Abstract
The dissipated energy even of a manipulators must be decreased in order to improve the environment of the earth. This paper describes an optimal path which minimizes the dissipated energy in PTP motions of a vertically articulated manipulator. The dynamic equation of the manipulator is non-linear due to centrifugal-Coriolis, gravity and Coulomb friction forces. Moreover the driving system of the joints has also non-linearity that the generating torque is expressed by polynomial of degree 3 with respect to current. Therefore an optimal path can not be obtained by solving a two-point boundary-value problem analytically.
In this paper an optimal path is searched by the Genetic Algorithm (GA) in the condition that all kinds of non-linear characteristic of the manipulator including a driving system are taken into consideration. The obtained optimal velocity functions are applied to a vertically articulated manipulators with 2 direct-drive motors. The dissipated energy is measured by integrating the input power to the motors. Experimental results agree with the simulation values only when all kinds of non-linearity are taken into consideration.
