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Lockheed Martin Challenge Avionics Systems Presentation, Fall 2008 Problem Statement • Problem Statement Current UAV technology is not capable of launching vertically using a rail launch system into the atmosphere. This presents the problem of not being practical for use in an urban environment because of the difficulty for soldiers to see preexisting dangers in an urban combat zone with current UAV technology. Need Statement • Need Statement The Iowa State LM Challenge Team has been asked to design an unmanned autonomous vehicle to take off from a vertical or near vertical pneumatic launch system within the confines of an urban environment. This vehicle will be used to fly low altitude reconnaissance missions prior to U.S. ground troops occupying the designated area. System Block Diagram Operating Environment • The UAV is to be designed to operate in an urban environment, likely in regions of current military operation such as the Middle East • Considerations of ground obstructions, heat, altitude, sand, hostile action Deliverables • Avionics package capable of autonomous navigation of aircraft using user-defined flightplan • Camera system capable of 6” target resolution at 100’ • Operational range of 1 to 3 miles for video transmission • Components integrated for a pneumaticallyassisted vertically-launched aircraft Layout Layout Layout Schedule Work Breakdown Estimated Time Commitment per Task per Person Hours Mike Plummer Daniel stone Ronald Teo Adam Jacobs Robert Gaul Camera/Video System Choose Camera System Choose Xmitter/Receiver System Test Camer/Xmitter/Receiver Systems Mount Camera/Xmitter Systems Retest in-flight 5 5 25 20 30 5 5 25 20 30 10 10 35 25 30 10 10 35 25 30 5 5 25 20 30 15 10 10 20 20 5 5 5 5 10 15 20 5 5 5 5 10 15 20 5 5 5 5 10 15 20 5 5 5 5 10 15 20 5 5 Determine power source required Compile components and test Refine Layout 10 20 5 20 5 10 15 5 20 5 10 15 5 20 5 10 15 5 20 5 10 15 5 20 5 Choose Autopilot system Choose transceiver system independent testing/calibration integrate with aircraft systems Re-test/Re-calibrate for in-flight 15 5 40 30 30 20 15 45 35 30 15 5 40 30 30 15 5 40 30 30 20 15 45 35 30 350 350 350 350 350 Onboard Power System Establish Requirements Choose Power Supply Choose Battery System Finalize interface with flight systems test onboard power system Mount on aircraft Test in-flight arrangement Ground Station Determine components required from video and autopilot systems Determine manual flight override in conjunction with ap development AutoPilot Total Time Autopilot Functional Requirements • Be capable of autonomously navigating an aircraft using pre-programmed waypoint navigation • Support communication with a ground station to display telemetry and position data Non-Functional Requirements • Operate off of 5 or 12V to simplify power system • User-programmable to aid in support of vertical pneumatic launch • Small size, weight, power requirements Technical Challenges • Complexity and time constraints promote purchase of a commercial autopilot system • No commercially available autopilot that supports our method of launch by default • Immense G-loads during launch saturate sensors(~15G) • Maintaining vertical orientation throughout launch phase • Detecting when UAV has left the launcher Key Considerations • • • • • Available technical support Support for user programmable control loop Support for custom code/command Ability to handle additional sensors RC override Key Considerations • • • • • • Ground Station software capabilities Sensors to aid in launch (eg, GPS) Error handling Size Weight Power consumption Market Survey • • • • Micropilot 2128 Procerus Kestral Cloudcap Piccolo O Navi Phoenix/AX These four products satisfy the functional requirements of our system and were deemed as finalists for selection based on their relative merits Trade Analysis Micropilot 2128 Pros Cons •Excellent technical support •High frequency GPS •High customizability (Xtender) •Excellent ground station software •User defined control loops •Allows additional I/O •RC override •Error Handling •Light weight •Small size •Low saturation point IMU(2 G) •Costly Trade Analysis Procerus Kestral Pros Cons •High IMU saturation point (10 G) •Extensive error handling •Lightweight •Small size •High power consumption •Low GPS frequency •Poor technical support Trade Analysis Cloudcap Piccolo Pros Cons •High frequency GPS •Built-in radio modem •Simple form factor •Low saturation point IMU(2 G) •Costly •Large size •Heavy •High power consumption Trade Analysis O Navi Phoenix/AX Pros Cons •Low power consumption •Small size •High IMU saturation point •No embedded or ground station software •Low GPS frequency Autopilot Selected