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4661.垂直腔表面发射激光器在传感器应用上的近期发展(后印本)
[电气机械和器材制造业,计算机、通信和其他电子设备制造业] [2013-12-28]
Vertical external cavity surface emitting lasers (VECSELs) have proven themselves to be a suitable semiconductor answer to many solid-state lasers. Their simplicity makes them a very versatile platform for accessing wavelengths from the UV through the THz through direct and frequency-converted emission. This wavelength flexibility, combined with an optical cavity accommodating additional tuning or nonlinear elements, make the VECSEL a uniquely suited solution to a variety of applications. We will present recent Air Force Research Laboratory progress in VECSELs and potential applications for these lasers.
关键词:传感器;激光器
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4662.适用于缺乏GPS环境精确导航的多普勒激光雷达传感器
[计算机、通信和其他电子设备制造业,铁路、船舶、航空航天和其他运输设备制造业] [2013-12-28]
Landing mission concepts that are being developed for exploration of solar system bodies are increasingly ambitious in their implementations and objectives. Most of these missions require accurate position and velocity data during their descent phase in order to ensure safe, soft landing at the pre-designated sites. Data from the vehicle's Inertial Measurement Unit will not be sufficient due to significant drift error after extended travel time in space. Therefore, an onboard sensor is required to provide the necessary data for landing in the GPS-deprived environment of space. For this reason, NASA Langley Research Center has been developing an advanced Doppler lidar sensor capable of providing accurate and reliable data suitable for operation in the highly constrained environment of space. The Doppler lidar transmits three laser beams in different directions toward the ground. The signal from each beam provides the platform velocity and range to the ground along the laser line-of-sight (LOS). The six LOS measurements are then combined in order to determine the three components of the vehicle velocity vector, and to accurately measure altitude and attitude angles relative to the local ground. These measurements are used by an autonomous Guidance, Navigation, and Control system to accurately navigate the vehicle from a few kilometers above the ground to the designated location and to execute a gentle touchdown. A prototype version of our lidar sensor has been completed for a closed-loop demonstration onboard a rocket-powered terrestrial free-flyer vehicle.
关键词:传感器;雷达
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4663.在DESIRE项目中的机器人开发过程
[计算机、通信和其他电子设备制造业,电气机械和器材制造业] [2013-12-28]
In this paper we give a general overview of the development process carried out in the DESIRE project. This process can be roughly split up into four main phases, from specification in the beginning over two integration phases up to optimisation in the end. With a large variety of technologies and expertises involved, the development of a complex service robot system such as the DESIRE technology platform proved to reveal many challenges on technical as well as organisational level. Several of these issues are highlighted in this paper with the goal to derive useful guidelines for other robotics projects.
关键词:机器人;开发;DESIRE
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4664.两足机器人位置控制与基于稳定的地面反作用力和速度限制
[电气机械和器材制造业] [2013-12-28]
This paper implements position control of a biped robot via velocity control with automatically generated joint torque and velocity limits so as to have zero overshoot of the COM and sliding, tipping and twisting of the robots feet while allowing the COM to move in mimimum time to a refferential position. This method allows the position controller to be robust to external disturbances and is able to reject the maximum amount of external force without letting the feet tip over(not unnecesserily compliant like some methods). This method is also general in the sense that all 6 axes can have ground reaction force limits so sliding, twisiting and tipping of the feet can be prevented. Also this method does not require a refferential ZMP trajectory. Friction and coriollis forces are detected via a type of workspace disturbance observer. Knowledge of the magnitude of this disturbance allows the motor torques to be limited so that the total ground reaction force doesnt lead to unstable conditions at the feet. The proposed method with velocity limits is verified on the biped robot MARI-3 and it is shown that overshoot is eliminated while being compliant to external disturbances.
关键词:机器人;ZMP;两足机器人;力量控制;速度限制
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4665.热红外传感器热子系统设计和已有经验
[计算机、通信和其他电子设备制造业,电气机械和器材制造业] [2013-12-28]
The Thermal Infrared Sensor (TIRS) is one of two instruments on the Landsat Data Continuity Mission (LDCM), which is scheduled to launch in February of 2013. The TIRS instrument was officially added to the mission later in the flow, which led to a highly aggressive schedule that became one of the main drivers during instrument development. The thermal subsystem design of the TIRS Sensor Unit is comprised of five thermal zones which range in temperature from less than 43 Kelvin to 330 Kelvin. Most zones are proportional heater controlled, and all are within a volume of 35 cu.ft. A two-stage cryocooler is used to cool the cold stage; including three QWIP detectors to less than 43 Kelvin, and cool the warm stage; to 105 Kelvin. The excess power dissipation from the cryocooler is rejected via ammonia transport heat pipes to a dedicated Cryocooler Radiator with embedded ammonia heat pipes. The cryogenic subsystem includes a series of shells used to radiatively and conductively isolate the cold stage from the warmer surroundings. The Optical System (telescope) is passively cooled to 180-190 Kelvin using a thermal link; (comprised of a Flexible Conductive Thermal Strap and an APG Bar) which couples the telescope stage to a dedicated radiator with embedded ethane heat pipes. The Scene Select Mechanism, which is responsible for moving the Scene Select Mirror to three distinct positions (including Nadir, Space, and On-board Black Body Calibrator pointing), runs nominally at 278 Kelvin and is thermally isolated from the cryogenic thermal zones. The On-board Black Body Calibrator requires a dedicated radiator which allows for a temperature range of 260-330 Kelvin at the Source. The detectors are powered by the FPE Box, which is mounted to the nadir external surface of the composite honeycomb structure. There are two additional electronics boxes which are wet-mounted directly to the spacecraft shear panel, the Main Electronics Box and Cryocooler Electronics Box; thermal control of these boxes is the responsibility of Orbital Sciences Corporation, the spacecraft developer. The TIRS thermal subsystem design was successfully verified during months of testing campaign, from component & subsystem level to two instrument-level thermal vacuum tests. The Instrument, despite an aggressive schedule, was delivered to the spacecraft vendor in February of 2012 and is currently undergoing the final stages of spacecraft environmental testing in preparation for launch.
