JP4650065B2 - Braking / driving force control device for vehicle - Google Patents

Description

  The present invention generally relates to a device that is mounted on a vehicle capable of at least two-wheel independent steering and driving, and controls the braking / driving force of the vehicle, and more particularly, a vehicle with improved vehicle operability during rotation including in-situ rotation. The present invention relates to a braking / driving force control device.

Conventionally, in a four-wheeled vehicle, the braking / driving force of at least two wheels is independently controlled by directing the directions of the four wheels in the tangential direction of a circle circumscribing a rectangle formed by connecting four points where each wheel contacts the ground. Thus, a vehicle that realizes “in-situ rotation” with a turning radius of zero as if it is mounted on a turntable is known (see, for example, Patent Document 1).
JP 2003-104222 A

  In the conventional vehicle disclosed in Patent Document 1, the steering operation (direction change direction determining operation) is performed by steering and the driving force control is performed by an accelerator pedal during “spot rotation” as in normal driving. (See, for example, the description of paragraphs [0014] and [0023] of Patent Document 1 above).

  However, the steering control by the steering and the driving force control by the accelerator pedal are operation systems that are suitable for moving the vehicle in the front-rear direction. It is not necessarily suitable as an operating system to be controlled.

  More specifically, according to the steering control by the steering and the driving force control by the accelerator pedal, the turning control of “in-situ rotation”, that is, in which direction at what speed and in which direction, the turning is stopped. It can be said that it is difficult for the operator (driver) to grasp sensuously about whether or not to make it happen.

  Thus, the conventional vehicle capable of “spot rotation” has a problem that the operability during “spot rotation” is not necessarily good for the vehicle driver.

  The present invention has been made to solve such problems, and a main object of the present invention is to provide a vehicle braking / driving force control device with improved vehicle operability during rotation including on-site rotation.

One aspect of the present invention for achieving the above object is a vehicular braking / driving force control device that is mounted on a vehicle capable of at least two-wheel independent steering and driving, and controls the braking / driving force of the vehicle. The direction of the wheel of the wheel is controlled in the shape of a letter C opened at the rear of the vehicle and / or the direction of the wheel of the rear two wheels is controlled in the shape of a letter C opened at the front of the vehicle. when, while stopping the driving force control corresponding to the amount of accelerator pedal operation, control of the driving force corresponding to the steering angle, or, while the braking force control according to the brake pedal operation amount is stopped, steering angle the braking force control, one of the conducts in response to, when the steering angle is within the predetermined angular range including the ± 0 ° generates a predetermined braking force, the steering angle is the predetermined angle range In the clockwise direction When the steering angle is within the angular range, a larger clockwise driving force is generated as the steering steering angle increases. When the steering steering angle is within the angular range beyond the predetermined angular range, the steering steering angle increases. A vehicular braking / driving force control device that generates a counterclockwise driving force as much as possible.
Alternatively, one aspect of the present invention for achieving the above object is a vehicle braking / driving force control device that is mounted on a vehicle capable of at least two-wheel independent steering and driving, and controls the braking / driving force of the vehicle, The direction of the wheels of the front two wheels is controlled in the shape of a letter C opened rearward of the vehicle, or the direction of the wheels of the rear two wheels is controlled in the shape of a letter C opened forward of the vehicle, when, while stopping the driving force control corresponding to the amount of accelerator pedal operation, control of the driving force corresponding to the steering angle, or, while the braking force control according to the brake pedal operation amount is stopped, steering angle the braking force control, one of the conducts in response to, when the steering angle is within the predetermined angular range including the ± 0 ° generates a predetermined braking force, the steering angle is the predetermined angle range Turn clockwise When the steering angle is in the counterclockwise direction, a larger clockwise driving force is generated as the steering angle increases. When the steering angle is in the counterclockwise angle range, the steering steering angle is increased. This is a vehicular braking / driving force control device that generates a greater counterclockwise driving force as the value of becomes larger.

  In this embodiment, “spot rotation” means that the front two wheels are in the shape of a letter C that is opened to the rear of the vehicle, the rear two wheels are in the shape of an inverted letter C that is opened in the front of the vehicle, and the right two wheels are Rotation in the same direction, and rotation of the left two wheels in the same direction opposite to the right two wheels, and rotation with zero turning radius around the center of the vehicle body.

