On-vehicle control device

Abstract

To suppress a torque shock that may occur when an accelerator pedal is turned on while deceleration support control is active.SOLUTION: An on-vehicle control device is mounted on an electric vehicle which comprises a travel motor and a hydraulic brake. When an accelerator pedal is turned off while a predetermined condition is met, the on-vehicle control device executes deceleration support control to control a deceleration speed using a regenerative brake of the motor and the hydraulic brake. When the accelerator pedal is turned on while the deceleration support control is active, the on-vehicle control device also controls the motor using either set torque based on an acceleration opening or corrected torque obtained by applying gradual change processing to the set torque whichever is smaller.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to an in-vehicle control device, and more particularly to an in-vehicle control device that is mounted on a vehicle and executes deceleration assist control. [Background technology]

[0002] Conventionally, as this type of on-board control device, there has been proposed a device that executes look-ahead deceleration support control including regeneration enhancement control that increases the braking force by the motor generator when a target position for deceleration of the electric vehicle is set, compared to when the target position is not set (see, for example, Patent Document 1). The look-ahead deceleration support control also includes accelerator off guidance control that notifies the driver of information encouraging the driver to release the accelerator pedal when a target position for deceleration of the electric vehicle is set. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-112204 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the above-mentioned vehicle-mounted control device, when the accelerator is turned on during execution of the deceleration support control, a torque shock may occur due to a sudden torque change, which may cause the driver and passengers to feel a deterioration in the ride comfort.

[0005] The main purpose of the on-vehicle control device disclosed herein is to suppress torque shock that can occur when the accelerator is pressed while deceleration assistance control is being executed. [Means for solving the problem]

[0006] The vehicle control device of the present disclosure employs the following means to achieve the above-mentioned main object.

[0007] The in-vehicle control device of the present disclosure includes: An in-vehicle control device is mounted on an electric vehicle having a motor for driving and a hydraulic brake, and performs deceleration assistance control to control deceleration using a regenerative brake by the motor and the hydraulic brake when an accelerator is released under a predetermined condition, When the accelerator is turned on during the execution of the deceleration support control, the motor is controlled using the smaller of a set torque that is set based on an accelerator opening degree and a correction torque that is obtained by performing a slow-change processing on the set torque. It is characterized by:

[0008] The vehicle-mounted control device of the present disclosure is mounted on an electric vehicle equipped with a motor for driving and a hydraulic brake, and executes deceleration support control for controlling deceleration using the regenerative brake by the motor and the hydraulic brake when the accelerator is released under a predetermined condition. The vehicle-mounted control device normally controls the motor using a set torque set based on the accelerator opening. When the accelerator is turned on during execution of the deceleration support control, the motor is controlled using the smaller of the set torque set based on the accelerator opening and the correction torque obtained by applying a gradual change process to the set torque. In this way, when the accelerator is turned on during execution of the deceleration support control, the motor is controlled using the smaller of the set torque and the correction torque obtained by applying a gradual change process, so that a sudden torque change can be suppressed and a torque shock that may occur when the accelerator is turned on during execution of the deceleration support control can be suppressed. Examples of the predetermined condition include a condition in which a preceding vehicle is found within a predetermined distance, a condition in which driving on a curve is predicted within a predetermined distance, and a condition in which driving at an intersection is predicted within a predetermined distance.

[0009] In the vehicle-mounted control device of the present disclosure, the motors may be a front-wheel drive motor connected to the front wheels and a rear-wheel drive motor connected to the rear wheels, and when the accelerator is on during normal operation, a first set torque to be output from one of the front-wheel drive motor and the rear-wheel drive motor is set using a torque distribution ratio of the set torque, and the one motor is controlled using the first set torque, and a second set torque to be output from the other motor after the first set torque is set, and the other motor is controlled using the second set torque, and when the accelerator is on during execution of the deceleration support control, the one motor is controlled using the smaller of the first set torque and a first correction torque obtained by subjecting the first set torque to a gradual change process. In this case, the other motor may be controlled using the second set torque even when the accelerator is on during execution of the deceleration support control. One of the motors is preferably a rear-wheel drive motor, and may be a front-wheel drive motor.