关键词:热红外传感器;TIRS仪器
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4666.使用鱼传感器对俄勒冈州福斯特大坝穿过鱼梁和一号机组鱼通道条件的描述,2012.
[农、林、牧、渔业] [2013-12-28]
Fish passage conditions through a Kaplan turbine and spillway fish weir at Foster Dam, located on the South Santiam River in Linn County, Oregon, were evaluated by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District, using Sensor Fish devices. The objective of the study was to describe and compare passage exposure conditions, identifying potential fish injury regions encountered during passage via specific routes. The investigation was performed in May 2012, concurrent with HI-Z balloon-tag studies by Normandeau Associates, Inc. Sensor Fish data were analyzed to characterize the passage exposure conditions through the spillway fish weir and turbine Unit 1 at Foster Dam at two forebay pool elevations (616 and 634 ft mean sea level (MSL)) and to estimate data relationships with live fish injury and mortality estimates. For the spillway fish weir evaluation, Sensor Fish and live fish were deployed through injection system piping mounted on the weir. The bottom of the injection pipe was at an elevation of approximately 614 ft during testing at the 616-ft MSL (low) forebay elevation and at 632 ft during the 634-ft MSL (high) forebay level tests. Two systems were useda 4-in. pipe for juvenile fish releases and an 8-in. pipe for adult releases at each elevation.
关键词:传感器;鱼
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4667.舱外活动应用中的光学气体传感器
[计算机、通信和其他电子设备制造业,铁路、船舶、航空航天和其他运输设备制造业] [2013-12-28]
The function of the infrared gas transducer used during extravehicular activity in the current space suit is to measure and report the concentration of carbon dioxide (CO2) in the ventilation loop. The next generation portable life support system (PLSS) requires next generation CO2 sensing technology with performance beyond that presently in use on the Space Shuttle/International Space Station extravehicular mobility unit (EMU). Accommodation within space suits demands that optical sensors meet stringent size, weight, and power requirements. A laser diode spectrometer based on wavelength modulation spectroscopy is being developed for this purpose by Vista Photonics, Inc. Two prototype devices were delivered to NASA Johnson Space Center (JSC) in September 2011. The sensors incorporate a laser diode-based CO2 channel that also includes an incidental water vapor (humidity) measurement and a separate oxygen channel using a vertical cavity surface emitting laser. Both prototypes are controlled digitally with a field-programmable gate array/microcontroller architecture. The present development extends and upgrades the earlier hardware to the Advanced PLSS 2.0 test article being constructed and tested at JSC. Various improvements to the electronics and gas sampling are being advanced by this project. The combination of low power electronics with the performance of a long wavelength laser spectrometer enables multi-gas sensors with significantly increased performance over that presently offered in the EMU.
关键词:红外气体传感器传感器;光学;舱外活动;宇航
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4668.机器人驱动电动机特性的测试计划。PackBot现代化项目。
[电气机械和器材制造业,汽车制造业] [2013-12-28]
A test plan to measure voltage and current of active drive motors on a small robot under repeatable test conditions. Several positive and negative slope conditions are included.
关键词:机器人;汽车;电压;运动测试
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4669.人机交互:意图识别和相互夹带
[计算机、通信和其他电子设备制造业,电气机械和器材制造业] [2013-12-28]
Waltz is a typical example of physical human-human interaction (pHHI) in a well-structured environment. Waltz involves two dancers. The goal is to reproduce the female dancer's abilities with a robot in pHRI. The project focused on the lower level interaction in pHRI, i.e., coupled dynamics, and proposed a framework which covers modeling, analysis, human state sensing and robot control in developing a cooperative female robot dancer. The two dancers' coupled dynamics was modeled as two physically connected inverted pendulums. Stability of this two pendulum system was analyzed. The human state was measured by two laser range sensors, while the measurement noise and bias were corrected by a Kalman filter. Several candidate robot controllers were discussed and evaluated in experiments.
关键词:机器人;耦合(交互);交互作用;控制系统;探测器
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4670.在辅导的场景中构建人机交互
[计算机、通信和其他电子设备制造业,电气机械和器材制造业] [2013-12-28]
Contrary to the assumptions underlying many current robot systems, teaching is an interactive process where the tutor needs to be continuously informed about the learner's internal states of understanding and perception. In an open ended learning situation this interaction can not be pre-modelled as the aspects that need clarification can not be foreseen. However, standard approaches do exactly this: they pre-define interactions by coupling system states with dialog acts. In our approach we target at losening this coupling between system and dialog states by providing general task and interaction patterns and means to relate them to each other. By this approach we are now able to provide on the one hand a dialog system that is relatively easily adaptable to new scenarios and on the other hand mixed-initiative interactions that allow the system to inform the tutor about internal representations when they become important for the interaction.
关键词:机器人;交互;辅助场景