The Digital Information Facility

The acceptance and implementation of advanced digital avionics and flight control systems is dependent on the successful integration of these systems into the current and future National Airspace System (NAS). This paper describes a digital avionics systems research facility known as the Digital Information Facility (DIF) developed to provide researchers with the ground systems and air-to-ground interfaces needed to conduct and document experiments involving a mix of new technologies within the existing NAS infrastructure. The DIF supports four NAS functions: Controller Pilot Data Link Communications (CPDLC), Flight Information Services (FIS), Differential Global Positioning System (DGPS) navigation, and Automatic Dependent Surveillance-Broadcast (ADS-B). The DIF also includes the capability to record pilot and air traffic management interactions and document research participant observations. The DIF capability includes connectivity to flight test and simulated aircraft in a fully immersive Communications, Navigation, and Surveillance (CNS) environment.     

民机驾驶舱显示触控系统人机工效综合评价

未来民机驾驶舱将广泛采用触控技术,但目前尚未形成针对民机驾驶舱显示触控系统的人机工效评价体系与评价方法。针对上述问题,首先梳理民机驾驶舱显示触控系统相关的现行标准与规范,结合适航规章中人为因素考察项,提出民机驾驶舱显示触控系统人机工效评价指标体系。其次,考虑到评价指标的模糊性与灰色性,基于灰色关联分析,对传统模糊层次综合评价算法从数据集结处理和指标权重确定两个方向进行改进,通过构造专家信度系数修正秩次矩阵,实现专家认知特性的定量描述,建立民机驾驶舱显示触控系统人机工效综合评价模型。最后,结合ACROSS项目下的民机驾驶舱显示触控系统人机工效评价试验案例,分析驾驶舱显示触控系统配置策略对系统人机工效的影响,验证了评价体系与评价方法的适用性和合理性。     

惯性导航系统仿真试验研究

惯性导航系统是通过测量加速度自动推算飞机速度和位置数据的自主式导航设备,其作用是保证飞机按预定的航线飞行,准确地抵达目的地。在航空电子设备试验中,采用惯导仿真器可以减少测试的复杂性,而且还能获得更好的动态效果。本文介绍了惯导系统功能控制逻辑和显示画面的验证方法,同时还介绍了仿真器的软件编制技术。     

民机驾驶舱扬声器啸叫成因研究与抑制方法

民用飞机驾驶舱扬声器是一个电声换能器件,安装在飞机驾驶舱中,可将电信号转为声信号输出,并将声学功率辐射到驾驶舱。驾驶舱扬声器不仅能够为驾驶舱内的机组人员提供与客舱乘务人员以及塔台管制人员的通话语音,还能够提供飞行导航音、选呼音和告警音的发声。因此,驾驶舱扬声器是飞机上不可或缺的机载设备,为飞机的飞行安全提供了保障。驾驶舱扬声器产生的尖锐刺耳啸叫让人难以忍受,导致飞行机组无法听到其他声音,甚至无法使用语音通信系统,严重时会影响到飞行安全。指出驾驶舱扬声器"啸叫"的危害,分析啸叫的成因,并在此基础上探讨驾驶舱扬声器"啸叫"的抑制方法,为民机驾驶舱音频系统的防啸叫设计提供一定的参考依据。     

GPS/INS integration on the Standoff Land Attack Missile (SLAM)

The Standoff Land Attack Missile (SLAM) is a worldwide, all-weather, precision-strike weapon system deployed from carrier-based aircraft. In the primary mode of operation, target location and other mission data are generated from intelligence sources available on the aircraft carrier and loaded into the missile prior to aircraft takeoff. After missile launch, the SLAM inertial navigation system (INS) guides the missile along the planned trajectory. Updating the missile INS from the Global Positioning System (GPS) during flight provides precise midcourse navigation and enhances target acquisition by accurate, on-target pointing of the SLAM Maverick seeker. The GPS/INS avionics and software integration used for SLAM are described in detail, along with some of the design tradeoffs that led to the approach. The avionics configuration integrates the Harpoon midcourse guidance unit, which includes a strapdown inertial sensor package and digital processor, with a Rockwell-Collins single-channel, sequential GPS receiver processor unit (RPU), a derivative of the GPS phase-III user equipment. In addition to the GPS receiver elements the RPU contains the navigation processor, which executes the SLAM navigation, Kalman filter algorithms, and other guidance algorithms including seeker pointing. Flight-test results of the SLAM GPS-aided INS are also included     