[0010] The on-vehicle control device of the present disclosure may be mounted on a hybrid vehicle equipped with an engine as an electrically powered vehicle. [Brief description of the drawings]

[0011] [Figure 1] 1 is a diagram showing an outline of the configuration of an electric vehicle 20 equipped with an on-board control device according to an embodiment of the present disclosure. [Diagram 2] 5 is a flowchart showing an example of a torque setting process immediately after deceleration support control executed by an electronic control unit 40. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] Next, a mode (embodiment) for carrying out the present disclosure will be described. Fig. 1 is a schematic diagram showing the configuration of an electric vehicle 20 equipped with an on-board control device as an embodiment of the present disclosure. The electric vehicle 20 of the embodiment includes a battery 21, a front wheel motor 22, a front wheel inverter 24, a rear wheel motor 32, a rear wheel inverter 34, an electronic control unit 40, a brake actuator 62, a navigation system 70, and a surrounding recognition device 80.

[0013] The battery 21 is configured as, for example, a lithium ion secondary battery or a nickel-hydrogen secondary battery, and is connected to the front wheel inverter 24 and the rear wheel inverter 34 by power lines.

[0014] The front wheel motor 22 is configured as a synchronous generator motor, and includes a rotor in which a permanent magnet is embedded, and a stator around which a three-phase coil is wound. The rotor of the front wheel motor 22 is connected to a drive shaft 26 that is connected to the front wheels 28a, 28b via a differential gear 27.

[0015] The front wheel inverter 24 is connected to the front wheel motor 22 and also to a power line. The front wheel inverter 24 is configured as a well-known inverter circuit having six transistors and six diodes, and drives the front wheel motor 22 by applying three-phase AC power to the front wheel motor 22 by switching-controlling the six transistors.

[0016] The rear wheel motor 32, like the front wheel motor 22, is configured as a synchronous generator motor and includes a rotor in which a permanent magnet is embedded and a stator around which a three-phase coil is wound. The rotor of the rear wheel motor 32 is connected to a drive shaft 36 that is connected to rear wheels 38a, 38b via a differential gear 37.

[0017] The rear wheel inverter 34 is connected to the rear wheel motor 32 and also to a power line. Like the front wheel inverter 24, the rear wheel inverter 34 is configured as a well-known inverter circuit having six transistors and six diodes, and drives the rear wheel motor 32 by applying three-phase AC power to the rear wheel motor 32 by switching-controlling the six transistors.

[0018] The electronic control unit 40 is configured as a microprocessor centered around a CPU 42, and in addition to the CPU 42, includes a ROM 44 for storing processing programs, a RAM 46 for temporarily storing data, a flash memory (not shown), an input / output port (not shown), a communication port (not shown), etc.

[0019] Signals from various sensors are input to the electronic control unit 40 via input ports. Examples of signals input to the electronic control unit 40 include rotational positions θmf, θmr from rotational position detection sensors (e.g. resolvers) 23, 33 that detect the rotational positions of the rotors of the front wheel motor 22 and the rear wheel motor 32, a voltage VB from a voltage sensor (not shown) attached between the terminals of the battery 21, and a current IB from a current sensor (not shown) attached to the output terminal of the battery 21. Other examples include a start signal from a start switch 50, a shift position SP from a shift position sensor 52 that detects the operation position of a shift lever 51, an accelerator opening Acc from an accelerator pedal position sensor 54 that detects the amount of depression of an accelerator pedal 53, a brake pedal position from a brake pedal position sensor 56 that detects the amount of depression of a brake pedal 55, and a vehicle speed V from a vehicle speed sensor. Information from a surrounding recognition device 59 is also input to the electronic control unit 40. The surrounding recognition device 59 is composed of a front camera, a rear camera, a millimeter wave radar, a quasi-millimeter wave radar, an infrared laser radar, a sonar, etc., and detects information about the vehicle and its surroundings (for example, the distance between the vehicle and other vehicles in front and behind the vehicle, the speed of other vehicles, the vehicle's position in the road lane, etc.).

[0020] Various control signals are output via output ports from the electronic control unit 40. Examples of signals output from the electronic control unit 40 include switching control signals to transistors of the front wheel inverter 24 and the rear wheel inverter 34, and drive control signals to a system main relay (not shown) attached near the battery 21 on the power line.

