Yaoxing Shang

The Nonlinear Accuracy Model of Electro-Hydrostatic Actuator

The electro-hydrostatic actuator (EHA) is a kind of power-by-wire (PBW) actuator. In this paper, a typical architecture of EHA is described and the block diagram model of EHA is established directly from the mathematic equations without transfer functions, which is a nonlinear accuracy model. The influence of refeeding circuit on the EHA system is discussed based on the comparison with conventional linear model. A gain-variable PID controller is introduced to this model to compensate the friction.

Analysis for the power loss of electro hydrostatic actuator and hydraulic actuator

This article describes the difference between traditional airborne hydraulic actuator and electro hydrostatic actuator in heat dissipation. The power loss of the two systems are analyzed based on the method of energy transfer under different working conditions. To decrease the heating loss of electro-hydrostatic actuator, this paper designs an efficient component of the motor-pump. Theoretical and experimental analysis show that electro hydrostatic actuator is more efficient, and it is available for power saving design according to the need for energy.

A new rotary voice coil motor suitable for short angular strokes-design, modeling and optimization

This paper describes a new design of a rotary voice coil motor (RVCM) which suitable for short angular stroke. Reluctance model of proposed RVCM is discussed. Aimed at the requirement of rotary direct drive valve, an optimization objective function which takes into account the maximum acceleration ability and the magnet circuit is formulated. The design parameters optimization is carried out by the particle swarm optimization(PSO) method. The optimized parameters are validated by the FEM method. It is shown that the new design enhances the maximum acceleration ability which means high frequency response.

Preliminary design and multi-objective optimization of electro-hydrostatic actuator

Electro-hydrostatic actuator is generally regarded as the preferred solution for more electrical aircraft actuation systems. It is of importance to optimize the weight, efficiency and other key design parameters, during the preliminary design phase. This paper describes a multi-objective optimization preliminary design method of the electro-hydrostatic actuator with the objectives of optimizing the weight and efficiency. Models are developed to predict the weight and efficiency of the electro-hydrostatic actuator from the requirements of the control surface. The models of weight prediction are achieved by using scaling laws with collected data, and the efficiency is calculated by the static energy loss model. The multi-objective optimization approach is used to find the Pareto-front of objectives and relevant design parameters. The proposed approach is able to explore the influence of the level length of linkage, displacement of pump and torque constant of motor on the weight and efficiency of the electro-hydrostatic actuator, find the Pareto-front designs in the defined parameter space and satisfy all relevant constraints. Using an electro-hydrostatic actuator for control surface as a test case, the proposed methodology is demonstrated by comparing three different conditions. It is also envisaged that the proposed prediction models and multi-objective optimization preliminary design method can be applied to other components and systems.

Generic Analytical Thrust-Force Model for Flapping Wings

The purpose of this paper is to propose a generic analytical flapping-wing cycle-average thrust-force estimation method by implementing elongated body theory into actuator disk theory. Compared wit...

Design and validation of hydraulic pump system driven by the electromotor under the high-power and long-time working state in an airborne

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 time Validation, and worked well and reliably.

A novel proportional pressure valve based on depressurization using hydraulic half-bridge

Traditional electro-hydraulic proportional valve has begun to gradually replace the traditional servo valve with the development of electronic technology. However, the traditional proportional valve has the common disadvantages that they all have the very large weight and volume, and this may lead to the limit of its development. This paper proposed a novel proportional valve based on depressurization using hydraulic half-bridge, which has smaller weight and volume than traditional proportional valve. This paper gives the basic principle of the novel valve, and a detailed mathematical model is established. Then, the software simulation is conducted to prove the validity and feasibility of the novel valve. The frequency characteristics of the valve under different parameters are analyzed and some instructional advice on the design of the novel valve is given in this paper. Then, a physical prototype is designed and some experiments are conducted to prove the principle of the novel valve. Finally, we got a conclusion in the last part of the paper.

Eliminate the surplus torque of electro-hydraulic load simulator using the actuator command dynamic compensation control

Electro-hydraulic load simulator (EHLS) is a typical closed-loop torque control system. It is used to simulate the load of aircraft actuator on ground hardware-in-the-loop simulation. In general, the movement of the actuator has interference torque for the EHLS named the surplus torque. The surplus torque is not only related to the velocity of the actuator movement, but also related to the frequency of actuator movement. Especially when the models of the actuator and the EHLS are dissimilar, the surplus torque is obviously different in the different frequencies. In order to eliminate the surplus torque for accurate load simulation, the actuator command dynamic compensation control (ACDC) is proposed in this paper. Under the condition of the velocity synchronization signal cannot be provided by the actuator control system, the actuator command is used for compensation of different frequency actuator movement to eliminate the surplus torque on different frequencies in this strategy. Firstly, the mathematical models of EHLS and the actuator system are established in detail, then the ACDC method is proposed. For verification, the simulations are conducted to prove that the new strategy performs well against low, medium and high frequency movement interference. The results show that this strategy can effectively eliminate the surplus torque in different frequencies actuator movement.

Pull-pull position control of dual motor wire rope transmission.

Wire rope transmission is very efficient because of the small total moving object mass. The wire rope could only transmit pulling force. Therefore it has to be kept in a tightened state during transmission; in high speed applications the dynamic performance depends on the ropes stiffness, which can be adjusted by the wire rope tension. To improve the system dynamic performance output, this paper proposes a novel pull-pull method based on dual motors connected by wire ropes, for precise, high speed position control applications. The method can regulate target position and wire rope tension simultaneously. Wire ropes remain in a pre-tightening state at all times, which prevents the influence of elasticity and reduces the position tracking error in the changing direction process. Simulations and experiments were conducted; the results indicate that both position precision and superior dynamic performance can be synchronously achieved. The research is relevant to space craft precision pointing instruments.