  Moreover, in this one aspect, “front wheel axle rotation” means that the rear two wheels are formed in a reverse C shape with the front of the vehicle opened, and the rear two wheels and / or the front two wheels are rotated in opposite directions, respectively. This refers to rotation with a small turning radius around the center of the front wheel shaft that is realized.

  Further, in this aspect, “rear wheel shaft rotation” is a letter C shape in which the front two wheels are opened rearward of the vehicle, the rotation of the rear two wheels is stopped, and the two front wheels are rotated in opposite directions. This refers to rotation with a small turning radius around the center of the rear wheel shaft that is realized.

  According to this aspect, during “in-situ rotation”, “front wheel shaft rotation”, and “rear wheel shaft rotation”, steering and driving can be performed only by a steering operation, so that operability is improved.

In this aspect, in order to enable the braking force control by steering operation, the direction of the front two wheels is controlled in the shape of a letter C opened to the rear of the vehicle, and / or When the direction of the rear two wheels is controlled in the shape of a square that opens in front of the vehicle , the braking force control according to the brake pedal operation amount is stopped and the braking force is controlled according to the steering angle. It is preferable to do.

  More specifically, the braking / driving force control by the steering operation is performed when, for example, the direction of the wheel is controlled to the direction for performing in-situ rotation, front wheel shaft rotation, or rear wheel shaft rotation. When the steering angle is within a predetermined angular range (stop region) including ± 0 °, a predetermined braking force is generated, and the steering steering angle exceeds the predetermined angular range in the clockwise direction (clockwise region). ), The larger the steering steering angle, the larger the clockwise driving force is generated. When the steering steering angle is in the angle range (counterclockwise region) beyond the predetermined angle range, the steering steering angle is increased. This is realized by generating a large counterclockwise driving force.

  ADVANTAGE OF THE INVENTION According to this invention, the vehicle braking / driving force control apparatus which the vehicle operability at the time of rotation including on-site rotation improved can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described with reference to the accompanying drawings. The structure / mechanism itself for realizing at least two-wheel independent steering / independent drive is already known to those skilled in the art, and a detailed description thereof will be omitted.

  Hereinafter, a vehicle braking / driving force control device according to an embodiment of the present invention will be described with reference to FIGS. As an example, the vehicle braking / driving force control device according to the present embodiment allows the host vehicle to perform in-situ rotation.

  FIG. 1 is a schematic configuration diagram of a vehicle braking / driving force control apparatus 100 according to the present embodiment.

  The vehicle braking / driving force control device 100 includes an accelerator pedal operation amount detection unit 101 that detects an operation amount of an accelerator pedal by a vehicle driver. In this embodiment, the accelerator pedal operation amount detection unit 101 is, for example, a pedal stroke sensor that measures the stroke angle of the accelerator pedal.

  The vehicle braking / driving force control device 100 further includes a brake pedal operation amount detection unit 102 that detects an operation amount of a brake pedal by a vehicle driver. In the present embodiment, the brake pedal operation amount detection unit 102 is, for example, a pedal stroke sensor that measures the stroke angle of the brake pedal.

  The vehicle braking / driving force control device 100 further includes a steering rudder angle detection unit 103 that detects the steering angle of the steering by the vehicle driver. In the present embodiment, the steering angle detector 103 is, for example, a steering angle sensor provided in the steering column.

  The vehicle braking / driving force control device 100 further includes a mode changeover switch unit 104 that is operated by a vehicle driver and switches a running mode of the vehicle. The operation switch of the mode changeover switch unit 104 is provided at a position where the vehicle driver can easily operate, for example, an instrument panel or a steering wheel. The function of the driving mode switching by the mode switching switch unit 104 will be described in detail later.

  Further, the vehicle braking / driving force control device 100 independently controls the driving force generated on each driving wheel of the vehicle (in other words, the power generated by the power source such as the engine is applied to each driving wheel. It has a driving force control unit 105 that can be independently distributed. In the present embodiment, the driving force control unit 105 controls the engine output by adjusting the opening of a throttle valve of the engine, for example.

  The vehicle braking / driving force control apparatus 100 further includes a braking force control unit 106 that controls the braking force generated on each braking wheel of the vehicle. In the present embodiment, the braking force control unit 106 controls the braking force by adjusting the hydraulic pressure of the brake master cylinder, for example.

  The vehicle braking / driving force control device 100 further includes a tire angle control unit 107 that can independently control the angle of each wheel with respect to the vehicle longitudinal axis.

