Friction compensation control of cam-rotor vane motor based on improved LuGre model

Cam-rotor vane motor (CRVM) is one of new continuous hydraulic servo motors with the characteristics of no pulsation of instantaneous flow rate and output torque, small volume and rotating inertia. In order to acquire better performance and minimize the trace error, the friction mechanism of cam-rotor vane motor was analyzed. As a novel friction description, LuGre friction model and its parameter had a few limitations because this model is only the friction description of a fixed position. Based on lots of friction experience and the characteristic of CRVM, a changeable maximum dynamic and static friction model which is based on LuGre model, was proposed and identified. Using structure invariance principle, a feedforward compensator was designed and verified. Experience results show that the control strategy designed by the improved LuGre friction model not only works well for rejecting torque trace error, but also improve the tracking performance of the CRVM.