Design and development of a Magneto-Rheological linear clutch for force controlled human safe robots

This paper proposes a Magneto Rheological linear clutch for use in human safe robotic applications. The force transmitted to the links of the robot must be precisely controlled for any manipulator if it has to be operated safely alongside humans. The traditional approaches to this problem is using various compliant actuating schemes like Series Elastic Actuators, Joint Torque Control etc. Research on the usage of smart materials that change their properties on application of electrical or magnetic fields for human safe robots have gained momentum recently. Studies on the feasibility of Magneto-Rheological actuators has been done already. This paper introduces a MR clutch which can control the force transmitted by a linear actuator. The electromechanical model of the linear clutch has been developed, implemented in hardware, and tested using a prototype one Degree of Freedom arm. The design of the clutch is detailed and the performance is characterized thorough a series of experiments. The results suggest that the linear clutch serves well for the precise force control of a linear actuator.