Patents by Inventor Krishna Rupavatharam
Krishna Rupavatharam 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: 20230384447Abstract: An autonomous vehicle control system may include one or more processors configured to receive an electrical signal generated based on a returned optical signal that is reflected from an object. The one or more processors may determine a Doppler frequency shift of the returned optical signal over a first duration of the electrical signal. The one or more processors may generate a corrected electrical signal based on the Doppler frequency shift. The one or more processors may determine a range to the object based on the corrected electrical signal over a second duration that is shorter than the first duration. The one or more processors may control at least one of a steering system or a braking system based on the range.Type: ApplicationFiled: September 6, 2023Publication date: November 30, 2023Applicant: BLACKMORE SENSORS & ANALYTICS, LLCInventors: Stephen C. Crouch, Zeb William Barber, Emil Kadlec, Krishna Rupavatharam
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Patent number: 11709267Abstract: A system and method for enhanced velocity resolution and signal to noise ratio in optical phase-encoded range detection includes receiving an electrical signal generated by mixing a first optical signal and a second optical signal, wherein the first optical signal is generated by modulating an optical signal, wherein and the second optical signal is received in response to transmitting the first optical signal toward an object, and determining a Doppler frequency shift of the second optical signal, and generating a corrected electrical signal by adjusting the electrical signal based on the Doppler frequency shift, and determining a range to the object based on a cross correlation of the corrected electrical signal with a radio frequency (RF) signal that is associated with the first optical signal.Type: GrantFiled: November 16, 2020Date of Patent: July 25, 2023Assignee: BLACKMORE SENSORS & ANALYTICS, LLCInventors: Stephen C. Crouch, Zeb William Barber, Emil Kadlec, Krishna Rupavatharam
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Publication number: 20230161038Abstract: Doppler correction of phase-encoded LIDAR includes a code indicating a sequence of phases for a phase-encoded signal, and determining a first Fourier transform of the signal. A laser optical signal is used as a reference and modulated based on the code to produce a transmitted phase-encoded optical signal. A returned optical signal is received in response. The returned optical signal is mixed with the reference. The mixed optical signals are detected to produce an electrical signal. A cross spectrum is determined between in-phase and quadrature components of the electrical signal. A Doppler shift is based on a peak in the cross spectrum. A device is operated based on the Doppler shift. Sometimes a second Fourier transform of the electrical signal and the Doppler frequency shift produce a corrected Fourier transform and then a cross correlation. A range is determined based on a peak in the cross correlation.Type: ApplicationFiled: January 20, 2023Publication date: May 25, 2023Applicant: Blackmore Sensors & Analytics, LLCInventors: Stephen C. CROUCH, Randy R. REIBEL, James CURRY, Michelle MILVICH, Krishna RUPAVATHARAM
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Patent number: 11656343Abstract: A LIDAR system including one or more processors configured to receive a plurality of electrical signals that are respectively associated with (i) a plurality of optical signals provided by a laser and (ii) a plurality of returned optical signals that are responsive to the plurality of optical signals provided by the laser; determine an internal reflection signal; determine a range to an object by adjusting a third electrical signal of the plurality of electrical signals using the internal reflection signal; and operate a vehicle based on the determined range to the object.Type: GrantFiled: August 24, 2020Date of Patent: May 23, 2023Assignee: BLACKMORE SENSORS & ANALYTICS, LLCInventors: Stephen C. Crouch, Emil Kadlec, Krishna Rupavatharam
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Patent number: 11585925Abstract: Doppler correction of phase-encoded LIDAR includes a code indicating a sequence of phases for a phase-encoded signal, and determining a first Fourier transform of the signal. A laser optical signal is used as a reference and modulated based on the code to produce a transmitted phase-encoded optical signal. A returned optical signal is received in response. The returned optical signal is mixed with the reference. The mixed optical signals are detected to produce an electrical signal. A cross spectrum is determined between in-phase and quadrature components of the electrical signal. A Doppler shift is based on a peak in the cross spectrum. A device is operated based on the Doppler shift. Sometimes a second Fourier transform of the electrical signal and the Doppler frequency shift produce a corrected Fourier transform and then a cross correlation. A range is determined based on a peak in the cross correlation.Type: GrantFiled: August 8, 2019Date of Patent: February 21, 2023Assignee: BLACKMORE SENSORS & ANALYTICS, LLCInventors: Stephen C. Crouch, Randy R. Reibel, James Curry, Michelle Milvich, Krishna Rupavatharam
