The development of validated multidisciplinary Integrated Vehicle Health Management (IVHM) tools, technologies, and techniques to enable detection, diagnosis, prognosis, and mitigation in the presence of adverse conditions during flight will provide effective solutions to deal with safety related challenges facing next generation aircraft. The adverse conditions include loss of control caused by environmental factors, actuator and sensor faults or failures, and damage conditions. A major concern in these structures is the growth of undetected damage (cracks) due to fatigue and low velocity foreign impacts that can reach a critical size during flight, resulting in loss of control of the aircraft. Hence, development of efficient methodologies to determine the presence, location, and severity of damage in critical structural components is highly important in developing efficient structural health management systems.

关键词：光机电；传感器；结构管理；表征破坏

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Many state departments of transportation have been collecting various traffic data through the Automatic Traffic Recorder (ATR) and Weigh-in-Motion (WIM) systems as outlined in the Traffic Monitoring Guide (TMG) published by USDOT. A pooled fund study led by MnDOT was conducted in 2002 to determine traffic data editing procedures. It is challenging to identify potential problems associated with the collected data and ensure data quality. The WIM system itself presents difficulty in obtaining accurate data due to sensor characteristics, complex vehicle dynamics, and the pavement changes surrounding the sensor over time. To overcome these limitations, calibration procedures and other monitoring activities are essential to data reliability and accuracy. Current practice of WIM calibration procedures varies from organization to organization. This project aims to understand the characteristics of WIM measurements, identify different WIM operational modes, and develop mixture models for each operation period. Several statistical data analysis methodologies were explored to detect measurement drifts and support sensor calibration. A mixture modeling technique using Expectation Maximization (EM) algorithm and cumulative sum (CUSUM) methodologies were explored for data quality assurance. An adjusting CUSUM methodology was used to detect data anomaly. The results indicated that the adjusting CUSUM methodology was able to detect the sensor drifts. The CUSUM curves can trigger a potential drifting alert to the WIM manager. Further investigation was performed to compare the CUSUM deviation and the calibration adjustment. However, the analysis results did not indicate any relationship between the computed CUSUM deviation and the calibration adjustment.

关键词：光机电；传感器；校准；系统

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The problem to be addressed in this project pertains to the monitoring and management of transportation infrastructural health through the use of fiber-optic sensing technology. In the project, we have demonstrated that the fiber-optic sensing technology is capable of offering superior performance and extensive capability to structural heath monitoring applications. We have conducted comprehensive performance evaluation for point and distributed fiber optic sensors aiming at the application for the long-span transportation infrastructural monitoring. In the research effort, validation of point and distributed fiber optic sensors is achieved through laboratory and field tests. A structural health monitoring system using a quasi-distributed sensor network and distributed sensors will be designed based on the results of this field test. The research team plans to collaborate with Caltrans engineers to conduct a field deployment test within the Southern California transportation infrastructure. The field-test data will be reviewed and analysed to obtain important information to justify fiber-optic sensing technology for future system installation. The prototype deployed in the selected section of the transportation infrastructure will continue to collect structural information for technology and design validation. A system design utilizing a fiber-optic sensor network used in the monitoring and management of transportation infrastructures will be proposed as the end of the research effort.

关键词：光机电；传感器；光纤；交通设施

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This paper explores a class of multiple-model-based fault detection and identification (FDI) methods for bias-type faults in actuators and sensors. These methods employ banks of Kalman-Bucy filters to detect the faults, determine the fault pattern, and estimate the fault values, wherein each Kalman-Bucy filter is tuned to a different failure pattern. Necessary and sufficient conditions are presented for identifiability of actuator faults, sensor faults, and simultaneous actuator and sensor faults. It is shown that FDI of simultaneous actuator and sensor faults is not possible using these methods when all sensors have biases.

关键词：光机电；传感器；故障检测；偏置型

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Flight systems operating new performance and stability limits require continuous, robust autonomy through real-time performance-based measurements.

