Planning and sensitivity analysis of automated assembly processes with robots

In this paper the sensitivity to interference between a robot and its environment is examined. We establish rules for generating robot trajectories which maximize the robots capabilities with respect to exerting forces while minimizing the strain on the drives. Another aspect is the calculation of the maximal tolerable position error that guarantees a certain assembly task to be completed within pre-defined force limits. Applying impact dynamics yields the impact forces when the mating parts come into contact. The transfer behavior of the robot to avoid unwanted oscillations under dynamically varying loads is examined. The dynamical model of the robot includes elasticity, damping, friction and backlash in the joints. The parts to be assembled may be rigid or elastic with Coulomb friction acting between them. The calculation methods are explained in detail and measurements conducted on a PUMA 562 robot complete the approach