Model MicroPilot 2128 – Support for additional sensors increases our chances of safe and reliable launch and recovery – MicroPilot has demonstrated excellent service and support – I/O ports and user-defined telemetry fields provide a superior ability to create a custom platform – HORIZON software provides excellent ground station as well as easy configuration of autopilot – Low saturation point of the IMU accelerometers, we feel can be overcome through the utilization of other onboard sensors and user defined launch sequence – RC override provides us with the option for manual launch. Video Subsystem Camera, Video Transmitter, Video Receiver, Antennae Functional Requirements • Shall provide real-time video to ground station • Shall operate in an urban environment • Shall be capable of resolving a 6 inch target from an altitude of 100 feet • Shall be a fixed-position camera • Shall be designed to enable a modular payload system Non-Functional Requirements • • • • Low-power consumption components Light-weight components Small physical size components Video transmission shall not occur in the 900 MHz band to prevent interference with autopilot communication • Components should utilize 5V or 12V when possible to simplify power requirements and increase modularity of design Camera: Necessary Resolution • Below are some sample images taken from a digital camera as a test of the resolving power required in the video system 18 pixels per inch 9 pixels per inch 4.5 pixels per inch Camera: Necessary Resolution Scenario One – Wide Angle x = 101.027 feet Scenario Two – Telephoto x = 9.87 feet • Given camera has an effective resolution of 768 horizontal lines • Ratio of available pixels to linear distance: – 0.63 pixels/inch in scenario one – 6.54 pixels/inch in scenario two • From the last slide, a 4.5 ppi image allows viewer to resolve a 6 inch target. The lens can provide a 6.5 ppi image, which exceeds this requirement Camera Alternatives • Few cameras designed for UAV use satisfy our resolution requirements • Many cameras small and light enough are too sensitive for use in our project Camera Alternatives • Genwac/Watec • Maker of Industrial Box cameras • Adjustable frame rate, easily configurable • Heavier than other alternatives • Not designed for vibration and varying temperature and humidity of our application Camera Selection: KT&C model KPC-650 • Exceeds resolution requirements • Demonstrated ability to perform in UAV’s • C and CS mount lens compatible - large variety of varifocal lenses from which to choose • Auto-iris compatible - the ability to dynamically adjust to changing light conditions during flight • NTSC video output using a coaxial connection (both standard – allows for simplicity of design and video transmission) Camera Selection: KT&C model KPC-650 • Specifications – – – – Power: 180mA @ 12VDC Effective pixels (NTSC): 768(H) x 494 (V) Weight: 137 grams Size: 31mm(W) x 31mm(H) x 55mm(L) Video Transmitter • Must be robust in environments with RF interference • Must not interfere with other aircraft systems • Direct line-of-sight (LOS) often not possible in an urban environment, reducing transmission range • These limitations necessitate a powerful transmitter using a unique frequency • FCC regulations limit RF transmissions for civilians (maximum of 1 Watt) • A transmitter of 1 Watt will require a Technician Class radio license to operate Video Transmitter: Estimated Bandwidth • Using the Shannon-Hartley Theorem: – – – – S C B log 2 1 N C is channel capacity B is bandwidth in Hz S/N is the signal-to-noise ratio (SNR) For a 2.4GHz, 1W transmitter, assuming 10dB of noise: 1W C 2.4 E 9 Hz log 2 1 10dB C 314.722Mbps – Standard NTSC signal (704 x 480 pixels at 30 frames/sec.) requires 243Mbps Video Transmitter: Compensating for Interference • Due to obstructions (buildings, etc.) in an urban environment, weather conditions, and altitude, it can be difficult to maintain signal contact • Other EM sources present in the area further degrade and interfere with the signal • Interference is offset by increased transmission power • As will be discussed, antenna choices also have a direct impact on the signal’s transmission range Video Transmitter Selection: LawMate TM-241800 • Chosen for maximum allowable power and small size • Demonstrated ability to work in UAV’s • Standard SMA connector allows antennas to be easily changed • Accepts video data in composite NTSC format – Readily compatible with our camera • Utilizes a 12V power source, simplifying onboard power requirements Video Transmitter Selection: LawMate TM-241800 • Specifications – – – – Power: 500mA at 12VDC Output: 1W RF power Weight: 30 grams Size: 26 x 50 x 13mm Video Receiver • Receiver is subject to less restrictive