scholarly journals Motion control of an aircraft electro-hydraulic servo actuator

2019 ◽  
Vol 610 ◽  
pp. 012073
Author(s):  
M Z Fadel ◽  
M G Rabie ◽  
A M Youssef
Keyword(s):  
Motion Control ◽  
Servo Actuator ◽  
Hydraulic Servo

scholarly journals Modelling and transient response study of hydraulic servo actuator

2021 ◽  
Vol 1172 (1) ◽  
pp. 012037
Author(s):  
E E Ibrahim ◽  
T Elnady ◽  
I Saleh ◽  
S Hassan
Keyword(s):  
Transient Response ◽  
Servo Actuator ◽  
Hydraulic Servo

Effect of Nonlinear Characteristic of the Gas Turbine Engine Fuel System With Hardware-in-the-Loop

2018 ◽  
Author(s):  
Jinwei Chen ◽  
Jingxuan Li ◽  
Shengnan Sun ◽  
Huisheng Zhang
Keyword(s):  
Gas Turbine ◽  
Dead Zone ◽  
Gas Turbine Engine ◽  
Supply System ◽  
Hardware In The Loop ◽  
Nonlinear Characteristics ◽  
Turbine Engine ◽  
Zone Width ◽  
Servo Actuator ◽  
Hydraulic Servo

Fuel supply system, the regulation system for fuel delivery to the combustor, is one of the most important auxiliary systems in a gas turbine engine. Commonly, the fuel supply system was always simplified as a linear system. In fact, gas turbine engines almost use a hydromechanical main fuel control system which consists of electro-hydraulic servo actuator and fuel metering unit. These components have several nonlinear characteristics such as hysteresis, dead zone, relay, and saturator. These nonlinear characteristics can directly affect the performance a gas turbine engine. In this paper, a three-shaft gas turbine engine was taken as a research object. Firstly, a mechanism model of the fuel control system considering the nonlinear links was developed based on the hydro-mechanical theory. Then, the effect of dead zone-relay characteristic of the servo amplifier in electro-hydraulic servo actuator was analyzed. The results show that the dead zone width has great effect on the dynamic performance of the gas turbine engine. The fuel flow rate will be oscillating with small dead zone width. The parameters of the gas turbine engine will be stable with the increase of dead zone width. However, the larger dead zone width causes the hysteresis and the increase of the dynamic response time. At the same time, an improvement method with a two-dimensional fuzzy compensation was proposed. The results show that the fuzzy compensation can effectively solve the oscillation problem caused by the dead zone-delay. Finally, a Hardware-In-the-Loop (HIL) system is developed which is based on an electro-hydraulic servo actuator facility and a real-time software component of the gas turbine engine. An experiment is conducted on the HIL test rig to validate simulation result. The results show that the experiment matches well with the simulation results.

EHSA Primary Flight Controls Seals Wear Degradation Model

2018 ◽  
Author(s):  
Antonio C. Bertolino ◽  
Rocco Gentile ◽  
Giovanni Jacazio ◽  
Francesco Marino ◽  
Massimo Sorli
Keyword(s):  
Power Systems ◽  
Health Management ◽  
Research Activity ◽  
Degradation Model ◽  
Cross Section Area ◽  
Section Area ◽  
Starting Point ◽  
Flight Controls ◽  
Servo Actuator ◽  
Hydraulic Servo

Seals are widely used in hydraulic power systems to prevent fluid leakages. However, several types of degradation can decrease the performance of these components such as wear, which induces changes in the geometry of the cross-section area, influencing their sealing capability. Over the years, their behaviour has been primarily investigated with several theoretical and experimental researches. All these valuable results can be considered as a starting point for further investigations on the interaction between seals and the complete hydraulic equipment and on the root of seals degradation. This article proposes a physical model of performance degradation acting on dynamic seals of an electro-hydraulic servo-actuator (EHSA) ram for primary flight controls. In this article, a dynamic non-linear seals degradation model has been developed, based on the Hart-Smith hyperelasticity model, which physically describes the stress and strain of “rubber-like” materials. Similarly, wearing has been assessment by using the Archard’s equation. Furthermore, different operating temperatures have been considered to analyze the effect on seals performances. The integration between the mentioned seals degradation model and the high-fidelity model of the complete EHSA allows to evaluate the influence of various wear levels on the actuator behaviour. This research activity is inserted into a more extensive project of Prognostic and Health Management (PHM) of EHSAs. The results of the proposed simulations reveal how the performance of an EHSA can be affected by seals degradations.

scholarly journals Integral Nonsingular Terminal Sliding Mode Control of Hydraulic Servo Actuator Based on Extended State Observer

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Zhenshuai Wan ◽  
Yu Fu
Keyword(s):  
Sliding Mode ◽  
State Observer ◽  
Extended State Observer ◽  
Extended State ◽  
Tracking Accuracy ◽  
Terminal Sliding Mode ◽  
Motion Trajectories ◽  
Nonsingular Terminal Sliding Mode ◽  
Servo Actuator ◽  
Hydraulic Servo

Hydraulic servo actuator always suffers from various disturbance and uncertainties, which makes it difficult to design a higher performance controller. In this paper, an integral nonsingular terminal sliding mode controller based on extended state observer (ESO-INTSM) is proposed to improve the robust performance of hydraulic servo actuator. The ESO is designed to estimate not only the parametric uncertainties but also the model disturbance. Based on the observed states of ESO, the proposed controllers could enable hydraulic servo actuator to track the desired motion trajectories. The stability of the synthesized controller is proved via Lyapunov analysis, which is very important for high-accuracy tracking control of hydraulic servo actuator. Simulation and experimental results demonstrate that the proposed control strategy can effectively attenuate the adverse influence caused by the uncertainties and apparently improve the tracking accuracy.

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