Stiffness direction stabilization and inertia matrix diagonalization of robot manipulator by biarticular muscle

Abstract

This paper suggests two advantages of the biarticular muscle which has been said to play an important role in human's motion control; one is stiffness direction stabilization of an end effector which results in stabilization of the posture, and the other is inertia matrix diagonalization in the dynamics of a robot manipulator.In order to analyze these characteristics, we adopt three-pair six-muscle model of human arm including biarticular muscles and derive simple relationship between an endpoint force/position and three muscle torques based on the absolute angle of two joints. Based on the derived equation, the relationship between the stiffness in the workspace and in the muscle torque space is calculated and the direction of stiffness that can be enhanced by the biarticular muscle is revealed.Finally, we suggest a new dynamics of the planar robot manipulator with three muscle torque input where the inertia matrix is diagonalized.

Neuro-controller for antagonistic bi-articular muscle actuation in robotic arms based on terminal attractors

“…In addition to the fast convergence and low computation cost, such attractors provide a robust and efficient approximation of inverse dynamics (Sira-Ramirez and Colina-Morales, 1993; Zak and Sira-Ramirez, 1990), to compensate for unknown nonlinear robot dynamics (Garcia-Rodriguez and Parra-Vega, 2009, 2011). Although quite simple linear models and control schemes have been proposed for AbA actuators, (Oh et al, 2009; Sano et al, 2012), we address, on one hand, uncertainty compensation with smooth control action, and on the other hand, the mechanical efficiency of payload to weight ratio of AbA. In this manuscript, we focus on the first issue, but we provide evidence of energy efficiency in a comparison study.…”

Development and verification of simple tension distribution considering tension limits for 2-joint arm with 3 pairs of 6 tendons

“…Although this Fig.1 are studied. Various advantages for control and passive motions due to the model have been reported [9] [10]. There are reduction of interaction among elements of both joints as an advantage of the model.…”