[0021] The brake actuator 62 is configured to adjust the hydraulic pressure of the pistons of the disc brakes 66a to 66d so that a braking force corresponding to the brake share of the braking force acting on the vehicle according to the pressure (brake pressure) of the brake master cylinder 60 generated in response to depression of the brake pedal and the vehicle speed V acts on the front wheels 28a, 28b and the rear wheels 38a, 38b, or adjust the hydraulic pressure of the pistons of the disc brakes 66a to 66d so that a braking force acts on the front wheels 28a, 28b and the rear wheels 38a, 38b regardless of depression of the brake pedal 55. Hereinafter, the braking force acting on the front wheels 28a, 28b and the rear wheels 38a, 38b by the operation of the brake actuator 62 may be referred to as a hydraulic brake. The brake actuator 62 is controlled by a brake electronic control unit (hereinafter referred to as a brake ECU) 64. The brake ECU 64 communicates with the electronic control unit 40, drives and controls the brake actuator 62 according to control signals from the electronic control unit 40, and outputs data relating to the state of the brake actuator 62 to the electronic control unit 40 as necessary.

[0022] The brake ECU 64 receives signals such as wheel speeds Vfr, Vfl, Vrr, Vrl from wheel speed sensors 68a-68d attached to the front wheels 28a, 28b and rear wheels 38a, 38b, and steering angles from a steering angle sensor (not shown), and calculates braking torques to be applied to the front wheels 28a, 28b and rear wheels 38a, 38b when the driver depresses the brake pedal 55. The brake ECU 64 then divides the braking torques to be applied to the front wheels 28a, 28b and rear wheels 38a, 38b into braking torques from the disc brakes 66a-66d and braking torques from the regenerative control of the front wheel motor 22 and rear wheel motor 32, and drives and controls the brake actuator 62 so that the braking torques to be applied from the disc brakes 66a-66d are applied. The braking torque generated by the regenerative control of the front wheel motor 22 and the rear wheel motor 32 is transmitted to the electronic control unit 40, which receives this and controls the switching of the transistors of the front wheel inverter 24 and the rear wheel inverter 34 so that the braking torque that should be output from the front wheel motor 22 and the rear wheel motor 32 is output.

[0023] The navigation system 70 is a system that guides the vehicle to a set destination, and is equipped with map information and a display unit. When a destination is set, the navigation system 70 sets a route and provides guidance based on the destination information, current location (current vehicle position) information acquired by a GPS (not shown), and map information. The navigation system 70 communicates with the electronic control unit 40 and exchanges various information.

[0024] In the electric vehicle 20 thus configured, when the accelerator is released when a predetermined condition is satisfied, the electronic control unit 40 executes deceleration support control. Examples of the predetermined condition include a condition in which the vehicle distance to another vehicle ahead is equal to or less than a predetermined distance as determined by the periphery recognition device 59, a condition in which a curve with poor visibility is detected ahead by the periphery recognition device 59 or the navigation system 70, and a condition in which an intersection is detected ahead by the periphery recognition device 59 or the navigation system 70. The deceleration support control is a control for driving the front wheel motor 22, the rear wheel motor 32, and the hydraulic brake so as to achieve a deceleration that is greater than the normal deceleration when the accelerator is released with the shift position SP set to a forward driving position (D position). Specifically, in the embodiment, a target deceleration is first set according to the vehicle distance to the other vehicle ahead detected by the periphery recognition device 59, the distance to the curve with poor visibility, the distance to the intersection, and the vehicle speed V. Next, the motor braking torque output from the front wheel motor 22 and the rear wheel motor 32 and the brake braking torque by the hydraulic brake for achieving the target deceleration are calculated. Regarding the motor braking torque, the regenerative torque to be output from the front wheel motor 22 and the regenerative torque to be output from the rear wheel motor 32 are calculated using a division ratio k, and the front wheel inverter 24 and the rear wheel inverter 34 are switched and controlled so that the regenerative torque is output from the front wheel motor 22 and the rear wheel motor 32, respectively. Meanwhile, the electronic control unit 40 transmits the brake braking torque to the brake ECU 64. Having received the brake braking torque, the brake ECU 64 calculates the braking torque to be applied to the front wheels 28a, 28b and the rear wheels 38a, 38b, and drives and controls the brake actuator 62 so that the braking torque to be applied from the disc brakes 66a-66d is applied.

