Precision Stabilization of a Ball Joint Gimbaled (BJG) Mirror

In Phase I, DSCI developed an approach for achieving precision stabilization of a ball joint gimbaled (BJG) mirror by providing the control system with a direct, high precision measurement of the angular position of the BJG mirror. This is accomplished by means of a novel, wide-field-of-regard (WFOR) optical tilt sensor. Combining the precise, but lower bandwidth, tilt sensor feedback with the high speed, but inaccurate, shaft encoder feedback results in precise, high bandwidth control of the BJG mirror. Simulink simulations indicate that line-of-sight stabilization of tens of microradians is achievable with this hybrid feedback approach. In Phase II, a prototype WFOR tilt sensor that is designed to be integrated into NAVAIR’s Build 4 BJG mirror system will be fabricated and tested. The sensor will then be integrated into the Build 4 BJG mirror system and the control algorithm modified to implement the hybrid feedback algorithm. This “precision stabilized” version of the Build 4 mirror will then be tested under simulated operational conditions in the laboratory at DSCI and China Lake to verify the line of sight stabilization performance of the system. Finally, the “precision stabilized” version of the Build 4 mirror will be tested under field conditions at China Lake.