Finite-Time Output Feedback Control for Electro-Hydraulic Servo Systems with Parameter Adaptation

Abstract

Measurement noise, parametric uncertainties, and external disturbances broadly exist in electro-hydraulic servo systems, which terribly deteriorate the system control performance. To figure out this problem, a novel finite-time output feedback controller with parameter adaptation is proposed for electro-hydraulic servo systems in this paper. First, to avoid using noise-polluted signals and attain active disturbance compensation, a finite-time state observer is adopted to estimate unknown system states and disturbances, which attenuates the impact of measurement noise and external disturbances on tracking performance. Second, by adopting a parameter adaptive law, the parametric uncertainties in the electro-hydraulic servo system can be much lessened, which is beneficial to averting the high-gain feedback in practice. Then, integrating the backstepping framework and the super-twisting sliding mode technique, a synthesized output feedback controller is constructed to achieve high-accuracy tracking performance for electro-hydraulic servo systems. Lyapunov stability analysis demonstrates that the proposed control scheme can acquire finite-time stability. The excellent tracking performance of the designed control law is verified by comparative simulation results.

Methods of Ensuring Invariance with Respect to External Disturbances: Overview and New Advances

“…The standard approach of obtaining an estimate of an external disturbance η3 (t) is to expand the state space using a dynamic model, simulating the action of external disturbance, and construction of extended observer [3][4][5]. In the case of parametric uncertainty of the control plant model, the identification and adaptation algorithms are additionally used to estimate the unknown parameters [6][7][8].…”

“…(i) The selection of switching plane parameters c 1,2 > 0 at which the reduced secondorder system is stable; (ii) Selection of the amplitude of discontinuous control (8), at which stabilization of the virtual elementary system of the first order is ensured. This decomposition simplifies the synthesis of a controller for the multidimensional system with vector control.…”

“…Amplitude is selected so as in a system with discontinuous control (8), that ensures |s(t)| ≤ 1/k ≤ ∆, t > t 0 , when |s(0)| > 1/k. Selection of k ≥ 1/∆ ensures the desired stabilization accuracy, and as a result, the fulfillment of ( 10) and (3).…”

Real-Time Hybrid Test Control Research Based on Improved Electro-Hydraulic Servo Displacement Algorithm

“…The electro-hydraulic servo system [ 4 , 5 ], as a subsystem of the real-time hybrid test, has high intrinsic frequency and loop gain, high control accuracy of displacement, velocity, force, and excellent tracking performance. In recent years, research on electro-hydraulic servo control systems has focused on the online identification of nonlinear parameters [ 6 , 7 , 8 , 9 , 10 ], state observation [ 11 , 12 , 13 , 14 , 15 , 16 ], fault detection [ 17 ], dead zone compensation [ 18 ], PID algorithms [ 19 ], sliding mode control [ 20 ], neural networks [ 21 , 22 , 23 ], and other methods to achieve accurate control of the system.…”

Research and Experimental Analysis of Hydraulic Cylinder Position Control Mechanism Based on Pressure Detection

“…Lan Li presented a novel nonlinear model and high-precision lifting motion control method of a hydraulic manipulator driven by a proportional valve [16]. Luyue Yin proposed a novel finite-time output feedback controller with parameter adaptation for electro-hydraulic servo systems [17]. However, because of low energy efficiency and high cost of these control valves, the application scenarios are limited [18].…”