Satellite based communications for small unmanned aircraft.

Transcription

1 27 th Bristol Unmanned Systems Conference 3 rd April, 2012 Satellite based communications for small unmanned aircraft. Dr Joseph Barnard joseph.barnard@barnardmicrosystems.com Barnard Microsystems Limited Unit 4, Coleridge Road London N8 8ED U.K.

2 This presentation is based on the UASatCom IAP Feasibility Study led by BML This is a nine month Feasibility Study supported by the European Space Agency in the form of an Integrated Application Promotion ( IAP ) ARTES 20 Project monitored and supported by Dr Stefan Gustafsson at ESA ESTEC that started on 30 th May 2011, involving: Barnard Microsystems Limited Lead U.K. Inmarsat Global Limited Sub-Contractor U.K. AnsuR Technologies AS Sub-Contractor Norway Fugro Airborne Surveys User Canada Sander Geophysics Limited User Canada Royal Dutch Shell User Netherlands investigating the technical, commercial and regulatory feasibility of using broadband satellite based data relay communications on small (< 35 kg take-off weight) unmanned aircraft flying Beyond Line of Sight using satellite based navigation services with the operators at the Ground Control Station having Ethernet open network protocol connectivity to the instruments and computers on the unmanned aircraft engaged in oil, gas and mineral exploration and production activities. Satellite based communications 2

3 A geophysical mapping is derived from a low altitude (20m AGL) airborne survey Satellite based communications 3

4 In pipeline monitoring, the User is interested in the detection of anomalies Above: timely (within 15 minutes) detection of an oil leak from a pipeline is valuable. The User needs to: routinely monitor many hundred km of oil pipeline; at least once every two weeks; detect and identify people and objects from at least 600 feet from a moving airborne platform. Satellite based communications 4

5 In pipeline monitoring, the User is interested in the detection of anomalies Above: timely (within 15 minutes) detection of an oil leak from a pipeline is valuable. The User needs to routinely monitor many hundred km of oil pipeline; at least once every two weeks; detect and identify people and objects from at least 600 feet from a moving airborne platform. Satellite based communications 5

6 How the requirements for oil and gas pipeline monitoring are performed today Consider examples of the monitoring of the oil and gas pipeline infrastructure: Monitoring by vehicle in Saudi Arabia Monitoring pipelines on foot in Nigeria In the UASatCom Workshop 2 at Shell Exploration Headquarters in Rijswijk, some of the pipeline monitoring staff from Shell pointed out that the problem with a foot patrol in Nigeria is that the person performing the patrol is susceptible to: bribery very real threats of extreme violence Satellite based communications 6

7 Object detection and identification at over 600 feet from a moving aircraft. Canon EOS 5D Mk II body 5,616 x 3,744 Pixels control via USB 2 price = 1,650 Canon EOS 5D Mk III body 5,760 x 3,840 Pixels control via USB 2 price = 2,600 Canon EF mm f/2.8l zoom lens viewing angle = 10 x 7 at 200mm 4 stop image stabilisation price = 1,700 Above: side looking photo from an unmanned aircraft travelling at 30 mph, 400 feet AGL, with no image enhancement. Satellite based communications 7

8 The UA need to be able to fly from 20m to 80m Above Ground Level Satellite based communications 8

9 Unmanned aircraft flight path adopted for use in oil pipeline monitoring. Satellite based communications 9

10 InView unmanned aircraft features at a glance for scientific, commercial and state missions Payload 4 kg comprehensive safety features Endurance 7+ hours modular and easily transportable Max speed 112 kph assembled and tested within an hour Loiter speed 24 kph can operate from a grass field Weight 19.5 kg without fuel capable of very slow flight Wingspan 4 m user definable payloads can be carried Fuel AVGAS 100LL fuel packs operates in manual, Microprocessor based autopilot and PC autopilot flight modes: moving towards more automation to reduce the errors introduced by human involvement. Propulsion 2x SAITO FG-30 engines Total Power = 3.6 kw Satellite based communications 10

11 Example of a unmanned aircraft for use in survey work: the 4m wingspan InView. Satellite communications unit supporting up to 200 kbps Ethernet based Inmarsat communications Two engines for safety... with the aircraft able to fly controllably on one engine Two rudders for safety with the ability to operate using one rudder Modular construction for ease of transportation, maintenance and upgrade Robust undercarriage for operation from rough terrain Satellite based communications 11

12 Satellite based data relay network, showing double hop link used in survey work. Satellite based communications 12

13 The InView Ground Control Station, using an Ethernet based connectivity. Satellite based communications 13

14 The satellite data relay network used in geophysical survey work. Satellite based communications 14

15 Example of a Ground Control Station suitable for pipeline monitoring work. Satellite based communications 15

16 The satellite data relay network used in pipeline monitoring work. Satellite based communications 16

17 Most UA with a satellite data communications unit have a large steerable dish. Example of a satellite communications dish on a larger unmanned aircraft: this time, a General Atomics Predator UA. Such a high gain, directional, antenna dish is: too large for a small UA too heavy for a small UA We need some other solution. Satellite based communications 17

