An Implementable Speed Measurement Method in Order to Eliminate Quantization Error while Using Rotary Incremental Encoders
Mahdi Maaref, Alireza Rezazadeh, Hassan Shokouhandeh · 2013
In this paper, we propose an implementable method to calculate motor speed base on incremental encoders. This method solves two major problems of calculating speed by the aid of quadrature encoder signals; first the discrepancies of speed pattern especially in high and low speeds and second the quantization error which occurs by differentiation of discrete quantity (i.e. motor position). In order to get a method which, has an ability of calculating the speed in wide range, it is inevitable to use different algorithms for different ranges of speed. But the important issue is to have a soft switching between these algorithms which is the scope of this approach. Our proposed method achieves high accuracy from low resolution encoders which is more efficient. The simulation and experimental results validate the precision of proposed method especially, in the moment of changing measurement algorithm. KEYWORDS—rotary incremental encoder, quadrature pulses, encoder resolution, sampling time.