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Patent number: 11366228Abstract: In some implementations, a light detection and ranging (LIDAR) system includes a transmitter configured to transmit an optical signal that is output from a laser and modulated based on a modulating signal, a receiver configured to receive a returned optical signal in response to transmitting the optical signal, and a processor. The processor is configured to produce a first optical signal based on the returned optical signal and a first version of the modulating signal, produce a second optical signal based on the returned optical signal and a second version of the modulating signal, generate a digital signal based on the first optical signal and the second optical signal, determine a Doppler frequency shift of the returned optical signal based, at least in part, on the digital signal, and provide data indicative of the Doppler frequency shift to a vehicle.Type: GrantFiled: May 26, 2021Date of Patent: June 21, 2022Assignee: BLACKMORE SENSORS & ANALYTICS, LLCInventors: Stephen C. Crouch, Krishna Rupavatharam
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Publication number: 20210278536Abstract: In some implementations, a light detection and ranging (LIDAR) system includes a transmitter configured to transmit an optical signal that is output from a laser and modulated based on a modulating signal, a receiver configured to receive a returned optical signal in response to transmitting the optical signal, and a processor. The processor is configured to produce a first optical signal based on the returned optical signal and a first version of the modulating signal, produce a second optical signal based on the returned optical signal and a second version of the modulating signal, generate a digital signal based on the first optical signal and the second optical signal, determine a Doppler frequency shift of the returned optical signal based, at least in part, on the digital signal, and provide data indicative of the Doppler frequency shift to a vehicle.Type: ApplicationFiled: May 26, 2021Publication date: September 9, 2021Applicant: BLACKMORE SENSORS & ANALYTICS, LLCInventors: Stephen C. CROUCH, Krishna Rupavatharam
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Patent number: 11041954Abstract: Doppler correction of broadband LIDAR includes mixing, during a first time interval, a returned optical signal with an in-phase version of the transmitted signal to produce a first mixed optical signal that is detected during the first time interval to produce a first electrical signal. During a non-overlapping second time interval the returned optical signal is mixed with a quadrature version of the transmitted signal to produce a second mixed optical signal that is detected during the second time interval to produce a second electrical signal. A complex digital signal uses one of the digitized electrical signals as a real part and a different one as the imaginary part. A signed Doppler frequency shift of the returned optical signal is determined based, at least in part, on a Fourier transform of the complex digital signal. A device is operated based on the Doppler frequency shift.Type: GrantFiled: July 18, 2019Date of Patent: June 22, 2021Assignee: BLACKMORE SENSORS & ANALYTICS, LLCInventors: Stephen C. Crouch, Krishna Rupavatharam
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Publication number: 20210072381Abstract: A system and method for enhanced velocity resolution and signal to noise ratio in optical phase-encoded range detection includes receiving an electrical signal generated by mixing a first optical signal and a second optical signal, wherein the first optical signal is generated by modulating an optical signal, wherein and the second optical signal is received in response to transmitting the first optical signal toward an object, and determining a Doppler frequency shift of the second optical signal, and generating a corrected electrical signal by adjusting the electrical signal based on the Doppler frequency shift, and determining a range to the object based on a cross correlation of the corrected electrical signal with a radio frequency (RF) signal that is associated with the first optical signal.Type: ApplicationFiled: November 16, 2020Publication date: March 11, 2021Applicant: Blackmore Sensors & Analytics, LLCInventors: Stephen C. Crouch, Zeb William Barber, Emil Kadlec, Krishna Rupavatharam
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Publication number: 20200386875Abstract: A LIDAR system including one or more processors configured to receive a plurality of electrical signals that are respectively associated with (i) a plurality of optical signals provided by a laser and (ii) a plurality of returned optical signals that are responsive to the plurality of optical signals provided by the laser; determine an internal reflection signal; determine a range to an object by adjusting a third electrical signal of the plurality of electrical signals using the internal reflection signal; and operate a vehicle based on the determined range to the object.Type: ApplicationFiled: August 24, 2020Publication date: December 10, 2020Inventors: Stephen C. Crouch, Emil Kadlec, Krishna Rupavatharam
