JP2768738B2 - Skid control system - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a skid control system that is mounted on a vehicle such as an automobile and maintains the steering stability of the vehicle.

<Conventional technology> Vehicles such as automobiles are used when the coefficient of friction of the road surface is extremely small, such as on a snowy road, or when the left wheel is grounded.
When there is a difference in the coefficient of friction between the right wheel and the road surface where the right wheel is in contact with the ground, a slight "trigger" can easily cause skid (side skid). If the stability is lost, it is difficult to regain the stability, which may lead to a major accident.

Conventionally, there has been an anti-skid brake system as a system for preventing the skid. this is,
When the brake is operated, the vehicle speed and the wheel speed are compared, and if the difference between the two exceeds a certain value, the skid is prevented by automatically releasing the braking force to avoid locking. is there.

<Problems to be Solved by the Invention> The above-mentioned "trigger" that causes the vehicle to skid is not limited to deceleration of the vehicle during brake operation. For example, even if the driver does not step on the brake, skid occurs due to deceleration by the engine brake. In addition, even if the vehicle is not decelerated, skid is also generated by acceleration caused by the driver's accelerator operation. If such acceleration or deceleration is performed during turning, skid is more likely to occur. In addition, even when driving at constant speed,
A skid is generated due to a change in the steering direction due to a driver's steering operation. Further, the vertical movement of the vehicle due to the unevenness of the road surface also changes the contact force between the wheels and the road surface, and causes skid.

As described above, any operation of the driver that attempts to change the behavior of the vehicle and the external force applied to the vehicle act as the above-mentioned "trigger", and a skid occurs.

The above-described anti-skid brake system deals with only one of the various situations where the vehicle skids, such as when the brake is operated.

On the other hand, a skilled driver in a snowfall area intentionally generates a skid in a vehicle when turning a corner, and often turns while adjusting the skid so that the nose of the vehicle is directed in a turning direction. It is known that the turning guidance by the skid as described above is more effective in running on snowy roads than in steering by steering wheel operation.

However, such a driving method requires an excellent driving technique and involves a risk of impairing steering stability.

An object of the present invention is to provide a skid control system capable of making a turning run using a skid without requiring advanced driving techniques.

<Means for Solving the Problems> To achieve the above object, a skid control system according to the present invention includes a steering angle sensor that detects a steering direction, a traveling direction sensor that detects a traveling direction of a vehicle, and a driver. A brake sensor for detecting a brake operation, and calculating a deviation angle between the steering direction and the traveling direction based on signals received from the steering angle sensor and the traveling direction sensor, wherein the deviation angle is equal to or more than a predetermined amount and When a brake operation detection signal is received from a brake sensor, the vehicle is provided with toe angle adjusting means for adjusting the toe angle so as to promote skid so that the vehicle is directed in the steering direction.

<Operation> According to the skid control system having the above configuration, the toe angle adjusting means adjusts the toe angle when the deviation angle is equal to or more than a predetermined amount and a brake operation detection signal is received from a brake sensor. Then, by making the braking force on the road surface of the left wheel and the braking force of the right wheel on the road surface of the front wheels and / or the rear wheels different, the skid can be caused to face the steering direction.

<Example> Hereinafter, an example will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic view showing one embodiment of a skid control system according to the present invention. In the figure, the skid control system includes a steering angle sensor (1) for detecting a steering angle of a steering wheel, and a traveling of a vehicle. Direction (B)
Direction sensor (2) for detecting the steering angle, and toe angle adjusting means for adjusting the toe-in angle (T) of the rear wheel (3) based on signals received from the steering angle sensor (1) and the traveling direction sensor (2). (4). (5) is a front wheel.

The steering angle sensor (1) comprises, for example, a rotary potentiometer mounted on a predetermined portion of a rotation transmitting portion of a steering mechanism.

The traveling direction sensor (2) includes an acceleration sensor and a gyroscope. As the above gyroscope,
A rotary type or a non-rotary type laser gyro used in an aircraft or the like can be used.

