EVALUATION OF THE PERFORMANCE OF ANTI-LOCK BRAKE SYSTEMS USING LABORATORY SIMULATION TECHNIQUES.

To improve the braking performance and to maintain the directional stability of road vehicles during braking, anti-lock devices are being used. An anti-lock system consists of three major parts, namely, a sensor, a control unit and a modulator. The sensor of an anti-lock system is usually an inductive pick-up which measures the angular velocity of the wheel. The control unit is a small electronic computer that monitors the motion of the wheel and makes the required decisions. The brake pressure modulator is an electro-pneumatic device (in the case of air brake systems) that receives command signals from the control unit and modulates the brake pressure accordingly. In this paper, laboratory facilities developed at Carleton for testing anti-lock brake systems are described. The test results of two commercially available anti-lock devices are presented to illustrate the utility of the test facilities. The slip performance, stopping distance, braking effectiveness and air consumption of these two systems are examined.