State Variables Estimation of Flexible Link Robot Using Vision Sensor Data

The estimation of state variables plays a significant role in the control of flexible link robots. Flexible robots can have very complex dynamic vibrations during their operations. A vision sensor (i.e. camera) realizing a contactless measurement sensor can be used to measure the deformations. Unfortunatly effects like limited accuracy and time delay occur, which are the main inherent problems of vision sensors. The effects and compensation are studied in this work. The dynamic model of the flexible link is derived using the finite element method. Two observers are designed, the first one to estimate the vibrations using strain gauges (fast and complete dynamics), and the second one to estimate the vibrations using vision data (slow dynamical parts). The effects of time delay and noise in states estimation are shown by the comparison of the states from different measured input data. The main goal of the work is to develop an approach to combine suitable measurement devices easy to realize with improved reliability. The contribution describes the combination of the two estimated dynamical parts of the system dynamics. The task to be solved is to combine the estimations of the slow observer (based on vision measurements) with those of the fast observer based on strain gauges.