Piston position estimation for an electro-pneumatic actuator at standstill

Abstract

a b s t r a c tIn 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.

Pressure control based on reinforcement learning strategy of the pneumatic relays for an electric-pneumatic braking system

“…19 To avoid direct processing of strong nonlinearity, the A-T transformation method is used to decouple the mechanical motion model and fluid model. 20 However, different from the servo-pneumatic system, the mechanical part of the PRV has an extremely short stroke and high speed, which results in a large stiffness of the system state transition equation due to the coupling between mechanical and fluid motion, therefore model-based control method can easily lead to severe oscillations. 13 In this circumstance, a motion decision algorithm that can combine the reliability of the model-based method and the flexibility of the reinforcement learning (RL) algorithm will be meaningful.…”

“…19 To avoid direct processing of strong nonlinearity, the A-T transformation method is used to decouple the mechanical motion model and fluid model. 20…”

Sliding-mode observers for state and disturbance estimation in electro-hydraulic systems

“…Over the past decade, observers have been used to improve the reliability of systems allowing fault detection and diagnostics [1,2]. Observers can also be adopted for reducing the number of sensors or for replacing sensors that may not be able to withstand some extreme environmental conditions [3]. Many interesting applications of observers in industrial applications are related to hydraulic actuation systems [4,5,6,7].…”