Robust position and speed control of variable displacement hydraulic motors

摘要

This paper addresses the position and speed control of a variable displacement hydraulic motor (VDHM) at a constant pressure net (also referred to as "secondary control"). The system specifications relate to the application in future large aircraft, where this modern type of hydraulic motors can help to reduce weight and energy consumption of flight control actuators. LQG/LTR and H_infinity design approaches are considered, emphasizing the problem of sufficiently precise position control in the face of nonlinear friction. Simulation results are compared with experiments performed a VDHM test rig. Finally, the use of mu analysis techniques is briefly outlined.