Toshio Morita

Development and evaluation of seven DOF MIA ARM

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.

Design and control of mobile manipulation system for human symbiotic humanoid: Hadaly-2

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.

Development of 4-DOF manipulator using mechanical impedance adjuster

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.

Development of one-DOF robot arm equipped with mechanical impedance adjuster

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.

Development of an anthropomorphic force-controlled manipulator WAM-10

This paper describes the development and evaluation of an anthropomorphic force-controlled manipulator WAM-10 (Waseda Automatic Manipulator-10). The manipulator consists of a seven degree-of-freedom (DOF) arm and a thirteen-DOF four-fingered hand. The goal of WAM-10 is the realization of human-robot symbiosis and collaboration for ensuring collision safety. The developed arm employs an original joint mechanism, called the mechanical impedance adjuster, which can realize ideal compliance and safety motion. The hand is designed with consideration of human interactive tasks. Results of the evaluation experiments show that the WAM-10 has the capability of realizing high performance in compliant motion control.

Double safety measure for human symbiotic manipulator

Summary form only given. This paper describes a design methodology for a human symbiotic manipulator which mainly focuses on guarantee of human safety and abilities of human-robot collaboration. Safety design parameters relate to manipulator cover materials, motion controls, collision statements, and safety indices. As a safety design methodology it is proposed that one select and use a viscoelastic material based on its peak force and deceleration effects; reduce the manipulator motion velocity when certain indices cannot be satisfied; and provide for emergency stops for cooperative work velocities of 1.0 m/s and passive compliance control for lower velocities. An actual safety cover is developed and attached to a 7-DOF force controlled manipulator.

Human Symbiotic Humanoid Robot with Whole-body Compliance

In this paper, we propose a design method of human-symbiotic humanoid robots with whole-body compliance composed of mechanical and controlled compliance, for securing a wide range of dynamic responsiveness to various types of physical interference with humans. First, a design idea of mechanical compliance for realizing quick reduction of impulsive force is described, incorporating softly deformable materials attached on the body surface and passively compliant joints equipped with a mechanical spring inside. Next, we propose a cover sensor that detects accurate external force vectors on the entire body surface, in order to generate whole-body compliant motions based on the tactile and force information detected. Finally, evaluation experiments of physical interference between humans and an actual anthropomorphic robot are presented to verify the effectiveness of the respective compliance. The results confirm that two measures for securing whole-body compliance faculty realize both quick and slow responsiveness to physical interference with humans and that the proposed method is useful for enhancement of human-robot coordination.