Direct calculation of minimum set of inertial parameters of serial robots

Experimental Identification of the Inverse Dynamic Model: Minimal Encoder Resolution Needed Application to an Industrial Robot Arm and a Haptic Interface

“…It is usually represented by the following equation: vs =A(q)q+H(q,q)+F q+F sign(q) (1) where is the torques vector of the actuators, q, and are respectively the joint positions, The kinetic and potential energies being linear with respect to the inertial parameters, so is the dynamic model (Gautier & Khalil, 1990). Equation (1) can thus be rewritten as:…”

Inertial parameter estimation of floating base humanoid systems using partial force sensing

“…In such a case, the matrix K will not be full column rank, and therefore not invertible by (8). However, this problem can be resolved using a singular value decomposition [1] or finding the minimal set of identifiable inertial parameters, φ B [19] and rewriting (6) as:…”

Closed-Loop Rigid Model Identification of an Industrial Robot

“…If the following conditions hold: DC j = 0 and dP j = 0 (6) the parameter X j has no effect on the dynamic model and does not belong to the base parameter set. Inertial parameter satisfying (6) are those of the axis near the base side, and there exist rules (Gautier and Khalil, 1988;Gautier and Khalil, 1990) to find those parameters without using (6).…”

“…Since the robot producers very rarely provide this information, users need to follow a reliable procedure allowing to recover a model valid in the frequency range of interest. The dynamic model of a robot depends on such parameters as links inertia, mass and center of mass, but only a subset of them, called Base Parameters (Gautier and Khalil, 1990;Gautier and Khalil, 1988;Mayeda et al, 1990;Pham and Gautier, 1991;Kozlowzki, 1998), must be estimated to avoid a rapid rise in computational complexity when the number of degrees-of-freedom (DoF) grows. Many identification methods exist for system operating in open loop (Ljung, 1987;Forssell and Ljung, 1999;Forssell and Ljung, 2000;Sun et al, 2000;Welsh and Goodwin, 2002), but several of them fail when the system is under closed-loop action, as in the robot case, where it cannot operate without an active controller, for safety reasons.…”