size, weight, and power limitations • Must operate in the 2.4GHz band to receive video signal from selected video transmitter • Easy output to the display was also a consideration Video Receiver Selection: LawMate RX-2480B • Chosen for portability and compatibility with our transmitter • Includes rechargeable battery – simplifying testing • Supports reception on 8 channels with signal indicator to optimize reception • Provides output in standard RCA composite video Video Receiver Selection: LawMate RX-2480B • Specifications – – – – Power: 800mA at 5V Battery life: ~3.5 hrs. Weight: 135 grams 110 x 70 x 20mm Video System Antennae • Weight, simplicity, range, and frequency (2.4GHz) were the driving factors when selecting an antenna for both the transmitter and the receiver • Directional antenna on-board is preferred to omnidirectional, but is not practical – Larger size/weight than omni-directional – Increased complexity – must be oriented to ground station at all times during flight • Ground station does not share these constraints, and thus a directional patch antenna will be utilized • Increases range while maintaining size and complexity only at the ground station DC-DC Converter • Requirements – Facilitate power requirements for onboard systems – Physical size must be small enough to fit easily into fuselage DC-DC Converter • Major Onboard System Power Requirements Component Current Rating Voltage Rating Video Camera 180 mA 12 Vdc Video Transmitter 500 mA 12 Vdc Autopilot Core 160 mA @ 6.5 Vdc 4.2 – 27 Vdc Radio Modem 730 mA 4.75 – 5 Vdc Voltage Level Total Estimated Current Total Estimated Power 12 Vdc 680 mA 8.16 W 5 Vdc 817 mA 4.085 W DC-DC Converter • Initial Research – Tri-M Systems HESC104 • +5Vdc @ 12A • +12Vdc @ 2.5A • 3.55 x 3.75 x 0.5 in., 200 grams – Fits power need but too large for fuselage DC-DC Converter • Initial Research – Tri-M Systems IDD-936360A • +5Vdc @ 10A • +12Vdc @ 3A • 1.57 x 3.94 in., 58 grams – Meets size and power needs but no enclosure DC-DC Converter • Selection – Murata Power Solutions – TMP-5/5-12/1-Q12-C • +5Vdc @ 5A • +12Vdc @ 1A • 3.04 x 2.04 x 0.55 in, 170 grams Onboard Radio Modem • Requirements – Driven by autopilot communication requirements – Minimum range of 3 miles – Physical size must be small enough to fit easily into fuselage Onboard Radio Modem • Initial Research – Xtend-PKG • 900MHz • Power Supply 7-28V • Max Current 900mA • Outdoor LOS Range 14 mi. • 2.75 x 5.5 x 1.13 in, 200 grams – Physical size too large for our fuselage – Can be used for ground station Onboard Radio Modem • Selection – 9Xtend-PKG OEM • 900 MHz • Power Supply 4.75-5.5Vdc • Max Current 730 mA • Outdoor LOS Range 14 mi. • 1.44 x 2.38 x 0.02 in, 18 grams Ground Station and User Interface • Requirements – Ability to communicate with and control autopilot – Ability to display real-time video feed – Mobile • Must fit in the back of a military humvee Ground Station and User Interface • Components – Driven by onboard component selection – Laptop Computer • Able to run HORIZON software package • Able to interface with Xtend-PKG radio modem – Portable Television • Able to interface with LawMate RX-2480B video receiver • Able to accept input from video storage device Ground Station and User Interface • HORIZON Software Package – Satisfies communication, control and telemetry display requirements – Designed by autopilot manufacturer for use with our chosen autopilot system, ensuring compatibility and reliability HORIZON Software Package Performance Project Requirements: Endurance – 2 hours is a desired max, 1 hour minimum Range – Must be able to cover a small urban area, approximated to 1-3 miles of linear distance Projected Avionics Endurance: - 2000 mAh battery - Avionics components draw maximum 1650 mA - 2000 / 1650 ≈ 1.3 hours Projected Transmission Range: -Based on reports of other users of our transmitter, receiver, and antenna setup report reliable reception out to 2 miles -Variables in our case include RF interference, altitude, antenna orientation System Testing • Video System – Independent from other systems – Test Camera Resolution – Test Camera Communication • Quality • Range – Antenna Positioning System Testing • Autopilot – Model flight characteristics of UAV during launch, flight and landing phases • Provided by Aero and Launch Teams – From models, determine necessary control loops to program using HORIZON • Simulate autopilot controls using HORIZON System Testing • Autopilot – Use Aero prototype to bench test autopilot system – Test communication systems • Similar procedure to Video System testing – Flight Test Integration and Test Issues - Integration - Communication: Radio modem and video transmission configuration and use, placement and adjustment of antennas - Configuration: Autopilot configuration to aircraft, configuration of sensors, integrating RC control with autopilot -Test -Restrictions: FCC & FAA regulations -Limitations: Time frame, lack of trained pilot amongst avionics team -Environment: Safety and legal issues prevent testing in target environment Questions? Specifications Appendix Physical Characteristics MicroPilot Weight 28 g Dimensions (L x W x H) 100 mm x 40 mm x 15 mm Power Requirements 140 mA @ 6.5 Volts Supply Voltage 4.2 – 26 V Separate supplies for main and servo power Yes Functional Capabilities Includes Ground Station software Yes Max # of Waypoints 1000 In-flight waypoint modification possible Yes GPS Update Rate 1 Hz Number of servos 24 Sensors Airspeed Yes, up to 500 kph Altimeter Yes, up to 12000 MSL 3-axis Rate Gyro/Accelerometers (IMU) Yes Accelerometer Saturation Point 2G GPS Yes Data Collection Allows user-defined telemetry Yes – max 100 Customization User-definable error handlers Yes – loss of GPS Signal, loss of RC Signal, loss of Datalink, low battery User-definable PID loops Yes – max 16 Autopilot can be loaded with custom program Yes – with XTENDER SDK (separate) Physical Characteristics Procerus Kestral Weight 16.65 g Dimensions (L x W x H) 52.65 mm x 34.92 mm x ? mm Power Requirements 500 mA Supply Voltage 3.3V and 5V Separate supplies for main and servo power Yes Functional Capabilities Includes Ground Station software Yes Max # of Waypoints 100 In-flight waypoint modification possible Yes GPS Update Rate 1 Hz Number of servos 12 Sensors Airspeed Yes, up to 130 m/s Altimeter Yes, up to 11200 MSL 3-axis Rate Gyro/Accelerometers (IMU) Yes Accelerometer Saturation Point 10 G GPS Yes Data Collection Allows user-defined telemetry Unspecified Customization User-definable error handlers Yes, Loss of Datalink, Loss of GPS, Low Battery, Imminent Collision, Loss of RC Signal User-definable PID loops Unspecified Autopilot can be loaded with custom program Yes, Developer’s Kit available for $5000 for one year license Physical Characteristics Cloudcap Piccolo Weight 109 grams Dimensions (L x W x H) 130.1 mm x 59.4 mm x 19.1 mm Power Requirements 5 Watts ( ~ 400 mA @ 12V ) Supply Voltage 4.8 – 24 Volts Separate supplies for main and servo power No Functional Capabilities Includes Ground Station software Yes, basic Max # of Waypoints 100 In-flight waypoint modification possible Yes GPS Update Rate 4 Hz Number of servos 6 Sensors Airspeed Yes Altimeter Yes 3-axis Rate Gyro/Accelerometers (IMU) Yes Accelerometer Saturation Point 2 G, 10G with external sensor package GPS Yes Data Collection Allows user-defined telemetry Unspecified Customization User-definable error handlers Yes User-definable PID loops Unspecified Autopilot can be loaded with custom program Yes Physical Characteristics O Navi Phoenix AX Weight 45 grams Dimensions (L x W x H) 88.14 mm x 40.13 mm x 19 mm Power Requirements 84 mA @ 12V Supply Voltage 7.2-24 Volts Separate supplies for main and servo power No Functional Capabilities Includes Ground Station software No Max # of Waypoints Unspecified In-flight waypoint modification possible Unspecified GPS Update Rate 1 Hz Number of servos 6 Sensors Airspeed No Altimeter Yes 3-axis Rate Gyro/Accelerometers (IMU) Yes Accelerometer Saturation Point 10 G GPS Yes Data Collection Allows user-defined telemetry Unspecified Customization User-definable error handlers Unspecified User-definable PID loops Unspecified Autopilot can be loaded with custom program Yes, REQUIRED REPORT DISCLAIMER NOTICE DISCLAIMER: This document was developed as a part of the requirements of a multidisciplinary engineering course at Iowa State University, Ames, Iowa. This document does not constitute a professional engineering design or a professional land surveying document. Although the information is intended to be accurate, the associated students, faculty, and Iowa State University make no claims, promises, or guarantees about the accuracy, completeness, quality, or adequacy of the information. The user of this document shall ensure that any such use does not violate any laws with regard to professional licensing and certification requirements. This use includes any work resulting from this student-prepared document that is required to be under the responsible charge of a licensed engineer or surveyor. This document is copyrighted by the students who produced this document and the associated faculty advisors. No part may be reproduced without the written permission of the course coordinator. Images within this presentation were obtained via the courtesy of their respective owners, listed below: Lockheed Martin Corporation MicroPilot Procerus Cloudcap Technology O Navi Genwac/Watec RangeVideo Tri M Engineering Murata Power Systems Digi Intl.