Patent application number | Description | Published |
20100280699 | SYSTEM AND METHOD FOR SIMULTANEOUS LOCALIZATION AND MAP BUILDING - An autonomous vehicle comprises at least one image sensor to provide measurements of landmark position for a plurality of landmarks; and processing functionality to estimate the position of the plurality of landmarks in a global frame and in the autonomous vehicle's frame, and to estimate the kinematic state of the autonomous vehicle in a global frame based, at least in part, on the measurements of landmark position from the at least one image sensor. The processing functionality is further operable to calculate errors in the estimated positions of the plurality of landmarks in the global frame and in the estimate of the kinematic state of the autonomous vehicle in the global frame by using a plurality of unit projection vectors between the estimated positions of the plurality landmarks in the autonomous vehicle's frame and a plurality of unit projection vectors between the estimated positions of the plurality of landmarks in the global frame. | 11-04-2010 |
20110257927 | SYSTEMS AND METHODS FOR DETERMINING INERTIAL NAVIGATION SYSTEM FAULTS - An inertial navigation system (INS) includes a primary inertial navigation system (INS) unit configured to receive accelerometer measurements from an accelerometer and angular velocity measurements from a gyroscope. The primary INS unit is further configured to receive global navigation satellite system (GNSS) signals from a GNSS sensor and to determine a first set of kinematic state vectors based on the accelerometer measurements, the angular velocity measurements, and the GNSS signals. The INS further includes a secondary INS unit configured to receive the accelerometer measurements and the angular velocity measurements and to determine a second set of kinematic state vectors of the vehicle based on the accelerometer measurements and the angular velocity measurements. A health management system is configured to compare the first set of kinematic state vectors and the second set of kinematic state vectors to determine faults associated with the accelerometer or the gyroscope based on the comparison. | 10-20-2011 |
20120104150 | PROJECTILE 3D ATTITUDE FROM 3-AXIS MAGNETOMETER AND SINGLE-AXIS ACCELEROMETER - A method to determine roll angle, pitch angle, and heading angle of a spinning projectile during a flight of the spinning projectile is provided. The method includes providing a magnetic unit vector in an inertial frame of the projectile at a projectile launch location prior to launch of the projectile; determining a magnetic unit vector in a body frame and in an inertial frame of the spinning projectile during the flight of the spinning projectile; determining a velocity unit vector in the body frame and in the inertial frame of the spinning projectile during the flight of the spinning projectile; and calculating the roll angle, the pitch angle, and the heading angle of the spinning projectile during the flight of the spinning projectile, regardless of the spin rate of the projectile. The roll angle and the pitch angle of the spinning projectile form an attitude of the spinning projectile. | 05-03-2012 |
20120239331 | CRANE JIB ATTITUDE AND HEADING REFERENCE SYSTEM AND METHOD - Methods and apparatus are provided for determining the attitude and heading angle of a crane jib. Crane jib angular velocity, crane jib roll angle, crane jib pitch angle, crane jib specific force, and magnetic field in the local operating environment of the crane jib are all sensed and supplied to a processor. All of these measurements are processed, in a processor, to estimate the attitude and heading angle of the crane jib. | 09-20-2012 |
20120271582 | CRANE JIB ATTITUDE AND HEADING REFERENCE SYSTEM CALIBRATION AND INITIALIZATION - Methods and apparatus are provided for calibrating and initializing/aligning an attitude and heading reference system of a crane jib. Magnetometer measurements are generated using a magnetometer that is attached to the crane jib, while crane jib maneuvers are performed including crane jib slewing. The magnetometer measurements are supplied to a processor that is configured to generate magnetometer calibration parameters using the magnetometer measurements and to initialize and align a plurality of filters. | 10-25-2012 |
20130046430 | SYSTEM AND METHOD FOR SIMULTANEOUS LOCALIZATION AND MAP BUILDING - An autonomous vehicle comprises at least one image sensor to provide measurements of landmark position for a plurality of landmarks; and processing functionality to estimate the position of the plurality of landmarks in a global frame and in the autonomous vehicle's frame, and to estimate the kinematic state of the autonomous vehicle in a global frame based, at least in part, on the measurements of landmark position from the at least one image sensor. The processing functionality is further operable to calculate errors in the estimated positions of the plurality of landmarks in the global frame and in the estimate of the kinematic state of the autonomous vehicle in the global frame by using a plurality of unit projection vectors between the estimated positions of the plurality landmarks in the autonomous vehicle's frame and a plurality of unit projection vectors between the estimated positions of the plurality of landmarks in the global frame. | 02-21-2013 |
20130304383 | SYSTEMS AND METHODS FOR LANDMARK SELECTION FOR NAVIGATION - Systems and methods are provided for selecting landmarks for navigation. In one embodiment, a system comprises an IMU that provides inertial measurements for a vehicle and at least one image sensor that acquires measurements of the vehicle's environment. The system also comprises a processing unit that calculates a navigation solution for the vehicle based on the inertial measurements, identifies a plurality of landmarks in the acquired measurements, and identifies a plurality of usable landmarks from the plurality of landmarks. The processing unit also selects a subset of useable landmarks from the plurality of useable landmarks such that the subset of landmarks has a smaller dilution of precision (DOP) than other possible subsets of landmarks from the plurality of useable landmarks, and calculates an updated navigation solution from the subset of landmarks. The DOP is an amplification factor of measurement errors derived from the geometry of the subset of useable landmarks. | 11-14-2013 |
20150019159 | SYSTEM AND METHOD FOR MAGNETOMETER CALIBRATION AND COMPENSATION - A system comprises an inertial measurement unit comprising one or more gyroscopes configured to measure angular velocity about a respective one of three independent axes and one or more accelerometers configured to measure specific force along a respective one of the three independent axes; a magnetometer configured to measure strength of a local magnetic field along each of the three independent axes; and a processing device coupled to the inertial measurement unit and the magnetometer; the processing device configured to compute kinematic state data for the system based on measurements received from the magnetometer and the inertial measurement unit. The processing device is further configured to calculate magnetometer measurement calibration parameters using a first technique when position data is unavailable and to calculate magnetometer measurement calibration parameters using a second technique when position data is available. | 01-15-2015 |