A novel robot motion control based on the decentralized robust servomechanism for each joint

The authors propose a decentralized joint control method for multiaxis robot manipulators by applying a two degrees of freedom (TDOF) robust position servosystem for each joint. This method enables realization of fast and precise trajectory control easily. They demonstrate that various kinds of motion control, such as impedance control, compliant motion control, force control, hybrid control of position and force, etc., can be realized in a unified way by using the proposed robust position controller. Another TDOF controller is applied to force control, which is quite robust to environment parameter variations. These ideas were implemented by using digital signal processor based controllers, and their efficacy was confirmed with experiments using a six-axis manipulator