Flexible Robot Collision Dynamics Effect Study

The flexible robot system contact-impact dynamics is essentially a time varying,nonlinear dynamic process with variable topology, the key to solve the impact dynamics inthe flexible robot system is to correctly establish the contact-impact model. To evaluate thedynamic characters of the system due to impact, this dissertation discusses the impactdynamics of a flexible robot colliding with its working environments. The systemconsidered here is a robot consisting of n slender, flexible or rigid-flexible links which areconnected by rotary joints. Based on the multi-flexible system dynamics theory, the impactdynamic effects of the flexible robot are studied. The kinematics of the system is describedby 4×4 homogeneous transformation matrices and the mode assumption method is used todescribed the link deflection. In order to research the system's dynamic behaviors of thecontact-impcat process, the Hertzian contact theory and nonlinear damping theory areadopted here. The system's dynamic equations which including impact process are derivedvia the Lagrangian method. The velocity in the resulting equations which have beenderived is continuous, so the equations could be solved directly. Then the computerprogramming is done, and the algorithms ensure the results are reasonable. The dynamicproperties of the flexible robot system due to the structural flexibility and its dynamicbehaviors during the impacting process are studied through several typical numericalsimulation examples, and the validity of the theories and the algorithms established in thisdissertation is also verified by those examples.