A 3 DOF exoskeleton for upper limb motion assist: consideration of the effect of bi-articular muscles

We have been developing exoskeleton systems to assist the motion of physically weak persons such as elderly, disabled, and injured persons. The proposed exoskeletons are controlled basically based on the electromyogram (EMG) signals. Even though the EMG signals contain very important information, however, it is not very easy to predict the user´s upper-limb motion (elbow and shoulder motion) based on the EMG signals in real-time because of the difficulty in using the EMG signals as the controller input signals. In this paper, we propose a control method for a 3DOF exoskeleton system for human upper-limb motion assist considering the effect of bi-articular muscles.