UAV + Onboard Pilot = enhanced performance Light Aircraft?

Transcription

1 Royal Aeronautical Society Light Aircraft Design: Methods and Tools November, 2014 UAV + Onboard Pilot = enhanced performance Light Aircraft? Dr Joseph Barnard joseph.barnard@barnardmicrosystems.com Barnard Microsystems Limited Unit 4, Coleridge Road London N8 8ED U.K.

2 Can UAV + Onboard Pilot = enhanced performance Light Aircraft? The systems being developed for Unmanned Aircraft Vehicles (UAVs) need to enable the UAV to operate safely with a remote pilot at a Remote Pilot Station. Some of the UAV systems, once characterised and extensively tested, could then possibly be used to increase the safety, or operational effectiveness, of light aircraft. By way of example, a relatively inexpensive satellite communication link will enable the location and status of a light aircraft to be logged on the ground. UAV + Onboard Pilot... by BML 2

3 We use a satellite data relay network to augment the situational awareness of the staff at the Remote Pilot Station (RPS) of the RPA and its environment. The hardware implementation of a double hop link is shown here. The location of the aircraft is known to, and logged by, staff on the ground at predefined intervals (from every second to longer intervals). UAV + Onboard Pilot... by BML 3

4 Many of the satcoms units in military UAVs cannot be used in smaller UAVs... UAV + Onboard Pilot... by BML 4

5 Satcoms unit with a steerable antenna mounted in the dome on the InView RPA Cost = 3,895 Weight = 5.8 kg UAV + Onboard Pilot... by BML 5

6 Latency in seconds Double hop message latency using the Inmarsat satellite data relay service 2.5 Measured packet switched double hop latency Trial number UAV + Onboard Pilot... by BML 6

7 Back-up satcoms = Iridium Short Burst Data (SBD) unit Left: underside view of the Iridium 9602 OEM unit mounted on a RockBlock SBD unit. The blue item is a 3F super capacitor used to provide power during a Short Burst Data transmit session. Right: the top side of the RockBlock unit, showing the very small satellite communications antenna with the iridium 9602 OEM unit mounted on the underside. The RockBlock unit has both a USB interface and an RS 232 interface. Message size = 160 characters Latency = 35 seconds (one way) Hardware cost = 250 UAV + Onboard Pilot... by BML 7

8 Use of a Mode S transponder is encouraged, but watch out for EM interference 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 UAV + Onboard Pilot... by BML 8

9 The pilot can talk to the Ground Office via satcoms: this is used for ATC voice relay UAV + Onboard Pilot... by BML 9

10 Can UAV + Onboard Pilot = enhanced performance Light Aircraft? A current hot topic is the development of a collision detect and avoid system, based on the use of several cameras with the optional use of an inexpensive RADAR unit. The system, if implemented in a light aircraft, could warn the pilot of an imminent collision. We combine optical imaging with a scanning RADAR sensor. UAV + Onboard Pilot... by BML 10

11 Detection range requirements for the Predator B RPA From presentation on "Small sense and avoid system" by Dr John F. McCalmont, USAF Research Laboratory at UAV 2007 Conference in Paris. UAV + Onboard Pilot... by BML 11

12 Results from the processing of images using optic flow Detection of a helicopter that is just over 5.8 km away, using the Lukas-Kanade optic flow algorithm on the present and previous images. The red line indicates the physical displacement between the two time frames, separated by 1 second: i.e. we are using 1 frame per second imagery, although the cameras are capable of 25 fps. Optic flow is useful for objects moving laterally. UAV + Onboard Pilot... by BML 12

13 A cloudy background presented less of a problem that we expected The distant Embraer EMJ190 aircraft is not easily visible in this digital photograph taken using a Hoya Yellow filter on the digital camera to filter out the blue sky background. A linear polariser has also been used, with the polarisation angle set at -45 to accentuate the clouds and suppress the background sky. The aircraft is 19.7 km away, and was detected using optic flow image processing. UAV + Onboard Pilot... by BML 13

