Machining, Measurement, and Control Laboratory

Influence of friction on high-precision positioning control
Tomoya Fujita, Atsushi Matsubara, Cefu Hong, Kazuo Yamazaki

To develop a high-speed and high-accuracy positioning system, it is important to analyze the influence of friction forces in the guideways. We consider that the friction force is influenced not only by the position and velocity of the moving mass but also by other states such as acceleration. We propose an experimental method for the analysis of the influences of potential state factors on friction forces. In this method, motion test patterns, which consists of several sets of a line segment command and a dwell command is used to separate positiondependent component and velocity-dependent component in the friction force. The measurement method is applied for the analysis of friction forces of a positioning system which consists of a linear motor and rolling guideways. From the test results, the influence of position, velocity and acceleration change of the drive table on the friction force is shown with their effect on positioning performance.