Piston position estimation for an electro-pneumatic actuator at standstill. (August 2015)

• Record Type: Journal Article
• Authors: Abry, Frédéric; Brun, Xavier; Di Loreto, Michael; Sesmat, Sylvie; Bideaux, Éric
• Is Part Of: Control engineering practice. Volume 41(2015)
• Page Start: 176
• Page End: 185
• Publication Date: 2015-08
• Subjects: Estimation -- Observability analysis -- Nonlinear observer synthesis -- Electro-pneumatic actuator -- Signal injection; Automatic control -- Periodicals; 629.89
• DOI: 10.1016/j.conengprac.2015.04.016
• Languages: English
• ISSNs: 0967-0661

Abstract

Abstract: In this paper, a first strategy to reconstruct the piston position of a pneumatic cylinder supplied by two servovalves is proposed using only the chambers pressure measurements. This work focuses on the position observation at standstill. Starting from a classical model of this actuator, a transformation of the inputs is used. This way, for the first time, a link is established between electro-pneumatic actuators and Permanent Magnet Synchronous Motors (PMSM). This allows to apply PMSM zero speed observation strategies to electro-pneumatic actuators. Thus, following an observability analysis, a signal injection based methodology is used to ensure the observability of the electro-pneumatic system. A non-linear position observer is synthesized and a Lyapunov function is provided to ensure the global stability. Experimental results confirm the proposed strategy efficiency. The proposed technique constitutes a first step toward sensorless position control of electro-pneumatic actuators. Abstract : Highlights: A parallel between electro-pneumatic actuators and PMSMs is drawn. The observability of the piston position is analyzed at standstill. A signal injection method is proposed to make this system observable. A non-linear observer is synthesized to reconstruct the piston position at standstill. A Lyapunov function is proposed to demonstrate the system global stability.