Study on mixed H2/H∞ output feedback control of maglev actuator for microgravity vibration isolation system. (February 2019)

• Record Type: Journal Article
• Authors: Chen, Changhao; Hu, Yefa; Wu, Huachun; Song, Chunsheng; Ran, Shaolin
• Is Part Of: Advances in mechanical engineering. Volume 11:Number 2(2019)
• Publication Date: 2019-02
• Subjects: Maglev -- actuator -- dynamic model -- mixed H2/H∞ control; Mechanical engineering -- Periodicals; 621.05
• DOI: 10.1177/1687814018819596
• Languages: English
• ISSNs: 1687-8132

Abstract

Aiming at how to specify the fundamental trade-off between robust stability and nominal performance of mixed H2 /H∞ control as well as lack of experimental studies on vibration control for the maglev actuator in microgravity vibration isolation system, a mixed H2 /H∞ output feedback controller based on the linear matrix inequality method is designed and analyzed. This article establishes a state–space realization for a one-dimensional vibration isolation system and the H-norm performance indices are identified and calculated. Furthermore, the curves of threshold values and true values of H∞ and H2 norms are plotted to specify the relationship between the system's robust stability and nominal performance. Therefore, the threshold value of system's H∞ norm is identified through repeated simulations, and the state–space realization of optimal controller with minimum H2 norm under the constraints of H∞ norm threshold value is obtained. The vibration control experimental apparatus of one-dimensional control system is designed and manufactured to test the actual application of mixed H2 /H∞ controller for the maglev actuator. The result presents that the designed mixed H2 /H∞ control has a better performance in suppressing acceleration vibration and has a higher attenuation amplitude than cascade proportional–integral–derivative control at each corresponding frequency, which proves the practicability and effectiveness of the design method.