Vehicle antilock brake control system

Abstract

A vehicular antilock brake control system does not require a lengthy extension piping from its actuator. The system provides for an accurate controlling method for maximizing a calculated road surface friction coefficient. Each wheel has a control unit consisting of a stress sensor, a controller and an actuator installed at the respective wheel. A stress value is detected, representative of road surface friction value or road surface friction coefficient value, for the corresponding wheel independently of the other wheels. In response to the output signal of the sensor, the controller regulates the actuator which controls brake fluid pressure applied to the respective wheel.

What is claimed is:  
     
         1 . An antilock brake system control system for a vehicle having at least a pair of axles in the rear or in the front of the vehicle, said control system having a control unit comprising: 
 a stress sensor for detecting a wheel stress;    an actuator controller providing an actuating signal to an actuator in response to an output signal provided by said stress sensor;    said actuator adjusting brake fluid pressure in response to said actuating signal from said controller;    said control unit being provided for each wheel or for a set of wheels of the vehicle;    the first axle of said pair of axles is provided with said control units a control unit being related to each of the wheels of said first axle; and    the wheels of the second axle of said pair of axles are connected through connecting pipes to the actuators of said control units of said first axle, each of said wheels being diagonally connected with one of said control units related to the wheel on the opposite side of the first axle.    
     
     
         2 . The control system of    claim 1   , wherein each control unit is supplied with a break fluid pressure fro a foot brake master cylinder.  
     
     
         3 . The control system of    claim 1   , wherein each control unit is provided with a control pressure source comprising a high-pressure control pressure generating means, a fluid reservoir means and a reversing means.  
     
     
         4 . The control system of    claim 3   , wherein said control pressure source is supplied with auxiliary oil pressure from said foot brake master cylinder to compensate deficiencies in control pressure in the control pressure generating means.  
     
     
         5 . The control system of    claim 4    wherein a signal transmission system is coupled to each actuator controller by signal lines.  
     
     
         6 . The control system of    claim 1   , wherein said stress sensor is a road surface friction coefficient detector utilizing a road surface friction force sensor and a vertical load sensor, each of said sensors comprising strain gauges for detecting the road surface friction force and the vertical reaction load respectively.