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Patent number: 10838061Abstract: A system and method for enhanced velocity resolution and signal to noise ratio in optical phase-encoded range detection includes receiving an electrical signal generated by mixing a first optical signal and a second optical signal, wherein the first optical signal is generated by modulating an optical signal, wherein and the second optical signal is received in response to transmitting the first optical signal toward an object, and determining a Doppler frequency shift of the second optical signal, and generating a corrected electrical signal by adjusting the electrical signal based on the Doppler frequency shift, and determining a range to the object based on a cross correlation of the corrected electrical signal with a radio frequency (RF) signal that is associated with the first optical signal.Type: GrantFiled: December 31, 2019Date of Patent: November 17, 2020Assignee: BLACKMORE SENSORS & ANALYTICS, LLC.Inventors: Stephen C. Crouch, Zeb William Barber, Emil A. Kadlec, Krishna Rupavatharam
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Patent number: 10768282Abstract: A system and method for optical detection in autonomous vehicles includes modulating an optical signal from a laser to generate a modulated optical signal and transmitting the modulated optical signal toward an object. The system and method include receiving, responsive to transmitting the modulated optical signal, a returned optical signal and mixing the returned optical signal with a reference optical signal associated with the optical signal from the laser to generate a mixed optical signal and detecting the mixed optical signal to generate an electrical signal. Based on the electrical signal and the modulated optical signal, a parameter of an internal reflection of the returned optical signal from one or more optical components is determined, which may be used to operate a vehicle.Type: GrantFiled: November 12, 2019Date of Patent: September 8, 2020Assignee: BLACKMORE SENSORS & ANALYTICS, LLCInventors: Stephen C. Crouch, Emil Kadlec, Krishna Rupavatharam
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Publication number: 20200150251Abstract: A system and method for optical detection in autonomous vehicles includes modulating an optical signal from a laser to generate a modulated optical signal and transmitting the modulated optical signal toward an object. The system and method include receiving, responsive to transmitting the modulated optical signal, a returned optical signal and mixing the returned optical signal with a reference optical signal associated with the optical signal from the laser to generate a mixed optical signal and detecting the mixed optical signal to generate an electrical signal. Based on the electrical signal and the modulated optical signal, a parameter of an internal reflection of the returned optical signal from one or more optical components is determined, which may be used to operate a vehicle.Type: ApplicationFiled: November 12, 2019Publication date: May 14, 2020Inventors: Stephen C. CROUCH, Emil Kadlec, Krishna Rupavatharam
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Publication number: 20190361122Abstract: Doppler correction of phase-encoded LIDAR includes a code indicating a sequence of phases for a phase-encoded signal, and determining a first Fourier transform of the signal. A laser optical signal is used as a reference and modulated based on the code to produce a transmitted phase-encoded optical signal. A returned optical signal is received in response. The returned optical signal is mixed with the reference. The mixed optical signals are detected to produce an electrical signal. A cross spectrum is determined between in-phase and quadrature components of the electrical signal. A Doppler shift is based on a peak in the cross spectrum. A device is operated based on the Doppler shift. Sometimes a second Fourier transform of the electrical signal and the Doppler frequency shift produce a corrected Fourier transform and then a cross correlation. A range is determined based on a peak in the cross correlation.Type: ApplicationFiled: August 8, 2019Publication date: November 28, 2019Inventors: Stephen C. Crouch, Randy R. Reibel, James Curry, Michelle Milvich, Krishna Rupavatharam
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Publication number: 20190339388Abstract: Doppler correction of broadband LIDAR includes mixing, during a first time interval, a returned optical signal with an in-phase version of the transmitted signal to produce a first mixed optical signal that is detected during the first time interval to produce a first electrical signal. During a non-overlapping second time interval the returned optical signal is mixed with a quadrature version of the transmitted signal to produce a second mixed optical signal that is detected during the second time interval to produce a second electrical signal. A complex digital signal uses one of the digitized electrical signals as a real part and a different one as the imaginary part. A signed Doppler frequency shift of the returned optical signal is determined based, at least in part, on a Fourier transform of the complex digital signal. A device is operated based on the Doppler frequency shift.Type: ApplicationFiled: July 18, 2019Publication date: November 7, 2019Inventors: Stephen C. Crouch, Krishna Rupavatharam
