An iterative learning approach to error compensation of position sensors for servo motors

  • Han, Seok-Hee (Department of Control and Instrumentation Engineering, Seoul National University, San 56-1, Shinrim-Dong, Kwanak-Ku, Seoul 151-742) ;
  • Ha, In-Joong (Department of Control and Instrumentation Engineering, Seoul National University, San 56-1, Shinrim-Dong, Kwanak-Ku, Seoul 151-742) ;
  • Ha, Tae-Kyoon (Department of Control and Instrumentation Engineering, Seoul National University, San 56-1, Shinrim-Dong, Kwanak-Ku, Seoul 151-742) ;
  • Huh, Heon (Department of Control and Instrumentation Engineering, Seoul National University, San 56-1, Shinrim-Dong, Kwanak-Ku, Seoul 151-742) ;
  • Ko, Myoung-Sam (Department of Control and Instrumentation Engineering, Seoul National University, San 56-1, Shinrim-Dong, Kwanak-Ku, Seoul 151-742)
  • Published : 1993.10.01

Abstract

In this paper, we present an iterative learning method of compensating for position sensor error. The previously known compensation algrithms need a special perfect position sensor or a priori information about error sources, while ours does not. To our best knowledge, any iterative learning approach has not been taken for sensor error compensation. Furthermore, our iterative learning algorithm does not have the drawbacks of the existing iterative learning control theories. To be more specific, our algorithm learns a uncertain function inself rather than its special time-trajectory and does not request the derivatives of measurement signals. Moreover, it does not require the learning system to start with the same initial condition for all iterations. To illuminate the generality and practical use of our algorithm, we give the rigorous proof for its convergence and some experimental results.

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