RQH Sampling Strategy Analysis with DF Method

This chapter introduces a novel sampling approach, termed Regular Quantization with Hysteresis (RQH), designed for networked control systems. RQH offers advantages over the widely used Symmetric-Send-On-Delta (SSOD) sampling strategy in event-based PID control loops. The RQH behavior is determined by two key parameters: signal quantification and hysteresis. The impact of these parameters on overall system performance is analyzed, and guidelines for their selection are provided, considering factors such as noise measurement and steady-state error. Investigation into potential limit cycle oscillations induced by RQH sampling is conducted, accompanied by the proposal of new robustness measures based on the Describing Function (DF) method to mitigate such oscillations. The chapter evaluates the applicability of certain tuning rules for continuous Proportional-Integral (PI) controllers when applied to systems employing RQH sampling, utilizing the proposed measures. Results indicate that these tuning rules can be effective under specific conditions.