JPS6277270A - Antiskid control device for vehicle - Google Patents

Abstract

PURPOSE:To assure a vehicle to be stopped in a minimum stopping distance by braking within the range in which the frictional coefficient between the ground and wheels is around at its maximum. CONSTITUTION:Slip ratio S of wheels can be calculated from an equation S=(V1-V2)/V1 according to the outputs from a wheel speed detector 6 and a ground speed detector 10. In the range in which the slip ratio S exceeds 1, the wheels are quickly locked. Thus, in order to brake in the range in which the slip ratio S is less than 1, the oil 1 pressure supplied to wheel cylinders 2 is gradually changed in increment of a predetermined constant value. It is determined according to outputs from drag sensors 8a-8d whether or not the drag is increased, and if it is increased, the oil pressure is increased by the constant value. If there is no increase in drag, the oil pressure is decreased by the constant value. This permits the drag to have a slip ratio of about 1.

Description

[Detailed description of the invention] Technical field The present invention relates to an anti-skid control device for an automobile.

At the back chikufujutsu destination, the vehicle speed is measured by a land speed detector, and the m wheel speed is detected by a rat wheel speed detector, and the information from these land speed detectors and wheel speed detectors is The slip ratio is calculated based on the output, and the brake means for braking the wheels is controlled so that the slip ratio becomes a predetermined value.

Problem to be Solved by the Invention In the prior art as in Problem 2, the slip (1) between the wheels and the ground is kept constant during braking. At the maximum value of the coefficient of friction, no braking force can be produced. Therefore, the stopping distance due to automatic braking has been improved.

An object of the present invention is to provide an anti-slip control system for a self-powered rickshaw that is capable of performing braking within a range where the coefficient of friction between the ground and the wheels is near its maximum value. That's true.

Means for Solving the Problems The present invention provides a drag sensor that is provided between the 111th floor and the I-mounted body and detects the drag between the +B wheel and the ground, and a brake means that brakes the 41st wheel. , a self-gJ vehicle characterized in that it includes means for controlling the braking means so as to generate braking force in a range where the drag force increases as the on-lip ratio increases and near the maximum value of the drag force. It is an anti-skid control device.

Function According to the present invention, the braking force is generated near the maximum value of the drag force, so that the distance between the ground and the wheels is 1'? It becomes possible to achieve braking near the maximum value of the friction coefficient, and it becomes possible to minimize the stopping distance during braking. In addition, this braking force is generated near the maximum value of the drag force within the range where the drag force increases as the slip ratio increases, so the drag force increases as the slip ratio increases, making it difficult to stop stably. It is possible to If the selection were made so as to obtain a value near the maximum value within the range in which the drag force decreases as the slip ratio increases, the wheels would immediately become locked and the vehicle's momentum would become unstable. Become. In the present invention, such self-locking during braking is prevented. IIJJB
An unstable posture can be avoided.

Example FIG. 1 is a system diagram of one embodiment of the present invention.

Wheels 1a to ld (hereinafter, suffixes a to d may be omitted in general regarding numerical references) are attached to the m-body 1G of the automobile. 811 Brake shoes for braking wheel 1, etc. are in shillings. 2. The cylinder 2 is supplied with pressure oil from a hydraulic control device 3 . A brake shoe 4 provided at the driver's seat drives a master ring 5, and the master ring 5 is connected to a hydraulic control device 3. Associated with the wheel 1 a wheel speed detector 6 is provided. Furthermore, on the axle 7 of the wheel 1
A drag sensor S is also provided. Outputs from the Ili wheel speed indicator 6 and the drag sensor 8 are given to a processing circuit 9 realized by a microcomputer or the like. This processing circuit 9 is given an output from the ground speed detection 1I) 10. The ground speed detector 10 may be implemented using a spatial filter, for example. The processing circuit 9 controls the hydraulic control device 3.

FIG. 2 is a simplified perspective view of the vicinity of the rear wheels 1c and ld. The rear wheels 1c, ld are connected to the propeller shaft 11 via the differential gear 12, and further axles 13c,
13d, and thus the rear wheels 1c, l
d is driven. The axle 13d is connected to the vehicle body via an upper link 14d. The second axle 13d is the lower link 1
5d and a drag sensor 3d.

The drag sensor 8d is realized by a so-called strain deno or the like, and a tensile force acts on the drag sensor 8d during braking, thereby making it possible to detect the drag force that the wheel 1d is receiving from the road surface.

FIG. 3 is a graph showing the characteristics of the drag sensor 8d.

A tension force acts on the drag sensor 8d during deceleration (braking), and a compression force acts on the drag sensor 8d during acceleration, and in this way the resistance value changes depending on the drag of the wheel 1d against the ground. changes.

