A Development of 2-D Force Display System with Redundant Low-voltage Driving ER Fluid Brakes

Passive-type force display systems have the merit of high safty, but there are some directions and link positions for which it is difficult to display the force by using only passive elements. To solve this problem, a method for improving the controllability by using redundant brakes had been proposed. This method, however, requires brakes with short response time; ER fluid brakes are suited for this purpose. In this paper, we develop a novel passive-type force display system with redundant brakes. We have developed new multi-cylinder ER fluid brakes which can be operated at relatively low voltage. For transmitting the force, a new linkage system is designed which does not require any belt-pully system. It has been demonstrated that this system can display forces in a wide direction by using our controlling algorithm. A potential application of this system to rehabilitation training is proposed.