Fluid-pressure and analogous brake systems – Speed-controlled – Having a valve system responsive to a wheel lock signal
Patent
1991-09-05
1993-09-14
Oberleitner, Robert J.
Fluid-pressure and analogous brake systems
Speed-controlled
Having a valve system responsive to a wheel lock signal
303108, B60T 868
Patent
active
052442594
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a method of anti-lock braking of a motorcycle, wherein the brake pressure in the brake of a front wheel or rear wheel is kept constant or reduced when the rotational retardation and/or slip of the wheel exceed a predetermined threshold value.
The invention further relates to a method of determining the coefficient of adhesion between a roadway and the wheels of a motorcycle, especially the determination of the longitudinal and lateral coefficients of adhesion.
DESCRIPTION OF PRIOR ART
Different varieties of anti-lock brake systems for motorcycles are known as such. With them, anti-lock brake systems (ABS) known for four-wheel vehicles are modified in consideration of the special characteristics of a single-track, two-wheel vehicle.
Methods are known, with four-wheel vehicles, of obtaining a statement on the instantaneous coefficient of adhesion between a wheel and the roadway by retarding that wheel more than another wheel for a brief moment so as to derive a statement on the coefficient of adhesion from the slip of the more strongly retarded wheel. In this case it is assumed that the driving stability of the four-wheel vehicle will not be impaired by such a short-term disturbance. With a two-wheel vehicle, on the other hand, that method would appear to be unsuited as both wheels necessarily have to remain stable.
SUMMARY OF THE INVENTION
The invention has for its aim to improve a conventional ABS braking system for a motorcycle, at little expenditure, such that information can be obtained about the coefficient of adhesion between the wheels and the roadway, on the one hand, and, on the other hand, the anti-lock control is adjusted in accordance with the coefficient of adhesion determined.
According to a first embodiment of the invention first it is determined if the motorcycle is in an inclined position, e.g. driving through a curve and, depending on the measured value of that sloping, either a threshold value of response for anti-lock control and/or a gradient of pressure rise for anti-lock control corresponding to the value measured of the sloping is set, this being done according to limited grading. Apart from the sloping of the motorcycle, also the transverse acceleration thereof may be determined by per se known means in order to adjust the anti-lock control. Adjustment in respect of the sloping and/or the transverse acceleration may be realized in predetermined stages, especially three different stages. The response threshold values and/or the pressure increase gradients relating to the anti-lock control may be varied in three steps, depending on the degree of inclination or the amount of transverse acceleration. And the response threshold values or the pressure increase gradients of the ABS control are set more sensitively with increasing sloping or transverse acceleration so that the retarded wheel can be caused to suffer a lower maximum slip upon braking as the inclination or transverse acceleration becomes greater.
In accordance with the invention provision is made for determining the coefficient of adhesion between the roadway and the wheels of the motorcycle by retarding the rear wheel of the motorcycle more than the front wheel, for a given time span, and comparing the rotational speeds and/or the rotational retardations of the front and rear wheels so as to derive the coefficient of adhesion from the result of the comparison.
The invention is based on the finding that, for a short period of time, a motorcycle quite well may be retarded more strongly at the rear wheel than at the front wheel without causing any considerable risk to the driving stability, even when driving through a curve. That is distinctly in contrast to the dynamics of four-wheel vehicles where overbraking of the rear wheels may generate a torque about the vertical axis, thus resulting in complete instability.
For braking during straightforward movement (without any sloping worth mentioning of the motorcycle) the slip between the rear wheel which is retarded somewh
REFERENCES:
patent: 4494800 (1985-01-01), Hayashi
patent: 4554990 (1985-11-01), Kamiya et al.
patent: 4626042 (1986-12-01), Burckhardt
patent: 4852951 (1989-08-01), Matsuda
patent: 4916619 (1990-04-01), Walenty et al.
patent: 4989922 (1991-02-01), Pickenhahn et al.
Fischer Martin
Pickenhahn Josef
Weidele Alois
Lucas Industries Public Limited Company
Muratori Alfred
Oberleitner Robert J.
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