Abstract:

The application of impedance control theory with 6 degrees of freedom (6-DOF) parallel manipulator is investigated for the purpose of generalized loading. The linearized impedance control model is derived, which explains the relationships among generalized force, cylinder force and cylinder displacement, and also helps to analyse the influencing factors of steadystate error. A model reference adaptive control (MRAC) based impedance controller is developed; and the related parameters can be adjusted according to the actual generalized force and cylinder force. Simulation of dynamic generalized loading are carried out to compare the performance of impedance controller with that of the classical PID controller, and the results indicate that the MRAC based impedance controller improves the response capability and robustness of loading system, and is capable to realize accurate and steady loading under laboratory condition.

Key words: 6-DOF , parallel , manipulator,  , impedance , control,  , MRAC,  , generalized , loading,  , robustness