Design method and experiment of robot joint flexible drive based on magnetorheological fluid

Traditional high-rigidity robots are difficult to meet the safety of human-machine interaction and the self-adaptability of complex environments. This paper proposed a new design method of variable stiffness flexible actuator for robot joints based on magnetorheological fluid, and completed relevant experiments. The magnetic field simulation results of the magnetorheological flexible actuator were analyzed, and the physical design was optimized to determine the final structure of the magnetorheological flexible actuator. The simulation model of the magnetorheological flexible actuator is established in Matlab/Simulink, so as to obtain the relationship between excitation current and maximum output torque of the magnetorheological flexible actuator. Finally, to analyze the effect of variable stiffness, an experimental prototype and a control system were fabricated to test the maximum torque of flexible actuator under different current. The results of position step test and collision test show that the new type of flexible actuator based on magnetorheological fluid designed realizes the function of variable stiffness, and its control system also meets the requirements.