Study on the Rigid-Flexible Coupling Dynamics of Welding Robot

The flexible factors in the large structure machine with large-scale movement make the rigid-flexible coupling become the key problem of research. Past research mostly focus on the flexibility of the link, ignoring the impact of joint flexibility. Through the dynamic analysis of simplified 3-link structure in space, different stiffness coefficients of flexible joint are given, and motion trajectory of robot’s is observed, comparing the displacement of joint under rigid state. The Lagrange method is used to deduce the rigid-flexible coupling dynamic equation which takes the gravity term into consideration. By comparing the dynamic simulation results of ADAMS with those in the rigid state, it shows that the flexible joint has an impact on the movement of the system. Vibration amplitude of different stiffness coefficient is different, and the associated vibration exists between each other. The motion response of the system is relatively large and motion error varies along with the movement path in X, Y and Z, which lay the foundation for the research of control system.