Dynamic parameter identification of actuation redundant parallel robots using their power identification model: Application to the DualV

Off-line robot dynamic identification methods are generally based on the use of the Inverse Dynamic Identification Model (IDIM), which calculates the joint forces/torques (estimated as the product of the known control signal - the input reference of the motor current loop - by the joint drive gains) that are linear in relation to the dynamic parameters, and on the use of linear least squares technique to calculate the parameters (IDIM-LS technique). However, as actuation redundant parallel robot are overconstrained, their IDIM has infinity of solutions for the force/torque prediction, depending of the value of the desired overconstraint that is a priori unknown in the identification process. As a result, the IDIM cannot be used for the identification procedure. On the contrary the Power Identification Model (PIM) of any types of robot manipulator has a unique formulation and contains the same dynamic parameters as the IDIM. This paper proposes to use the PIM of actuation redundant robots for identification purpose. The identification of the inertial parameters of a planar parallel robot with actuation redundancy, the DualV, is then carried out using its PIM. Experimental results show the validity of the method.