In the paper, authors present a design of a novel input device, in which, thanks to two ergonomically placed wheels, the operator can control the multi-axis manipulator with a single hand. The application of rotating elements provides the following benefits: achieving unlimited angular displacement, controlling numerous number of axes thanks to the certain combination of wheels motions, assigning force and position amplification individually, what helps to obtain both high speed and precision. In order to generate feedback force in the joystick, dedicated MR brakes were designed and built. The proposed feedback approach is an example of admittance control [1]. The joystick was built and tested at the Institute of Mechanical Technology of Poznan University of Technology. In the article, a theoretical model of the brake was shown together with analysis and discussion of its parameters. Additionally, it was supplemented with the results of theoretical and simulative studies. The paper also contains the outcome of the initial study focused on the analysis of the functionality, ergonomics and possibility of two-, three- and four axis control. It showed that the control algorithms played an essential role in motion control. They allow a rapid change of the generated resistance force during the change of motion direction. The obtained results validated the assumed design of the joystick with rotary elements and applied MR brakes due to the possibility of precisely control the motion resistance.
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