Pseudo Random Number Coding for Lift Car Position Sensing

Abstract

Aiming at the disadvantages of the traditional positioning for lift car applications, a novel binary bar coding and sensing technology is presented in this paper. It studies the relationship of the addressable length and the number of digits to be sensed. A more systematic approach is demonstrated to generate the pseudo random code more efficiently than the random sorting method used in the example case. Finally, a function of vector distance is developed to measure the difference of any two groups of the digits to be sensed along the complete code sequence. By searching the maximum of the vector distance, the optimal sequence can be achieved to reduce the chance of decode error.