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Patent number: 10422880Abstract: Doppler correction of phase-encoded LIDAR includes a code indicating a sequence of phases for a phase-encoded signal, and determining a first Fourier transform of the signal. A laser optical signal is used as a reference and modulated based on the code to produce a transmitted phase-encoded optical signal. A returned optical signal is received in response. The returned optical signal is mixed with the reference. The mixed optical signals are detected to produce an electrical signal. A cross spectrum is determined between in-phase and quadrature components of the electrical signal. A Doppler shift is based on a peak in the cross spectrum. A device is operated based on the Doppler shift. Sometimes a second Fourier transform of the electrical signal and the Doppler frequency shift produce a corrected Fourier transform and then a cross correlation. A range is determined based on a peak in the cross correlation.Type: GrantFiled: February 3, 2017Date of Patent: September 24, 2019Assignee: BLACKMORE SENSORS AND ANALYTICS INC.Inventors: Stephen C. Crouch, Randy R. Reibel, James Curry, Michelle Milvich, Krishna Rupavatharam
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Patent number: 10401495Abstract: Doppler correction of broadband LIDAR includes mixing, during a first time interval, a returned optical signal with an in-phase version of the transmitted signal to produce a first mixed optical signal that is detected during the first time interval to produce a first electrical signal. During a non-overlapping second time interval the returned optical signal is mixed with a quadrature version of the transmitted signal to produce a second mixed optical signal that is detected during the second time interval to produce a second electrical signal. A complex digital signal uses one of the digitized electrical signals as a real part and a different one as the imaginary part. A signed Doppler frequency shift of the returned optical signal is determined based, at least in part, on a Fourier transform of the complex digital signal. A device is operated based on the Doppler frequency shift.Type: GrantFiled: July 10, 2017Date of Patent: September 3, 2019Assignee: Blackmore Sensors and Analytics Inc.Inventors: Stephen C. Crouch, Krishna Rupavatharam
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Publication number: 20190011558Abstract: Doppler correction of broadband LIDAR includes mixing, during a first time interval, a returned optical signal with an in-phase version of the transmitted signal to produce a first mixed optical signal that is detected during the first time interval to produce a first electrical signal. During a non-overlapping second time interval the returned optical signal is mixed with a quadrature version of the transmitted signal to produce a second mixed optical signal that is detected during the second time interval to produce a second electrical signal. A complex digital signal uses one of the digitized electrical signals as a real part and a different one as the imaginary part. A signed Doppler frequency shift of the returned optical signal is determined based, at least in part, on a Fourier transform of the complex digital signal. A device is operated based on the Doppler frequency shift.Type: ApplicationFiled: July 10, 2017Publication date: January 10, 2019Inventors: Stephen C. Crouch, Krishna Rupavatharam
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Publication number: 20180224547Abstract: Doppler correction of phase-encoded LIDAR includes a code indicating a sequence of phases for a phase-encoded signal, and determining a first Fourier transform of the signal. A laser optical signal is used as a reference and modulated based on the code to produce a transmitted phase-encoded optical signal. A returned optical signal is received in response. The returned optical signal is mixed with the reference. The mixed optical signals are detected to produce an electrical signal. A cross spectrum is determined between in-phase and quadrature components of the electrical signal. A Doppler shift is based on a peak in the cross spectrum. A device is operated based on the Doppler shift. Sometimes a second Fourier transform of the electrical signal and the Doppler frequency shift produce a corrected Fourier transform and then a cross correlation. A range is determined based on a peak in the cross correlation.Type: ApplicationFiled: February 3, 2017Publication date: August 9, 2018Inventors: Stephen C. Crouch, Randy R. Reibel, James Curry, Michelle Milvich, Krishna Rupavatharam
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Patent number: 7265712Abstract: Techniques for analog processing of high time-bandwidth-product (TBP) signals use a material with an inhomogeneously broadened absorption spectrum including multiple homogeneously broadened absorption lines. A first set of signals on optical carriers interact in the material during a time on the order of a phase coherence time of the homogeneously broadened absorption lines to record an analog interaction absorption spectrum. Within a time on the order of a population recovery time for a population of optical absorbers it the material, the interaction absorption spectrum in the material is read to produce a digital readout signal. The readout signal represents a temporal map of the interaction absorption spectrum, and includes frequency components that relate to a processing result of processing the first set of signals. The techniques allow processing of RADAR signals for improved range resolution to a target, as well as speed of the target, among other uses.Type: GrantFiled: May 12, 2003Date of Patent: September 4, 2007Assignee: Montana State UniversityInventors: Kristian Merkel, Zachary Cole, Krishna Rupavatharam, William R. Babbitt, Kelvin Wagner, Tiejun Chang