Modeling of One Link Robot using Friction Compensator

摘要

Many robots excel at their positioning and trajectory tracking using software control and most successful robotic application utilize this ability – examples include CNC machining, robotic welding, painting and pick-and-place board assembly. A robot is an integrated system of electronics, software, and mechanical, and each part of the system limits or enables the behavior of the whole. For dynamic behaviors such as running, the performance limitations of robot are often due to limitations of friction. Friction effects are particularly critical for industrial robots. Friction deteriorates the performance of industrial robots cause’s disturbances such as positioning errors, tracking errors and stick-slip errors in robotics. The effects of friction in robotics are greatly compensated by friction models. The objective of this paper is to derive a friction compensation strategy for a one link robot, which reduces steady-state errors. II. Friction Models To compensate the effect of friction in robotics friction models are used. Each friction model incorporates one or more friction phenomena. The models are divided in two groups, static models and dynamic models. Static friction model incorporates only static friction phenomena and are a static function of velocity. A major problem of the static friction models during simulation is the discontinuity at zero velocity. [4] Dynamic friction models contains behind static friction phenomena and also some dynamic friction phenomena. A. Static Friction Model Static friction models have a static dependency on velocity.The major problem with static friction model is their discontinuity at zero velocity [6].