Delta-Sigma based bit-stream controller for a D.C. motor

Abstract

The present paper proposes a Delta Sigma (ΔΣ) modulator based control to control linear systems. This control method processes bit stream signals to control physical systems and offers various advantages compared to traditional methods of controller implementation, which uses multi-bit processing. To evaluate the performance of the bit-stream controller in real-life control applications, a digital controller based on a delta operator is used as a benchmark to which the controller utilizing bit-stream technique is compared. The effectiveness of the proposed bit-stream controller is experimentally validated considering an example of a DC motor. The results of the experiment show that the technique utilizing bit-stream signals are more attractive as an alternative to processing of multi-bit digital signal. Although both controllers display a comparable performance in simulation and experiment, the controller utilizing bit-stream uses approximately 400 logic elements (LE) on an Altera Cyclone FPGA comparing to the conventional controller which costs 600 (LE) and 17 9-bit multipliers.