Bandwidth extension of dynamical test benches by modified mechanical design under adaptive feedforward disturbance rejection

In this paper we present a mechatronical approach for bandwidth extension of a combustion engine test bench consisting of the reconfiguration of the mechanical design and the introduction of an adaptive feedforward like disturbance rejection scheme. The mechanical design of the test bench is improved by the use of a stiff shaft engine to dynamometer connection. This yields a shift of the resonance frequency of the test bench into the frequency range excited by the combustion oscillations and hence results in the need of a disturbance suppression algorithm. Therefore the repeatability of the almost periodic disturbance is exploited to predict an estimate of future values using an extended FIFO memory to compensate input delays. The algorithm is tested in simulation and furthermore applied to a real test bench. The experimental results will verify the effectiveness of the proposed method.