Identification of physical parameters including ground model parameters of walking robot rabbit

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