Abstract:
A global navigation satellite sensor system (GNSS) and gyroscope control system for vehicle steering control comprising a GNSS receiver and antennas at a fixed spacing to determine a vehicle position, velocity and at least one of a heading angle, a pitch angle and a roll angle based on carrier phase position differences. The system also includes a control system configured to receive the vehicle position, heading, and at least one of roll and pitch, and configured to generate a steering command to a vehicle steering system. The system includes gyroscopes for determining system attitude change with respect to multiple axes for integrating with GNSS-derived positioning information to determine vehicle position, velocity, rate-of-turn, attitude and other operating characteristics. Relative orientations and attitudes between motive and working components can be determined using optical sensors and cameras. The system can also be used to guide multiple vehicles in relation to each other.
Abstract:
A method for calibrating spatial errors induced by phase biases having a detrimental effect on the measurements of phase differences of radio signals received by three unaligned receiving antennas of a vehicle. An inter-satellite angular deviation of a pair of satellites is estimated in two different ways: on the basis of the respective positions of the vehicle and of the satellites to obtain a theoretical inter-satellite angular deviation; and on the basis of the respective directions of incidence of the satellites relative to the vehicle, which are determined from phase measurements, to obtain an estimated inter-satellite angular deviation. The space errors are estimated on the basis of said theoretical and estimated inter-satellite angular deviations. Also, a method and system for estimating the attitude of a vehicle, in particular a spacecraft.
Abstract:
Methods, systems, and machine-interpretable coding for causing a processor of a vehicle controller installed in a vehicle such as a rubber-tired gantry (RTG) to generate, using known position associated with a base station and signals received from a Global Navigation Satellite System (GNSS) receiver located at the base station, a satellite observation error estimate; generate, using the satellite observation error estimate and a position of vehicle determined using signals received from a GNSS receiver mounted on the vehicle, at least one control signal representing a navigation command executable by at least one control device of the vehicle; and to output the control signal for execution by the control device. Generation of control signals can include use of synchronous and asynchronous processing, ambiguity resolution processes, and as fuzzy logic and PID and other control feedback loops.
Abstract:
A global navigation satellite sensor system (GNSS) and gyroscope control system for vehicle steering control comprising a GNSS receiver and antennas at a fixed spacing to determine a vehicle position, velocity and at least one of a heading angle, a pitch angle and a roll angle based on carrier phase position differences. The roll angle facilitates correction of the lateral motion induced position errors resultant from motion of the antennae as the vehicle moves based on an offset to ground and the roll angle. Alternative aspects include multiple-antenna GNSS guidance methods for high-dynamic roll compensation, real-time kinematic (RTK) using single-frequency (L1) receivers, fixed and moving baselines between antennas, multi-position GNSS tail guidance (“breadcrumb following”) for crosstrack error correction, guiding multiple vehicles and pieces of equipment relative to each other, and snow grooming equipment and method applications.
Abstract:
The design of the low cost GPS/IMU positioning and data integrating method, which employs integrated global positioning system/inertial measurement unit enhanced with dual antenna GPS carrier phase measurements to initialize and stabilize the azimuth of the low cost GPS/IMU integrated system, is performed. The utilization of the raw carrier phase measurement for the integration speeds up the ambiguity search.
Abstract:
An attitude angle detecting apparatus receives radio waves transmitted from a plurality of position-fixing satellites with multiple antennas located at specific positions of a mobile unit, determines relative positions of the antennas and detects the heading and attitude of the mobile unit by determining carrier phase ambiguities quickly and accurately. When it is needed to redetermine integer ambiguities after recovery from an interruption of the radio waves from the position-fixing satellites or as a result of a change in combination of the position-fixing satellites, for example, the attitude angle detecting apparatus redetermines the integer ambiguities by using attitude angles and an attitude angle error covariance obtained from previous observation. This enables the attitude angle detecting apparatus to uninterruptedly obtain information on the heading and attitude of the mobile unit.
Abstract:
A method for detecting lock slip using inertial information is provided. The method involves an epoch comparison of a predicted delta phase range with a measured delta phase range. The predicted delta phase range is calculated by subtracting a previous inertial solution from a current inertial solution. The measured delta phase range is calculated by subtracting a previous carrier phase measurement from a current carrier phase measurement. If a difference between the predicted delta phase range and the measured delta phase range is greater than a threshold amount, a lock slip is declared. The method allows for lock slip detection in Global Positioning System (GPS) attitude determinations without relying on a lock slip notification from the GPS.
Abstract:
A carrier phase-based relative positioning apparatus comprises a plurality of antennas of which at least one is installed on a mobile unit. The apparatus determines the position of each antenna other than one antenna used as a reference antenna relative to the reference antenna by receiving radio signals transmitted from a plurality of position-fixing satellites with the multiple antennas, observing a single difference phase or a double difference phase, and calculating an integer ambiguity of the single difference phase or the double difference phase. The apparatus judges that the integer ambiguity has been incorrectly determined if the position of any of the antennas relative to the reference antenna (or the angle of a flat plane formed by those two antennas) falls out of a preset range in which the relative position (the angle of the flat plane) falls under normal conditions.
Abstract:
An improved positioning and data integrating process and system can substantially solve the problems encountered in system integration for personal hand-held applications, air, land, and water vehicles, wherein an integrated global positioning system/inertial measurement unit, enhanced with optional other devices to derive user position, velocity, attitude, and body acceleration and rotation information, and distributes these data to other onboard systems, for example, in case of aircraft application, flight management system, flight control system, automatic dependent surveillance, cockpit display, enhanced ground proximity warning system, weather radar, and satellite communication system.
Abstract:
System and methods are disclosed for employing one or more radiators having non-unique phase centers mounted to a body with respect to a plurality of transmitters to determine location characteristics of the body such as the position and/or attitude of the body. The one or more radiators may consist of a single, continuous element or of two or more discrete radiation elements whose received signals are combined. In a preferred embodiment, the location characteristics are determined using carrier phase measurements whereby phase center information may be determined or estimated. A distributed antenna having a wide angle view may be mounted to a moveable body in accord with the present invention. The distributed antenna may be utilized for maintaining signal contact with multiple spaced apart transmitters, such as a GPS constellation, as the body rotates without the need for RF switches to thereby provide continuous attitude and position determination of the body.