Singularity-based mechanism with high responsiveness

We propose a singularity-based mechanism (S8M) to exploit the singular configuration that improves the angular acceleration instead of constraining the movement. The tradeoff between the responsiveness and the range of motion is achieved by varying a length of linkage in the S8M. In this paper, we clarify the responsiveness of the S8M using the dynamics analysis. For the demonstration, we build an experimental S8M system with the high responsiveness, a practical range of motion, and a size comparable to a human arm. In the experiment, the effectiveness of the S8M is shown in a vertical lifting task. The characteristic of the S8M that generates a large acceleration at start is similar to the human arm moved by a muscle. The similarity between the S8M and the human arm is analyzed in terms of the static torque.