Deere & Company

Navcom Technology, Inc.

Michael Alan Zeitzew

Liwen L Dai

Yunfeng Shao

F Adhika Pradipta Lie

Min Wang

David Chiu

Scott Adam Stephens

Kenneth Edward Hunt

David Roy Holm

Mark Alvin Schmidt

Yiqun Chen

Yujie Zhang

A tracking module processes the determined correlations to track a carrier of the received composite signal for estimation of a change in phase over a time period between a receiver antenna and one or more satellite transmitters that transmit the received signal as the receiver changes position with respect to an initial position during the time period. A relative position estimator estimates the relative position of the navigation receiver with respect to an initial position over the time period time by time-differencing of the phase measurements of the one or more tracked carrier signals. Bias estimators can estimate or compensate for errors in initial position and temporal changes in receiver clock and tropospheric delay.

Satellite navigation receiver for relative positioning with bias estimation

A receiver or method uses an offset vector to provide seamless switching between a real-time kinematic (RTK) mode and a precise positioning mode (e.g., precise point positioning, PPP) mode. An offset module or data processor is arranged to determine an offset between precise position and the RTK position estimate. Upon loss of the RTK signal, switching to a precise position mode based a last available RTK position (e.g., if the precise position mode is converged on a position solution with resolved ambiguities of the carrier phase), wherein the next precise position estimate is compensated by the offset or reference frame bias to avoid a jump or discontinuity in the next precise position estimate.

Satellite navigation receiver and method for switching between real-time kinematic mode and precise positioning mode

A system or method uses an offset vector to provide seamless switching between a real- time kinematic (RTK) mode and a precise positioning mode. A correction wireless device is adapted to receive, at the reference receiver, a precise signal encoded with precise correction data. A precise positioning estimator of the reference receiver is arranged to determine a precise position based on the measured carrier phase of the received satellite signals and the received precise correction data in a precise correction mode. At the reference receiver, an offset module can determine a base offset vector between the precise position and a reference RTK position for the reference receiver. At the reference receiver, a wireless communications device is capable of transmitting, via an RTK signal, RTK correction data.

An offset module or navigation positioning estimator determines a reference frame bias between precise point positioning (PPP) reference frame and an RTK reference frame, where the PPP reference frame is associated with relative position estimates generated by the relative position estimator and where the RTK reference frame is associated RTK position estimates generated by the RTK position estimator. Upon loss of the RTK correction signal, the navigation positioning estimator or controller switches to a relative position mode based a last available RTK position. The relative position estimator determines an estimated relative position based on time-differenced phase measurements by the mobile receiver in the relative position mode. The relative position estimator or offset module offsets the estimated relative position in the relative position mode.

Satellite navigation receiver and method for switching between real-time kinematic mode and relative positioning mode

A satellite navigation receiver and associated methods are described that can provide improved integer ambiguity resolution and more accurate positioning information. A modified BIE process may be utilized to enable the receiver to perform the integer ambiguity resolution more optimally. The output of the modified BIE process may be time-domain smoothed to provide a solution which is smoother in ambiguity space, and therefore also provide a position solution that is smoother in time. Transitions between an ambiguity-determined solution to a float solution, when necessary, may be smoothed in time. A weighting scheme may dynamically blend the ambiguity-determined solution and the float solution to leverage the advantages of both solutions, such as faster pull-in, higher accuracy, and more stable and smooth performance.

Satellite navigation receiver with improved ambiguity resolution

A satellite clock error is determined for each navigation satellite based on the pseudo-range code measurements, the carrier phase measurements, and broadcast satellite clock errors provided by a receiver network. Differences are determined between the computed satellite clock errors and the broadcast clock errors for each satellite. For each constellation, a clock reference satellite is selected from among the navigation satellites, where the clock reference satellite has the median value of clock error difference for that satellite constellation. A correction is determined for the broadcast clock error by applying a function of the reference satellite's clock error to the broadcast clock error for each satellite in the one or more constellations.

Method and system for determining clock corrections

The present invention is for a modular, extensible software system for use with multi-modal, autonomous, or semi-autonomous vehicles. The design of the present invention involves the coherent integration of modules with responsibilities for human-interaction, training, path planning, mission execution, navigation, and safety to develop and complete missions. The present invention provides a modular software system that expresses vehicle behaviors through numerous small-grain elements to complete a mission. The system can be easily adapted or modified by adding new software modules or modifying existing modules as missions change or expand, with the smaller-grain modules being easier to adapt and reuse.

Method and system for modular data processing for a vehicle control system

A first location determining receiver determines a first location estimate of a vehicle. The first location determining receiver is associated with satellite beacons. A second location determining receiver determines a second location estimate of a vehicle. The second location determining receiver is exclusively associated with terrestrial beacons. A selector selects the first location estimate of the vehicle as a preferential location in accordance with an initialization scheme for the vehicle in a work area. A filtering module applies a first weight to a first location and a second weight to the second location to derive a weighted estimate as the preferential location upon satisfactory completion of the initialization scheme.

Method and system for determining the location of a vehicle

A two-way ultrasonic positioning and navigation system and method involve a plurality of objects each capable of transmitting and receiving ultrasonic signals. A first object transmits an initiating ultrasonic signal and identifies a second object for responding to the initiating ultrasonic signal. The second object transmits a responding ultrasonic signal after a predetermined time delay from receiving the initiating ultrasonic signal. The first objectives the responding ultrasonic signal, and determines a distance between the first object and the second object based on a time period starting at the transmission of the initiating ultrasonic signal and ending at the reception of the responding ultrasonic signal, and on knowledge about the predetermined time delay and other known in advance time delays.

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Redondo Beach, CA, United States of America

Michael Alan Zeitzew