MODELING OF FRICTIONS IN THE TRANSMISSION ELEMENTS OF A ROBOT AXIS FOR ITS IDENTIFICATION

摘要

Control in robotics needs more and more precise models of the mechani- cal parts of the structure and specially for a complex system such as a biped robot. An important but di±cult aspect of this work is the modeling of the mechanical loss due to friction in the chain of transmission from the motor to the axis. Each part losses are defined as a sum of three terms, one constant, another depending only on the speed and the last depending on the torque transmitted. The robot joint kinematic chain is modeled with three elements: the motor, the gearbox and a rotational joint at the leg. The results show a good adequacy between measurement and simulation with the proposed identification method in comparison with a classic least square identification method.