Optimization of impact motions for humanoid robots

When a human needs to generate a large force, the human will try to apply an impulsive force cooperating whole body. This paper proposes a way to generate impact motions for humanoid robots to exert a large force keeping a balance. In the proposed method, the Sequential Quadratic Programming (SQP) is used to solve a nonlinear programming problem in which an objective function and constraints may be nonlinear functions of the motion parameters. Impact motions are generated using SQP so that the impact force is maximized while the angular momentum is minimized to keep stability. Breaking wooden boards by Karate-chop is taken as a case study because it is a typical example of tasks that utilize impulsive force. A humanoid robot motion for the Karate-chop is generated by the proposed method. In order to validate the designed motion, experiments are carried out using a small humanoid robot Fujitsu HOAP-2. The Karate-chop motion generated by the proposed method is compared with the motion designed by a human. The results of the breaking wooden boards experiments clearly show the effectiveness of the proposed method.