Robust Control for V 2500 FDRV

Abstract

FDRV (Fuel Diverter and Return Valve) is one of the hydraulic servo valves used in V 2500 turbofun engines in order to control fuel temperature. FDRV, currently in production, is manufactured to meet its specification which allows appropriate tolerance. Hence, there are some performance variation of FDRV. Also, performance of FDRV may significantly vary with operating conditions. In order to meet engine control objectives, performance of the FDRV control system is also specified, which includes response time, overshoot, offset, and sensor noise. To satisfy the above requirements, a compensator, which is part of FADEC(Full Authority Digital Engine Control) software, is used. Single compensator which can accommodate specified performance variation of FDRV is required since it is not practical to adjust parameters in the compensator for each FDRV.
In this paper, we design a compensator based on H_∞ control theory and evaluate its performance by experiments on bench test stand. Here, we do not use adaptive compensator. We consider performance variation due to the manufacturing tolerance as uncertainty of nominal model and variation due to the operating condition as distarbance to nominal model. Then, we synthesize a robust compensator that satisfies the system performance specification under existence of the uncertainty and the disturbance.