The toe angle adjusting means (4) is attached to a frame (not shown) so as to be rotatable around a shaft (61), and is attached to an arm (6) supporting the rear wheel (3) and also to the frame. A hydraulic cylinder (7) in which a rod (71) is connected to the arm (6), and pressure oil supplied to the hydraulic cylinder (7) through a pipe (9).
It comprises a hydraulic pressure generator (8) for expanding and contracting 1), and a control circuit (10) connected to the hydraulic pressure generator (8).

The hydraulic cylinder (7) can increase the toe-in angle (T) by advancing the rod (71), and decrease the toe-in angle (T) by retreating the rod (71). Is available.

The control circuit (10) is composed of a general microcomputer, and receives an input signal from the steering angle sensor (1) and the traveling direction sensor (2) and converts the signal into a digital signal that can be handled by the microcomputer. 11)
And a deviation angle α between the steering direction (A) and the traveling direction (B) is calculated based on the digital signal, and if the deviation angle α is equal to or larger than a preset value, the deviation angle α is calculated based on the deviation angle α. A calculating unit (12) for calculating an appropriate toe-in angle (T), and an output unit (13) for outputting a control signal corresponding to the toe-in angle (T) calculated by the calculating unit (12) to the hydraulic pressure generator (8) ).

Generally, the cornering force (side force) received by the vehicle has a relationship as shown in FIG. 5 with respect to the above-mentioned deviation angle α. That is, until the deviation angle α reaches a predetermined value, the cornering force and the deviation angle α are substantially proportional. Therefore, until the deviation angle α becomes a predetermined angle, the toe-in angle (T) increases with the deviation angle α.
The calculation by the calculation unit (12) is performed so that is larger.

Hereinafter, the operation of this system will be described. FIG. 3 shows a state in which a vehicle that has been traveling straight on a slippery road surface having a small coefficient of friction has begun to skid due to some trigger, and the nose (16) of the vehicle has turned to the right. At this time, a force (F) for rotating the vehicle clockwise around the center of gravity (15) of the vehicle is generated.

In the non-spin state, the steering direction (A) ahead of the vehicle and the traveling direction (B) of the vehicle match as shown in FIG. 4, but when spin occurs, the traveling direction of the vehicle ( B) deviates from the steering direction (A), resulting in a deviation angle α.

The control circuit (10) calculates the deviation angle α by an operation unit (12), and when the deviation angle α is equal to or larger than a predetermined value, an appropriate toe-in angle in accordance with the deviation angle α. (T) is calculated. Then, a control signal corresponding to the toe-in angle (T) is output from the output unit (13) to the hydraulic pressure generating device (8), and the hydraulic oil is supplied to the hydraulic cylinder (7) to contract the rod (71). Thus, the toe-in angle (T) of the rear wheel (3) can be appropriately increased.

In the state where the toe-in angle (T) is not increased, as shown in FIG. 3, the angle β formed by the left rear wheel (31) with the traveling direction (B) and the right rear wheel (32) with the traveling direction (B). Since the angle γ is equal, the braking force (C) of the left rear wheel (31) and the braking force (D) of the right rear wheel (32) are equal. On the other hand, when the toe-in angle (T) is increased as described above, the fourth
As shown in the figure, since the angle β is greater than the angle γ, the braking force (C) of the left rear wheel (31) is reduced by the right rear wheel (3
It becomes larger than the braking force (D) of 2). Accordingly, a force (G) for rotating the vehicle counterclockwise about the center of gravity (15) acts, and the skid of the vehicle is suppressed against the force (F) and the vehicle is prevented from being skid. The nose (16) can be rotated counterclockwise to restore the vehicle to a straight-ahead state. Thereafter, the toe-in angle (T) is reduced by the toe-angle adjusting means (4), and the state returns to the state before the system operation.

It should be noted that the case where the vehicle that is turning clockwise and starts skidding by shaking the tail at the corner can be considered in the same manner as the state shown in FIGS. 3 and 4 described above. Therefore, also in this case, the nose (16) can be turned in the original turning direction by suppressing the skid and rotating the nose (16) of the vehicle counterclockwise about the center of gravity.

