Patent application number | Description | Published |
20080319667 | HEADING STABILIZATION FOR AIDED INERTIAL NAVIGATION SYSTEMS - A method of stabilizing heading in an inertial navigation system is provided. The method includes operating an inertial measurement unit comprising horizontal-sensing elements and off-horizontal-sensing elements while the inertial measurement unit is in a first orientation, calibrating the horizontal-sensing elements of the inertial measurement unit based on horizontal aiding measurements, forward-rotating the inertial measurement unit by a selected-rotation angle about a horizontal-rotation axis so that the inertial measurement unit is oriented in a second orientation, operating the forward-rotated inertial measurement unit while the inertial measurement unit is in the second orientation, and calibrating the rotated off-horizontal-sensing elements based on horizontal aiding measurements while the inertial measurement unit is in the second orientation. When the inertial measurement unit is in the first orientation, the horizontal-sensing elements are oriented in a horizontal reference plane. When the inertial measurement unit is in the second orientation, the off-horizontal-sensing elements are oriented in the horizontal reference plane. | 12-25-2008 |
20090238042 | METHODS AND SYSTEMS FOR UNDERWATER NAVIGATION - A method for navigating underwater is disclosed. The method uses a navigation system to project a first velocity measurement along one or more signal beams having a second velocity measurement, where the second velocity measurement is related to at least one of the one or more signal beams. The method determines a position and location of an object associated with the navigation system based on a prediction of at least the second velocity measurement, and the navigation system is adjusted to perform within a prescribed measurement range based on a covariance of the first and second velocity measurements. The performance adjustments made in determining the position and location of the object are operable independent of the navigation system maintaining each of the signal beams due to one or more external environmental conditions. | 09-24-2009 |
20120078510 | CAMERA AND INERTIAL MEASUREMENT UNIT INTEGRATION WITH NAVIGATION DATA FEEDBACK FOR FEATURE TRACKING - A navigation device is provided herein comprising an inertial measurement unit (IMU), a camera, and a processor. The IMU provides an inertial measurement to the processor and the camera provides at least one image frame to the processor. The processor is configured to determine navigation data based on the inertial measurement and the at least one image frame, wherein at least one feature is extracted from the at least one image frame based on the navigation data. | 03-29-2012 |
20120150441 | SYSTEMS AND METHODS FOR NAVIGATION USING CROSS CORRELATION ON EVIDENCE GRIDS - Systems and methods for navigation using cross correlation on evidence grids are provided. In one embodiment, a system for using cross-correlated evidence grids to acquire navigation information comprises: a navigation processor coupled to an inertial measurement unit, the navigation processor configured to generate a navigation solution; a sensor configured to scan an environment; an evidence grid creator coupled to the sensor and the navigation processor, wherein the evidence grid creator is configured to generate a current evidence grid based on data received from the sensor and the navigation solution; a correlator configured to correlate the current evidence grid against a historical evidence grid stored in a memory to produce displacement information; and where the navigation processor receives correction data derived from correlation of evidence grids and adjusts the navigation solution based on the correction data. | 06-14-2012 |
20120209520 | ESTIMATION OF N-DIMENSIONAL PARAMETERS WHILE SENSING FEWER THAN N DIMENSIONS - Embodiments of the present invention provide improved systems and methods for estimating N-dimensional parameters while sensing fewer than N dimensions. In one embodiment a navigational system comprises a processor and an inertial measurement unit (IMU) that provides an output to the processor, the processor providing a navigation solution based on the output of the IMU, wherein the navigation solution includes a calculation of an n-dimensional parameter. Further, the navigational system includes at most two sensors that provide an output to the processor, wherein the processor computes an estimate of an n-dimensional parameter from the output of the at most two sensors for bounding errors in the n-dimensional parameter as calculated by the processor when the trajectory measured by the IMU satisfies movement requirements, wherein ānā is greater than the number of the at most two sensors. | 08-16-2012 |
20120326918 | MOTION-BASED ADAPTIVE FREQUENCY ESTIMATION OF A DOPPLER VELOCITY SENSOR - A system and method for motion-based adaptive frequency estimation of a Doppler sensor is provided. The system comprises a Doppler sensor configured to output a digitized Doppler data signal, and a Doppler velocity estimation module operatively coupled to the Doppler sensor to receive the Doppler data signal. An inertial navigation system is operatively coupled to the Doppler velocity estimation module, and one or more inertial sensors is operatively coupled to the inertial navigation system. The inertial sensors are configured to transmit inertial navigation data to the inertial navigation system. The Doppler velocity estimation module calculates a speed or velocity estimate based on the Doppler data signal and the inertial navigation data. The speed or velocity estimate is then transmitted to the inertial navigation system. | 12-27-2012 |
20130131981 | USING STRUCTURED LIGHT TO UPDATE INERTIAL NAVIGATION SYSTEMS - A navigation system includes host and remote units. Host unit includes positioning device to determine absolute position/orientation of host unit; first communication device to communicate signals; first processor; and first memory. Remote unit includes second communication device to receive signals from first communication device; second processor; and second memory. First or second processor compares first aspects of known pattern with second aspects of image of captured pattern positioned on surface at either host unit or remote unit. First or second processor determines relative position/orientation of remote unit relative to host unit based on comparison of first aspects and second aspects. First or second processor determines absolute position/orientation of remote unit based on relative position/orientation of remote unit relative to host unit and absolute position/orientation of host unit. Either absolute position/orientation of host unit or absolute position/orientation of remote unit are communicated from host unit to remote unit. | 05-23-2013 |
20150081213 | SYSTEMS AND METHODS FOR A LIMB STRIKE DETECTOR - Systems and methods for a limb strike detector are provided. In certain embodiments, a system for detecting limb strikes comprises an inertial measurement unit (IMU) that provides inertial measurements; and a processing unit that receives the inertial measurements from the IMU. In certain embodiments, computer readable instructions direct the processing unit to determine multiple local vertical acceleration samples, wherein each local vertical acceleration sample in the multiple local vertical acceleration samples defines an acceleration component along the local vertical axis and an associated time; integrate the multiple local vertical acceleration samples to determine multiple local vertical velocity samples; identify limb strike regions from the multiple local vertical velocity samples, wherein a limb strike region is associated with a local vertical velocity sample in the plurality of local vertical velocity samples; and determine limb strike times based on the identified limb strike regions and the multiple local vertical acceleration samples. | 03-19-2015 |