High-performance multi-scale control scheme for stable, integrating and unstable time-delay processes

• Published in: Journal of process control 2013-11, Vol.23 (10), p.1333-1343
• Main Authors: Nandong, Jobrun, Zang, Zhuquan
• Format: Article
• Language: English
• Subjects: Multi-scale control; PID; Smith predictor; Time-delay; Unstable process
• ISSN: 0959-1524; 1873-2771
• DOI: 10.1016/j.jprocont.2013.08.007

•New control scheme for stable and integrating/unstable time-delay processes.•The design principle is to decompose a given plant into a sum of basic modes.•An individual sub-controller is specifically designed to control each mode.•The sub-controllers are combined to enhance cooperation among the plant modes.•Numerical study demonstrates the applicability and effectiveness of the scheme. This paper presents a new multi-scale control scheme which is applicable to both stable and integrating/unstable time-delay processes. The salient feature of the proposed scheme is to decompose a given plant into a sum of basic modes, where an individual sub-controller is specifically designed to control each of these modes. An overall multi-scale controller is then synthesized by combining all the sub-controllers in such a way to achieve good cooperation among the different plant modes as to achieve good nominal performance and performance robustness. Extensive numerical study shows that the proposed multi-scale control scheme provides substantial improvement in control performance/robustness over the classical Smith predictor and some of its well-established variants.