As described above, according to this embodiment, when the vehicle starts skidding, the toe-in angle (T) is increased to generate a force in a direction against the skid, thereby suppressing the skid and improving the vehicle speed. The direction can be returned to the state before the skid.

In addition, the conventional anti-skid brake system can prevent skid only when the brake is operated, but suppresses skid in all situations where skid occurs during acceleration, deceleration, cruising at constant speed and sudden turning. And the steering stability of the vehicle can be significantly improved.

FIG. 6 shows a toe angle adjusting means (not shown) provided with a brake sensor (20) for detecting a driver's braking operation.
However, when the brake operation detection signal is received from the brake sensor (20) and the deviation angle α is equal to or more than a predetermined amount, the toe angle is adjusted to promote the skid so that the vehicle is directed in the steering direction. The example shown in FIG. As shown in FIG. 6, when the toe-out angle (T) of the rear wheel is increased, the angle γ formed by the right rear wheel (32) with the traveling direction (B) is increased.
However, the braking force (D) of the right rear wheel (32) is larger than the braking force (C) of the left rear wheel (31) since the angle β formed by the left rear wheel (31) and the traveling direction (B) is larger. Also increases. Therefore,
The force (H) for rotating the vehicle clockwise about the center of gravity (15) acts, and the skid of the vehicle can be promoted. In this manner, when the driver performs a brake operation at the start of turning of the vehicle, skid is actively generated, and the vehicle can be turned without requiring advanced driving skills. In this case, a steering adjusting means for steering to further promote the skid may be provided.

In each of the above embodiments, only the toe angle of the rear wheel (3) is adjusted. However, only the toe angle of the front wheel (5) may be adjusted, and both the front wheel (5) and the rear wheel (3) may be adjusted. May be adjusted.

Further, the skid control system according to the present invention can also be applied to an aircraft traveling on a runway or an introduction path to the runway.

<Effect of the Invention> As described above, according to the skid control system according to the present invention, when the toe angle adjusting unit receives a brake operation detection signal from a brake sensor and the deviation angle is equal to or more than a predetermined amount, By adjusting the toe angle so that the braking force of the front wheel and / or the rear wheel on the road surface of the left wheel and the braking force of the right wheel on the road surface are different, the vehicle is positively directed to the steering direction of the vehicle. The skid can be guided by turning the vehicle, and the vehicle can be turned on a slippery road surface without requiring advanced driving skills.

[Brief description of the drawings]

FIG. 1 is a schematic diagram showing one embodiment of the skid control system of the present invention, FIG. 2 is a block diagram, FIG. 3 is a schematic diagram showing a state in which the vehicle starts skidding, and FIG. It is the schematic which shows the state which adjusted. FIG. 5 is a diagram showing a relationship between a side force and a deviation angle, and FIG. 6 is a schematic diagram showing a state in which the vehicle is accelerated by skid. (1) ... steering angle sensor, (2) ... traveling direction sensor, (3) ... rear wheel, (4) ... toe angle adjusting means, (5)
... front wheel, (20) ... brake sensor, (A) ... steering direction, (B) ... traveling direction, (T) ... toe-in angle, toe-out angle, α ... deviation angle.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁶ , DB name) B62D 6/00 B62D 7/14 B60G 7/00

Claims (1)

(57) [Claims] 1. A steering angle sensor for detecting a steering direction, a traveling direction sensor for detecting a traveling direction of a vehicle, a brake sensor for detecting a brake operation by a driver, and a signal received from the steering angle sensor and the traveling direction sensor. The deviation angle between the steering direction and the traveling direction is calculated based on the obtained signal,
When the deviation angle is equal to or greater than a predetermined amount and a brake operation detection signal is received, the toe-out angle of at least one of the front wheel and the rear wheel is increased to promote skid and to turn the vehicle in the steering direction. A skid control system.