Optimization of the division operation for real-time control systems

This paper consider the utilization of the division operation in real-time motion control microcontroller systems. It is shown that the most typical case is calculation of the inverse DC-link voltage for the correction of the inverter control signals due to DC-link voltage deviations. The benchmark of the division operation shows that it takes approximately 30 or more CPU cycles to perform division on fixed- or floating-point microcontrollers. Also programmer should use right math libraries to achieve good results. At last it is suggested to use Newton-Raphson equation for inverse DC-link voltage calculation. The accuracy of this method and its benchmark are given.