STOCHASTIC ESTIMATE PCA ALGORITHM FOR PLANAR INDUSTRIAL MANIPULATOR CONTROL

In this paper an innovative Stochastic Estimate Algorithm based on Principal Components Analysis (PCA) and on Maximum Likelihood technique, which is applied to estimate nonlinear multi – input – multi - output model (M.I.M.O.) of a manipulator with two link and non-flexible joints, is proposed. As is well known, a problem in mathematical model of a robotic manipulator concerns non-modeled dynamics, for example the static and dynamic friction. A training algorithm is necessary for estimating parameters of a approximate model with linear or nonlinear structure. The proposed algorithm is able to train parameters of a linear digital filter with infinite impulsive answer (I.I.R.). The filter is called "LPC (Last-Principal-Component)", because the solution of the optimization’s problem is the last principal component. Input – Output training set has been opportunely extracted from proportional-derivative (PD) control system of a robotic manipulator which is a centralized control system. Algorithm’s efficiency is validated by digital simulation’s experiments using Matlab 6.5 software. Trajectories for testing PCA algorithm have been implemented in C language using software, hardware and graphic interface of an industrial manipulator.