title: An energy-saving nonlinear position control strategy for electro-hydraulic servo systems.
abstract: The electro-hydraulic servo system (EHSS) demonstrates numerous advantages in size and performance compared to other actuation methods. Oftentimes, its utilization in industrial and machinery settings is limited by its inferior efficiency. In this paper, a nonlinear backstepping control algorithm with an energy-saving approach is proposed for position control in the EHSS. To achieve improved efficiency, two control valves including a proportional directional valve (PDV) and a proportional relief valve (PRV) are used to achieve the control objectives. To design the control algorithm, the state space model equations of the system are transformed to their normal form and the control law through the PDV is designed using a backstepping approach for position tracking. Then, another nonlinear set of laws is derived to achieve energy-saving through the PRV input. This control design method, based on the normal form representation, imposes internal dynamics on the closed-loop system. The stability of the internal dynamics is analyzed in special cases of operation. Experimental results verify that both tracking and energy-saving objectives are satisfied for the closed-loop system.
authors.affiliation: Mechanical Engineering Department, Amirkabir University of Technology, Tehran, Iran.
authors.forename: Keivan
authors.initials: K
authors.lastname: Baghestan
authors.affiliation: Mechanical Engineering Department, Amirkabir University of Technology, Tehran, Iran. Electronic address: smrezaei@aut.ac.ir.
authors.forename: Seyed Mehdi
authors.initials: SM
authors.lastname: Rezaei
authors.affiliation: Electrical Engineering Department, Amirkabir University of Technology, Tehran, Iran.
authors.forename: Heidar Ali
authors.initials: HA
authors.lastname: Talebi
authors.affiliation: New Technologies Research Centre, Amirkabir University of Technology, Tehran, Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Zareinejad
keywords: Electro-hydraulic systems; Energy saving; Position control