Application of SDRE control to servopneumatic drives

Servopneumatic drives are characterized by significant nonlinearities due to the compressibility of the air, nonlinear characteristics of the servo valve and high static friction forces by the sealing utilities. To achieve high accuracies in positioning control these nonlinearities have to be considered in the control design. This paper applies the state dependent Riccati equation (SDRE) strategy to a servopneumatic cylinder, because it is a systematic approach allowing nonlinearities in the system states and providing additional flexibility in the design through state-dependent matrices. Measurement results of a experimental setup are presented to prove the efficiency of the proposed control.