Abstract
This paper presents a model based observer synthesis to design an observer for an existing LQ servo controller used for an electro-pneumatic gearbox actuator. An extended dynamic model of the electro-pneumatic actuator is built up and the observability of the model is examined. The observability is checked by the nonlinear observability rank condition test. The observer design is based on the dynamic model of the system, and is verified by simulation. Besides the unknown parameters of the observer are identified with offline identification. In this way, the existing LQ servo control system can be amended into a cost-efficient one. In the paper, the modeling, the observability test, the observer design, the open-loop observer verification in software in the loop environment are presented. It is followed by offline parameter identification using measurement records. Lastly the measurement results are demonstrated in hardware in the loop environment, with the closed-loop control system on a complete gearbox test bench.
Keywords: transmission, electro-pneumatic actuator, observability, observer, LQ servo