ELEC 432

MAV Camera

Background

The Rice ME department has an ongoing project to design a Micro Air Vehicle (MAV), a small, unmanned platform for surveilance applications. A key component of this system is a camera for visual observations combined with a communication link to deliver the images to the base station. Unfortunately, off-the-shelf video components have been unable to provide satisfactory results, so a custom video system is required. Since the MEs have their hands full with the mechanical and aerodynamic aspects of the system, they have kindly allowed us to develop this component.

Description

The MAV camera will be a self contained system which will be mounted to the bottom of the vehicle. It will provide a downward- or forward-looking view of the ground, depending on the angle of mounting. Although mechanically and optically self contained, the camera may utilize electrical power from the vehicle, subject to constraints given below.

The complete system will consist of the camera, any necessary antennas, and a base station to receive and display the images and to issue commands to the camera.

What Doesn't Work

Several attempts have been made to utilize commercial (analog) wireless video cameras operating in the 2.4 GHz band, with unacceptable results. Image quality was poor, even in good conditions; interference was serious (and inescapable on the Wi-Fi saturated Rice campus); and maximum range was only a few hundred feet. Although higher transmitter power could improve performance, it would not be legal without an appropriate license, and the increased battery drain would reduce the maximum flight time.

Specifications

Weight.: Less than 30 grams.
Power.: If your system has its own battery, its weight must be included in the total. If you take your power from the MAV battery, you must not reduce the flight time by more than 10%. The battery must support operation for the length of a typical MAV mission or 10 minutes, whichever is greater.
Range.: Reliable operation at an appropriate data rate (see next item) should be possible at a range of 1000 ft. or more.
Image Quality and Image Rate.: Remote control of the craft when it is out of visual contact of the operator will require real time continuous video at a sufficient frame rate to allow stable control. Once the destination is reached, high resolution images of the target are required. Supplying both simultaneously will require a high data rate, which may be impossible to provide at maximum range.
To allow maximum utilization of channel capacity, your system should provide independent control of frame rate and image resolution. A range of frame rates from 1 frame/sec to 30 frames/sec and a range of image resolutions from 160x120 to 1024x768 should be available. In addition, a single shot mode should be provided. At close range, a rate of 10 320x240 frames/sec should be achievable.