Software intensive systems safety analysis

Two important elements in the avionics suite of modern aircraft are: the flight control system (FCS) and the flight management system (FMS). The FCS provides the capability to stabilize and control the aircraft, while the FMS is responsible for flight planning and navigation. A clear trend in the aerospace industry is to place greater reliance on software systems, and many FCS and FMS subsystems are implemented primarily in software. For example, within the FCS is the flight guidance system (FGS) that generates roll and pitch guidance commands. Similarly, within the FMS is the vertical navigation (VNAV) function that acts like a third crew member in the cockpit, ordering mode change requests and resetting target altitude values to enable the aircraft to track the vertical flight plan. We have developed formal, executable models of the requirements for the mode logic of a FGS and for portions of the VNAV functionality. We have also conducted a comprehensive software safety analysis on the FGS mode logic model, and are completing the analysis of the VNAV model. This analysis uses as its starting point several "traditional" safety analysis techniques such as a functional hazard assessment (FHA), a fault tree analysis (FTA), and a failure mode effects analysis (FMEA). However, we are also using formal methods techniques known as model checking and theorem proving to verify the presence of safety properties in the model. This paper summarizes the (now completed) safety analysis that was performed on the FGS model, and highlights the similarities and differences with the (still on-going) safety analysis of the FMS model. In particular, we summarize progress made to date in the use of formal methods to verify the presence of the required safety properties in the models themselves.     

Digital Cartographic Data: A Case for Electronic Delivery

The demand for digital cartographic data and information is expanding rapidly, most dramatically in navigation. Electronic chart and map display systems are now reaching the market for land, sea and air navigation and rapid delivery of the latest data is absolutely essential. Commercial aviation is moving rapidly toward the automated cockpit with the new generation Flight Management Computer System. Marine navigation is experiencing a similar growth in integrated navigation systems and every major automobile manufacturer has plans for digital map navigation systems. The largest, most complete data bases to meet these requirements are Government held and difficult to access, thus most private sector firms re-digitize and agencies maintain near duplicate data. Present inefficiencies, introduced errors, and delays stem from lack of rapid access and delivery of digital data. Use of newly developed satellite data broadcast technology offers a solution.     

基于车载平台的飞行管理系统DR/GPS 导航试验验证

飞行管理系统是民用飞机的关键航空电子系统。飞行管理系统制造商有责任对飞行管理系统开展大 量的试验以验证飞行管理系统功能和性能的符合性。考虑数字验证的局限性和飞行试验验证的巨大代价,本文 利用车载平台开展飞行管理系统综合导航功能的验证,试验结果表明设计的飞行管理系统DR/GPS 导航方法能 够满足95% 的飞行时间水平方向达到0.1 海里的导航精度要求,为实际的飞行测试提供了试验数据参考。     

某飞机座舱和设备舱温度检测仪的设计

某飞机的大多数设备为模拟系统,座舱的温度通过指针指示,显示不直观.利用单片机P89LPC922FDH、温度传感器DS18820和显示器LM016L等器件,设计的数字式温度检测仪能实时显示座舱和设备舱的温度.该系统具有结构简单、精度高、可靠性高、实用性好的特点,可以大大提高飞行员及机务维修人员的工作效率.     

Aging avionics and net-centric operations

The transformation to net-centric operations necessitates evaluation of existing avionics capabilities, identification of deficiencies of these avionics for net-centric operations, and evaluation of alternative avionics that can provide the needed capabilities. The Global Information Grid (GIG) enables net-centric operations. The purpose of the GIG is to provide end users real-time or near-real-time access to multiple information sources ranging from airborne/satellite/ground sensors (video imagery and processed visual information/data) to databases. The end users in an aircraft view and interact with this information through the human system interface (HSI) or "smart" displays. The information is transmitted across a Gigabit Ethernet on-board the aircraft that interfaces with multiple channels of a software programmable radio that acts as a hub in the GIG network, or on-board sensors and processors. This paper presents the mandated capabilities, and the processes involved in determination of upgrades needed to achieve net-centric operations.     

