Measurement of Angular Valve Displacement in High Vibration Environments

Controlling the functioning of wind tunnels at AEDC requires the measurement of the angular displacement of large air valves. Reliably sensing these valves positions has been problematic due to the large vibrations that are encountered; the sensors break frequently resulting in significant down time. A sensor / device is needed to measure these valve positions. IAC proposes to develop a robust valve position sensing system using commercial off-the-shelf wireless video camera technology coupled with remote PC based image processing. Rather then have a physical connection between the valve and the sensor, a visual target is affixed to the end of the valve. A video camera, that is physically separated from valve and it's housing, and thus isolated from the wind tunnel / valve vibrations, is used to video the target on the valve. Using built-in wireless technology, the video signal is transmitted to a remote PC. Image processing is performed on the remote PC to determine the valve position. The PC can be networked with the remainder of the wind tunnel control system to supply the valve position feedback for control. A single PC can be used to process signals from several different monitored valves.