Abstract:Aiming at the walking assistant demand of smart walker on slope, a method of implementing active/passive torque is proposed. The method utilizes the characteristic of controllable resistance torque of magnetorheological (MR) brake, combines the MR brake, worm gear reducer and DC motor to compose an active/passive hybrid actuator. Controllable active and passive torques are obtained through the coordination operation of the MR brake and DC motor. An MR brake with the rotor section of Tshape was designed, then finite element method was used to analyze the magnetic circuit inside the brake, and the mechanical performance parameters of the brake were obtained. On this basis, the active/passive hybrid actuator was developed, its mechanical performance test system was established and the experiment study was completed. The experiment results show that the proposed method can provide both controllable active torque and controllable passive torque, and the developed active/passive hybrid actuator can meet the functional requirements of walking assistant of the smart walker on slope.