Minimum jerk motion planning for a prosthetic finger

In this paper we propose a method, based on both physiologic and engineering considerations, for the motion planning of a prosthetic finger. In particular, we exploit a minimum jerk approach to define the trajectory in the Cartesian space. Then, cubic splines are adopted in the joint space. The redundancy problem arising from the presence of three links is solved by assuming that there is a constant ratio between the second and the third joint motion. The value of the proportional constant is determined by minimizing the maximum jerk in the joint space. It is found that this constant value can be suboptimally but effectively set to one for all the movements. This approach guarantees a natural movement of the finger as well as reduced vibrations in the mechanical structure and increased control performances.