A New Alternating Predictive Observer Approach for Higher Bandwidth Control of Dual-Rate Dynamic Systems

• Published in: IEEE transactions on circuits and systems. II, Express briefs Vol. 70; no. 7; p. 1
• Main Authors: Shao, Liren, Yang, Jun, Li, Shihua, Yi, Yang
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.07.2023; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Actuators; alternating predictive observer; Bandwidth; Bandwidths; Closed loops; Control systems; dual-rate dynamic system; Dynamical systems; Feedback control; higher control bandwidth; Interpolation; Observers; Output feedback; Permanent magnets; Sampling; Stability analysis; Synchronous motors; Velocity measurement; virtual measurement
• ISSN: 1549-7747; 1558-3791
• DOI: 10.1109/TCSII.2023.3235934

Dual-rate dynamic systems consisting of a sensor with a relatively slow sampling rate and a controller/actuator with a fast updating rate widely exist in control systems. The control bandwidth of these dual-rate dynamic systems is severely restricted by the slow sampling rate of the sensors, resulting in various issues like sluggish dynamics of the closed-loop systems, poor robustness performance. A novel alternating predictive observer (APO) is proposed to significantly enhance the control bandwidth of a generic dual-rate dynamic systems. Specifically, at each fast controller/actuator updating period, we will first implement the prediction step by using the system model to predict the system output, generating a so-called virtual measurement, when there is no output measurement during the slow sampling period. Subsequently, the observation step is carried out by exploiting this virtual measurement as informative update. An APO-based output feedback controller with a fast updating rate is developed and rigorous stability of the closed-loop system is established. The superiority of the proposed method is demonstrated by applying it to control a permanent magnet synchronous motor system.