Small UAV Automation Using MEMS

This paper presents a framework for the automation of a small UAV using a low cost sensor suite, MNAV, and an embedded computing platform, Stargate, which together provide a complete avionics package for aerial robotic applications. In order to provide a complete INS solution (i.e., attitude, velocity, position, and biases), an extended Kalman filter algorithm is developed and implemented in real-time. A devised control strategy utilizes multiple PID loops with a hierarchy enabling simple attitude stabilization to full waypoint navigation. The developed ground station unit, a laptop computer, communicates with the avionics package via 802.11b WiFi, displays the aircraft critical information, provides in-flight PID gain tunings, and uploads waypoints through a simple GUI. The system is installed in an off-the-shelf delta-wing R/C aircraft and demonstrates its performance for aerial robotic applications     

Firewire in modern integrated military avionics

High performance communications, navigation, and identification (CNI) functions on modern military aircraft are increasingly required for mission readiness. The operation of simultaneous waveforms through an integrated avionics rack of shared resources becomes a test in moving data rapidly from one signal processing stage to the next. The IEEE 1394, or Firewire, is a commercial high bandwidth bus whose 64-bit addressing and maximum 400 Mbits/second throughput satisfies this demanding military avionics interconnect need. The challenge in applying this commercial product to integrated avionics is the requirement to seamlessly add message priority encoding. By having message priorities, the slower strategic communications links will not impair the performance of higher data rate tactical communications, thereby avoiding potentially life-threatening bottlenecks. The flight environment imposes additional challenges to ruggedize the cabling between integrated avionics racks and to utilize the full capabilities of the Firewire bus. A discussion of the physical, data link, network, and transport layers, as used in avionics applications will be done. Additionally, the versatility of 1394 in military avionics with its variable channel sizes, bandwidth on demand, hierarchical addressing, and upgrade to 800 and 1600 Mbps with a 64-bit wide data path, is emphasized. Finally, system maintenance advantages of 1394's hot pluggable features are discussed, with an eye toward cost reduction on the flight line and total operational time of the aircraft avionics systems     

Terrain intervisibility-believe it or not?

Computer generated digital maps with terrain intervisibility displays are becoming a common addition to aircraft cockpits. Also known as masking plots, these displays show dangerous regions exposed to threats, highlight terrain visible from the current (or future) aircraft location, and keep track of regions hidden from view during searches with various types of sensors. High resolution displays of semi-transparent intervisibility overlaid on sharp clear digital maps are very convincing but can they be believed? Not completely. Intervisibility displays serve a valuable function. But to build and use these systems wisely, it is good to understand the errors and limitations involved. At LMFS, we have integrated digital maps from other companies into avionics systems such as Army Special Operations Aircraft and MH-53J, and have analyzed the errors associated with the use of level 1 and level 2 terrain elevation data from the National Imagery and Mapping Agency (NIMA). We have also developed a number of real-time intervisibility and probabilistic intervisibility functions using a hybrid of multiresolution techniques and algorithms to obtain the best results possible for a given set of computer resources. This paper explores some of the problems, solutions, and human/machine interface considerations associated with the generation and use of intervisibility     

Aviation electronics/avionics

International regulations prohibit aircraft from entering high-density airspace and heavily trafficked over-ocean airways without suitable avionics. The widespread use of GPS navigation and increasing complexity of passenger entertainment systems have become the latest electronics trends on large commercial aircraft. The cost of avionics plus software is approaching 50% of the total. New aircraft have multiple computers and millions of lines of software. The following sections present the most important avionics subsystems and highlight some differences between military and commercial aircraft     

Confluence of navigation, communication, and control in distributedspacecraft systems

This research details the development of technologies and methodologies that enable distributed spacecraft systems by supporting integrated navigation, communication, and control. Operating at the confluence of these critical functions produces capabilities needed to realize the promise of distributed spacecraft systems, including improved performance and robustness relative to monolithic space systems. Navigation supports science data association and data alignment for distributed aperture sensing, multipoint observation, and co-observation of target regions. Communication enables autonomous distributed science data processing and information exchange among space assets. Both navigation and communication provide essential input to control methods for coordinating distributed autonomous assets at the interspacecraft system level and the intraspacecraft affector subsystem level. A technology solution to implement these capabilities, the Crosslink Transceiver, is also described. The Crosslink Transceiver provides navigation and communication capability that can be integrated into a developing autonomous command and control methodology for distributed spacecraft systems. A small satellite implementation of the Crosslink Transceiver design is detailed and its ability to support broad distributed spacecraft mission classes is described     

