Zero-phase tracking human interface using EMG signals and EMD

In this study, a delay between the start of electromyogram (EMG) signals and the start of actual human motions which is called Electro Mechanical Delay (EMD) is used in order to eliminate a delay such as a mechanical delay and a communication delay in manipulating systems. The man-machine interface to accomplish zero-phase tracking eliminating some delay is proposed in this paper. This interface consists of the nonlinear ARX (NARX) model which estimates human joint angle from EMG signals, and discrete-time model-following controller so that a controlled object tracks human motions. The effectiveness of proposed interface is discussed from viewpoint of phase differences and errors between a human joint angle and the angle of a controlled 1 DOF manipulator.