Decoupling torque control system for automotive engine tester

This paper presents a novel decoupling control method for the engine torque control of an automobile engine tester. The engine tester is mainly composed of a dynamometer control system and an engine control system. The conventional engine tester has the problem that the performance of the engine torque control system is deteriorated by the influences of the interference between the dynamometer speed control system and the engine torque control system. The authors proposed the practical engine torque control system based on an observer and an identification system to eliminate the interference of the dynamometer speed control system. The effect of observer´s parameter error on the engine torque estimation response was analyzed. According to the result of this analysis, a practical method is proposed to identify the engine inertia moment and the shaft spring coefficient that are parameters of the observer. The authors confirmed through simulation and experiments that the proposed decoupling engine torque control system realizes a robust control system from the interference with the dynamometer speed control system