A method of the diagnosis through descriptor model of a constrained dynamic motion of a robot Gripper by the Indirect measurement

This work aims to develop a method for a system diagnosis regarding to an automatic screw or welding assembly line via the industrial robot that builds a constraint system with counterparts at the moment of working. The timely righteous estimation and judgment of the states is very important for the safe operation in time domain system. The synthesis of this problem presumes that all state variables are observable for concerned system. But it seems that it is not feasible to measure all modes of states of velocities, accelerations, forces and moments directly. A practical solution to this problem, which should be tried, is the estimation of the states or its velocities by the use of an observer which can estimate a system characteristics of linear or nonlinear states and effects as a mode, so called, “Indirect measurement”. For this procedure, the mathematical model of the concerned physical system which consists of links over joints and Gripper with the end effector, is derived with the significant remarks such as friction, gravitation, and Coriolis force. This is a basic system. The concrete assignment is to design the observer that estimates the characteristics of the states and velocities based on the measurement vectors. The main artifice is to approximate the characteristics with a fictitious model that may describe the modes of system errors. As a practical and convenient fictitious model, the characteristics of nonlinear effects are assumed as approximately stepwise contact. An identity observer is obtained whose state variables are the estimate of the state variable of the corresponding “observer system”. It consists of a simulated model with a correction feedback of the estimation.