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作者:
Steven Blandford - Royal Australian Air Force
产品:
PXI-6533, PXI-1000, LabVIEW, PXI-6602, PXI-8156B
挑战:
Instrumenting the Black Hawk helicopter for flight test.
解决方案:
Creating a PXI-based system and providing real-time data acquisition, analysis, logging, and display functions using NI LabVIEW software.
"Using NI LabVIEW software resulted in a flexible, reprogrammable, graphical user interface with the familiar Windows look and feel, plus a short development time."
Designing a System for Flight Test and Data Gathering
The Royal Australian Airforce (RAAF) Aircraft Research and Development Unit (ARDU) provides expert instrumentation and flight-test support to the Australian Defense Force (ADF). ARDU engineers designed and developed an Airborne Data Acquisition and Recording System (ADARS) using National Instruments PXI components and LabVIEW software to assist in flight test and data gathering exercises for the Australian Army’s Black Hawk helicopters.
The key requirements of the ADARS system included the ability to acquire, process, and display up to 80 airborne parameters in real time, including engine, flight control, rotor, air, time, space, and position data, as well as day and night cockpit video and audio.
Using Hardware Flexible Enough to Reconfigure and UpgradeWe designed the ADARS with a modular construction so we could reconfigure and upgrade the system in the future. Important design criteria included survivability in extreme environmental conditions, such as temperature, pressure, humidity, shock, and vibration. The ADARS system also needed to meet aerospace crash loading safety requirements and satisfy the strict electromagnetic compatibility requirements of military aircraft.
Advanced use of drafting, 3D modeling, finite element analysis, and numerically controlled machining software tools permitted ARDU engineers to design and integrate more than 4,000 parts for the ADARS system. The system comprises a sealed modular 19-inch rack system, incorporating twin heat exchangers, shelving, and antivibration mounts. We developed components that we can readily remove and reinstall for enhanced serviceability. With its three-part design, we can reconfigure the system for alternative aircraft types with minimal redesign effort.
A National Instruments PXI-1000 chassis and DC power supply accommodates a Pentium class PXI-8156B controller and several data acquisition modules combining small size, high performance, and ruggedness, while complying with strict electromagnetic and environmental requirements. A PXI-6071E analog-to-digital converter acquires up to 64 channels of analog data. The NI PXI-6533 and PXI-6602 modules provide for the acquisition of discrete and periodic-pulsed inputs. We can synchronize a CompactPCI-based Datum time code generator to external Inter-Range Instrumentation Group (IRIG B) or Global Positioning System time sources and then time stamp all acquired data. Spare slots within the PXI-1000 chassis accommodate future channel expansion.
The modular nature of PXI provides for the inclusion of a faster processor or alternative modules for future flight testing with specialized requirements. A full compartment of analog signal conditioning and anti-alias filter modules ensures compatibility with a range of aircraft transducers including strain gages, RTDs, synchro transmitters, thermocouples, and linear position transducers. A military-grade 18-inch LCD display enables enhanced off axis, day, and night time visibility for the flight test engineer. A splash-proof membrane style keyboard and tracking device allows the operator to control ADARS while wearing flight gloves. With its innovative slide mechanism, operators can fold the keyboard upward in a stowed position and allow unimpeded ingress and egress from the aircraft in an emergency situation. A wide area solution differentially corrected GPS unit and associated aero-antennas, combined with a fiber optic gyro-based inertial motion unit, provides accurate aircraft time space and position information.
Using triple deck Hi-8 mm video recorder we can capture cockpit video and audio from a mixture of day or night image-intensified cameras. All video is time stamped from the system time code generator. An RS232 link between the video recorder and PXI controller provides control of the recorder from within LabVIEW. With an IMAQ-1408 video capture card, the flight test engineer can view any one of the three video sources in real time on the LCD screen. Twin, RS232- driven, cockpit-mounted vertical inline displays (VIDS) provide aircrew with a visual indication of selected "critical parameters." An uninterruptible power supply provides a reliable source of DC power to the ADARS system in the absence of aircraft power or during temporary power outages. We can download data from ADARS onto a flash disk or Zip drive via a USB port for the purpose of post processing and archiving.
Cutting Development Time with Flexible LabVIEW SoftwareUsing LabVIEW software resulted in a flexible, reprogrammable, graphical user interface with the familiar Windows look and feel, plus a short development time. Low-level assembler and C code provide a generic data acquisition engine for selected timing and stability critical functions. High-level LabVIEW code provides a graphical user interface to the flight test engineer. Multiple hot key selectable screens provide access to data pages containing critical parameters, flight control, time space and position, performance, pilot workload, engine, and rotor data. We can also select screens for calibration, video monitoring, controlling the video recorder, hardware configuration, data recording, replay, and analysis. The crew can determine ballast and fuel required for each test point from the performance calculator’s real-time updates.
Cutting Flight Trials from Months to WeeksIn recent months, the ADARS system proved instrumental during the First of Class Flight Trials (FOCFT) of Army Black Hawk helicopters for embarked operations from Australian Navy landing platforms amphibious class HMAS Manoora. Data acquired and displayed by the ADARS system enabled us to establish Ship Helicopter Operating Limits (SHOL) for several combinations of sea states, wind speeds and directions, takeoff or landing, aircraft fuel, all-up weight, and center-of-gravity limits.
By providing advice to the aircrew and automating production of the SHOL plot, flight trials that once took several months now are possible in several weeks. Improvements in data quality and the speed with which we can gather data enhanced the ADFs ability to certify aircraft for embarked operation onto Royal Austrian Navy ships of various types and class. The aircrew community can rely on its data and expect reduced risk and enhanced safety margins. For the Australian community, defense forces are better able to respond to a contingency situation and minimize downtime of defense assets.
The ADARS system already has helped Black Hawk operate from landing platform amphibian (LPA) class ships. Beyond FOCFT, we anticipate using ADARS not only on Black Hawk but also other fixed and rotary wing aircraft types for engine performance, pilot workload, fatigue monitoring, night vision goggle investigations and more. The ADARS system has enhanced Australia’s aerospace capability and will serve the ADF well for the foreseeable future.
