Title: Identification of a non-linear hydraulic actuator considering rate saturation using particle swarm optimisation algorithm

Authors: Pouria Sarhadi; Nemat Ollah Ghahramani; Iman Shafeenejhad

Addresses: Department of Control Engineering, Islamic Azad University, South Tehran Branch, Iran, Babolsar, Postal Code:363, Tehran, Iran ' Amir Kabir University of Technology, Hafez Av., Tehran, Iran ' Islamic Azad University, Jask Branch, Emam Khomeini Blv., Bandare Jask, Postal Code: 79795-118, Iran

Abstract: In this paper, non-linear model of a hydraulic actuator considering amplitude and rate saturations is identified by an innovative method. Actuator model is taken into account with a first-order transfer function and non-linear functions of saturation with unknown parameters. Next, by defining objective function and invoking particle swarm optimisation (PSO) optimising method, unknown parameters of the non-linear model are estimated. As innovation of this work, the identified model has appropriately described the non-linear behaviour of the actuator and has higher fidelity compared to the conventional linear models. A comparison between non-linear simulation results using the new model and the experimental tests confirms the accuracy and effectiveness of the presented model. This model has large applications in autopilot design of practical flying systems, and it could also be used in simulation laboratory as a substitute for the costly real actuators.

Keywords: identification; hydraulic actuators; nonlinear modelling; particle swarm optimisation; PSO; rate saturation; amplitude; simulation; autopilot design.

DOI: 10.1504/IJMIC.2013.052329

International Journal of Modelling, Identification and Control, 2013 Vol.18 No.2, pp.136 - 145

Published online: 31 Jul 2014 *

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