatic driving, and manned automatic driving mode is level 1 to 2 automatic driving. If it is manned automatic driving mode, the process proceeds to step S40, where the hardware protection control unit 84 performs hardware protection / driving performance balancing control.

[0026] If the current driving mode is unmanned automatic driving mode, the process proceeds to step S50, where the hard protection control unit 84 executes driving performance priority control.

[0027] As described above, in this embodiment, it is possible to use three types of hardware protection control: hardware protection priority control, hardware protection / driving performance balance control, and driving performance priority control. Furthermore, when the driving mode is manual driving mode, hardware protection control with a higher level of protection performance for on-board components is executed than when the driving mode is automatic driving mode. Hardware protection / driving performance balance control and driving performance priority control correspond to the "first hardware protection control" in this disclosure, and hardware protection priority control corresponds to the "second hardware protection control" in this disclosure.

[0028] In hardware protection control, methods to enhance hardware protection performance include, for example, using at least one of the following: <Method M1> Lower the first threshold T1 of the component-related parameter Tp. When using method M1, the first threshold T1 is set to the lowest value in hard protection priority control, the highest value in driving performance priority control, and an intermediate value in hard protection / driving performance compatible control. <Method M2> Reduce the delay time Δt. When using method M2, the delay time Δt is set to the longest value in hard protection priority control, the shortest value in driving performance priority control, and an intermediate value in hard protection / driving performance compatible control. <Method M3> Lower the protection enhancement limit value Lim2. When using Method M3, the protection enhancement limit value Lim2 is set to the lowest value in hard protection priority control, the highest value in driving performance priority control, and an intermediate value in hard protection / driving performance balanced control. Furthermore, you may use two or more of methods M1 to M3, or you may use any other method.

[0029] Thus, in this embodiment, when the driving mode is manual driving mode, hardware protection control with higher protection performance for on-board components is executed than when the driving mode is automatic driving mode. The reason for this is that in manual driving mode, the driving environment and driver operation are unknown, so it is necessary to execute hardware protection control assuming the worst-case scenario, and it is desirable to execute hardware protection control with high hardware protection performance. On the other hand, in automatic driving mode, since the vehicle 100 drives according to the driving plan, the driving environment is almost known, so the possibility of malfunctions such as failures in on-board components is low, and it is desirable to improve driving performance. In particular, in unmanned automatic driving mode, the predictability of the driving environment is even higher, so it is desirable to place even greater emphasis on driving performance. In particular, in unmanned automatic driving mode, which drives on a predetermined course, there is a strong tendency to want to place emphasis on driving performance, as it is possible to perform gear shift control that traces the driving of a professional driver. In such unmanned automatic driving mode, the component-related parameter Tp exceeds the first threshold T1 for a very short time and then immediately decreases, so it is expected that the possibility of malfunctions such as failures in on-board components is low.

[0030] Note that step S20 in Figure 4 may be omitted, and the same hardware protection control may be performed for all autonomous driving modes, regardless of their level. In this case as well, it is preferable that the hardware protection control in manual driving mode provides higher protection for in-vehicle components than the hardware protection control in autonomous driving mode.

[0031] In this embodiment, the autonomous driving modes are classified into a manned autonomous driving mode, which is autonomous driving at levels 1 to 2, and an unmanned autonomous driving mode, which is autonomous driving at levels 3 to 5. However, the autonomous driving modes may be classified into three or more levels. In this case as well, it is preferable that the hardware protection control unit 84 performs hardware protection control such that the protection performance of the in-vehicle components is higher when the autonomous driving level is the first level than when the autonomous driving level is the second level, which is higher than the first level. This makes it possible to improve the protection performance of the in-vehicle components when the autonomous driving level is lower.

[0032] As described above, in this embodiment, when the driving mode is manual driving mode, hardware protection control with higher protection performance for on-board components is performed than when the driving mode is automatic driving mode. As a result, the protection performance for on-board components can be improved in manual driving mode compared to automatic driving mode, and the driving performance of the vehicle can be improved in automatic driving mode compared to manual driving mode.

[0033] Although the above embodiments described a vehicle equipped with a power transmission system including an engine, this disclosure is also applicable to electric vehicles such as battery electric vehicles.

[0034] Other forms: This disclosure is not limited to the embodiments described above, and can be implemented in various forms without departing from its spirit. For example, this disclosure can also be implemented in the following forms (aspects). The technical features in the embodiments described above that correspond to the technical features in each of the forms described below can be replaced or combined as appropriate in order to solve some or all of the problems of this disclosure, or to achieve some or all of the effects of this disclosure. Furthermore, if such technical features are not described as essential in this specification, they can be deleted as appropriate.

[0035] This disclosure can also be implemented in various forms other than vehicle control devices and control methods. For example, it can be implemented in the form of a computer program that performs vehicle control, or a non-transitory storage medium on which the computer program is recorded. [Explanation of Symbols]

[0036] 10...Engine, 20...Motor drive unit, 21...Battery, 22...Inverter, 30...Transmission, 31...First clutch, 32...Electric motor, 33...Lock-up clutch, 34...Automatic transmission, 40...Differential, 50...Drive wheels, 61...Accelerator pedal, 62...Brake pedal, 63...Shift lever, 70...Wheel speed sensor, 71...Accelerator opening sensor, 72...Brake pedal sensor, 73...Shift position sensor, 74...Water temperature sensor, 75...Oil temperature sensor, 76...Clutch temperature sensor, 77...Battery temperature sensor, 78...Motor temperature sensor, 79...Intake air temperature sensor, 80...Vehicle control device, 81...Vehicle control unit, 82...Automatic driving control unit, 83...Driving mode setting unit, 84...Hardware protection control unit, 100...Vehicle

Claims

1. A vehicle control device used in a vehicle having an automatic driving mode and a manual driving mode as driving modes, When the driving mode is the automatic driving mode, the first hardware protection control is executed according to component-related parameters that represent the state of the in-vehicle components or the operating environment. A vehicle control device that, when the driving mode is the manual driving mode, executes a second hard protection control that provides higher protection performance for the in-vehicle components than the first hard protection control, according to the component-related parameters.

2. A vehicle control device according to claim 1, The aforementioned autonomous driving modes include a manned autonomous driving mode and an unmanned autonomous driving mode. The vehicle control device is configured such that, in the first hardware protection control, the protection performance of the in-vehicle components is higher in the manned automatic driving mode than in the unmanned automatic driving mode.

3. A vehicle control device according to claim 1, The vehicle control device is capable of executing the automatic driving mode at multiple levels of automatic driving, The vehicle control device is configured such that when the automated driving level is a first level, it provides a higher level of protection for the in-vehicle components than when the automated driving level is a second level, which is higher than the first level.

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