Electro-hydrostatic actuator (EHA) is a novel high-performance servo actuator originating in the field of aviation and is becoming a common basic component of major equipment. Research is ongoing to develop an efficient and scientific design method of EHA due to its multidisciplinary coupling and hi...

A new type of gas metal arc welding (GMAW) method was proposed and a novel hybrid ultrasonic frequency pulsed GMAW power source was developed. In this method, an ultrasonic frequency pulse current was superposed upon the conventional pulsed GMAW current with frequency from 20 to 80 kHz, current ampl...

For various threats in the enemy defense area, in order to achieve covert penetration and implement effective combat against enemy, the unmanned aerial vehicle (UAV) formation needs to be reconfigured in the process of penetration, and the multi-UAV collision avoidance problem and communication cons...

To efficiently solve the problems of queue time constraints and quality loss caused by machine degradation during production activities, a joint optimization mathematical model considering both preventive maintenance and the control of the buffer capacity was constructed in this paper. First, gamma ...

The idea of piecewise linear approximation and piecewise iterations is extended to the anti-ship missile's piecewise velocity prediction. Time-to-go estimation algorithms suitable for anti-ship missiles with time varying velocity are designed for proportional navigation guidance law and a biased pro...

For the bottom of the weld, weak connection and other defects in the friction stir welding(FSW) of aircraft skin, due to the narrowing of the FSW process window, in order to explore a new method that is more suitable for long-range stable welding of large aircraft skin, skinned contrast test between...

To solve the problems that helicopter trim model has multivariate nonlinear equations, it is difficult to determine its initial value and the global optimal solution is non-unique, an efficient hybrid iteration algorithm is presented in this paper, which combines the genetic algorithm and the quasi-...

This paper discusses the vibration mechanism of gear transmission and modification methods to reduce vibration and noise with a specific automatic transmission as the research object. Using SimulationX and test methods, the gears that have the most contribution to system vibration can be found. The ...

A novel 2-2PRUR parallel mechanism is proposed to fit the actual demand of industrial production line. Kinematics analysis and workspace optimization are performed based on scatter plot. A method is presented by splitting the moving platform into two parts and adding planetary gear train, which coul...

In order to enhance the flight performance of parafoil, the effects of canopy fabric's air permeability on parafoil aerodynamic performance were studied. The canopy external flow field was modeled by the incompressible Reynolds-averaged Navier-Stokes (RANS) equations, and the governing equations for...

In order to meet the requirements of spacecraft fly-around technology in on-orbit service mission, spacecraft forced fly-around formation design and control scheme was investigated. Based on the analytic solution of the C-W(Clohessy-Wiltshire) equations, bi-teardrop formation was proposed. Then mult...

To solve the problem that the position vector of the first satellite, the position difference vector between dual satellites and the speed difference vector between dual satellites are coplanar when the fixed emitter with known altitude is located by dual satellites using time difference of arrival ...

Adopting the flight dynamic model of coaxial rigid rotor helicopter, this paper sets the XH-59A coaxial rigid rotor helicopter as research object and analyzes the influence of rotor control phase angle on longitudinal trim characteristics, helicopter power required and hub bending moment of upper an...

Aimed at the strong nonlinearity, complicated couplings and high uncertainties of hypersonic vehicle, a reduced step control scheme based on high-order tracking differentiator is put forward. The longitudinal model of hypersonic vehicle is transformed as strict-feedback form. A tracking differentiat...

Severe aerodynamic heating phenomenon occurs in hypersonic flight. Thermal protection system design can be effectively guided by considering the influence of hypersonic thermo-chemical non-equilibrium on aerodynamic thermal environment. Park and Gupta's thermo-chemical non-equilibrium models were us...

Morphing aircraft can adaptively alter configuration according to the different flight conditions or a variety of missions to ensure the optimal aerodynamic performance in flight. A class of variable-span morphing aircraft were considered, and the controller design synthesis for linear parameter var...

The foundation of countering the towed radar active decoy (TRAD) is the presence detection of decoy. Derivation of monopulse radar angle error output of balanced phase discriminator (BPD) with and without towed radar active decoy was demonstrated. According to the principle of BPD, the conclusion ca...

In order to achieve the online condition prediction for avionic devices, a sparse kernel incremental extreme learning machine (ELM) algorithm is presented. For the problem of Gram matrix expansion in kernel online learning algorithms, a novel sparsification rule is presented by measuring the instant...

An integrated leg-arm quadruped robot with a function multiplexing limb is presented in this paper, and it can realize both walking and operating. The walking mode and the operating mode of the robot are studied. First, a positive kinematic model of a single leg is established and inverse kinematics...

Compressed sensing (CS), which could break through the bottleneck of the Nyquist sampling theorem, makes the high resolution signal acquisition possible. Reconstruction algorithm is the key part of compressed sensing, and the iterative greedy algorithm is one of highly significant research direction...

Aerodynamic force generation in a dragonfly intermittent flapping flight with modeled wings was studied using the method of numerical simulation. The computational results show that the average lift coefficient and average thrust coefficient of the modeled wing decrease with the increase of the inte...

The purpose of this study is to enhance the machine tool's processing capability by improving the machine tool from 4-axis to 4+2-axis, which endows the machine tool the ability to process impeller using the barrel cutter. We first analyzed the dynamic performance of the 4+2-axis machine tool with t...

Considering the diversity of target scattering characteristics with different observation angle and information redundancy of multi-aspect images, this paper proposes a novel multi-aspect SAR image fusion method based on wavelet transform and edge detection. First, wavelet transform was performed to...

In view of current research situation that the ballistic performance and constraints are unable to be guaranteed by traditional prediction correction algorithm in the reentry process, a new reentry guidance method was proposed, which combines the offline trajectory optimization based on simple param...

Aimed at the relative position cooperative control problem of electromagnetic spacecraft formation flight, an adaptive cooperative controller was designed based on the consensus theory. Firstly, primary principles and accurate nonlinear dynamics equation of the relative motion of electromagnetic spa...

To improve the anti-AM jamming performance of FM Doppler fuze, the AM jamming mechanism was quantitatively studied, and the anti-jamming performance of FM Doppler fuze under different AM jamming was quantitatively studied with signal to jamming ratio (SJR) gain as descriptive parameter. The SJR gain...

Aimed at the problem of traditional recognition models that parameter rule description is not complete, a hierarchical model suitable for multi-function radar (MFR) is proposed in this paper. This model reflects the operating mechanism of MFR system through three levels of task, state and parameter....