Simplified Method for Calculation of the Frequency Spectrum of Time and Value Discretized Signals

Common digital control systems rely on time and value discretized signals. A smaller value quantization step size results in a more precise digital representation of the real continuous valued signal, but might result in higher cost, e.g. for computational hardware or sensors. The effects of quantization of time discrete signals in frequency domain are analyzed in a simplified manner. This knowledge is especially useful in view of filter design, control bandwidth, sensor resolution, and word size in still commonly used fixed point arithmetic controllers. A flexible link, large scale, low speed, angular servo system with low eigenfrequencies is considered as reference application. For this system, the minimum resolution for the used angular position sensor will be determined.