In:
Proceedings of the Institution of Mechanical Engineers, Part I: Journal of Systems and Control Engineering, SAGE Publications, Vol. 232, No. 10 ( 2018-11), p. 1325-1336
Abstract:
A vacuum pressure tracking system with high-speed on-off valves is a discontinuous system due to the discrete nature of high-speed on-off valves. Chamber pressure changes in the system are determined by the mass flow rates during the processes of charging and discharging. Here, a sliding mode controller with an asymmetric compensator based on average mass flow rate is designed for accurate vacuum pressure tracking. The controller output signal is converted into the duty cycles of the high-speed on-off valves via a pulse width modulation pulsing scheme. Owing to the extreme asymmetry of the processes, an asymmetric structure comprising one high-speed on-off valve in the charging unit and three high-speed on-off valves in the discharging unit is applied to weaken the impact of asymmetry. In addition, an asymmetric compensator is also designed to modify the pulse width modulation pulsing scheme to further eliminate the asymmetry. Experimental results indicate that the proposed controller achieves better performance in pressure tracking with the asymmetric compensator overcoming process asymmetry and enhancing system robustness.
Type of Medium:
Online Resource
ISSN:
0959-6518
,
2041-3041
DOI:
10.1177/0959651818780866
Language:
English
Publisher:
SAGE Publications
Publication Date:
2018
detail.hit.zdb_id:
2024903-2
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