JP6323681B2 - Vehicle control device - Google Patents

Description

  The present invention relates to a control device for a vehicle that provides assistance for escaping a vehicle from a stacked state.

  Conventionally, various techniques for escaping a vehicle from a stacked state are known. For example, in the device of Patent Document 1, when the rear wheel fits into a depression on the road surface and is stacked, the motor for driving the rear wheel is driven alternately in the normal rotation direction and the reverse rotation direction so that the rear wheel is driven in the depression. Increase the reciprocating stroke of the wheel. In this case, during the forward drive or reverse drive of the motor, the rotational direction of the motor is reversed when the wheel speed difference between the front wheel (driven wheel) and the rear wheel becomes equal to or greater than the slip determination value. That is, in the apparatus of Patent Document 1, the rotation direction of the motor is switched at the timing when the rear wheel starts to idle, and the rear wheel is reciprocated in the recess.

JP 2010-149697 A

  However, in the apparatus of Patent Document 1, when the rear wheel is reciprocated in the recess, there is a possibility that unexpected forward or backward movement of the vehicle may occur.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to support the escape of a vehicle from a stack state so that an unexpected forward or backward movement of the vehicle does not occur.

In order to achieve the above object, the features of the present invention are:
In the vehicle control device (30) for assisting the vehicle to escape from the stack state,
A driving device (11, 12, 13) for driving the front wheel and the rear wheel so that the forward and reverse rotation can be switched independently of each other;
A stack escape operation device (32) operated by a driver when trying to receive support for letting the vehicle escape from the stack state;
When the stack escape operation device is operated, the rear wheel is driven in the reverse rotation direction that is the direction in which the vehicle moves backward, and the front wheel is the same as the rear wheel in the forward rotation direction that is the direction in which the vehicle moves forward. And front and rear wheel control means (S11 to S19) for driving with a large driving force.

  The present invention relates to a vehicle control device that assists a vehicle to escape from a stack state, that is, to escape from a stack state in which the vehicle cannot travel due to a failure in a road surface on which the vehicle travels, and includes a drive device and a stack escape operation. And a front and rear wheel control means. The drive device drives the front wheels and the rear wheels so that they can be switched between forward and reverse rotation independently of each other. For example, the drive device can not only rotate the front wheel and the rear wheel in the same direction, but also can rotate the front wheel in the forward direction and simultaneously rotate the rear wheel in the reverse direction.

  The stack escape operation device is an operation device that is operated by a driver when attempting to receive assistance for causing the vehicle to escape from the stack state. The front and rear wheel control means drives the rear wheel in the reverse rotation direction, which is the direction in which the vehicle moves backward, and moves the front wheel in the forward rotation direction, which is the direction in which the vehicle moves forward, when the stack escape operation device is operated. Drive with the same driving force as

  For example, when the front and rear wheels are fitted in an off-road mud and the vehicle is in a stacked state, the driver operates the stack escape operation device. As a result, the front wheels are idled by mud, and the idling of dirt or soil (referred to as mud) on the ground contact surface of the front wheels is scraped off and thrown behind the front wheels. At the same time, the rear wheel idles in mud, and this idle rotation scrapes the mud on the ground contact surface of the rear wheel and throws it forward of the rear wheel. Therefore, a wheel scaffold in which mud is collected is formed between the front wheels and the rear wheels (the road surface at the center position in the longitudinal direction of the vehicle).

  Therefore, after the wheel scaffolding is formed, the vehicle can easily escape from the stack state by placing the wheel (front wheel or rear wheel) on the wheel scaffold. Also, when driving the front and rear wheels, the driving force that drives the front wheels in the forward rotation direction and the driving force that drives the rear wheels in the reverse rotation direction are the same magnitude, so the vehicle is not expected by the driver It is possible to prevent a sudden jump in the direction.

  In the above description, in order to help the understanding of the invention, the reference numerals used in the embodiments are attached to the configuration of the invention corresponding to the embodiments in parentheses, but each constituent element of the invention is represented by the reference numerals. It is not limited to the embodiments specified.

It is a schematic block diagram of the control apparatus of the vehicle which concerns on this embodiment. It is a flowchart showing a stack escape support control routine. It is explanatory drawing explaining the condition which scrapes mud with the front wheel and the rear wheel and forms the scaffold for wheels. It is explanatory drawing explaining the condition which escapes from a stack state using a wheel scaffold. It is a schematic block diagram of the control apparatus of the vehicle as a modification which applied the in-wheel motor to the right-and-left rear wheel.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic system configuration diagram of a vehicle 1 including a vehicle control device of the present embodiment.

