Figure 4.

Example kinematics when optimizing reaching to a target with three and eight synergies, and the full-dimensional system. Kinematics are shown for the model’s five degrees-of-freedom, which include the elevation plane, shoulder elevation (or thoracohumeral angle), shoulder rotation (where internal rotation is positive), elbow flexion and forearm rotation (where pronation is positive) [30]. Kinematics are from a representative run, but the multiple runs were qualitatively similar. We also show some key poses in the movement for the full-dimensional controller. In the bottom rightmost panel, we compare the performance on the cost for each controller for the kinematics in the plots above. We show the proportion of the cost due to the task term, the effort term and all other terms (final velocity near 0, joint limits, etc.; see equation (2.1)).