Design of a Micro Wireless Instrumented Payload for Unmanned Vehicle Testing

The testing of unmanned vehicles presents a need for an independent device capable of accurately collecting position and orientation data. While commercial-off-the-shelf components could be pieced together to sense and record this information, this is an expensive, large, and heavy solution, not suitable for small or aerial vehicles. The micro wireless instrumented payload, or μWIP, was designed precisely for this purpose.

The μWIP includes a GPS receiver, 3-axis accelerometer, 3-axis gyroscope, and 3-axis magnetometer which are used to measure an unmanned vehicle's position and orientation. The device also uses a secure digital card for data storage, and an 802.11b module to provide wireless connectivity. Additionally, the μWIP contains a on-board battery and the circuitry required to charge it. Firmware for the ARM7 processor was written to allow sensor calibration and data transmission, and a user interface was designed to run on a personal computer.

The finished design is a tiny 3''x5''x1'', and weighs a mere 0.8 pounds including battery and antennas. It is capable of continuously streaming accurate GPS and inertial data over an 802.11b wireless network for over 5 hours. Having a bill of materials cost just over $600, the μWIP is also more cost effective than any alternative solutions.

This thesis details the hardware and software design of the μWIP, as well as the initial testing, calibration, and evaluation of the device.