  The vehicle braking / driving force control device 100 further includes a main control unit 108 that controls these components in an integrated manner. In the present embodiment, the main control unit 108 is, for example, an ECU (Electronic Control Unit).

  Next, the function of the vehicle braking / driving force control apparatus 100 of this embodiment having such a configuration will be described with reference to FIGS.

  In the present embodiment, the vehicle braking / driving force control device 100 has, for example, two modes, a normal traveling mode and an in-situ rotation mode. Of these modes, the normal travel mode is the default, and the in-situ rotation mode is set only while the mode changeover switch unit 104 is on.

  In the normal travel mode, as shown on the left side of FIG. 2, in the straight traveling state, the tire angle control unit 107 sets each wheel to a tire angle parallel to the vehicle longitudinal direction, and the front wheels are steered according to the steering operation.

  In the normal travel mode, the main control unit 108 causes the driving force control unit 105 to generate a driving force according to the accelerator pedal operation amount detected by the accelerator pedal operation amount detection unit 101 and rotate the front two wheels to rotate. One of driving, rear wheel driving for rotating the rear two wheels, or four wheel driving for rotating the four wheels is realized.

  In the normal travel mode, the main control unit 108 causes the braking force control unit 106 to generate a braking force according to the brake pedal operation amount detected by the brake pedal operation amount detection unit 102.

  In the normal travel mode, the main control unit 108 controls the tire angle of the steered wheels so that the tire angle control unit 107 realizes the steering angle corresponding to the steering angle detected by the steering angle detection unit 103. Let

  As described above, in the normal travel mode, the vehicle driver controls the steering angle of the steered wheel by the steering operation, controls the driving force of the drive wheel by the accelerator pedal operation, and controls the braking wheel by the brake pedal operation. Control the braking force. When the vehicle is driven, all the wheels are driven to rotate in the same direction.

  On the other hand, when the mode changeover switch unit 104 is operated by the vehicle driver and the mode switch (SW) is turned on (ON), the main control unit 108 transitions to the spot rotation mode. The main control unit 108 maintains the in-situ rotation mode until the mode changeover switch unit 104 is operated again and the mode SW is turned off (OFF).

  When the in-situ rotation mode is entered, the main control unit 108 instructs the tire angle control unit 107 to form a square shape with the front two wheels opened rearward of the vehicle as shown on the right side of FIG. Is formed in the shape of an inverted letter C opened in front of the vehicle, and a tire angle is realized in which the direction of each wheel overlaps the tangent of the same circle centering on the turning center O of the vehicle.

  In the in-situ rotation mode, the main control unit 108 temporarily disconnects the functional relationship between the accelerator pedal operation amount detection unit 101 and the driving force control unit 105 and generates driving force according to the accelerator pedal operation amount. Stop.

  In the in-situ rotation mode, the main control unit 108 temporarily disconnects the functional relationship between the brake pedal operation amount detection unit 102 and the braking force control unit 106, and the braking force according to the brake pedal operation amount. Stop generating.

  Instead, the main control unit 108 changes the driving force control unit 105 and the braking force control unit 106 according to the steering rudder angle detected by the steering rudder angle detection unit 103 with the relationship shown in FIG. Control.

  FIG. 3 is a graph showing the magnitude of the braking / driving force generated according to the steering angle, where the vertical axis represents the braking / driving force and the horizontal axis represents the steering angle. Here, as an example, the vertical axis represents the driving force as positive and the braking force as negative. That is, in the region where the vertical axis above the horizontal axis is positive, the driving force increases as it goes up, and in the region where the vertical axis below the horizontal axis is negative, the braking force increases as it goes down.

  Similarly, as an example, for the horizontal axis, rightward steering is represented as positive and leftward steering is represented as negative. That is, in the region where the horizontal axis to the right of the vertical axis is positive, the steering angle to the right increases as it goes to the right, and in the region where the horizontal axis to the left of the vertical axis is negative, it steers to the left as it goes to the left. The angle is large.

  As shown in the figure, in the example shown in FIG. 3, the main control unit 108 applies the maximum braking force to the braking force control unit 106 when the steering angle detected by the steering angle detection unit 103 is ± 0 °. Is generated. Then, the main control unit 108 gradually weakens the braking force generated by the braking force control unit 106 as the steering is steered, and when the steering rudder angle reaches a predetermined left and right angle (± θ °), the main control unit 108 The power is set to zero, and then the driving force control unit 105 starts to generate the driving force. Here, an angle range of the steering angle −θ ° to + θ ° in which only the braking force is generated and no driving force is generated is referred to as a stop region.

