Study on the control of variable resistance for isokinetic muscle training system.

<bold>Background: </bold>Isokinetic muscle strength training is presently the most advanced method of muscle strength training. However, the existing control schemes of the training equipment are usually limited to the structure of the brake.<bold>Objective: </bold>In order to solve this problem, this paper presents a solution to an isokinetic system based on the force control of a DC servomotor.<bold>Methods: </bold>A new fuzzy impedance nonlinear controller is designed by analyzing the relevant requirements of isokinetic motion. A series of force tracking comparison experiments between a fuzzy PI controller and a classical PI controller are studied. In addition, some strength training experiments employing different driving forces and target speeds are also conducted.<bold>Results: </bold>The results demonstrate the effectiveness of this fuzzy impedance force tracking control strategy.<bold>Conclusion: </bold>Using the aforementioned methods, a comprehensive motion algorithm was designed. [ABSTRACT FROM AUTHOR]