基于TMS320F2812和C8051F040的目标测量系统电模拟器研制

本文应用TMS320F2812DSP和C8051F040微处理器,对某型卫星地面电联试系统中的目标测量系统电模拟器进行开发,以实现目标测量系统电模拟器的电接口和通信协议与目标测量系统原型样机的完全一致,同时通过应用软件开发来实现各目标测量系统电模拟器的测量功能。基于TMS320F2812DSP和C8051F040单片机所开发的目标测量系统电模拟器具有处理功能强大、接口功能丰富、软件开发效率高、通用性强等优点。最后将所研制的目标测量系统电模拟器接入某型卫星地面电联试系统中,完成了该卫星地面电联试系统的飞行任务演示闭环试验,从而为某型卫星目标测量系统的方案论证提供了有效的实验和验证平台。     

Light transmission efficiency of daylight guidance systems: An assessment approach based on simulations and measurements in a sun/sky simulator

New and more advanced guidance systems are nowadays available, allowing bringing natural light into buildings and offering potentials for energy savings associated to well-being for occupants. From a design point of view, the key factor is the knowledge of their photometric performances in terms of global light transmission efficiency, so as to predict the daylight availability in an interior space due to an array of guidance systems (or, the other way around, to predict the number of pipes needed to produce a minimum natural light illuminance according to standard requirement) through known analytical methods such as the lumen method. In spite of this, determining the global light transmission efficiency of advanced guidance systems is a quite complicate matter because of the redirecting optical properties these elements rely on even in the case of simple typologies (for instance, passive domes with micro-prismatic profiles and micro-prismatic or holographic films used as pipe’s coating).This paper presents an approach to characterize photometric performances of tubular daylight guidance systems in terms of light transmission efficiency: the global system efficiency is the result of the product of the efficiencies of the three individual components (collector, pipe and diffuser) and each efficiency is determined as the ratio of the flux emitted through the output window to the flux hitting the input window, accounting for both the beam and the diffuse efficiency. The approach, based on both measurements on physical models and simulations, was applied to different typologies of pipes and passive collectors and the obtained data were used to eventually calculate the global efficiency for the analyzed system.     

电视跟踪系统动态目标电子模拟器

介绍了电视跟踪系统动态目标电予模拟器的设计方案、工作原理、性能和测试结果。     

SimuRed: A flit-level event-driven simulator for multicomputer network performance evaluation

The interconnection network is one of the most important multicomputer components, since it has a great impact on global system performance. Many models and simulators have been proposed to evaluate network performance. This paper presents SimuRed, an event-driven flit-level, cycle-accurate simulator to evaluate different orthogonal network configurations. The core of the simulator has been designed to be expandable and portable to different situations. Some of the advantages of this simulator over other similar tools are its visual interface, its fast execution and its simplicity. Moreover, it is multiplatform and its source code versions (C++ and Java) are freely available under GNU open-source license. The performance of this simulator has been evaluated, including a performance impact study of injection channels and deterministic/adaptive routing for meshes and hypercubes.     

Workload perception in drone flight training simulators

Workload perception was measured in a drone flight training Simulator computerized situation. There has been increasing research in recent years on the topic of Remotely piloted aircrafts (RPA). Eleven participants were tested for workload perception during a drone flight simulator training. Reliability, sensitivity and correlations were studied for the workload scale and its relationship with the simulator training tasks. Overall, there were clear effects of mental demand as showed in the workload perception during the training tasks. Reliability for the workload scale showed good score and sensitivity showed mental demand as the most important factor compared to the other parameters measured obtaining highest correlations with landing tasks and number of errors. In our results, we have seen how the AWT (adapted from NASA-TLX) showed good sensitivity in assessing the mental burden of participants. In our research, participants scoring higher in the mental demand subscale showed greater difficulty finishing training tasks, and also showed longer time delays in performing both training sections of the simulation. These types of tools measuring workload perception and virtual training systems can be used in future research, to see how this cognitive aspect affects piloting skills and its possible safety and training implications.     

Crash avoidance in response to challenging driving events: The roles of age,serialization, and driving simulator platform

We examined the crash avoidance behaviors of older and middle-aged drivers in reaction to six simulated challenging road events using two different driving simulator platforms. Thirty-five healthy adults aged 21–36 years old (M = 28.9 ± 3.96) and 35 healthy adults aged 65–83 years old (M = 72.1 ± 4.34) were tested using a mid-level simulator, and 27 adults aged 21–38 years old (M = 28.6 ± 6.63) and 27 healthy adults aged 65–83 years old (M = 72.7 ± 5.39) were tested on a low-cost desktop simulator. Participants completed a set of six challenging events varying in terms of the maneuvers required, avoiding space given, directional avoidance cues, and time pressure. Results indicated that older drivers showed higher crash risk when events required multiple synchronized reactions. In situations that required simultaneous use of steering and braking, older adults tended to crash significantly more frequently. As for middle-aged drivers, their crashes were attributable to faster driving speed. The same age-related driving patterns were observed across simulator platforms. Our findings support the hypothesis that older adults tend to react serially while engaging in cognitively challenging road maneuvers.     

Pin Power Reconstruction Methods of the Few-Group BWR Core Simulator NEREUS

An improved pin power reconstruction method has been incorporated in the few-group nodal BWR core simulator NEREUS, which is based on the analytic polynomial nodal method. With the analytic polynomial nodal method, accurate node surface fluxes are available, which are used later to reconstruct pin powers. The intranodal homogeneous thermal flux is corrected using a semi-empirical proportional relation between surface transition components of the homogeneous and heterogeneous fluxes. This correction method is effective for BWR calculations, especially for controlled assemblies or mixed loading of off-set assemblies. A unified model accounting for effects of spectral histories, caused by spectral interactions between fuel assemblies and the control blade insertion, was also developed for intranodal burnup correction. The change in pin powers due to the control blade history can be predicted well, without laborious assembly depletion calculations with control blade insertion. R-factors used in critical power ratio calculations are also reconstructed from the pin powers. The NEREUS pin power reconstruction method was verified against heterogeneous multi-assembly depletion calculations.     

旋翼结构故障数据收集和可靠性评估

对旋翼结构在现场数据收集的基础上，采用威布尔分布的极大似然估计法估计了各种故障的分布，并用蒙特卡罗模拟法得出了旋翼结构的可靠度曲线。     

A simple approach to improve the robustness of equation-oriented simulators: Multilinear look-up table interpolators

Equation-oriented simulators have some advantages over the modular sequential ones, but improvements are still necessary to deal with nonlinearities, while preserving the robustness of the solver. Linear approximations and/or surrogate models can be used in place of nonlinear models, but the loss of predictive accuracy may be a drawback. An alternative to circumvent this problem is the use of grid-based look-up tables for interpolating responses from rigorous models. This methodology was integrated in an equation-oriented simulator (EMSO). A case study involving the production of bioethanol from sugarcane is used to demonstrate the robustness of this approach. Look-up tables replaced the models of two distillation column trains and of the cellulose hydrolysis reactor. These models were included into the global process and an optimization problem aiming at the maximum production of ethanol was successfully solved by a PSO algorithm varying the solid mass fraction in the hydrolysis reactor.