Patents by Inventor Liwen Dai
Liwen Dai has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Publication number: 20240255949Abstract: An electronic data processor, a reference frame converter, or a transformer is configured to transform or converting the second position in the PPP reference frame into a transformed second position in a universal reference frame. The electronic data processor is configured to assign an identifier to the first position observation and the second position observation, where the identifier indicates whether the observations are associated with a guidance path or a boundary of a field or work area.Type: ApplicationFiled: August 1, 2023Publication date: August 1, 2024Inventors: Liwen Dai, Yunfeng Shao, Marlon W. Bright
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Patent number: 12032077Abstract: The system and method facilitates Real-Time-Kinematic (RTK) GNSS with long baseline between a rover receiver and a base station receiver, even in the presence of scintillation or ionospheric disturbances that spatially fluctuate. Residual atmospheric errors can be estimated by a dual error model in a filter to promote efficient fixing or resolution of carrier phase ambiguities.Type: GrantFiled: May 13, 2022Date of Patent: July 9, 2024Assignee: DEERE & COMPANYInventors: Yufeng Zhang, Liwen Dai
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Patent number: 11808861Abstract: A first pair of a wide-lane (WL), zero-difference (ZD) bias filter and corresponding supplemental WL bias predictive filter determines the time-variant wide-lane bias for a corresponding satellite based on adaptive estimation responsive to tuned dynamic noise provided by the supplemental wide-lane bias predictive filter for each satellite. A second pair of narrow-lane (NL), zero-difference (ZD) bias filter and corresponding NL bias filter/code-phase bias filter determines the time-variant narrow-lane bias (e.g., refraction corrected (NL) code-phase bias) for a corresponding satellite based on adaptive estimation on adaptive estimation responsive to tuned dynamic noise within a narrow-lane bias/code-phase bias filter for each satellite. The electronic data processor of a data processing center is configured to provide a correction signal comprising the wide-lane ambiguities, the time-variant wide-lane bias and the narrow-lane ambiguities and the time-variant narrow lane bias.Type: GrantFiled: September 22, 2021Date of Patent: November 7, 2023Assignee: Deere & CompanyInventors: Liwen Dai, Yiqun Chen
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Publication number: 20230288577Abstract: The system and method facilitates Real-Time-Kinematic (RTK) GNSS with long baseline between a rover receiver and a base station receiver, even in the presence of scintillation or ionospheric disturbances that spatially fluctuate. Residual atmospheric errors can be estimated by a dual error model in a filter to promote efficient fixing or resolution of carrier phase ambiguities.Type: ApplicationFiled: May 13, 2022Publication date: September 14, 2023Inventors: Yufeng Zhang, Liwen Dai
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Publication number: 20230288576Abstract: The system and method facilitates Real-Time-Kinematic (RTK) GNSS with long baseline between a rover receiver and a base station receiver, even in the presence of scintillation or ionospheric disturbances that spatially fluctuate. Residual atmospheric errors can be estimated by a dual error model in a filter to promote efficient fixing or resolution of carrier phase ambiguities.Type: ApplicationFiled: May 13, 2022Publication date: September 14, 2023Inventors: Yufeng Zhang, Liwen Dai
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Publication number: 20220252732Abstract: A first pair of a wide-lane (WL), zero-difference (ZD) bias filter and corresponding supplemental WL bias predictive filter determines the time-variant wide-lane bias for a corresponding satellite based on adaptive estimation responsive to tuned dynamic noise provided by the supplemental wide-lane bias predictive filter for each satellite. A second pair of narrow-lane (NL), zero-difference (ZD) bias filter and corresponding NL bias filter/code-phase bias filter determines the time-variant narrow-lane bias (e.g., refraction corrected (NL) code-phase bias) for a corresponding satellite based on adaptive estimation on adaptive estimation responsive to tuned dynamic noise within a narrow-lane bias/code-phase bias filter for each satellite. The electronic data processor of a data processing center is configured to provide a correction signal comprising the wide-lane ambiguities, the time-variant wide-lane bias and the narrow-lane ambiguities and the time-variant narrow lane bias.Type: ApplicationFiled: September 22, 2021Publication date: August 11, 2022Inventors: Liwen Dai, Yiqun Chen
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Patent number: 10379225Abstract: 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.Type: GrantFiled: September 29, 2016Date of Patent: August 13, 2019Assignee: DEERE & COMPANYInventors: Liwen Dai, Michael Zeitzew
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Patent number: 10222483Abstract: 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.Type: GrantFiled: September 29, 2016Date of Patent: March 5, 2019Assignee: DEERE & COMPANYInventors: Liwen Dai, Michael Zeitzew
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Patent number: 10222484Abstract: 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.Type: GrantFiled: September 29, 2016Date of Patent: March 5, 2019Assignee: DEERE & COMPANYInventors: Liwen Dai, Michael Zeitzew
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Publication number: 20170269230Abstract: 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.Type: ApplicationFiled: September 29, 2016Publication date: September 21, 2017Inventors: Liwen Dai, Michael Zeitzew
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Publication number: 20170269229Abstract: 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.Type: ApplicationFiled: September 29, 2016Publication date: September 21, 2017Inventors: Liwen Dai, Michael Zeitzew
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Publication number: 20170269228Abstract: 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.Type: ApplicationFiled: September 29, 2016Publication date: September 21, 2017Inventors: Liwen Dai, Michael Zeitzew
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Patent number: 9599721Abstract: A primary phase measurement device measures a first carrier phase and a second carrier phase of carrier signals received by the location-determining receiver. A secondary phase measurement device measures the third carrier phase and the fourth carrier phase of other carrier signals. A real time kinematic engine estimates a first integer ambiguity set associated with the measured first carrier phase and a second integer ambiguity set associated with the measured second carrier phase. The real time kinematic engine estimates a third ambiguity set associated with the measured third carrier phase and a fourth ambiguity set associated with the measured fourth carrier phase. A compensator is capable of compensating for the inter-channel bias in at least one of the third ambiguity set and the fourth ambiguity set by modeling a predictive filter in accordance with various inputs or states of the filter estimated by an estimator.Type: GrantFiled: December 14, 2012Date of Patent: March 21, 2017Assignee: DEERE & COMPANYInventors: Liwen Dai, Chaochao Wang
