AUTOMATIC TESTING OF SENSORS IN ABS SYSTEMS

Worldwide development of automatic anti blocking systems for car brakes started around mid of the sixties. In the meantime development of microprocessors and rising reliability of electronic components has led to a widespreaded use of such systems. Important components are the sensors for detection of the wheels motion, errorfree function and high quality production are essential. On the cars axes toothed wheels are mounted which induce an electrical signal, its frequency proportional to the rotating speed, in a coil wounded around a magnet. These toothed wheels have to be tested very carefully before the actual assembly stage as e.g. damaged teeth or bad centering of the wheels have direct influence on the function of the ABS system. An automatic working test system for such wheels, which has been installed in two factories of a well known german car producer and in another factory of a swedish company, is described.