Human-like motion based on a geometrical inverse kinematics and energetic optimization
ABSTRACT For humanoid robotics the cooperation with human beings makes human like behavior indispensable. The robots of our days have to feature human like form and structure. But, more importantly its ways of motion and reactions should be like that expected with human. In this paper, we propose an algorithm for solving the human arm inverse kinematics problem (position and orientation). The proposed method eliminates the singular configurations faced in the classical inverse kinematics methods. Our algorithm is based on the choice of a special reference frames in the workspace of the different parts of human arm. The geometrical projection in local frames gives the aimed results. The proposed redundancy resolution criterion for 7ddl human like arm is obtained through an energetic optimization. The proposed algorithm could be used for humanoid robots arm, in upper limb prosthesis application, as well as in computer animations. It gives the solution for the inverse kinematics of the arm. Simulation results within ADAMS software are presented. Our study takes the result of a detailed grasping research which gives an associated object reference frame indicating the way to grasp the object.
- IEEE Transactions on Biomedical Engineering 02/1985; 32(1):67-9. · 2.35 Impact Factor
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ABSTRACT: Humanoid robotics is a new challenging field. To cooperate with human beings, humanoid robots not only have to feature human-like form and structure but, more importantly, they must possess human-like characteristics regarding motion, communication and intelligence. In this paper, we propose an algorithm for solving the inverse kinematics problem associated with the redundant robot arm of the humanoid robot ARMAR. The formulation of the problem is based on the decomposition of the workspace of the arm and on the analytical description of the redundancy of the arm. The solution obtained is characterized by its accuracy and low cost of computation. The algorithm is enhanced in order to generate human-like manipulation motions from object trajectories.Intelligent Robots and Systems, 2003. (IROS 2003). Proceedings. 2003 IEEE/RSJ International Conference on; 11/2003
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ABSTRACT: The aim of our investigation is to understand the mechanisms which control the movement of the human arm. The arm is here considered as a redundant system: the shoulder, elbow and wrist joints, which provide three degrees of freedom, combine to move the hand in a horizontal plane, i.e. a two dimensional space. Thus the system has one extra degree of freedom. Earlier investigations of the static situation led to the hypothesis that independent cost functions were attached to each of the three joints and that the configuration chosen for a given target position is that which provides the minimum total cost (Cruse 1986). The aim of the current investigation was to look for measurable values corresponding to the hypothetical cost functions. Experiments using pointers of different lengths attached to the hand showed that the strategy in choosing the joint angles are independent of the limb length. The muscle force necessary to reach a given angle is increased by a spring mounted across a joint. In this situation the angles of the loaded joint are changed for a given target point to give way to the force effect. This leads to the conclusion that the hypothetical cost functions are not independent of the physiological costs necessary to hold the joint at a given angle. The cost functions seem to depend on joint angle and on the force which is necessary to hold the joint in a given position. Cost functions are measured by psychophysical methods. The results show U-shaped curves which can be approximated by parabolas. The position of minimum cost (maximum comfort) for one joint showed no or weak dependency on the angles of the other joints. For each subject these "psychophysical" cost functions are compared with the hypothetical cost functions. The comparison showed reasonable agreement. This supports the assumption that the psychophysically measured "comfort functions" provide a measure for the hypothetical cost functions postulated to explain the targeting movements. Targeting experiments using a four joint arm which has two extra degrees of freedom showed a much larger scatter compared to the three joint arm. Nevertheless, the results still conform to the hypothesis that also in this case the minimum cost principle is applied to solve the redundancy problem. As the cost function for the whole arm shows a large minimum valley, quite a large range of arm positions is possible of about equal total costs.(ABSTRACT TRUNCATED AT 400 WORDS)Biological Cybernetics 02/1990; 62(6):519-28. · 2.07 Impact Factor