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Patent number: 8803736Abstract: A primary phase measurement device measures a first carrier phase and a second carrier phase of carrier signals received by the location-determining receiver. A secondary phase measurement device measures the third carrier phase and the fourth carrier phase of other carrier signals. A real time kinematic engine estimates a first integer ambiguity set associated with the measured first carrier phase and a second integer ambiguity set associated with the measured second carrier phase. The real time kinematic engine estimates a third ambiguity set associated with the measured third carrier phase and a fourth ambiguity set associated with the measured fourth carrier phase. A compensator is capable of compensating for the inter-channel bias in at least one of the third ambiguity set and the fourth ambiguity set by modeling a predictive filter in accordance with various inputs or states of the filter estimated by an estimator.Type: GrantFiled: April 27, 2010Date of Patent: August 12, 2014Assignee: Navcom Technology, Inc.Inventors: Liwen Dai, Chaochao Wang
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Patent number: 8766848Abstract: A method and system for estimating the position comprises measuring a first carrier phase of a first carrier signal and a second carrier phase of a second carrier signal received by a location-determining receiver. A primary real time kinematic (RTK) engine or receiver data processing system estimates a primary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carder phase. A quality evaluator determines if a primary integer ambiguity set is resolved correctly to the predefined reliability rate during an earlier evaluation period. A secondary real time kinematic (RTK) engine or receiver data processing system estimates a secondary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase during a later period following the earlier evaluation period.Type: GrantFiled: January 29, 2013Date of Patent: July 1, 2014Assignee: Navcom Technology, Inc.Inventors: Liwen Dai, Chaochao Wang, Daniel Eslinger
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Patent number: 8665145Abstract: A system and method for determining the heading angle of a vehicle includes first and second antennas associated with the vehicle. The first and second antennas are configured to receive signals comprising global positioning system data. A receiver front end is configured to receive the signals comprising global positioning system data. An electronic data processor is capable of receiving the global positioning system data from the receiver front end. The data processor is configured or programmed to execute a method to determine the attitude of the vehicle which may include the heading angle of the vehicle.Type: GrantFiled: April 25, 2011Date of Patent: March 4, 2014Assignee: Navcom Technology, Inc.Inventors: Liwen Dai, Yunfeng Shao, Daniel J. Eslinger
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Publication number: 20130265192Abstract: A method and system for estimating the position comprises measuring a first carrier phase of a first carrier signal and a second carrier phase of a second carrier signal received by a location-determining receiver. A primary real time kinematic (RTK) engine or receiver data processing system estimates a primary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carder phase. A quality evaluator determines if a primary integer ambiguity set is resolved correctly to the predefined reliability rate during an earlier evaluation period. A secondary real time kinematic (RTK) engine or receiver data processing system estimates a secondary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase during a later period following the earlier evaluation period.Type: ApplicationFiled: January 29, 2013Publication date: October 10, 2013Inventors: Liwen Dai, Chaochao Wang, Daniel Eslinger
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Patent number: 8427365Abstract: A method and system for estimating the position comprises measuring a first carrier phase of a first carrier signal and a second carrier phase of a second carrier signal received by a location-determining receiver. A primary real time kinematic (RTK) engine or receiver data processing system estimates a primary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase. A quality evaluator determines if a primary integer ambiguity set is resolved correctly to the predefined reliability rate during an earlier evaluation period. A secondary real time kinematic (RTK) engine or receiver data processing system estimates a secondary integer ambiguity set associated with at least one of the measured first carrier phase and the measured second carrier phase during a later period following the earlier evaluation period.Type: GrantFiled: April 27, 2010Date of Patent: April 23, 2013Assignee: Navcom Technology, Inc.Inventors: Liwen Dai, Chaochao Wang, Daniel J. Eslinger
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Publication number: 20110267227Abstract: A system and method for determining the heading angle of a vehicle includes first and second antennas associated with the vehicle. The first and second antennas are configured to receive signals comprising global positioning system data. A receiver front end is configured to receive the signals comprising global positioning system data. An electronic data processor is capable of receiving the global positioning system data from the receiver front end. The data processor is configured or programmed to execute a method to determine the attitude of the vehicle which may include the heading angle of the vehicle.Type: ApplicationFiled: April 25, 2011Publication date: November 3, 2011Inventors: Liwen Dai, Yunfeng Shao, Daniel J. Eslinger
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Publication number: 20110267225Abstract: A system and method for determining the heading angle of a vehicle includes first and second antennas associated with the vehicle. The first and second antennas are configured to receive signals comprising global positioning system data. A receiver front end is configured to receive the signals comprising global positioning system data. An electronic data processor is capable of receiving the global positioning system data from the receiver front end. The data processor is configured or programmed to execute a method to determine the attitude of the vehicle which may include the heading angle of the vehicle.Type: ApplicationFiled: July 19, 2010Publication date: November 3, 2011Inventors: Liwen Dai, Yunfeng Shao, Daniel J. Eslinger