14 Example of scanning RADAR sensor characteristics Rate of rotation (mechanical antenna rotation) Field of view when mounted in the nose of a RPA Operating frequency Tx signal modulation type 24 / 36 / 48 rpm -110 to +110 of direction of flight 9.3 to 9.4 GHz (X Band) FMCW Vertical FWHM antenna beam width 25 Horizontal FWHM antenna beam width Output CW microwave power level Electrical power requirement Range to detect 30 sq m cross section target Weight 2.6 or 5.2 (switchable) 165 mw 20 Watts (typically) at 13.8 Volts 66 km 7.4 kg without cables Work is currently underway to quantify the detection characteristics (detection range versus target cross section) of a low microwave output power scanning RADAR sensor. UAV + Onboard Pilot... by BML 14

15 Can UAV + Onboard Pilot = enhanced performance Light Aircraft? Another topic concerns the development and proving of an adaptive autopilot system that can manage the degradation in, and in some cases the failure of, a component of the aircraft. Human error causes most Predator crashes Air Force researcher finds that biggest problem is operator mistakes. Research shows that most Predator mishaps are the result of: inadequate skills lack of teamwork lack of situational awareness. Above: Col. Charles W. Manley pilots a training simulator for the Air Force's MQ-1 Predator at the March Air Reserve Base in Riverside County, Calif. UAV + Onboard Pilot... by BML 15

16 Our own experience with unmanned aircraft incidents Event Comment Ascribed to IV-01 sheared off undercarriage pre-flight check error human error IV-02 crash after failure of one engine lack of situational awareness design error pre-flight check deficiency human error IV-03 crash due to little rudder authority design deficiency design error IV-05 manually landed on top of tall trees pilot perception error human error IV-06 sheared off undercarriage hard manual landing human error IV-07 sheared off undercarriage hard manual landing human error design deficiency design error Most accidents occurred during take-off and landing. So, as far as we are concerned, unmanned aircraft testing in the U.K. under CAA CAP 722 regulations is fine. Our test flight experience has convinced us that the human is the weak link, and that more pre-flight test automation and flight control machine intelligence will lead to increased safety. UAV + Onboard Pilot... by BML 16

17 Even with significant training, human error remains a notable cause of UA crashes From presentation by Dubi Lavi at AUVSI Israel Chapter Conference, March UAV + Onboard Pilot... by BML 17

18 The introduction of more flight automation is needed to help the business case. From presentation by Dubi Lavi at AUVSI Israel Chapter Conference, March UAV + Onboard Pilot... by BML 18

19 Rockwell Collins are also working along the same lines... From presentation by Eric Thomas at AUVSI Israel Chapter Conference, March UAV + Onboard Pilot... by BML 19

20 Rockwell Collins have demonstrated the use of real time adaptive flight control to continue flying, and then landing, a severely damaged unmanned aircraft. UAV + Onboard Pilot... by BML 20

21 Relatively small, with full autonomy and adaptive flight control. No landing strip needed Advanced aerodynamics Sense and avoid system included 250 cc If we aspire to imbue a 35kg MTOW unmanned aircraft with the capabilities of a parrot, we would need a bird brain volume of 250 cc e.g. 25mm x 100mm x 100mm. 35 kg UAV + Onboard Pilot... by BML 21

22 Conclusions My personal view is that some of the UAV systems, once characterised and tested, could then be used to increase the safety, and / or operational effectiveness, of light aircraft. Lightweight, relatively low cost (< 7,500) satellite communications systems are available as Commercial Off The Shelf (COTS) items. These systems will enable the logging of the aircraft location, and enable to pilot to communicate with base regardless of his location. Current optical and RADAR sensor hardware and software technology can meet the detection requirements for a collision detection system on a medium sized civilian RPA. Work is ongoing to implement automatic collision avoidance procedures. We see automatic, adaptive, flight control as a way in which to enable the UAV to adapt to system degradation and even failure, maintaining a predictable flight performance. I can be contacted at joseph.barnard@barnardmicrosystems.com Acknowledgements Much of this work was supported by: Innovate UK (previously called the U.K. Technology Strategy Board) and the European Space Agency support for the UASatCom and SURMON Projects. UAV + Onboard Pilot... by BML 22