LuGre model-based adaptive robust control of 1 DOF mechanical systems using only position measurement

In a large number of mechanical systems, both structured and unstructured uncertainties often degrade control performance. Among the structured uncertainties, friction force is a common cause of motion control performance degradation. In order to improve the motion control performance in the presence of various uncertainties, this paper presents the LuGre friction model based adaptive robust control (ARC) scheme combined with a reduced order proportional-integral (PI) observer. The reduced order PI observer is utilized to estimate unstructured disturbances as well as the velocity information. Comparative computer simulations are carried out to test the performance of the proposed controller.