三轴飞行姿态仿真转台高性能指标及其实现

本文详细讨论了三轴飞行姿态仿真转台（三轴均由液压摆动马达驱动）的主要性能指标及影响它们的主要因素，在此基础上，给出了实现三轴飞行姿态仿真转台高性能指标的途径。同时，对三轴飞行姿态仿真转台中框架双液压马达同步驱动方案进行了探讨。     

OUT型闭式三轴转台的结构设计

本文介绍了ＯＵＴ型闭式三轴转台的结构型式，具体讨论了各轴系的轴承布置、精度计算等设计问题，并分析、总结了该三轴转台的结构特点。     

三轴陀螺漂移测试转台台体动力学建模及控制系统设计

带宽的保证是三轴陀螺漂移测试转台（以下简称三轴转台）伺服系统设计的主要困难，从使用的角度出发，要求转台伺服系统有较大的带宽，以使三轴转台有较快的响应速度，对干扰有较强的抑制能力，提高三轴转台的跟踪精度，但一些客观因素使带宽指标受到限制，其中机械台体的谐振对带宽的影响是决定性的。本所讨论的三轴转台动力学模型，是三轴转台控制系统设计的依据。     

三轴仿真转台外框电液位置伺服系统自适应神经元网络控制

本文针对三轴飞行姿态仿真转台外框电液位置伺服系统的特点和技术要求，采用自适应神经元网络控制策略对其控制。仿真结果表明，自适应神经元网络控制以其特有的自学习、非线性等优点，完全满足三轴飞行姿态仿真转台外框电液伺服系统对控制策略的要求，由其构成的控制系统既具有良好的动态性能，又具有较强的鲁棒性与适应性。     

三轴仿真转台数据通讯接口设计

本文介绍了三轴仿真转台数据通讯接口的设计，给出了接口关键部分的软硬件结构。     

有限元法在三轴转台机械系统设计中的应用

本文探讨了三轴转台机械系统的设计与计算问题，以惯性三轴测试转台和三轴模拟台为例，确定了多种运转状态下的有限元法计算模型，并对其进行了静、动态特性计算，比较分析了计算结果，为合理结构的设计提供了重要数据，说明了在三轴转台机械系统设计中有限元法的重要性     

用三轴转台减小陀螺加速度表输入失调角的试验研究

为了减小陀螺加速度表输入失调角，从理论上分析了陀螺加速度表输入失调角存在对陀螺加速度表测试精度的影响，提出了利用三轴转台设计减小陀螺加速度表输入失调角的试验方法。试验结果表明，利用三轴转台可以成功地将陀螺加速度表测试精度提高一个数量级。     

三轴转台框架的形状优化设计

本文叙述了三轴转台四种不同的布局型式。提出了用Ｂｅｚｉｅｒ曲线和Ｆｏｕｒｉｅｒ级数描述三轴转台框架的形状，将形状优化设计问题转换为可用参数优化设计方法求解的形式。建立了ＯＵＴ型三轴转台外框架结构的形状优化设计数学模型，然后给出了用增广乘子法对问题进行求解的步骤     

惯性导航平台的三轴伺服测试

本文分析了三轴惯性导航平台的三轴伺服测漂问题,首先分析平台轴和转台轴之间的座标变换,然后分析转台轴相对地球的不同安装方式下的运动方程。在无漂移时转台的表现运动得到解析解,这对有漂移时的数据处理方法提供了理论基础。此时漂移运动分量和表现运动分量应从总运动过程中分离出来。     

三轴飞行模拟仿真转台的设计及控制问题研究

论述了三轴仿真转台的总体设计布局，驱动元件及控制方案等问题，分析了影响转台控制系统性能的因素并提出了相应的解决措施。最后，对转台最重要的指标之一低速问题进行了详细的探讨。     

一种新型高精度大功率电动飞行仿真转台的驱动方案设计

针对一种新型电动飞行仿真转台高精度、大功率的突出特点,设计了十分有效的驱动方案。首先简要介绍了该电动飞行仿真转台的主要技术指标,然后提出了高精度大功率飞行仿真转台驱动方案的详细设计策略,驱动方案中采用PWM功率放大器驱动,最后给出了该驱动方案在飞行仿真转台控制系统中的设计实现。实际应用表明:该驱动方案可以很好地满足新型电动飞行仿真转台的高精度、大功率要求,具有很强的抗干扰性和鲁棒性,完全适合在高精度大功率电动仿真转台上应用。     

半物理仿真试验用运动模拟试验转台的动态要求

通过使用简化模型方法,分析了一种半物理仿真(HILS)试验用运动模拟试验转台的基本动态要求。其研究结果对各类运动模拟试验台控制器的设计具有普遍意义。     

基于CPLD的导弹惯性测量单元模拟器设计

介绍了采用CPLD器件开发的导弹用惯性测量单元（IMU）模拟器的设计原理及其实现方法。该模拟器采用软硬件相结合的方式，可模拟某型真实惯性测量单元（IMU）的接口与输出信号。通过软件控制硬件输出的脉冲个数，可模拟真实惯性测量单元在静态和动态工作时的状态。该模拟器具有硬件体积小、成本低、可连续长时使用等特点和可轻松修改模拟器硬件电路的优点。该模拟器在某型号空空导弹惯导系统仿真实验中已经得到实际应用。     