18 Inmarsat were aware of a small Sat Comms unit carried on the Solar Impulse. Satellite based communications 18

19 The Cobham South Africa SB-200 satellite data communications relay unit. Data rate kbps Class 15 Weight 3.8 kg Cost ~ $35,000 Satellite based communications 19

20 Fitting of the 3.8 kg Cobham SB-200 satellite data terminal in the InView UA. Satellite based communications 20

21 Electromagnetic signal interference is a huge problem in small unmanned aircraft Mode S transponder Rx at 1,030 MHz Tx at 1,090 MHz 250 Watts O/P! GPS L1 signal 1, MHz 10 MHz USB and LSB RH Circularly Polarised L1 C/A code -130 dbm Wireless Ethernet Bridge IEEE a MicroHard VIP-5800 unit GHz to GHz (ISM) OFDM modulation Tx at 1 Watt Rx sensitivity is -94 dbm at 6 Mbps Cobham SB-200 Sat Comms Tx Up to 20 dbw = 100 Watts! 1,626.5 MHz 1,660.5 MHz RH Circularly Polarised signal GHz VHF transceiver: ICOM IC-A24E Tx / Rx from 118 MHz MHz Rx from 108 MHz MHz AM modulation 25 KHz channel spacing 1 Watt CW output power Rx sensitivity < - 3 dbuv Futaba R6014HS receiver 2,400 MHz 2,483 MHz band Spread Spectrum signal used for manual flight control Satellite based communications 21

22 Two unmanned aircraft on patrol can provide improved identification capability. UA at 8,000 feet AGL provides wide area coverage 2.4 GHz IEEE N WLAN link UA flying at 400 feet AGL provides high resolution side looking image for ID Satellite based communications 22

23 The closer the UA flies to the polar regions, the shallower the satellite elevation... Left: Inmarsat geostationary satellite coverage Low gain satellite communications antenna EM interference with very sensitive Caesium beam magnetometer Satellite based communications 23

24 Example of an UA used in oil pipeline monitoring, fitted with hybrid propulsion. Automation / limited autonomy and a sense and avoid capability are needed in a lost link situation in a BLOS geophysical survey mission to save the unmanned aircraft and the payload and avoid a crash in which people might be injured and / or property might be damaged Satellite based communications 24

25 Activities to ensure a cost effective pipeline monitoring capability We use the AnsuR ASMIRA software at both the client (UA) and the server (Ground Control Station) sides to manage the video bit rate, and optimise the video and still image quality. Satellite based communications 25

26 The ASMIRA software has enabled us to optimise the double hop video data link The AnsuR ASMIRA software has provided a suitable resolution for pipeline monitoring at: 10 fps frame rate 640 x 480 pixel resolution 80 kbps bit rate Satellite based communications 26

27 The Inmarsat geostationary satellite voice and data relay configuration Inmarsat Satellite Communications Link Circuit switched Packet switched Messaging Supplementary services AMBE+2 modem voice at 4 kbps 64 kbps Streaming 8 kbps 16 kbps Standard SMS 32 kbps 3.1 khz Audio ISDN UDI ISDN RDI 64 kbps 128 kbps X-Stream Pay by the minute 2x hop latency < 800 ms Pay by the kbyte 2x hop latency ~ 1.5 s Satellite based communications 27

28 On board sensor data processing will enable a massive data bit rate reduction. The computers on the unmanned aircraft are achieving a 94% detection rate for vehicles in scenes (of the M11 in the U.K.) from Google Earth. The red boxes encompass an area of interest, including false alarms. The false alarm rate is 35% for 102 cars in 50 photographs. If all positive selection boxes and false alarm boxes are relayed in place of the original photographs, the communications unit would only use 1.782% of the number of bits. Satellite based communications 28

29 Conclusions Ethernet standard based satellite communications can be supported on small (<50 kg MTOW) unmanned aircraft. The use of satellite communications is a requirement for unmanned aircraft operating beyond line of sight in oil, gas and mineral exploration and production activities. Flight automation and a degree of autonomy are necessary in a lost link situation in which the UA might need to perform an auto-landing at a pre-designated landing site without an outside communications link A technical issue that surfaced during our UASatCom Feasibility Study Proof of Concept tests is the need to reduce the interference between the powerful signals from the low gain satellite antenna and the other receivers and sensors on a small unmanned aircraft. Acknowledgements European Space Agency for Artes 20 IAP UASatCom Feasibility Study support U.K. T.S.B. INMARA Intelligent Machine Reasoning and Action Feasibility Study U.K. T.S.B. STUAC Project to use sensors to monitor the health of Unmanned Aircraft. You are welcome to contact me at joseph.barnard@barnardmicrosystems.com. Satellite based communications 29