For robots working in human environment, human safety is one of the most serious and important aspects to be considered. Appropriate intrinsic and / or functional safety design must be employed for collaborative robots in order to reduce the human injury risks through physical human-robot interaction. Above all the situations that such interactions are possible to occur, it is reported that clamping humans with robot and its environment is of great danger in a sense of human injury risks. We have conducted experiments and simulations that mimic clamping-human accident in some different situations varying robot's inertia, velocity, thickness of robot's soft cover and joint stiffness. Furthermore, some collision detection and reaction measures are implemented on the experimental system and their contributions to human safety were evaluated. From the results of these experiments and simulations, the joint stiffness was found to play an important role on human safety considerably affecting the performance of collision reaction.

In this paper, a finishing system with a mounted abrasive tool is proposed for polishing of metallic molds. The shape of the mounted abrasive tool is a ball-end type. When a metallic mold with curved surface is polished, not only the orientation of the mounted abrasive tool is fixed but also its revolution is locked. The motion of the mounted abrasive tool is feedforward controlled based on an initial trajectory calculated in advance. The surface is polished by the polishing force which consists of a contact force, motion and viscous friction forces acting between the mold and tool. In this case, the velocities in the normal and tangent directions are delicately regulated so that the polishing force can track the desired value. The effectiveness of the proposed system is proved by experiments using an industrial robot with a PC based controller.

We have developed a humanoid robot HRP-2P with a biped locomotion controller, stereo vision software and aural human interface to realize cooperative works by a human and a humanoid robot. The robot can find a target object by the vision, and carry it cooperatively with a human by biped locomotion according to the voice commands by the human. A cooperative control is applied to the arms of the robot while it carries the object, and the walking direction of the robot is controlled by the interactive force and torque through the force/torque sensor on the wrists. The experimental results are presented in the paper.

This paper presents a prototype humanoid robotics platform developed for HRP-2. HRP-2 is a new humanoid robotics platform, which we have been developing in phase two of HRP HRP is a humanoid robotics project, which has been launched by Ministry of Economy, Trade and Industry (METI) of Japan from 1998FY to 2002FY for five years. The ability of the biped locomotion of HRP-2 is improved so that HRP-2 can cope with rough terrain in the open air and can prevent the possible damages to a humanoid robot's own self in the event of tipping over. The ability of whole body motion of HRP-2 is also improved so that HRP-2 can get up by a humanoid robot's own self even tough HRP-2 tips over. In this paper, the mechanisms and specifications of developed prototype humanoid robotics platform, and its electrical system are introduced.