Virtual torsional spring based bilateral control system for soft manipulation

In recent years, although there are many researches on bilateral control, there is only little research on improvement of operationality. It will be so effective for operators to improve the operationality of the bilateral control system. In a bilateral control system, the law of action and reaction between master system which the operator manipulates, and the slave system which has contact with the environment is realized. Objective of this research is to eliminate the chattering and to reduce the impact on human operator at contact motion and to introduce controlling force to the slave manipulator to provide more comfort at the human operator's end. In this paper, a new method of improving the operationality which is based on a virtual torsional spring between master and slave system is discussed. Disturbance observer is used as the disturbance compensation tool and also to improve the system robustness. Then proposed method is applied by altering the bilateral control system. Finally the experimental results show the viability of the proposed method.