This paper deals with the high performance force control of hydraulic load simulator. Many previous works for are based on their linearization equations, but inherent nonlinear properties and uncertainties make conventional feedback proportional-integral-derivative not yield to high-performance requirements. In this paper, a system model is derived linear parameterization made adaptive control. Then discontinuous projection-based robust controller developed The proposed constructs an...

Electro-hydrostatic actuator (EHA) is a highly integrated local hydraulic actuation system for more electric aircraft (MEA). However, the motor heating has always been bottleneck in actual applications. In this paper, novel energy-recovery EHA (ER-EHA) with specific energy recovery unit proposed to solve problem. ER-EHA can reduce of motor, which beneficial improve reliability and mean time before failure system. Besides, power resistor eliminated new system, so volume reduced,...

As a traditional communication method, image is widely used because it easier to process than text. However, the user's environment may be very dangerous. In this case, security of information becomes crucial. Therefore, encryption method convert into another that not easy understand important maintain transmitted information. The primary objective paper introduce novel approach for leverages machine learning and cryptographic techniques. This employs pixel substitution convolutional neural...

This paper investigates motion coupling disturbance (the so called surplus torque) in the hardware-in-the-loop (HIL) experiments. The "velocity synchronization scheme" was proposed by Jiao for an electro-hydraulic load simulator (EHLS) 2004. In some situations, however, scheme is limited implementation certain reasons, as case when actuator's valve signal not available or it seriously polluted noise. To solve these problems, a "dual-loop developed EHLS. dual-loop combination of torque loop...

As a kind of actuation mechanism for power-by-wire (PBW) systems more/all electrical aircraft, an electro-hydrostatic actuator (EHA) is highly integrated local hydraulic system. It volume control system consisting motor, pump, actuator, etc., which has features high efficiency and reliability. However, the poor dynamic characteristic one main factors restricting its wide application in aircraft. In this paper, reason EHA revealed from perspectives natural frequency power requirement,...

The aircraft antiskid braking system is an important hydraulic for preventing tire bursts and ensuring safe take-off landing. brake adjusts the force applied on discs by controlling pressure. Traditional systems achieve performance pressure with electrohydraulic servo valve. Because pilot stage of valve easily blocked carbonized oil, would become a dangerous weak point safety. This paper proposes new approach that uses on-off array to replace control. Based this control component, efficient...

The hydraulic flight motion simulator (HFMS) is the key equipment for hardware-in-the-loop simulation in field of aerospace and has been widely used on occasions requiring high maneuverability large power. However, three mismatched uncertainties, including nonlinear friction torque, unbalanced gravity unknown inertia, bring some certain difficulties receiving high-precision outer frame position control HFMS. In this article, first, by means an ingenious experimental design, coupled torque...

The wheel brake system of an aircraft is the key to ensure its safe landing and rejected takeoff. A wheel's slip state determined by torque ground adhesion torque, both which have a large degree uncertainty. It this nature that brings upon challenge obtaining high deceleration rate for control. To overcome disturbances caused above uncertainties, braking control law designed, consists two parts: runway surface recognition tracking. In recognition, identification rules balancing safety...

This paper studies a nonlinear robust control algorithm of the electro-hydraulic load simulator (EHLS). The tracking performance EHLS is mainly limited by actuator's motion disturbance, flow nonlinearity, and friction, etc. developed controller based on loading model. problems disturbance nonlinearity are considered. To address friction problem, model motor identified experimentally. compensated using obtained Therefore, this considers main three factors comprehensively. easy to apply since...

The electro-hydrostatic actuator (EHA) used in more electric aircraft (MEA) has been extensively studied due to its advantages of high reliability and integration. However, this integration results a small heat dissipation area, leading high-temperature problems. Generally, reduce the temperature, wet cooling method using pump leakage oil cool motor is adopted, which can also increase difficulty accurately predicting system temperature early design stage. To solve problem, dynamic coupling...

Electro-hydrostatic actuator (EHA) is a type of in more electric aircraft, which highly integrated local volume control hydraulic actuator, and can improve the reliability efficiency. However, motor heating hardly be taken out due to feature closed hydrostatic system, especially under heavy load. In order solve problem, direct load sensitive EHA an effective way reduce heat, but dynamic performance inevitably sacrificed. To achieve targets both low heat generation high response, novel active...

The aircraft braking system is a critical used to slow down and stop the aircraft. Typically, usually uses electro-hydraulic pressure servo-valve (EHPSV) regulate of However, pilot stage EHPSV which has very precise orifice easy be blocked leads terrible fault. <sc xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">on</small> / xmlns:xlink="http://www.w3.org/1999/xlink">off</small> valve robust oil contamination better stability, but it challenging...

An electro-hydraulic load simulator (EHLS) is a typical case of torque systems with strong external disturbances from hydraulic motion systems. A new velocity synchronizing compensation strategy proposed in this paper to eliminate disturbances, based on theoretical and experimental analysis structure invariance method traditional controller (TVSM). This only uses the servo-valve's control signal system feedback system, which could avoid requirement acceleration method, effectively achieve...

Electro-hydrostatic actuator is generally regarded as the preferred solution for more electrical aircraft actuation systems. It of importance to optimize weight, efficiency and other key design parameters, during preliminary phase. This paper describes a multi-objective optimization method electro-hydrostatic with objectives optimizing weight efficiency. Models are developed predict from requirements control surface. The models prediction achieved by using scaling laws collected data,...