The study described aims to develop human symbiotic robots, which have the abilities of carrying out physical, informational, and psychological interaction, and support daily work in a human's living space. We mainly discuss two essential design requirements for realizing human-robot symbiosis, such as safety and dexterity. First, through the development of human symbiotic robot WENDY (Waseda ENgineering Designed sYmbiont), a mechanical design method is proposed. Next, the effectiveness of the method is evaluated by several basic experiments, such as object grasping by using visual information, impact safety motion, and pressure control on the fingertip. Finally, performances of WENDY are also exhibited from several experiments that require high level integration of whole body mechanisms.

The authors describe the control methods used for a humanoid's compliant behavior following human force and motions while fulfilling given tasks under various constraint conditions during Physical InterFerence (PIF) with a human. PIF is a form of physical interaction viewed from the robot's point of view. In cases of PIF occurrence, PIF Adapting Behaviors for attenuating physical influences caused by PIF on both a human body and a robots' task are required. First, a base control method for compliantly following PIF by coordinating multiple joints of the arms and trunk is presented. By utilizing this method, PIF force produced on several areas of the robot's entire body is efficiently reduced. Next, the control methods for fulfilling given tasks, as well as following PIF at the same time, are proposed. In these methods, the idea is incorporated that if the utilization of redundancy is needed for task fulfillment or constraint conditions and attributes of the given task are changed, the role of each joint needs to change as well. Adapting to the diversity of task attributes and also the necessity of utilizing redundancy, the proposed control methods enable the robots to realize both force following and task fulfillment at the same time. Finally, from the evaluation of the experiments, it was confirmed that the proposed methods realize a humanoid's capability of compliantly adapting to human motions while fulfilling tasks by efficiently utilizing redundancy.

An objective of this study is to find out design requirements for developing human symbiotic robots, which share working space with humans, and have the ability of carrying out physical, informational, and psychological interaction. The paper mainly describes design strategies of the human symbiotic robots, through the development of a test model of the robots, WENDY (Waseda ENgineering Designed sYmbiont). In order to develop WENDY, mobility and dexterity of a humanoid robot Hadaly-2, which was developed in 1997, are improved on. The performances of WENDY are evaluated by experiments of object transport and egg breaking, which require high level integration of the whole body system.

In this paper, a comprehensive new concept concerning situations where robots physically contact with human such as tactile contacts and collisions is proposed, which is named physical interference (PIF). In order to realize PIF adaptation with human, it is required for robots to recognize PIF with human as well as secure human safety. First, information of PIF with human for recognizing PIF in detail is specified. Next, a hybrid PIF adapting hardware system composed of a mechanical passive compliant arm and PIF recognizing covers with viscoelastic materials is proposed and was developed. Finally, in order to evaluate the hardware system, experiments of adapting to PIF with human, using an arm equipped with MIA (mechanical impedance adjuster) and the developed surface covers, were carried out. From the results of the evaluation experiments, the validity of the developed hardware system for basic PIF adaptation with human was confirmed.

The objective of this study is to investigate design and control strategies for realizing human-robot symbiosis, and to develop a human symbiotic humanoid robot, Hadaly-2, which can communicate and collaborate with human. In this paper, mechanism design methodologies, specifications, and control strategies of a mobile manipulation system of the Hadaly-2 will be described. First, mechanism design concepts of the manipulation system for the human symbiotic robot are proposed. Next, two force controlled anthropomorphic manipulators (WAM-10R, and L) and a body-vehicle mechanism are developed in consideration of the design concepts. Then, the communication and collaboration abilities of Hadaly-2 are evaluated by means of several behaviors, such as gesture motion, shaking hands with human, and block carrying tasks. From the results of evaluation experiments, it is confirmed that the Hadaly-2 can realize efficient interaction and collaboration with human.

This study aims to realize passive impedance control of the robot joint by mechanical elements (MIA), and to develop an anthropomorphic manipulator using this mechanism. The mechanism has the advantage of conventional method of the force control in realizing high compliance. The manipulator which employs this joint mechanism is appropriate for the human-robot cooperative tasks, because each joint can realize safety motion. This paper presents a development of the anthropomorphic manipulator (seven DOF MIA ARM) which consists of shoulder, elbow and wrist. This paper also describes a dynamic model of multiple-DOF MIA and an experimental evaluation of the seven DOF MIA ARM by means of trajectory control. The experimental results show that the seven DOF MIA ARM can realize high performance in motion control with consideration to the effect of dynamics, selfweight and damping.

The objective of our study is to realize passive impedance of the robot joint by mechanical elements (MIA), and to develop an anthropomorphic multiple DOF manipulator using this mechanism. This mechanism has the advantage of a conventional method of force control in realizing high compliance. This paper presents the development of the 4-DOF MIA ARM which is an upper arm of the manipulator. This paper also describes the experimental evaluation of the 4-DOF MIA manipulator by means of step responses and circular trajectory. The experimental results show that the 4-DOF MIA ARM has high performance not only in force control but also in motion control.

The object of our work is to realize passive impedance on the joints of robot fingers by mechanical elements, as leaf springs and brakes, and to develop robot fingers using the new mechanism to grasp objects softly. This paper presents a new joint mechanism, named "mechanical impedance adjuster", and an impedance control method of the robot finger joint by this mechanism. The effectiveness of this method is shown by the experiment on a 1-DOF finger model.

In order to realize constraint tasks by a manipulator, it is effective to adjust the joint impedance to the appropriate value. Most of the previous studies use the active force control method that uses information from force sensors. Using this method, the performances are limited by the responses of the servo systems, the non-linear characteristics of the force sensors and the dynamics of the manipulator. The object of this study is to adjust the joint impedance of the manipulator to an ideal degree by a mechanism which consists of a spring and a damper. In a previous study, the authors proposed a compliance adjustment method using the spring mechanism, the structure and control of the pseudo-damper system, and simple control algorithms for the coordinated system. In this paper, the authors discuss the evaluation of the effect of these mechanisms and the control method using the 1-DOF Arm Model which was newly developed as a base model to build a multiple degrees of freedom manipulator.