Multiple Sensor Inertial Measurement Unit

The U.S. Air Force has identified a need to develop innovative inertial sensor configurations and algorithms that utilize multiple low-cost, low-performance sensors to produce an inexpensive inertial measurement unit (IMU) with relatively high performance. A multiple-sensor IMU uses several low-performance sensors per axis and blends their outputs to attain an accuracy comparable to a higher-performance, higher-cost conventional IMU. It is envisaged that an order-of-magnitude improvement could be realized using multiple sensors per axis, where for instance, multiple gyros each exhibiting a 10 deg/hr bias stability would provide an equivalent bias stability of 1 deg/hr. The critical issues that must be addressed for this concept involve the tradeoffs between the number of sensors required to achieve the order-of-magnitude accuracy improvement and the size, cost, and electronic packaging requirements of those sensors.The focus of this research is to: (1) identify inertial sensors and sensor configurations which are candidates for the multiple-sensor IMU concept, (2) develop innovative algorithms which optimally blend the data from multiple sensors to achieve a high-accuracy integrated solution, and (3) conduct simulation-based performance integration algorithms. Particular emphasis will be placed on assessing the applicability of micromachined inertial sensors for the multiple-sensor IMU concept. Requirements for sensing electronics and IMU fabrication and packaging will also be specified.