Advanced Low-Cost Integrated Inertial Systems with Multiple Consumer Grade Sensors

Last generation consumer grade MEMS inertial sensors have several distinctive features that make their use of interest also for professional navigation applications such as the ones related to attitude determination of advanced small drones. Several advantages arise when using low-cost consumer grade MEMS gyros, such as reduced weight, compact configuration, low power consumption and easy integration with electronic boards. Conversely, some drawbacks are determined in terms of accuracy, since the overall error is more than an order of magnitude worse than industrial grade sensors. To improve the accuracy of inertial units based on commercial grade MEMS gyros, redundancy is exploited in this paper. It consists in adopting a skewed sensors configuration, i.e. a defined number of sensors placed on the faces of a regular polyhedron. This configuration guarantees the self-calibration of the bias of sensors placed on opposite faces of the polyhedron. To test the proposed method, the world's densest sensor board, the SensorTile™, by ST Microelectronics™ has been adopted. Test results show that, by averaging multiple measurements about the same axis, the overall level of accuracy in flight attitude determination will be improved.