The onboard avionics are compatible with the advanced Ground Control System and powered by an Analog Devices Blackfin at 500MHz processor. The capsule can be nose-loaded with the help of a bayonet fitting to the UAV fuselage or belly-fitted in the case of larger crafts. The Attitude Heading Reference System (AHRS) is made up primarily by two modules a GPS module and a 3-axis IMU. The inertial measurement unit (IMU) contains 3 orthogonally mounted gyro-scopes, accelerometers and magnetometers, the signals from which are combined in a compensation algorithm to stabilize the outputs. Fine altimetry measurement is performed by a laser proximity module in the range 0-1.00 meter and by a MEMS barometric pressure sensor in the range .50m-3,000 meters. The standard camera we are mounting on our micro-UAV initially is an Omnivision OV9655 1.3 Megapixel Sensor fitted with a 6.5mm lens F3.2. The GCS programming environment is Linux UBUNTU 7.10 and the whole application is written in small C and C++, compiled using gcc.
Ours is a second generation avionics system for unmanned vehicles offering on-board sophisticated programming capabilities, rather than the limited servo-control, sensor-recording and telemetry formerly associated with these units. Communication with the GCS is performed via a WiFi link for testing purposes and can be changed to a VHF link or other system as specified by the client. Currently, we offer an optional radio link aided by a directional antenna able to communicate at a maximum of 60 Km in line-of-sight as standard.
Main on-board processor
All modules are housed in a cylindrical water-proof container, housing the GPS antenna and provided with the camera on one of its round sides and power and other sensor connectors on the other. The main board’s specifications are:
The camera module has two pan-and-tilt servo motors mounted on the front of the avionics stack to provide a general purpose vision capability, with the following capabilities:
Omnivision OV9655 1.3 Megapixel Sensor (1280x1024 pixels max)
We currently offer an extensible sensor board from which vehicles such as blimps, helicopters and fixed-wing aircraft can be controlled. The common sensors found in all UAVs are housed in this board and include:
16-bit dsPIC33 digital signal controller core for rapid first-stage processing and efficient communication over SPI to the main processor.