Stereo-DIC Calibration and Speckle Image Generator Based on FE Formulations

Stereo digital image correlation (stereo-DIC) is being accepted by the industry as a valid full-field measurement technique for measuring shape, motion and deformation, and it is therefore of utmost importance to provide uncertainties on the obtained measurements. However, the influences on a stereo-DIC measurement are not fully understood; indeed, stereo-DIC is a complex optical-numerical process and it is not always clear how errors are propagating throughout the measurement chain. In order to investigate the magnitude of the different error-sources a simulator for stereo-DIC is proposed. This simulator is able to generate realistic synthetic images as if they were made during a real set-up, so the error sources can be investigated separately and an optimal set-up can be chosen before any physical test is performed. We present in this paper the mathematical approach to the DIC simulator including details on how to convert FE displacement field results to stereo-DIC images. The simulator includes the ability to control the lighting and to create synthetic calibration images. The synthetic images are compared to simulations for a bulge test as a validation of the simulator. Synthetic calibration images are compared to experimental calibration studies to verify those. Finally a brief look at how the simulator could be used for looking at calibration quality is conducted.     

Experimental investigation on tunnel sonic boom

Upon the entrance of a high-speed train into a relatively long train tunnel, compression waves are generated in front of the train. These compression waves subsequently coalesce into a weak shock wave so that a unpleasant sonic boom is emitted from the tunnel exit. In order to investigate the generation of the weak shock wave in train tunnels and the emission of the resulting sonic boom from the train tunnel exit and to search for methods for the reduction of these sonic booms, a 1300 scaled train tunnel simulator was constructed and simulation experiments were carried out using this facility.In the train tunnel simulator, an 18 mm dia. and 200 mm long plastic piston moves along a 40 mm dia. and 25 m long test section with speed ranging from 60 to 100 m/s. The tunnel simulator was tilted 8° to the floor so that the attenuation of the piston speed was not more than 10 % of its entrance speed. Pressure measurements along the tunnel simulator and holographic interferometric optical flow visualization of weak shock waves in the tunnel simulator clearly showed that compression waves, with propagation, coalesced into a weak shock wave. Although, for reduction of the sonic boom in prototype train tunnels, the installation of a hood at the entrance of the tunnels was known to be useful for their suppression, this effect was confirmed in the present experiment and found to be effective particularly for low piston speeds. The installation of a partially perforated wall at the exit of the tunnel simulator was found to smear pressure gradients at the shock. This effect is significant for higher piston speeds. Throughout the series of train tunnel simulator experiments, the combination of both the entrance hood and the perforated wall significantly reduces shock overpressures for piston speeds ofu _p ranging from 60 to 100 m/s. These experimental findings were then applied to a real train tunnel and good agreement was obtained between the tunnel simulator result and the real tunnel measurements.     

Analog simulation of magnetic hysteresis and its application

An analog simulation of hysteresis phenomena based on the magnetic domain theory is proposed. Hysteresis curves are simulated by superposition of a number of backlash elements which are followed by output limiters. The interaction of magnetization between domains is taken into account. This consideration makes it possible to simulate individual characteristics of various magnetic materials. A satisfactory performance of the simulator is obtained for an arbitrary form of the input; thus, the simulation of initial magnetizing curves, hysteresis loops and minor loops is found to agree with experimental observation. As an application of the simulator, the author applied this simulator to the analog computer setup and carried out a computer analysis of the series resonant circuit including a saturable core. The frequency response curves and the regions of initial conditions leading to the various oscillations which are obtained by the simulation found to agree with the experimental results.     

A finite element simulator for incompressible two-phase flow

This paper describes a finite element simulator for incompressible two-phase flow. This simulator is based on numerical techniques which are novel to the field of reservoir simulation. It uses irregular meshes, discontinuous high-order finite elements for the approximation of saturations (including Riemann solvers and slope limiters), and the mixed-hybrid formulation of mixed finite elements for an efficient and precise approximation of pressures and velocities. Each injection or production well is simulated by a few one-dimensional implicit models arranged to form a macroelement. This simulator is able to handle gravity, capillary pressures, porosity and permeability (both absolute and relative), and heterogeneity. Numerical results are shown which illustrate the capabilities of the code.     

光学目标模拟器总体结构方案分析及关键技术

光学目标模拟器是光学成像制导仿真系统中的关键设备之一。本文在介绍圆弧导轨式和框架式两种光学目标模拟器机械结构方案的基础上，详细分析了框架式机械结构的诸多优点。最后，总结了框架式目标模拟器研制中的一些关键技术     

Techniques for testing structures permitted to sway

Mechanisms are described that eliminate the restraining effects of the loads and the lateral bracing on test specimens permitted to sway. One mechanism, called the gravity-load simulator, maintains a vertical orientation of load even as a structure sways. The other is a lateral-bracing mechanism which moves freely with a test structure even at large deflections, and it does not require any adjustments during a test. A gravity-load simulator and a lateral-bracing system designed for use in testing full-size building frames on the equipment itself and tests of building frames utilizing the mechanisms show very satisfactory behavior of the gravity-load simulator and the lateral-bracing system. Some actual test setups using the mechanisms are described. Tests on three-story full-size building frames (30-ft high) and a frame-buckling test are included.     

Nonlinear stability analysis of miscible displacements

A simulator for three-dimensional horizontal miscible displacements in porous media is developed. Using this simulator, we examine the initiation and development of instabilities, viscous fingers and gravity tongues.With the only perturbations to the system being truncation and round-off errors, a density ratio (the ratio of the density of the displacing fluid to that of the displaced fluid) different from one is responsible for the initiation of the instabilities, and an unfavorable mobility ratio (the ratio of the viscosity of the displaced fluid to that of the displacing fluid) is responsible for the growth of the instabilities.