Development of friction identification methods for feed drives of CNC machine tools
Source: The International Journal of Advanced Manufacturing Technology, Volume 52, Numbers 1-4, January 2011 , pp. 263-278(16)
Abstract:Friction exists in the feed drive servomechanisms of CNC machine tools and usually affects their motion. Although many experiments have been performed to identify the friction characteristics of a feed drive servomechanism, problems such as unmodeled dynamics and position-dependent perturbations still exist and significantly affect the friction identification results. In this study, in order to obtain reliable friction and velocity data values, a modified velocity control system is developed to reduce the effects induced by unmodeled dynamics, and a friction extraction method is developed to remove the adverse effects of position-dependent perturbations. Furthermore, several experiments and motion tests are carried out on a three-axis CNC milling machine to demonstrate the feasibility of the proposed friction identification method. The experimental results indicate that the friction-compensated motion control system with the friction model obtained in this study reduces the root mean square value of tracking errors by 44.16%. Moreover, as compared to a conventional identification method, the root mean square value of tracking errors is found to further reduce by 9.52% in the experiments.
Document Type: Research Article
Affiliations: 1: Department of Mechanical Engineering, National Taipei University of Technology, Taipei, 10608, Taiwan, Email: email@example.com 2: Mechanical and Systems Laboratories, Industrial Technology Research Institute, Hsinchu, 310, Taiwan
Publication date: 2011-01-01