Constant force grinding control method for unknown curve part based on force/torque information

A method of constant grinding force following unknown curve part based on force/torque information is presented in this paper. A new estimation method of the unknown curve normal direction is proposed based on force and torque information. According to the method, the force control and position control directions of the hybrid force/position control can be estimated. The conventional proportion integration (PI) force control method is tested at first. Since the force PI control parameters are difficult to determine, fuzzy PI control is introduced to optimise the force PI control parameters automatically. According to the experiment result, the method can greatly reduce the contact force fluctuation during grinding wheel contact with part contour, and the contact force during estimating curve surface is in the desired range of ± 2 N. And during grinding procedure, the acting force fluctuation is in the desired range of ± 7 N. [Received 20 April 2015; Revised 17 February 2016; Accepted 23 February 2016]