P L R. Flight Test Data. Recording and Processing. System. March 2000

Transcription

1 Flight Test Data Recording and Processing System March 2000 P L R Poleg Industrial Park POB 8130 Netanya Israel Tel: Fax:

2 Introduction Any flight-testing involves recording large amounts of data. The result is lengthy processing and post flight analysis sessions. A typical processing session will include calibration, choice of parameters of interest, selecting a specific time interval, displaying the results and analyzing them. As all Flight Test Engineers know, this is a tedious task, requiring expertise and is time consuming. Much of this effort is devoted to picking out sections of relevance to the defined test, separating it from all the non-relevant data and concentrating on the sections of importance. The Flight Test Data Recording and Processing System provides the Flight Test Engineer with tools which greatly simplify these tasks. Files containing only data of interest are generated in seconds. Test Reports are prepared in a number of hours instead of days. Running the videotape to that point can pick a section of the Test Flight, which is of interest. As soon as this point is reached, the relevant recorded data, synchronized with the video, can be viewed. Running the tape backwards and forwards has no effect on synchronization and data and video are viewed together. Flexibility is provided in various forms, such as providing easy interface with standard data handling software (Excel, Matlab, etc.). Both hardware and software, airborne and ground based components are an integral part of the system, providing the Test Pilot or Test Engineer with a complete and overall solution to his Recording and Processing requirements. Airborne Platform The Flight Data Recorder is a cockpit mounted unit, which fits into a standard instrument slot in one of the cockpits side panels. Data is stored on standard PCMCIA Flash Memory cards capable of recording over 3 Giga Bytes of data. The FDR can record both digital and analog data. The digital data is normally read from one of the busses in the system, such as a 1553 Mux Bus, ARINC-429, RS-232/422/485. Flight Data Recorder The recorded data is then stored on rugedized PCMCIA Flash Memory Cards. The cards are inserted into two slots on the front panel of the unit, which features a rugged retention and ejection mechanism with a sealed access cover. The use of commercially available PCMCIA Cassettes provides an attractive solution for mass data storage, both in its availability, low cost and its ease of use. Such Flash Memories have become very common in numerous applications and are today readily available. 1

3 The FDR also includes a number of RS-232/422 channels and a 10 BaseT Ethernet channel. The serial RS channels enable the FDR to be interfaced to additional aircraft systems. The Ethernet channel can be used for either ground based or in air high-speed data transfer. Flight Data Recorder aircraft interconnections The system records raw data supplied by various sensors and bus data from the 1553 Mux Bus or an ARINC 429 bus. Data from analog and discrete inputs can also be stored. The recorded data is then analyzed on the ground after the completion of the test. During the actual test, all of the data or any selected parts of it, can be transferred via a dedicated Ethernet link to an on board computer (such as a laptop or any other computer), providing real time, on line monitoring processing and analysis. An additional feature of the FDR is its capability to synchronize a video picture with the relevant aircraft data. The unit communicates with the onboard VCR and inserts a Time Code on the videotape, with no deterioration to the recording. The recorded time base is then used by the Ground Station to accurately synchronize video, audio and the recorded flight data. The video source is either from a HUD camera, a Symbol Generator, an externally mounted camera or any other video source. Initially, the parameters of interest are chosen via the set up program. This defines which bus parameters will be recorded, calibrates the signal conditioner, and defines which parameters will be transmitted to the on board computer for on line monitoring and analysis. 2

4 Ground Based Debriefing Station The Debriefing Station is a PC based system with conventional commercially available peripheral equipment. The Station provides a versatile and flexible tool capable of replaying data and video recorded during flight. The Stations monitors display the recorded video synchronized with the recorded data parameters. The Stations host PC has a PCMCIA Drive and dedicated software packages, which provide the following functionality: * Full control of the VCR via the PC mouse and keyboard. * The software provides the user with the capability to designate "start" and "stop" points while replaying the VCR, providing time related reference points to the corresponding data on the PCMCIA card. * Several Start-Stop points can be designated in series without interrupting background File creation activity. * The designated data is re-arranged in a sub-file in ASCII format and transformed to Physical units. * The file format is compatible with EXCEL, MATLAB and other commercially available data processing programs. * Synchronization of the Video output to the PCMCIA recorded data. * Windows 95 man-machine interface. * The MMI of the process is fluent and does not require exiting and re-entering different programs - all file transfers are done by "Drag and Drop" or by other Microsoft MMI methods. The PC is capable of controlling an 8 mm VCR (TEAC V-80 ABF) via an RS-422 remote control channel. If required, more than one VTR can be synchronously controlled. The recorded video is displayed on a dedicated monitor. The flight data is displayed on an additional monitor. Data display formats are user defined and include horizontal or vertical bars, analog or digital readouts and graphs. Debriefing Station 3

5 Data Processing Procedure Working with the Flight Test Data Recording and Processing System can be divided into a number of sequential steps, each executed at a different point in the process: - Pre Flight: - Define Database: This is a one-time operation and dedicated to a specific avionics system design. The database can be edited when design changes are incorporated. - Setup: Defines the communication parameters of each input channel, defines which parameters will be recorded, their units of measure and their calibration. - Flight: - Record: A pilot or operator initiated operation using the FDR Record On/Off switch. - Quicklook: Defines which parameters will be monitored on line and the display format for each parameter. - Post Flight: - Debriefing Data View: Replays the recorded data, which can be viewed in the same manner as in Quicklook, whilst viewing the corresponding videotape. - Data Dump: Creates separate files of each section of the flight that is of interest, which are used to generate Test Reports. Each section can include a separate sub set of parameters. The Setup Software Package Prior to each test, the parameters of interest are chosen via the set up program. This defines which bus parameters will be recorded, calibrates the signal conditioners, and defines which parameters will be transmitted to the on board computer for on line monitoring and analysis. The Setup program lets you create a new setup and modify an existing one for both the airborne recording unit and for the Ground Debriefing Station. The program generates an autoexec.cmd file for the FDR unit. This file contains information on recorded input sources and provides input source communication parameters, as well as recorded message definition, described to the single parameter level containing parameter name, type and calibration definition. A window in the SetUp Program 4

6 Debriefing Data View Sections, or all, of the test flight can be run at normal speed, higher or lower speeds. Before the beginning of a debriefing session, the display is set up as desired, choosing parameters to be displayed and the display format for each. The section of the Test Flight to be analyzed is reached either by viewing the videotape or by searching for events on the parameter display. Data presentation during a debriefing session Data Dump Module The Data Dump module is used to convert the flight recorded data file into a calibrated ASCII format output file. The user can run several passes on different specified start and stop times. The output text files generated will have a common time tag for all the parameters selected and it is compatible with EXEL, MATLAB and other general-purpose electronic spreadsheet software packages. 5