Abstract
Currently, most of the manipulators used in industry are fixed in a single position, and the work range is limited. From now on, to expand the ability of a manipulator, it is necessary that a manipulator itself will have a mobile ability like that of human beings. A human being performs a variety of work by coordinating hands, arms, and legs. This study aims to clarify basic rules of human motion, from the standpoint of biomechanism, by analyzing the results of an experiment in handling a mainpulator based on a guide shaft with body movements, and to apply them to task planning for a mobile anthropomorphic manipulator. This is a different approach from the conventional method, which uses an evaluation function with weighting coefficient. This paper presents the analysis of human motions between the upper body and legs, and application of the rule to a two-wheeled robot with a 7-degrees-of-freedom manipulator and 1 degree of freedom for rotating the manipulator itself. The experiment was conducted under conditions which require 1500-mm hand movement from three different start positions and angles. From the analysis of the results, three basic rules are derived as follows: (1) Human beings change the direction of the body as the first step in the motion to obtain mobility for walking. (2) Human beings do not change posture in the body coordinate, and mainly conduct the work by the legs. They keep an upper body posture for which the manipulability measure is high, and it is approximately 60% to 80% in the maximum work range of the arm. (3) In a straight line trajectory, human beings keep the same velocity of movement and hand, and keep a track parallel to the given hand trajectory. These basic rules are applied to the task planning algorithm for a mobile anthropomorphic manipulator which needs to determine the path of the two-wheeled robot and the redundancy of the manipulator. From the simulation, the hand is always determined in the range of 60% to 80% in the maximum work range of the arm in which the manipulability measure is high, and the minimum radius path is considered for the wheeled robot. The simulation result shows that it can make a plan which considers the manipulability of the manipulator and the motion of the wheeled robot.
