Moog Gmbh

Michael A Horton

Ralph Michael Kling

Qiyue-John Zhang

Darren S Liccardo

Qiyue Zhang

John J James

Walter K Stockwell

Semen Shtigluz

Martin A Williams

David J Zaziski

A true north heading is determined by using gyroscopes of differing accuracy and orienting a gyroscope of a higher accuracy to a direction that is more sensitive to azimuth change (e.g., an east/west direction). A gyroscope with a lower accuracy is placed perpendicular to the gyroscope with a higher accuracy and can be oriented towards a north or south direction. The gyroscopes may be placed on a rotatable platform to properly orient the gyroscopes. The higher-accuracy gyroscope may be implemented by using multiple gyroscopes oriented in the same direction.

North-finding using inertial navigation system

Embodiments relate to a MEMS IMU having an automatic gain control. The dynamic measurement range of the MEMS IMU is controlled by controlling the gain of a signal amplifier before the analog to digital converter (ADC) to make full use of the ADC range. In one embodiment, two or more MEMS inertial sensor sets are installed in the IMU. One of the sensor sets is for high accuracy with low dynamic range, and the other set or sets is for higher dynamic range with less resolution or accuracy. In one implementation, a digital processor determines which of the sensor sets to be used according to the system dynamic estimation. In another implementation, the system weights the sensor outputs from the sensor sets according to the system dynamics.

High accuracy and high dynamic range MEMS inertial measurement unit with automatic dynamic range control

A spatially distributed MEMS inertial sensor array is designed to reduce or cancel measurement errors and to increase the signal detection accuracy. By combining the measurements from a pair of sensors having sensing axes in two different, non-orthogonal directions, the correlated error due to the environmental changes are cancelled or reduced and the uncorrelated random noise is also reduced by the square root of two. By sequentially sampling the sensor array in the time domain, the number of the ADC circuits can be largely reduced. A two dimensional signal processing method is used to process the sensor array output data, in order to further reduce the remaining errors. Namely, one dimension uses the outputs from multiple spatially distributed sensor sets and the other dimension is the time domain. The signal to noise ratio is increased by using the signal correlation in both the spatial domain and the time domain.

Inertial sensing with spatially distributed sensor array and two dimensional data processing

A system and method for more accurately and robustly determining the heading of a vehicle by taking measurements of angle rates using rate sensors mounted on a movable mechanical assembly. In a quasi-static state of the vehicle, the mechanical assembly is rotated around axes perpendicular to the tangent plane of the Earth, and angle rates are measured by the rate sensors at different rotational angles of the mechanical assembly. The measurements of the angle rates are then computed to determine the initial heading of the vehicle relative to the true north of the Earth in the quasi-static state of the vehicle. After determining the initial heading, navigation state propagation is performed to determine the heading of the vehicle in non-quasi-static state of the vehicle. By taking measurements of the rate sensors at different rotation angles and performing computation, the heading of the vehicle relative to the Earth's true north can be determined using less accurate angle sensors.

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Mountain View, CA, United States of America

Michael A Horton