Study on error compensation of machining force in aspheric surfaces polishing by profile-adaptive hybrid movement–force control

The hybrid movement–force control policy has been widely used to deal with the coupling of the movement control subsystem and the force control subsystem in a compliant control system by a Jacobi matrix while its position and/or posture changing. But the Jacobi matrix, which is used to decouple the coupling of movement–force control, could not restrain the disturbance of the errors of position and posture to the force control. For their great uncertainty and non-linearity, the errors of position and posture in the movement controlling place lots of troubles to the force controlling in the engineering applications. In this paper, a kind of profile-adaptive compliant control policy is added to reduce the errors of position and posture of the polishing tool and to restrain their disturbance to the machining force in a hybrid movement–force control system. The new policy has been used to polish aspheric surfaces by CNC machine tools of two axes. Experimental results show that it could compensate the errors of machining force and improve surface quality obviously.