SENSOR-ACCURACY PRECISION POSITIONING WITHTHE EXISTENCE OF STATIC FRICTION PART I -DYNAMIC MODEL OF FRICTION DURING THEPRE-SLIDING RANGE

摘要

One of the main difficulties in dealing with precision positioning problems is the friction force andthe induced nonlinear behavior existing in the mechanism. In this research, the static friction behavioris observed experimentally for a direct drive torque motor system. It is found that the qualitativebehavior of static friction can be summarized in several simple rules. The deformation in stictionphase is the result of two motions: plastic deformation that demonstrates creep and work hardening,and nonlinear spring deformation that demonstrates hysteresis with memory and wipe out effects. It isalso found that these phenomena are common to lots of mechanical friction. Furthermore, it is veryclose to the behavior of a standard plastic solid. A new static friction model that consists of a plasticmodule and a nonlinear spring module is introduced. This model is of a simple structure and is provedto satisfy all those rules relating to qualitative behavior. Simulation results show that this model doesmatch those experimental results conducted by the authors as well as by other investigators.