Speed fluctuation compensation in vehicle roller tester - using summing amplifier circuit to compensate tachometer output signals and two rollers with revolution counters

摘要

The compensation system for motor vehicle roller testing equipment provides correction for errors due to oscillating movement between the vehicle wheel and the measuring rollers. The test apparatus comprises two rollers. The load roller (11) and the support roller (12) are fitted with revolution counters (16,17). The load roller also has a flywheel (15) which gives it a greater moment of inertia. The oscillating variations in speed of rotation of the rollers differ in amplitude and phase. Compensation is effected by adding the amplitudes of the two values. An operational amplifier connected as a summing amplifier is used. The ratio of the two input resistors is equal to the ratio of the inertia moment ratio of the two rollers.