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This paper studies the energy reverse transmission of a new type collaborative rectification structure pump, which uses a linear reciprocal machine drives a piston directly to pump hydraulic fluid. This pump is designed for a novel electro-hydrostatic actuator which is a kind of volume control electro-hydraulic servo system. For servo control application, the pump is usually required to transfer energy...
With the development of the hydraulic system of higher pressure and power, the fluid borne pulsation in pipelines becomes extremely harmful to the whole system. Therefore, the control of fluid borne pulsation is very significant for improving the performance of practical hydraulic systems. The traditional active control methods of fluid borne pulsation were found to be effective, while the existing...
A improved delta robot with a novel transmission mechanism to reduce abrasion and a new configuration of end effector is proposed in this paper. Specifically, the traditional telescopic chain which employs prismatic pair is replaced by parallel mechanism with four rods hinged. The frication in the connection can be significantly decreased. The motor that drives the telescopic chin is fixed on the...
This article presents a methodology for preliminary design of the electro-hydrostatic actuator. This methodology based on the modeling library of components of EHA. The modeling library of components are built with Modelica language. These model libraries are advantage of reuseability and non-causality and object orientedness and then the model of EHA can be fully integrated by these components. A...
This paper studies the influence of stator's various parameters of longitudinal linear switched reluctance motor (LSRM) on tangential force and magnetic field strength. A series of typical candidates are applied to these parameters analyzed. The proposed LSRM configurations are compared by using two dimensional finite element analysis (FEA). And then we change the parameters of the initial to improve...
The composition and working principle of an aircraft hydraulic energy system were introduced, the flow and pressure requirements of hydraulic users was analyzed by combining with the normal condition for each phase of flight missions, and the selection design of main components of the pump source was completed. The flow and pressure in line with supply and demand of the hydraulic system under the...
Pressure servo valve is usually used to regulate the pressure of the braking actuator to stop the wheel in traditional aircraft anti-skid braking system. The disadvantages of pressure servo valve include complex structure, high production costs, and the requirement for high quality of the hydraulic oil. In addition, its pilot stage is easy to block by contamination and has a constant leakage. This...
This paper extends an analysis developed for double tubular Halbach permanent-magnet motors to account for the thrust fluctuation associated with the primary design parameters of linear motors. Established by equivalent magnetic circuit method (EMC), the air-gap magnetic field distribution, provides an accurate means of predicting the cogging force that results from end effects. Comparison shows that...
Affected by the mutation of runway condition, crosswind, unbalance load and different performance of brake device on both sides of the wheels, there will generally appear yaw angle and lateral offset while the unmanned aerial vehicle (UAV) is taxiing. The UAV would skid off the runway and cause serious accident if the yaw angle and lateral offset are not corrected in time. In this paper, a dynamic...
This paper introduced a type of aircraft electric hydraulic pump system working principle, the key points of the system are analyzed and described, including calculation of boost pressure, system oil temperature control design, environmental temperature checking, starting logic design, the system validation and verification methods are expounded. This system passed through the ground test and flight...
Linear oscillating motor attracts considerable focus in industrial applications due to its high efficiency and power density. Despite it has maximum efficiency on its resonant frequency, achieving accurate resonant frequency recognition and tracking is difficult, especially under complicated hydraulic load. In this paper, a novel resonant frequency recognition and tracking strategy is proposed for...
The mechanical vibration transfer path model of the axial piston pump was established for aiming at the aviation hydraulic vibration that it has been more intense with the development trend of high speed and high pressure. In this paper, firstly, based on the first-order trajectory sensitivity method to solve the time-domain sensitivity function curves, the system parameters that have influence on...
This paper proposes a simple synchronous control scheme for a linear servo system applied to driving the horizontal axis of far-field target motion simulators(TMS). The investigated horizontal axis is driven by two parallel linear motors, which are arranged at both ends of the vertical axis. This layout, which can improve the system dynamics, overall thrust and structural stiffness, requires accurate...
A improved delta robot with a novel transmission mechanism to reduce abrasion and a new configuration of end effector is proposed in this paper. Specifically, the traditional telescopic chain which employs prismatic pair is replaced by parallel mechanism with four rods hinged. The frication in the connection can be significantly decreased. The motor that drives the telescopic chin is fixed on the...
This paper proposes a new generalized equivalent magnetic circuit model for the preliminary design of a toroidally wound limited angle servo motor. In the model, the magnetic networks are formulated as a function of the pole number and geometric dimensions. Nonlinear saturation effect of the ferromagnetic material is also taken into consideration. A multi-objective optimization function involving...
The precise position control for electro-hydraulic servo system (EHSS) is a key technical problem for modern industry control. This paper presents a model reference adaptive control (MRAC) strategy combining fractional order calculus theory and neural network to solve the high nonlinearity and parameter uncertainties in the EHSS. The reference model in the MRAC strategy is a fractional second-order...
Linear oscillating motor is the source of power in LEHA system and its heat dissipation performance plays an important role in achieving high power density. To enhance cooling capacity, flooded motor is generally adopted as a solution, which utilizes oil for cooling and lubrication. However, oil-film lubrication always causes severe decline of system damping ratio and deteriorates control stability...
Owing to spherical actuator control system uncertain parameters generated control errors, our project established offline learning neural network identifier to correct systematic errors. But BP neural network identifier only learning or training offline, which can not be used for errors correcting online, that means control accuracy is susceptible to interference field. Therefore, this paper proposes...
This paper presents a rectangle direct-acting solenoid valve. The rectangle direct-acting solenoid valve have advantages of compact size, light weight, high reliability, fast response and high motion precision. Based on analytical method, this paper presents the eddy current calculation model of the moving-iron considering the skin effect. Then, the three-dimensional finite element modeling is established...
The improved particle swarm optimization (PSO) algorithm is used to optimize the structure of permanent magnetic spherical motor with four pairs of rotor poles. The objective is to maximize peak value of output torque and peak value of magnetic flux density. Seven variables are selected which are rotor radius, rotor core radius, the longitudinal angle and the latitudinal angle of single rotor pole,...
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