| Nano IMU Antenna Stabilization Application |
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Initial Considerations
The noise resolution : Nano IMU < gyros 1.0 °/s, maximum The antenna array and its environment: An antenna that points towards the horizon, that is, an antenna that rotates about a vertical axis, “Z”. Wind affects the motion of the array in the “X” and “Y” axes (horizontal plane). The array’s motion may be corrected via a servo motor or other mechanism.
The Character of the Inertial Data The maximum deflection has been stated to be ~10mrad. Assuming a sine wave character for the position of the array’s target axis with time we can make some observations. A plot of the motion in the horizontal plane may look something like this ideally.
At 10 mrad of deflection per 0.0125 sec (20 Hz) If the resolution was 1deg/s we would be able to resolve deflections on the order of
Latency Another aspect of the antenna stabilization application is latency between when the dynamic occurs and the control system produces a counteracting force. The Nano IMU, for instance, has a latency of approximately 4ms. As seen in the figure above the rise time of a 20Hz sine wave is 25ms this should allow ample time for the Nano IMU to sense and communicate the dynamic to the control system so that the control system can counteract the force of the perturbing dynamic. Summary Despite the very preliminary and general parameters for this application, it is within reason that our sensors may be a solution. Attitude data from a number of products offered by MEMSense may be utilized in a feedback stabilization system of this kind. Accelerometer and magnetic compass data is available in the same packages and may also be utilized to enhance the performance of a feedback system. Further details on MEMSense IMUs and sensors can be found at memsense.com. |
