An Impact Motion Generation Support Software

When a robot applies force statically on a target object, magnitude of the force is limited by the maximum force or torque of the actuators. In order to exert a large force on the target beyond this limitation, it is effective to apply impulsive force. We describe the motions that perform tasks by applying impulsive force as “impact motion.” There are difficult problems introduced by impacts between a robot and a target. Uchiyama proposed a control algorithm constitution method and dynamic control modes for performing a nailing task by a 3 DOF manipulator (Uchiyama, 1975). Zheng and Hemami discussed mathematical modelling of a robot that collides with the environment (Zheng & Hemami, 1985). Asada and Ogawa proposed the virtual mass for analyzing dynamic behaviour of a manipulator arm and its end effecter that interacts with the environment (Asada & Ogawa, 1987). Around the same time, Khatib and Burdick proposed the effective mass (Khatib & Burdick, 1986). Walker investigated the effect of different configurations of kinematically redundant arms with impact force at their end effectors during contact (Walker, 1994). These works mentioned above used rigid robotic manipulators fixed on the ground. Yoshida and Sashida investigated impact dynamics in free-floating multibody systems in space (Yoshida & Sashida, 1993). Lew discussed about contact force control of a long-reach flexible micro/macro manipulator (Lew, 1997). These studies focused on trying to minimize the impulsive force since the force causes fatal problems in a space robot or a flexible arm. A few attempts on tasks applying impulsive force by a humanoid robot have been reported in recent years. Arisumi et al. discussed a motion generation method for dynamic lifting by a humanoid robot based on a planar model (Arisumi et al., 2007). The strategy for lifting is based on centre of percussion for maintaining stability. The main goal of our research is to develop a scheme to generate an optimal humanoid robot’s impact motion for a given task considering multibody dynamics. To effectively generate impact motion, impact motion generation software is developed as the first step of the impact motion research. The developed impact motion generation support software visualizes not only a designed motion but also an experimented motion. Force and torque measured in experiments are visualized on the experimented motion. The visualized ZMP (Zero-Moment Point) (Vukobratovic et al., 1990), GCoM (Ground Projection of the Center of Mass), force, moment 11