  The vehicle 1 is a four-wheel drive hybrid vehicle, and includes a hybrid having an engine 11 and a front motor 12 that drive the left front wheel WFL and the right front wheel WFR, and a rear motor 13 that drives the left rear wheel WRL and the right rear wheel WRR. A system 10 is provided. Hereinafter, the left front wheel WFL and the right front wheel WFR are referred to as a front wheel WF, and the left rear wheel WRL and the right rear wheel WRR are referred to as a rear wheel WR. Further, when there is no need to distinguish between the front wheel WF and the rear wheel WR, they are referred to as wheels W.

  In the hybrid system 10, the output shaft of the engine 11 and the output shaft of the front motor 12 are connected to a planetary gear 14 (including a power split planetary gear and a reduction planetary gear). The rotation of the output shaft of the planetary gear 14 is transmitted to the left and right front wheel axles 16L and 16R via a differential gear 15 (including a reduction gear), whereby the left and right front wheels WFL and WFR are rotationally driven.

  The driving force of the rear motor 13 is transmitted to the left and right rear wheel axles 18L and 18R via a differential gear 17 (including a reduction gear), whereby the left and right rear wheels WRL and WRR are rotationally driven.

  The front motor 12 and the rear motor 13 are connected to the inverter 20. The inverter 20 is connected to the battery 22 via the DC / DC converter 21. The inverter 20 converts DC power supplied from the battery 22 (DC power whose voltage is adjusted by the DC / DC converter 21) into three-phase AC, and the converted AC power is independent of the front motor 12 and the rear motor 13. And supply. Therefore, the inverter 20 includes an inverter circuit connected to the front motor 12 and an inverter circuit connected to the rear motor 13 independently.

  The front motor 12 and the rear motor 13 are configured to be capable of being driven independently of forward rotation in the forward direction of the vehicle and reverse rotation in the backward direction of the vehicle by energization control of the inverter 20. Accordingly, the front motor 12 and the rear motor 13 can be simultaneously driven in the rotation directions opposite to each other, and the magnitude of the driving force can be independently controlled by the front wheel WF and the rear wheel WR. . The inverter 20 also has a function of converting regenerative power generated by the front motor 12 and the rear motor 13 into direct current and charging the battery 22 via the DC / DC converter 21.

  The engine 11, the front motor 12, and the rear motor 13 are driven and controlled by the drive ECU 30. The drive ECU 30 is a control device that includes a microcomputer as a main part and includes an input / output interface, a drive circuit, a communication interface, and the like. The drive ECU 30 inputs a detection signal of an accelerator sensor 31 that detects an accelerator operation amount, calculates a driver request drive force according to the accelerator operation amount, and distributes the driver request drive force to the front wheel side and the rear wheel side. The engine 11, the front motor 12, and the rear motor 13 are controlled so as to transmit the front wheel target driving force and the rear wheel target driving force to the front wheel WF and the rear wheel WR, respectively.

  A stack escape switch 32 is connected to the drive ECU 30. The stack escape switch 32 is used when the vehicle is stuck (when the vehicle slips (drifts due to a road surface failure and the vehicle cannot travel)) and the vehicle is unable to travel. This switch is operated by the driver.

  The vehicle 1 also includes friction brake mechanisms 41FL, 41FR, 41RL, and 41RR (referred to as friction brake mechanisms 41) provided on the left and right front and rear wheels WFL, WFR, WRL, and WRR, a brake actuator 42, and a brake ECU 40. ing. The friction brake mechanism 41 includes brake discs 41dFL, 41dFR, 41dRL, 41dRR (referred to as brake discs 41d) fixed to the wheels W, and brake calipers 41cFL, 41cFR, 41cRL, 41cRR (fixed to the vehicle body). And called a caliper 41c) by operating a wheel cylinder built in the brake caliper 41c by hydraulic pressure of the hydraulic oil supplied from the brake actuator 42 to generate a hydraulic braking force by pressing the brake pad against the brake disc 41d. .

  The brake actuator 42 is a known actuator that independently adjusts the hydraulic pressure supplied to the wheel cylinder built in the brake caliper 41c. The brake actuator 42, for example, provides a control hydraulic pressure that can be controlled independently of the brake pedal depression force in addition to a pedal hydraulic circuit that supplies hydraulic pressure to the wheel cylinder from a master cylinder that pressurizes hydraulic oil by the depression force of the brake pedal. Is equipped with a control hydraulic circuit that is supplied independently. The control hydraulic circuit has a booster pump and an accumulator to generate a high-pressure hydraulic pressure, adjusts the hydraulic pressure output from the power hydraulic pressure generator, and supplies the hydraulic pressure controlled to the target hydraulic pressure for each wheel cylinder. And a hydraulic pressure sensor for detecting the hydraulic pressure of each wheel cylinder (the elements constituting the brake actuator 42 are not shown).