The slip rate S of the wheel 1 can be calculated from the first equation based on the outputs of the wheel speed detector 6 and the H ground speed detector 10.

Here, Vl is the vehicle speed detected by the 3'Ii degree above the ground detector 10, and 2 is the wheel speed detected by the wheel speed detector 6.

The rlJa of such slip ratio S and drag force R is the th!
Shown in [ ]. In a range where the slip ratio is less than 81, the drag increases as the slip ratio increases. Therefore, the vehicle can be stopped in a stable position during braking. When the slip ratio exceeds the value s1, the drag force decreases as the slip ratio increases. In a range exceeding S1, the wheels 1 lock rapidly during braking, and the attitude of the vehicle becomes unstable. Like this b
In order to do so, it is necessary to sufficiently reduce the oil pressure applied to the foil sill ring 2 to return the slip ratio to a value below 81. In the present invention, when the slip ratio is within a range of less than 81, the anti-skid control is disabled when the drag is near the maximum value R1 (-F).

FIG. 5 is a 70-chart for explaining the operation of the processing circuit 9. Moving from step 1 to step 2, the oil pressure supplied to the foil cylinder 2 is increased step by step by a predetermined constant value, that is, by a constant pressure increment. At step 3, it is determined whether the drag has increased based on the output from the drag sensor 8, and if it has increased, step +n
Return to step 2 and increase the oil pressure by a fixed increment. In this way, when the drag stops increasing after increasing by the predetermined value, that is, after reaching the maximum drag R1 in FIG. 4, the process moves to step 04. In step m4, the oil pressure supplied to the foil sill 2 is reduced by the predetermined increment. As a result, a drag force close to the maximum drag value R1 can be obtained at a slip ratio lower than the slip ratio S1 at which the maximum drag force R1 is obtained.

In step I5, the oil pressure set in step va4 is maintained. In step l116, it is determined whether the slip ratio has increased, and if it has not increased, the process returns to step UA2.

When it is detected in step 16 that the slip ratio has increased, the process moves to step u7, where the oil pressure of the wheel sill 2 is reduced by a predetermined value.

In Step 8, check whether the slip ratio has reached a predetermined reference value, for example 1096, which is a sufficiently small value.
If it is not, go to step +97 again. When the slip rate reaches the reference value, step (a) 8
Then move on to Step II]2. When the slip ratio increases in this case, the oil pressure of the wheel sill 2 is reduced so that the slip ratio decreases, and locking of the wheels 1 is avoided.

Generally, the coefficient of friction μ between the ground and the wheels changes depending on the slip ratio, as shown in FIG.

On a so-called high-μ road having a high coefficient of friction such as an asphalt road surface, characteristics as shown in Line No. 1 are obtained. Furthermore, on slippery so-called low-μ roads, the characteristics shown by Line No. 2 are obtained. According to the present invention, even on road surfaces with different coefficients of friction μ, braking force can be generated within a range where the drag increases as the slip ratio increases, and near the maximum f1α of the drag. become. Therefore, it becomes possible to stop the vehicle with the minimum stopping distance.

Effects As described above, according to the present invention, the braking means is controlled so that the braking force is generated in the range where the drag force increases as the slip ratio increases and near the maximum value of the drag force, so that the braking force is generated in the vicinity of the maximum value of the drag force. This makes it possible to stop the vehicle in the shortest possible stopping distance while maintaining a stable posture.

[Brief explanation of drawings]

Fig. 1 is a system diagram of an embodiment of the present invention, and Fig. 2 is a rear wheel 1c.
, a simplified perspective view of the vicinity of ltl, FIG. 3 is a graph showing the characteristics of the drag sensor 8, and FIG. 4 is a graph showing the slip ratio S and the drag force R.
FIG. 5 is a graph showing the relationship between the slip ratio and the coefficient of friction. FIG. 5 is a graph showing the relationship between the slip ratio and the coefficient of friction. 1a to 1d...Wheel, 2a to 2d...Foil shilling, 3a to 3d...Hydraulic control device, 4...Plak silling, 5...Mask shilling, 6a to 6d...1
1 wheel speed detection 2'': i, 8a to 8d...Drag sensor agent Patent attorney Number of strokes Keiichi part 2 Figure 3 Accelerating 5 While in a state of mind 4 Figure Tatami 11b77 Hand S ('/,) 6th Figure 11-/Fj← S(@/,) Figure 5

Claims (1)

[Scope of Claims] A drag sensor provided between a wheel and a vehicle body to detect drag between the wheel and the ground, a brake means for braking the wheel, and a range in which the drag increases as the slip rate increases. in,
and means for controlling the braking means so as to generate braking force near the maximum value of the drag force.