[0025] Next, a description will be given of an operation when the driver depresses the accelerator pedal 53 (when the accelerator is on) while deceleration support control is being executed by the electronic control unit 40 of the electric vehicle 20 of the embodiment. Fig. 2 is a flowchart showing an example of a torque setting process immediately after deceleration support control executed by the electronic control unit 40. This process is repeatedly executed at predetermined time intervals.

[0026] When the torque setting process is executed immediately after the deceleration assist control, the electronic control unit 40 inputs the accelerator opening Acc from the accelerator pedal position sensor 54 and the vehicle speed V from the vehicle speed sensor 58 (step S100), and sets the target torque T* to be output from the front wheel motor 22 and the rear wheel motor 32 based on the accelerator opening Acc and the vehicle speed V (step S110).

[0027] Next, the target torque T* is multiplied by the division ratio k to set the provisional rear wheel torque Trtmp (step S120). A correction torque Trt is set by a gradual change process from the rear wheel torque Tr* set when this process was executed last time (hereinafter referred to as the previous rear wheel torque Tr*) toward the provisional rear wheel torque Trtmp (step S130). This gradual change process can be a smoothing process or a rate limit process. Then, the smaller of the provisional rear wheel torque Trtmp and the correction torque Trt is set as the rear wheel torque Tr* (step S140). After the rear wheel torque Tr* is set in this way, the rear wheel inverter 34 is controlled so that the rear wheel torque Tr* is immediately output from the rear wheel motor 32. In this way, the correction torque Trt is set by the gradual change process from the previous rear wheel torque Tr* toward the provisional rear wheel torque Trtmp, and the smaller of the provisional rear wheel torque Trtmp and the correction torque Trt is set as the rear wheel torque Tr*, thereby suppressing a sudden change in the rear wheel torque Tr*. By suppressing such a sudden change in the rear wheel torque Tr*, it is possible to suppress the torque shock that may occur when the accelerator is pressed while the deceleration support control is being executed.

[0028] Once the rear wheel torque Tr* is set, the target torque T* is multiplied by the division ratio (1-k) to set the front wheel torque Tf* (step S150), and this process ends. Once the front wheel torque Tf* is set, the front wheel inverter 24 is controlled so that the front wheel torque Tf* is immediately output from the front wheel motor 22. The reason why the slow-change process is not used for the front wheel torque Tf* is that it is effective to apply the slow-change process to either the front wheel torque Tf* or the rear wheel torque Tr*, and because the rear wheel torque Tr* is set prior to setting the front wheel torque Tf*, torque shock can be suppressed by using the slow-change process for the rear wheel torque Tr*.

[0029] In the electronic control unit 40 of the electric vehicle 20 of the embodiment described above, when the driver depresses the accelerator pedal 53 (when the accelerator is on) while the deceleration support control is being executed, the rear wheel torque Tr*, which is set prior to setting the front wheel torque Tf*, is set as the rear wheel torque Tr* to the smaller of the provisional rear wheel torque Trtmp obtained by multiplying the target torque T* by the division ratio k and the correction torque Trt obtained by applying a slow-change process from the previous rear wheel torque Tr* to the provisional rear wheel torque Trtmp. This makes it possible to suppress torque shock that may occur when the accelerator is on while the deceleration support control is being executed.

[0030] In the electric vehicle 20 of the embodiment, when the rear wheel torque Tr* is set prior to setting the front wheel torque Tf*, the smaller of the provisional rear wheel torque Trtmp obtained by multiplying the target torque T* by the division ratio k and the correction torque Trt obtained by applying a slow-change process from the previous rear wheel torque Tr* to the provisional rear wheel torque Trtmp is set as the rear wheel torque Tr*. However, when the front wheel torque Tf* is set prior to the rear wheel torque Tr*, the smaller of the provisional front wheel torque Tftmp obtained by multiplying the target torque T* by the division ratio (1-k) and the correction torque Tft obtained by applying a slow-change process from the previous front wheel torque Tf* to the provisional front wheel torque Tftmp may be set as the front wheel torque Tf*.