  The brake ECU 40 is an electronic control device including a microcomputer as a main part, and is connected to the brake actuator 42 to control the operation of the brake actuator 42. The brake ECU 40 inputs a detection signal of the brake sensor 43 that detects the brake operation amount, calculates a driver-requested braking force according to the brake operation amount, and distributes the driver-requested braking force to the front wheel side and the rear wheel side. The operation of the brake actuator 42 is controlled so that the front wheel target braking force and the rear wheel target braking force are generated at the front wheel WF and the rear wheel WR, respectively. In the vehicle 1 of the present embodiment, with such a configuration, at least the braking forces of the front wheel WF and the rear wheel WR can be controlled independently of each other. The brake ECU 40 is communicably connected to the drive ECU 30 and can transmit and receive a command relating to the braking force and a command relating to the driving force.

  By the way, when the vehicle 1 is traveling off-road, if the wheel W is fitted in mud, the wheel W may slip (idle) and the vehicle may be stuck. In this case, if the driver depresses the accelerator pedal strongly to generate a large driving force on the wheel W, the rotation of the wheel W causes the mud to be wound up backward, and it may become impossible to escape from the stack state. Further, when the traction control is activated by slipping (idling) of the wheel W, the driving force is limited, and thus the driving force necessary for escape from the stack may not be obtained.

  In such a case, the stack escape support control is performed by turning on the stack escape switch 32. FIG. 2 shows a stack escape support control routine executed by the drive ECU 30.

  When the stack escape support control routine is activated, the drive ECU 30 determines whether or not the stack escape switch 32 is turned on in step S11 and waits until it is turned on. When detecting that the stack escape switch 32 is turned on, the drive ECU 30 determines whether or not the vehicle 1 is stopped (travel stopped) in step S12. For example, it may be determined whether or not the vehicle 1 is stopped based on a detection signal of an acceleration sensor (not shown) that detects longitudinal acceleration or a detection signal of a vehicle speed sensor. When the stack escape switch 32 is on, the wheel W is idled as will be described later, so that the traction control for preventing idling is stopped.

  When the vehicle 1 is not stopped, the drive ECU 30 returns the process to step S11 and repeats the above-described process because the vehicle 1 is not stuck.

  The drive ECU 30 repeats such processing, and when the determinations in steps S11 and S12 are “Yes”, the rotation direction of the rear wheel WR is switched to the reverse rotation direction in step S13. That is, the rotation direction of the rear wheel WR is switched to the direction in which the vehicle 1 moves backward. The rotation direction may be switched by reversing the direction of the current flowing through the rear motor 13 by switching control of the inverter 20.

  Subsequently, in step S14, the drive ECU 30 refers to the accelerator map and calculates a front wheel target drive force Ff * corresponding to the accelerator operation amount. Next, in step S15, the drive ECU 30 determines whether or not the front wheel target drive force Ff * is greater than or equal to the rear wheel drive force limit Fr_lim (upper limit of drive force permitted to be generated by the rear motor 13). To do.

  When the front wheel target driving force Ff * is greater than or equal to the rear wheel driving force limit Fr_lim (S15: Yes), the drive ECU 30 sets the rear wheel target driving force Fr * to the same value as the rear wheel driving force limit Fr_lim in step S16. (Fr * ← Fr_lim) and the front wheel target driving force Ff * is set to the rear wheel target driving force Fr * (Ff * ← Fr *). Thereby, the front wheel target driving force Ff * and the rear wheel target driving force Fr * are set to the maximum values that can be set to the same magnitude. Accordingly, the front wheel WF is driven to rotate forward with the front wheel target driving force Ff *, and the rear wheel WR is driven to rotate reversely with the rear wheel target driving force Fr * (= front wheel target driving force Ff *). In this stack escape support control routine, the front wheel WF and the rear wheel WR are rotated in opposite directions with the same driving force, but the driving force that can be generated by the front wheel WF is more than the driving force that can be generated by the rear wheel WR. Therefore, the front wheel target driving force Ff * is limited to the rear wheel driving force limit Fr_lim.

