The aim of this paper is to present and to compare some linear and non-linear control laws for an electropneumatic positioning system both for point-to-point control and for tracking control. The experimental results are presented in terms of repeatability for each control law implemented on the same device: an in-line electropneumatic servo-drive. Different kinds of model, namely a non-linear affine model, linearized tangent model and a reduced linearized tangent model, are presented to synthesize the different control laws. For this a new mathematical modelling of the servo-distributor flow stage is described.

This paper focuses on a comparison between two control laws of an half meter stroke electropneumatic dissymetrical cylinder controlled by two three ways servo-distributors: a classical pole placement method and a with scheduling gains control law. Using physical laws, a nonlinear model of this process is described in the first part of this paper and the difficulty for the obtention of the servodistributors mass flow rates is carried out. Nevertheless, a particular choice of the control input leads to a single input one and around an equilibrium point, a tangent linearized model is obtained. Two control laws are described and implemented using a well kwown dSPACE interface card. Experimental results obtained for point to point control are presented and discussed.

This article proposes a new strategy for pneumatic cylinder control using an innovative control synthesis model of the system. A backstepping based control law is synthesized to take advantage of the system two degrees of freedom and a thorough tuning method of the closed-loop stiffness and damping is provided.

HAL is a multidisciplinary open access archive for the deposit and dissemination of scientific research documents, whether they are published or not. The documents may come from teaching and research institutions in France or abroad, or from public or private research centers. L'archive ouverte pluridisciplinaire HAL, est destinée au dépôt et à la diffusion de documents scientifiques de niveau recherche, publiés ou non, émanant des établissements d'enseignement et de recherche français ou étrangers, des laboratoires publics ou privés.