关键词：光机电；传感器；气动伺服弹性；弹性控制；飞行控制

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Microelectromechanical systems (MEMS) inertial sensors are commonly used in applications such as inertial navigation and human motion tracking. These inertial sensors provide three-dimensional (3D) orientation, acceleration, rate of turn, and magnetic field information. Manufacturers specify both static and dynamic accuracy for the 3D orientation output of MEMS inertial sensors. The dynamic accuracy is in the form of a root-mean-square (RMS) error and is only valid for certain motions, which are not specified. In this thesis, an investigation of the dynamic accuracy of the Xsens Motion Tracker (MTx) inertial sensor was conducted. The yaw or heading dynamic accuracy of the Microstrain 3DM-GX3-25 inertial sensor also was investigated. A pendulum test apparatus from a previous work was used to test the MTx and GX3. An encoder is installed to the pendulum axis of rotation and provides the reference data needed to calculate the dynamic accuracy of the MTx and GX3. After a series of motion tests, it was concluded that the MTx was within manufacturer specifications for static accuracy but not for dynamic accuracy. More specifically, the heading or yaw accuracy of the MTx and GX3 did not meet manufacturer specifications under the testing motions chosen in this study.

关键词：光机电；微机电系统(MEMS)；惯性传感器；惯性导航；人体运动

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Radars consist of transmitter and receiver modules, which help in the detection of objects by transmitting and receiving radio waves. They determine speed, direction, range, and altitude of various objects. They are usually used in military applications, but with changing times and needs, the demand for their use in applications such as: remote sensing, air traffic control, law enforcement, highway security, navigation, ship safety, and space programs has emerged. Because of this increasing demand, vendors are investing more in the R&D of radar technologies.

关键词：雷达；发送器；接收器；无线电波

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Argon is a flight-ready sensor suite with two visual cameras, a flash LIDAR, an on- board flight computer, and associated electronics. Argon was designed to provide sensing capabilities for relative navigation during proximity, rendezvous, and docking operations between spacecraft. A rigorous ground test campaign assessed the performance capability of the Argon navigation suite to measure the relative pose of high-fidelity satellite mock-ups during a variety of simulated rendezvous and proximity maneuvers facilitated by robot manipulators in a variety of lighting conditions representative of the orbital environment. A brief description of the Argon suite and test setup are given as well as an analysis of the performance of the system in simulated proximity and rendezvous operations.

关键词：光机电；传感器；模拟飞行；性能测量

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An accurate calibration of an electric-field sensor is difficult to carry out due to challenges involved in generating a uniform electric field over the sensor volume. Additionally, capacitive coupling between the field source and the sensors and related instrumentation tends to distort the measured field further. Sensor characterization includes not only calibration, but also determination of the frequency response (both magnitude and phase), noise power spectral density, dynamic range, and linearity. In this paper, we discuss characterization techniques for an unpackaged microelectromechanical systems (MEMS) electric field sensor in a vacuum chamber. The use of oppositely charged square plates at a spacing of half the plate width is advised by the IEEE 1308-1994 standard for generation of a uniform electric field. Previously, the U.S. Army Research Laboratory (ARL) has shown that by employing guard tubes in the construction of an electric field generating chamber, the fringing fields can be controlled, and the spacing between the endplates can be increased while maintaining a uniform field. A similar, smaller apparatus for generating a uniform axial electric field was constructed to fit into a vacuum bell jar. The considerations and techniques for minimizing error due to fringing and distortion from metal conductors will be presented, along with the techniques and laboratory equipment used for characterizing the sensor.

关键词：光机电；传感器；MEMS电场；表征技术

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Differential Global Positioning Systems (DGPS) are susceptible to outages due to blocked or missing satellite signals and/or blocked or missing DGPS correction messages. Outages arise primarily due to environmental reasons: passing under bridges, passing under overhead highway signs, adjacent foliage, etc. Generally, these outages are spatially deterministic, and can be accurately predicted. These outages distract drivers using DGPS-based driver assistive systems, and limit the system robustness. Inertial measurements have been proposed as an augmentation for DGPS. Tests have shown that error rates for even emerging technologies are still too high; a vehicle can maintain lane position for less than three to four seconds. Ring laser gyros can do the job, but $100K per axis is still too expensive for road-going vehicles. To provide robust vehicle positioning in the face of DGPS outages, the IV Lab has developed a technique by which a non-contact, 2D true ground velocity sensor is used to guide the vehicle. Although far from fully developed, the system can maintain vehicle position within a lane for GPS outages of up to 20 seconds. New dual frequency, carrier phase DGPS systems generally require less than 20 seconds to acquire a 'fix' solution after a GPS outage, so the performance of this system should be adequate for augmentation. Proposed herein is basic research which may lead to the development of an inexpensive, 2D, non-contact velocity sensor optimized for vehicle guidance during periods of DGPS outages.

关键词：光机电；传感器；GPS；差分全球定位系统(DGPS)

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