  If the front wheel target driving force Ff * is less than the rear wheel driving force limit Fr_lim (S15: No), the drive ECU 30 sets the rear wheel target driving force Fr * to the front wheel target driving force Ff * in step S17. Set to the same value (Fr * ← Ff *). Accordingly, the front wheel WF is driven to rotate forward with the front wheel target driving force Ff *, and the rear wheel WR is driven to rotate reversely with the rear wheel target driving force Fr * (= front wheel target driving force Ff *).

  Subsequently, in step S18, the drive ECU 30 determines whether or not the stack escape switch 32 is turned off. If the stack escape switch 32 is not turned off, the drive ECU 30 returns the process to step S14 and repeats the above-described process. Therefore, while the stack escape switch 32 is on, the front wheel WF is driven in the forward rotation direction, and the rear wheel WR is driven in the reverse rotation direction with the same driving force as the front wheel WF. When the stack escape switch 32 is turned off (S18: Yes), the drive ECU 30 returns the rotation direction of the rear wheel WR to the normal rotation direction in step S19, and once ends this routine. The drive ECU 30 starts this routine again after a predetermined interval has elapsed.

  According to this stack escape support control routine, when the driver turns on the stack escape switch 32 and depresses the accelerator pedal, the front wheel WF is normally rotated with the driving force determined by the accelerator operation amount, and at the same time the rear wheel WR. Is driven in reverse. At this time, the target driving forces Ff * and Fr * are set within the range of the driving limit of the rear wheel WR so that the driving force is the same between the front wheel WF and the rear wheel WR.

  As a result, as shown in FIG. 3, the front wheel WF is rotated (idling) to scrape the mud or soil (referred to as mud) on the ground contact surface of the front wheel WF and fly backward, and the rear wheel WR is rotated to the rear (idling). The mud on the ground contact surface of the wheel WR can be scraped off and thrown forward. Thus, a wheel scaffold A in which mud is collected is formed between the front wheel WF and the rear wheel WR (the road surface at the center position in the longitudinal direction of the vehicle 1). When the mud is scraped, the front wheel WF and the rear wheel WR are driven with the same magnitude of driving force, so that the vehicle 1 is prevented from suddenly jumping in the direction unexpected by the driver. Further, since the mud is scraped by both the front wheel WF and the rear wheel WR, the wheel scaffold A can be formed by collecting a large amount of mud at the center of the vehicle.

  The driver releases the accelerator pedal and turns off the stack escape switch 32 when the wheel scaffold A is formed to some extent. Then, the driver operates the accelerator pedal to swing the vehicle body back and forth. Thereby, as shown in FIG. 4, the rear wheel WR can be placed on the wheel scaffold A, and the vehicle 1 can be escaped from the stacked state.

  As a result, according to the present embodiment, the stack escape capability can be improved.

  The vehicle control device according to the present embodiment has been described above. However, the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the object of the present invention.

  For example, in the present embodiment, the rear wheel WR is applied to the vehicle 1 driven by a single rear motor 13, but as shown in FIG. 5, the in-wheel motor incorporated in the rear wheels WRL and WRR. The present invention can also be applied to a vehicle 1 ′ of a type in which the left rear wheel WRL and the right rear wheel WRR are driven independently by 13L and 13R.

    DESCRIPTION OF SYMBOLS 1 ... Vehicle, 10 ... Hybrid system, 11 ... Engine, 12 ... Front motor, 13 ... Rear motor, 13L, 13R ... In-wheel motor, 20 ... Inverter, 21 ... Converter, 22 ... Battery, 30 ... Drive ECU, 31 ... Accelerator Sensor, 32 ... Stack escape switch, 40 ... Brake ECU, 41FL, 41FR, 41RL, 41RR ... Friction brake mechanism, 42 ... Brake actuator, 43 ... Brake sensor, A ... Scaffold for wheel, WF ... Front wheel, WR ... Rear wheel, WFL, WFR, WRL, WRR ... Left and right front and rear wheels.

Claims (1)

In a vehicle control device for assisting the vehicle to escape from the stack state,
A drive device for driving the front wheel and the rear wheel so that they can be switched between forward and reverse rotation independently of each other;
A stack escape controller that is operated by a driver when trying to receive assistance to let the vehicle escape from the stack; and
When the stack escape operation device is operated, the rear wheel is driven in the reverse rotation direction that is the direction in which the vehicle moves backward, and the front wheel is the same as the rear wheel in the forward rotation direction that is the direction in which the vehicle moves forward. A vehicle control device comprising: front and rear wheel control means for driving with a driving force having a magnitude.

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