Calibration Techniques for Skew Redundant Inertial Measurement Units

Redundant inertial measurement units have been traditionally used in applications requiring high-reliability inertial space navigation and, more recently, have been shown to improve the performance of micro electromechanical systems-based inertial measurement units. Various redundancy schemes for inertial measurement units have been documented. Such schemes range from doubling the number of sensors arranged in classical 3 orthogonal axes configurations to positioning them in skewed axes configurations. In the latter case, the sensors are usually arranged based on cones and platonic solids configurations. Without loss of generality, this paper presents two calibration and correction techniques for dodecahedron-based skew redundant inertial measurement units. The advantages and disadvantages of the two techniques are analyzed and suggestions made for their possible application areas. The paper also analyzes the pros and cons of two different body frames, one that is better from a packaging standpoint and another one that is better from a redundancy standpoint, and it lays the groundwork for a future study on the usage of virtual body frames in the optimization of dodecahedron-based skew redundant inertial measurement units.