[0031] The electric vehicle 20 of the embodiment is equipped with the front wheel motor 22 and the rear wheel motor 32, but it may be equipped with only the front wheel motor 22 or only the rear wheel motor 32. Also, it may be equipped with an engine in addition to the front wheel motor 22 and the rear wheel motor 32.

[0032] The correspondence between the main elements of the embodiment and the main elements of the invention described in the section on Means for Solving the Problems will be described below. In the embodiment, the rear wheel motor 32 corresponds to the "motor", the brake master cylinder 60, the brake actuator 62, the brake ECU 64, and the disc brakes 66a to 66d correspond to the "hydraulic brakes", and the electronic control unit 40 corresponds to the "vehicle control device".

[0033] Note that the correspondence between the main elements of the embodiment and the main elements of the invention described in the Means for Solving the Problem column does not limit the elements of the invention described in the Means for Solving the Problem column, since the embodiment is an example for specifically explaining the form for implementing the invention described in the Means for Solving the Problem column. In other words, the interpretation of the invention described in the Means for Solving the Problem column should be made based on the description in that column, and the embodiment is merely a specific example of the invention described in the Means for Solving the Problem column.

[0034] The present disclosure has been described above using embodiments, but the present disclosure is not limited to these embodiments in any way, and it goes without saying that the present disclosure can be embodied in various forms without departing from the gist of the present disclosure. [Industrial Applicability]

[0035] The present disclosure can be used in the manufacturing industry of in-vehicle control devices, etc. [Explanation of symbols]

[0036] 20 electric vehicle, 21 battery, 22 front wheel motor, 23, 33 rotational position detection sensor, 24 front wheel inverter, 26 drive shaft, 27 differential gear, 28a, 28b front wheels, 32 rear wheel motor, 34 rear wheel inverter, 36 drive shaft, 37 differential gear, 38a, 38b rear wheels, 40 electronic control unit, 42 CPU, 44 ROM, 46 RAM, 50 start switch, 51 shift lever, 52 shift lever position sensor, 53 accelerator pedal, 54 accelerator pedal position sensor, 55 brake pedal, 56 brake pedal position sensor, 58 vehicle speed sensor, 59 surrounding recognition device, 60 brake master cylinder, 62 brake actuator, 64 brake electronic control unit, 66a to 66d disc brake, 68a to 68d wheel speed sensor, 70 navigation system.

Claims

1. An in-vehicle control device is mounted on an electric vehicle having a motor for driving and a hydraulic brake, and performs deceleration assistance control to control deceleration using a regenerative brake by the motor and the hydraulic brake when an accelerator is released under a predetermined condition, When the accelerator is turned on during the execution of the deceleration support control, the motor is controlled using the smaller of a set torque that is set based on an accelerator opening degree and a correction torque that is obtained by performing a slow-change processing on the set torque.

2. An in-vehicle control device comprising:

2. 2. The vehicle-mounted control device according to claim 1, the motor is a front-wheel drive motor connected to the front wheels and a rear-wheel drive motor connected to the rear wheels, When the accelerator is on during normal operation, a first set torque to be output from one of the front wheel drive motor and the rear wheel drive motor is set using a torque distribution ratio of the set torque, and the one motor is controlled using the first set torque, and after setting the first set torque, a second set torque to be output from the other motor is set, and the other motor is controlled using the second set torque, When the accelerator is turned on during the execution of the deceleration assist control, the one motor is controlled using a smaller one of the first set torque and a first correction torque obtained by performing a slow-change processing on the first set torque. In-vehicle control device.

3. 3. The vehicle-mounted control device according to claim 2, The other motor is controlled using the second set torque even when an accelerator pedal is turned on during execution of the deceleration assist control. In-vehicle control device.

4. 4. The vehicle-mounted control device according to claim 2, the one motor is the rear wheel drive motor; In-vehicle control device.

5. 4. The vehicle control device according to claim 1, The electric vehicle is a hybrid vehicle equipped with an engine. In-vehicle control device.

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