Human Factors R&D Requirements for Future Aerospace Cockpit Systems

Cockpits are rapidly changing from dedicated instruments to multifunction displays, integrated controls, and computer controlled subsystems. Solid-state displays, voice recognition, and artificial intelligence are just a few of the emerging technologies that will help the pilot perform his mission in the future. Early investigations involving mission analysis, sensor data, software development, and evaluations will be required to insure total integration. These new technologies will require extensive human factors research in the areas of anthropometry, displays, controls, human/computer interface, automation, and workload assessment to support the integration process. This research will help provide weapons systems that have increased survivability and reduced pilot workload. This paper addresses some of the human factors research that will be needed to help develop future cockpit systems. It also reviews the basic evolution of the crew station and some of the emerging technologies that will drive human factors research in the 1990s. In the past, crew systems were designed to provide each aircraft function with a corresponding instrument display, such as airspeed indicator, altimeter, attitude direction indicator, vertical velocity indicator, etc. The bulk of the information had to be integrated by the pilot. Present systems are in a state of transition. We are rapidly moving from individual instruments to multifunction displays. The C-17, HH-60, F-15E, B-1B, F-111D, and F-16C/D aircraft use multifunction, cathode-ray tube displays, some of which are color. Another trend is the continued increase in the use of integrated controls.     

Digital Avionics?The Best is yet to Come!!!

This paper reviews some of the history and background of digital avionics and offers some tantalizing possibilities for the future. There are payoffs in many areas from digital avionics; however, the ultimate benefits are increased mission effectiveness and lower costs. Two major U. S. Air Force avionics programs designed to increase mission effectiveness are reviewed. Major barriers to the expanded use of digital avionics in civil transports as a means to lower operating costs are examined. The paper also examines lightning effects, architectures, optical components, displays, and voice interactive control which are current research areas that promise to yield significant advances for digital avionics systems. Finally, in a notice of optimism, it is concluded that the best is yet to come. As good as contemporary avionics are, we have only begun to visualize their ultimate potential.     

小型飞机先进综合座舱电子系统架构研究

以Garmin1000系统为例,从系统功能、基本架构、容错策略和通用性方面分析了小型飞机先进综合座舱电子系统架构的设计特点。先进综合座舱电子系统架构包括了设备级和系统级两个层面,在设备级阐述了航电设备集成化的发展趋势,在系统级采用了不同的容错策略,保证系统规模最小化时容错能力达到最大化。同时,网络应用增强了系统架构的通用性,支持多种系统规模的扩展。     

飞机着陆时的容错导航

研究了飞机在微波着陆环境中的传感器容错系统。该系统的主要目的是检测辅助导航设备和机载传感器的故障,并在这些传感器可能发生故障时提供可靠的飞机状态估计值。自动导航和控制系统利用这些状态估计控制和引导飞机按预定路线降落。     

基于视觉SLAM的飞机模拟座舱三维地图构建

针对飞机座舱副驾驶的研究需要,为使得机械臂能够在飞机座舱完成导航任务,旨在构建一个可用于机械臂导航的飞机模拟座舱三维地图。针对特征点分布情况对即时定位与地图构建(simultaneous localization and mapping,简称SLAM)的建图精度的影响,通过实验对比,验证了ORB-SLAM改进的ORB(oriented FAST and rotated BRIEF)特征检测算法相对于OpenCV库中SIFT,SURF和ORB算法检测提取的特征点分布更加均匀,更适用于SLAM。采用Kinect V2.0作为深度信息图像和彩色图像的数据采集设备,在飞机模拟座舱真实的环境下,结合ROS系统和ORBSLAM2系统框架,构建了飞机座舱内的三维稠密点云地图。针对点云地图存在数据大和难以实现导航等问题,采用了OctoMap数据模型,该数据模型能够压缩点云,调节分辨率和判断空间是否被占据,将点云地图转化为八叉树地图,最终获得数据小和适用于导航的三维八叉树地图。