Investigation of joint clearance effects on welding robot manipulators

In this study, effects of joint clearance on a welding robot manipulator are investigated. Theoretical analysis is performed for different clearance sizes. By using the nonlinear spring-damper characteristic, contact model in revolute joint with clearance is established and the friction effect is performed using the Coulomb friction model. Then the simulation is carried out to investigate the kinematic and dynamic characteristics of the welding robot manipulator with joint clearance. For the case of two different clearance sizes, the results show that the joint clearance causes to degradation of kinematic and dynamic performance of the system. Even if the clearance size is small, it has a crucial role on amplitudes of the end-effector's accelerations and joint forces.

► Effects of joint clearance on a welding robot manipulator were investigated.
► Nonlinear spring-damper characteristic was used for contact modeling.
► Friction effect was performed using the Coulomb friction model.
► Higher size of clearance increases the amplitudes of accelerations and forces.
► Lower size of clearance leads to higher frequencies at the system responses.