A 2-DOF MR actuator joystick for virtual reality applications

The paper presents the design and development of a magnetorheological (MR) fluid-based haptic system and studies its applications in virtual reality. The developed system consists of three main parts: MR joystick, control and display hardware, and software. The MR joystick was constructed of two disc-shaped MR actuators positioned perpendicularly with a gimbal structure, which transfers the movement of the joystick handle into two actuator rotary movements. Therefore, operators can feel the resisting force generated by the two actuators. The dimensions of the actuators were optimized using finite element analysis. The steady-state performance of the actuators was measured and a subhysteresis model was proposed to effectively predict the actuator performance. The kinetics of the joystick in terms of working space and resistance was discussed. The applications of the MR joystick in virtual reality were demonstrated by using four typical 2D and 3D interface examples designed with LabVIEW software package.