Multi-constrained motion planning of a planar type humanoid using kinematic redundancy

The human being carries out multiple works simutaneously. Generally, two legs are constrained to the ground while two arms are performing some other jobs. Sometimes not only two legs but also any parts of the human body such as hand, elbow, head, etc. are kinematically constrained to the environment for special purpose. Sawing motion is one example of the multi-constrained motions. When a person saws a wood, two legs are constrained to the ground and one arm holds the object being sawn on the table so that another arm carries out a stable sawing task. In this paper, we introduces a new motion planning algorithm for a multi-constrained planar type humanoid robot, which exploits "redundant degrees of freedom" of the whole-body humanoid structure. A sequential redundancy resolution algorithm is employed, which ensures the ZMP stability and the planned multi-constrained motion. The feasibility of the proposed algorithm is verified by simulating a sawing motion for a planar humanoid model.