In this paper, a radial basis neural network adaptive sliding mode controller (RBF−NN ASMC) for nonlinear electromechanical actuator systems is proposed. The function (RBF−NN) control algorithm used to compensate the friction disturbance torque in system. An law was adjust weights of achieve real−time compensation friction. designed suppress model uncertainty and external effects stability RBF−NN ASMC analyzed by Lyapunov’s theory, effectiveness method verified simulation. results show that...

This paper describes an inverse design method for calculating the shape of meridional plane centrifugal impeller. permits shroud and hub contours to be indirectly calculated by medial axis contour constraint equations. The process is computationally inexpensive can conveniently modify shapes as design’s demand. Based on this method, new equations are used a that lead uniform velocity distribution in inlet Numerical simulations employed investigate fluid flows fan. After validation numerical...

A numerical optimum study on three-dimensional unsteady viscous flow in a centrifugal fan with backward-curved blades was performed. The influence of the inlet angle, outlet blade angle and number aerodynamic performance analyzed concerning whole impeller-volute configuration. Response Surface Methodology (RSM) based three-level, three -variable Box-Behnken Design (BBD) used to evaluate interactive effects factors such as (37°-41°), (61°-65°) (10-14) efficiency. deriving via RSM were: 37°,...

High-voltage electron guns can commonly be damaged by surface flashover, which occur across the insulator of gun as a result emission around triple junction structure. Using secondary avalanche (SEEA) theory basis, in 90 kV is optimized this work to avoid damage from effects discharges. A metal shielding structure used reduce flashover caused and ensure that provides reliable high voltage performance. The aim proposed design method field strength occurs within Simultaneously, it shown SEEA...

An integrated guidance and control (IGC) scheme considering the field-of-view (FOV) constraint is proposed in this paper for hypersonic skid-to-turn (STT) missiles with a strapdown seeker intercepting high-speed maneuvering target, which based on backstepping (BC), barrier Lyapunov function (BLF), sliding mode (SMC), dynamic surface (DSC), reduced-order extended state observer (ESO). First, fifth-order strict feedback IGC model rudder delay dynamics derived, also considers drag effect axial...

The accelerating electrode of a four-dimensional transmission electron microscope gun is modeled. general expression the electric-field distribution derived for any point on axis in cylindrical coordinate system, and equations shape parameters plate are obtained. accuracy field determined different parameters, further investigated. This work can provide theoretical basis initial design retrofit gun.

Pneumatic regulating valves are the most common actuators in industrial production and play a decisive role control of flow media process. In response to demand modern industry for intelligent algorithm valve, system pneumatic based on STM32F4 chip is designed. The designed nonlinear problem corresponding genetic fuzzy PID Simulation results show that can improve performance design feasible hardware circuit platform. proves this Advantages algorithms design.

In the electron optical design of a magnetic lens, selection gap width S and bore diameter D as structural parameters pole piece system is very important. this paper, we choose second-order finite element method to calculate axial properties given lens at specified ampere-turn beam voltage. Consequently, with change three (the S, upper D1 lower D2) are obtained.

Poor information means incomplete and insufficient information, such as unknown probability distributions trends. In this case, many statistical methods may become ineffective. So a fusion method based on the poor theory is proposed. The contains five methods, three concepts, one rule. include rolling mean method, membership function maximum grade moving bootstrap arithmetic method. concepts comprise solution set estimated true value, series, terminal value. rule range centrifugal fan...

The output current of conventional voltage-doubling rectifier circuit high voltage power supply is small, the paper designs an improved program.Based on circuit,a providing` load increased, both potential, but also ensure a larger current. simulated using Multisim11.0 software, and successfully applied to design in 200kV transmission electron microscope. Experiments show good results.

The application of variable axis lens (VAL) technology to high-resolution electron microscopes has been well established. In the present study, a focusing-deflection composite system space beam guns is designed based on curvilinear (CVAL) theory achieve effective deflection for welding in space. addition, conditions combining magnetic and electrostatic deflectors are deduced, optical two parabolas introduced as trajectory. Finally, through adjustment stimulation angle deflectors, function...

Abstract The laser seeker is an important part of navigation guided weapons. working principle the was expounded, and optical system designed according to index requirements. Its mainly composed a receiving lens combination four-quadrant detector. According performance technical indicators such as detection distance seeker, clear aperture, distortion, imaging spot diameter center position range were simulated. model established by using CODE-V software. And quality optimized evaluated...

The laser seeker, which is the main dependent object of missile to achieve reliable target attack, provides position information for laser-guided weapon. During flight, missile's disturbance was coupled servo stabilization system seeker in various ways. This will affect stability visual axis as well reducing accuracy locating target. basic structure and principle achieving were analyzed this paper. In order solve problem a Fuzzy Sliding Mode Control(FSMC) method proposed. Control(SMC) has...

In the ultrafast transmission electron microscopy (UTEM), speed of will be close to light, when pulse passes through acceleration field. So radiation effect produced beam moves at high speed, which cause energy loss. this paper, performance femtosecond mode photoemission gun is analyzed and studied by simplifying model. According knowledge electrodynamics, power pulsed deduced, corresponding obtained, can provide a reference for dynamics research design gun.

Abstract In this paper, the electric field intensity of electrode structure thermally emitted electron gun UTEM is simulated, and relation between distribution plate analyzed. Using electronic optics software, optical system performance parameters are obtained, advantages disadvantages whole The research results paper can provide a reference for design simulation similar gun.

According to request of the vacuum system on status various failures TEM, return and exit mechanisms based auto-triggered method is designed for troubleshooting. By analyzing failure modes response measurement, emergency operation plan determined, fault handling process planned, mechanism established. mode, control achieves automatic a variety reasonable so as ensure stable TEM. Through actual operation, test results show that troubleshooting effective, processing satisfies requirements.

For the normal operation of TEM, required vacuum must be achieved in order to avoid interaction electrons and gas molecules within column. According demand system structure is marked out, then pumping flow designed which adopt parallel method pump. This shortens time heightens use efficiency actualizing automatic pumping, object pump exchanged by controlling open or close isolation valve with PLC computer programming. Finally, measurement results indicate that can fulfil pre-established demand.