  In the area on the right side of this stop area, that is, in the area where the steering angle is larger in the clockwise direction than + θ ° (referred to as the clockwise area), the main control unit 108 causes the driving force control unit 105 to turn the vehicle clockwise. A driving force that rotates in a field is generated. That is, the front two wheels are rotated in opposite directions, the rear two wheels are rotated in opposite directions, the right two wheels are rotated in the reverse direction during normal driving, and the left two wheels are rotated in the forward direction during normal driving. By doing so, the in-situ clockwise rotation is realized.

  As shown in FIG. 3, the main control unit 108 increases the driving force control unit 105 so that the driving force (≈rotational speed) for realizing the clockwise rotation in the spot increases as the clockwise steering angle increases. To control.

  The same applies to the counterclockwise direction. In an area on the left side of the stop area, that is, in an area where the steering angle is greater counterclockwise than -θ ° (referred to as a counterclockwise area), the main control unit 108 causes the driving force control unit 105 to turn the vehicle counterclockwise. A driving force that rotates in a field is generated. That is, the front two wheels are rotated in opposite directions, the rear two wheels are rotated in opposite directions, the right two wheels are rotated in the forward direction during normal driving, and the left two wheels are rotated in the reverse direction during normal driving. To achieve counterclockwise in-situ rotation.

  Further, as shown in FIG. 3, the main control unit 108 increases the driving force (≈rotational speed) for realizing the counterclockwise in-situ rotation as the counterclockwise steering rudder angle increases. To control.

  As described above, in the in-situ rotation mode according to the present embodiment, the determination of the rotation direction, the driving force control, and the braking force control are all performed by the steering operation. Therefore, when performing in-situ rotation, the vehicle driver can easily realize in-situ rotation only by steering the steering in the direction in which the steering is desired to be performed without having to operate the accelerator pedal and the brake pedal.

  Further, by realizing the relationship between the steering angle and the braking / driving force as shown in FIG. 3, the stop area of the steering angle −θ ° to + θ ° functions as a so-called “play” portion, so that the steering is slightly It is possible to prevent the occurrence of a situation where the spot rotation is carried out just by moving it.

  Also, since the braking force decrease (stop region) and driving force increase (clockwise / counterclockwise region) are both performed slowly when the steering is turned off, the vehicle driver gradually steers while watching the situation. A desired rotational speed can be easily realized by steering.

  When the mode change switch unit 104 is operated by the vehicle driver and the mode SW is turned off (OFF), the main control unit 108 returns to the normal travel mode again, and instructs the tire angle control unit 107 based on the tire angle. Returning, the functional relationship between the steering angle detection unit 103, the driving force control unit 105, and the braking force control unit 106 is cut off, and the driving force control according to the accelerator pedal operation amount and the control according to the brake pedal operation amount are cut off. Return to power control.

  As described above, according to the present embodiment, the “spot rotation” of the vehicle is realized only by the steering operation, so that the operation becomes easy and the operability at the time of the spot rotation is improved.

  In addition, according to the present embodiment, by using the steering operation that is a turning operation, turning the steering wheel to the right realizes “in-situ rotation” in the clockwise direction. “Rotation of the field” is realized, and the rotation speed can be increased as the steering wheel is rotated greatly. Therefore, the operation is intuitively understandable for the driver, and the operability during the field rotation is improved.

  Furthermore, according to this embodiment, since a predetermined angle range including the steering angle ± 0 ° is set as a region where no driving force is generated even when steering is performed, unexpected in-situ rotation unintended by the driver occurs. Can be prevented, and the safety and operability when rotating on the spot can be improved.

  In the above embodiment, for the sake of convenience, the vehicle braking / driving force control device according to the present invention has only the “spot rotation” mode as a switchable mode other than the default normal driving mode. As will be apparent to those skilled in the art, the present invention is not limited to such a form. In the vehicle braking / driving force control device according to the present invention, instead of or in addition to the “in-situ rotation” mode, a “front wheel shaft rotation” mode and / or a “rear wheel shaft rotation” mode can be realized.

