Applied Mechanics and Materials Vols. 325-326

Abstract: The disturbance factors in the missile flight are obvious,so the analytical equations of missile longitudinal disturbance of movement is derived . The missile body longitudinal aerodynamic parameters are fitting out with wind tunnel experimental data. The equation of system state takes the aerodynamic coefficient errors interference source and GPS error sources as the state variables, and the system measurement equation adopts GPS pseudo-range measurements. In passive segment, the aerodynamic coefficients disturbing errors sources of th missile longitudinal plane is estimated optimally with extended Kalman filter. The results show that the method accelerate the convergence speed of the disturbance source errors, and improve the estimation accuracy of the perturbation errors.

Abstract: This paper describes the new Calibration test method of Height Adjusting System for Automobile High Lighting. Come up with the problem of working efficiency for Calibration test, study the parameters tuning method of Height Adjusting System for High Lighting based on uniform design experiment. Analyze experimental data by using direct analysis method and range analysis method, find the factor which affects the high lightings height most. Verify the result of orthogonal experiment on the test platform. The test shows that the new Calibration test method is reliable and efficient.

Abstract: The input voltage of off-grid PWM converters has a great dynamic range in amplitude and frequency. In addition, the frequent changing of these parameters also makes it hard to measure preciously via traditional ways. Details of window function are presented. A modified FFT spectrum analyzing method using interpolation is also given and checked. Finally, a feasible solution which balances both precision and real-time data processing comes up considering the speed of MCUs mainly used in industry. Simulations and experiments show that this solution settles the troubles which cant be cleared up by traditional methods.

Abstract: Working state parameters of Road Header is the basis on analysis of field performance of a road header and improving its design. This paper studied the development of data recorder, and by tracing the long time recording state parameters of road header under the coal mine, including the voltage, current, temperature and other information of cutting motor. Calculate the cutting motor power signal and take it as random load signal, through the statistical analysis of the cutting motor operating parameters determine road header field work load distribution for its performance, provides a basis for the optimization.

Abstract: An iterative method of active shimming has been presented, which is based on the Laplaces Spherical Harmonics and the least square theory. This approach makes the inhomogeneity of magnetic field to acceptable restriction. With analysis of the method, this paper gives the computer-aided program. The simulation results approve that the method is feasible and valid. Because of its simple and easy to implements, this approach can also be used for the shimming of the other magnets such as the nuclear magnetic resonance magnets.

Abstract: The paper explores the threat posed by terrorism in aviation domain, especially surface-to-air missile attacks against transport aircraft. While the focus of this paper is the mitigation of security risks in the aviation domain, the proposed solution based on concerted countermeasure systems discussed here may be developed in the context of homeland security policy promoting the principle of flight safety. The reception and the processing of data through the detection of signals emitted by various sources are proceeding in the absence of users interest about the form of the wave of the message. The detection of the presence / absence of the signal or the identification of its value is proceed by identifying the signal associated to each value of the message, considered a discrete variable, hence triggering of the adequate defence mechanism.

Abstract: In this paper, a torus is designed as an adding mass to modify the dynamic characteristics of the tool-holder system in free boundary condition and in fixing boundary condition. The torus is fixed on the holder of a given face milling cutter, which may change the mass distribution and the stiffness distribution of the system, to adjust the frequency and damping ratio of the tool tip. Although the dynamic characteristics of the tool tip are significantly influenced by holder-spindle interface, the influence of the tool-holder can’t be neglected. In this attempt, by adding mass on the tool holder, the first order frequency decreased by 37% in free boundary condition and 6.7% in fixing boundary condition. The first damping radio increased by 48% in free boundary condition and 4.5% in fixing boundary condition. Chatter suppression is verified in the cutting process by adding mass on the holder.

Abstract: The engine lubrication system plays an important role in the engine working process. Engine electronic oil pressure sensor based on piezoresistor pressure sensor MEMS with contactless measure technology is designed in this paper. This sensor includes a signal disposal chip which provides zero point pressure compensation, temperature compensation and sensitivity compensation and a chip which is used to adjust the duty cycle according to the output voltage of the signal disposal chip. The experiments show that the Engine electronic oil pressure sensor works well with excellent characteristic.

Abstract: Any system based on data acquisition from different sensors has important characteristics of quality and fiability that are given by the detection and the isolation of the sensors faults. This paper presents two methods of fault detection, applicable in aerospace domain, used in satellite systems, and the simulation of the functionalities of the methods using Matlab. Both methods are based on the estimation of the sensors fault by analysing the differences between the measured value and the estimated one, using an EKF estimator [. Keywords: EKF filter, fault detection, satellite sensors, t-test

Abstract: This paperwork presents the most frequent applications of the pneumatic drives on universal machine-tools, particularly on CNC machine-tools. It also presents modern calculation and verification methods with simulation software.