THE APPLICATION OF THE METHOD OF SIMULTANEOUS STABILIZATION TO THE CONTROL OF A NONLINEAR SERVO VALVE

The method of simultaneous stabilization is used to design a single li near compensator that stabilizes a servo valve with significant nonlin ear dynamics. The servo valve is part of an automotive exhaust gas rec irculation (EGR) system. Linear models of the response of a servo valv e at distinct operating points are developed using the actual hardware . A simultaneous stabilizing compensator (c(ss)) is designed based on these models and implemented as an analog controller. The performance of the compensator is compared to results previously achieved using a conventional PI control scheme. As a result of the c(ss) control's abi lity to stabilize the plant for small valve openings, the minimum gasf low rate achievable is improved by a factor of five when compared to c onventional PI control, and valve response at high flows does not dete riorate. Several techniques for applying the method of simultaneous st abilization to real problems are presented.