  Examples of the front wheel shaft rotation mode and the rear wheel shaft rotation mode are shown in FIGS. 4 and 5, respectively. In the front wheel shaft rotation mode, as shown in FIG. 4, the rear two wheels are formed in a reverse letter C shape that is opened forward of the vehicle, and the front two wheels and / or the front two wheels are rotated in the opposite directions, respectively. A rotation with a small turning radius is realized with the center O ′ of the wheel shaft as the center of rotation. Also, in the rear wheel shaft rotation mode, the front two wheels are formed in the shape of a letter C opened rearward of the vehicle, the rotation of the rear two wheels is stopped, and the front two wheels are rotated in the opposite directions, respectively. A rotation with a small turning radius is realized with O ″ as the center of rotation.

  As will be apparent to those skilled in the art, the relationship between the steering angle and the braking / driving force as shown in FIG. 3 is easy for front wheel shaft rotation and rear wheel shaft rotation as shown in FIGS. According to the present invention, an improvement in operability similar to that described for the in-situ rotation in the above-described embodiment can be realized even when the front wheel shaft is rotated and the rear wheel shaft is rotated.

  The present invention can be used for an apparatus for controlling braking / driving force in a vehicle capable of at least two-wheel independent steering and driving. The appearance, weight, size, running performance, etc. of the vehicle to be mounted are not limited.

1 is a schematic configuration diagram of a vehicle braking / driving force control device according to an embodiment of the present invention. It is a state transition diagram which shows the mode switching state between two modes of the braking / driving force control apparatus for vehicles which concerns on one Example of this invention. It is a graph which shows the relationship between the steering rudder angle and braking / driving force in the spot rotation mode of the braking / driving force control apparatus for vehicles which concerns on one Example of this invention. It is a figure which shows an example of direction of the tire in the front-wheel-shaft rotation mode implement | achieved by the braking / driving force control apparatus for vehicles which concerns on another one Example of this invention. It is a figure which shows an example of direction of the tire in the rear-wheel axle rotation mode implement | achieved by the braking / driving force control apparatus for vehicles which concerns on another one Example of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 Vehicle braking / driving force control apparatus 101 Accelerator pedal operation amount detection part 102 Brake pedal operation amount detection part 103 Steering angle detection part 104 Mode switch part 105 Driving force control part 106 Braking force control part 107 Steering control part 108 Main control Part

Claims (2)

A vehicle braking / driving force control device mounted on a vehicle capable of at least two-wheel independent steering and driving and controlling braking / driving force of the vehicle,
The direction of the wheels of the front two wheels is controlled in the shape of a letter C opened at the rear of the vehicle and / or the direction of the wheels of the rear two wheels is controlled in the shape of a letter C opened at the front of the vehicle. When, when
While stopping the driving force control according to the accelerator pedal operation amount,
Control of the driving force corresponding to the steering angle, or,
While stopping the braking force control according to the amount of brake pedal operation,
Control of the braking force according to the steering angle, and performs one of the,
When the steering angle is within a predetermined angle range including ± 0 °, a predetermined braking force is generated,
When the steering angle is in an angle range exceeding the predetermined angle range in the clockwise direction, a larger clockwise driving force is generated as the steering angle is increased,
A vehicular braking / driving force control device that generates a counterclockwise driving force as the steering steering angle increases when a steering steering angle is in an angle range exceeding the predetermined angle range in a counterclockwise direction. A vehicle braking / driving force control device mounted on a vehicle capable of at least two-wheel independent steering and driving and controlling braking / driving force of the vehicle,
The direction of the wheels of the front two wheels is controlled in the shape of a letter C opened rearward of the vehicle, or the direction of the wheels of the rear two wheels is controlled in the shape of a letter C opened forward of the vehicle, When
While stopping the driving force control according to the accelerator pedal operation amount,
Control of the driving force corresponding to the steering angle, or,
While stopping the braking force control according to the amount of brake pedal operation,
Control of the braking force according to the steering angle, and performs one of the,
When the steering angle is within a predetermined angle range including ± 0 °, a predetermined braking force is generated,
When the steering angle is in an angle range exceeding the predetermined angle range in the clockwise direction, a larger clockwise driving force is generated as the steering angle is increased,
A vehicular braking / driving force control device that generates a counterclockwise driving force as the steering steering angle increases when a steering steering angle is in an angle range exceeding the predetermined angle range in a counterclockwise direction.

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