Robust MPC–PIC force control for an electro-hydraulic servo system with pure compressive elastic load

• DOI: 10.1016/j.conengprac.2018.07.009
• Publication Date: 2018-08-17T13:49:53Z
• Authors: Hai-Bo Yuan; Hong-Cheol Na; Young-Bae Kim
• Keywords: Servomechanism; Robustness; Model Predictive Control; State-space representation

Abstract For accurate force tracking of an electro-hydraulic servo system (EHSS), this paper presents a state-space representation of model predictive control (MPC). EHSS is highly nonlinear because of the transmission nonlinearities, variations of the trapped fluid volume, internal friction, and nonlinear load-based nonlinearities. A nonlinear mathematical model is built, and model parameters are identified using a grey-box system identification method. Then MPC is firstly designed, and to improve the robustness, a nominal mathematical model with proportional integral control (PIC) is constructed for MPC design. Three implementation scenarios are investigated in MATLAB/Simulink and real-time LabVIEW-based experimental rig. The control performance is compared between and among PIC, MPC, and hybrid MPC–PIC controller.