Measuring distance covered by vehicle test bed, e.g. for calibrating tachograph - counting pulses generated by measurement roller and correcting for wheel circumference changes caused by thermal expansion

摘要

The method involves using a measurement roller rotating with a wheel of the vehicle to generate distance pulses which are counted between a start command and a stop command, which is given when a defined distance has been covered, and displayed. The effective wheel circumference is measured at normal operating temp. The number of complete revolutions between start and stop commands is counted and the distance covered determined from the diffrence between the pulse count before the start and after the last complete wheel revolution and a circumference correction. ADVANTAGE - Increased measurement accuracy.