Vertical Reference Unit

VRU 2005

The Watson Industries Vertical Reference System is a solid-state gyro package used to measure angular displacement and rate, especially where dynamic motion may interfere. Under these conditions, the effects of lateral accelerations severely limit the performance of an ordinary accelerometer or pendulous device. The Watson Vertical Reference achieves improved performance by integrating the output of a vibrating structure gyro to get an estimate of the attitude, which is then compared to the output of conventional accelerometers to find the error. This error is then filtered over a long time constant and subtracted from the rate gyro output to correct biases as a closed loop error correction system. This system lets the gyro dominate the attitude accuracy above the correction loop frequency while the accelerometer reference dominates the lower frequencies.
The Watson Vertical Reference can be a functional replacement for mechanical vertical gyros, which are often more expensive and less reliable than this solid-state sensor. The Vertical Reference Unit is especially suited for applications where there is limited bank and elevation such as ships, underwater vehicles, some land vehicles, and certain camera applications. This is because the VRU uses a linear coordinate system. For better performance, a full three axis system, with either an Euler or Quaternion coordinate system would be required. Consult the factory about your application.

Applications:

The VRU is used to stabilize and control ships and submersibles, to stabilize antenna platforms, to instrument automobiles, and for many other applications.

Features:

 

•		Solid State, Strapdown System
•		High Accuracy
•		Low Cost, Low Power
•		Rugged, High Reliability
•		Analog and RS-232 Digital Outputs
•		One Year Limited Warranty
•		Engineering Support