Dynamic Position Control and Dimensional Extension of Dynamics Based on Orbit Attractor

Abstract

For dynamic control of a robot, a torque/force control will be necessary because the robot model is represented by a dynamic equation. A torque/force control requires a torque/force sensor or a current sensor(for DC servo motor) for feedback loop, however, they occupy large volume and weight or have low precision and time delay. Therefore, the robot system sometimes has a local position control in the motor drivers from the safety point of view. In this paper, we propose a design method of position-based dynamic control using an autonomous control method based on an orbit attractor, which is realized by a simple deformation of the conventional algorithm. In addition, for the orbit attractor control, it is necessary that an orbit of the state variable is not crossing in the state space. When the orbit is very close, vector field of the orbit attractor along the orbit can not be defined correctly. A dimensional expansion of dynamics is also proposed to design a controller. These methods are evaluated by experiments using a two-dimensional biped robot.