Rapid Modelling and Grinding of Workpieces’ Inner-surface by Robot with Impedance Model Based Fuzzy Force Control Algorithm

School of Mechanical Engineering & Automation, Northeastern University, 110819, Shenyang, China

Abstract

To achieve rapid automatic grinding of workpieces’ inner-surface by industrial robot, a rapid translational detection strategy of workpieces’ inner-surface and fuzzy force control algorithm of grinding are proposed in this paper. The rapid translational detection strategy introduces a way to establish an inner-surface’s model quickly by recording key points of the axial section contour which reflects big curvature changes of the contour. The established model is feasible but imprecision. The force control algorithm is based on impedance model. To promote adaptability to the imprecision of the established inner-surface’s model, a fuzzy adjusting strategy is introduced in the force control algorithm. By adopting an adjusting factor, which determined by force response and a fuzzy logic, the strategy can adjust the reference trajectory of impedance model in time. Taking advantage of proposed detection and force control method, grinding experiments shows that the contact normal force maintains approximately constant, the relative mean error is within 6.5%, and the material removal thickness of the inner-surface is approximately consistent. The proposed strategy’s feasibility is verified.