Patents by Inventor Ajay Raghavan

Ajay Raghavan 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).

  • Publication number: 20240035905
    Abstract: A system includes a sensor network comprising a network of optical sensors coupled to structural members of a structure loaded by vehicles or by an environmental event. A processor is operatively coupled to the sensor network. The processor is configured to receive the strain measurements from the network of optical sensors, calculate total strain energy using the received strain measurements, detect a heavy load on the structure in response to the total strain energy exceeding a total strain energy threshold developed for the structure, and determine whether the heavy load results from a superload vehicle or the environmental event. A transmitter is operatively coupled to the processor and configured to transmit one or both of an alert and a condition assessment report for the structure to a predetermined location in response to determining that the heavy load results from the superload vehicle or the environmental event.
    Type: Application
    Filed: July 21, 2023
    Publication date: February 1, 2024
    Inventors: Tu Hoang, Turki Haj Mohamad, Jin Yan, Ajay Raghavan
  • Publication number: 20240039630
    Abstract: A method comprises receiving streaming data in the form of peak readings developed from spectrum data produced by multiplexed optical sensors of one or more optical fibers. The streaming data comprises wavelength and intensity data associated with the sensors. The method comprises determining, for a particular fiber, whether a number of the peak readings is the same as, or differs from, an expected number, N, where N corresponds to a total number of sensors of the particular fiber. The method also comprises correcting anomalous streaming data in response to determining that the number of the peak readings differs from the expected number, N. The method further comprises storing nominal wavelength and intensity streaming data and the corrected wavelength and intensity streaming data in a structured data table indexed by fiber ID and sensor ID.
    Type: Application
    Filed: July 27, 2023
    Publication date: February 1, 2024
    Inventors: Jin Yan, Tu Hoang, Qiushu Chen, Turki Haj Mohamad, Ajay Raghavan, Peter Kiesel, Ozan Celik
  • Patent number: 11860242
    Abstract: A monitoring system for a power grid includes one or more power transformer monitors. Each power transformer monitor includes a plurality of optical sensors disposed on one or more optical fibers that sense parameters of the power transformer. Each optical sensor is configured to sense a power transformer parameter that is different from a power transformer parameter sensed by at least one other sensor of the plurality of optical sensors. An optical coupler spatially disperses optical signals from the optical sensors according to wavelength. A detector unit converts optical signals of the optical sensors to electrical signals representative of the sensed power transformer parameters.
    Type: Grant
    Filed: December 16, 2021
    Date of Patent: January 2, 2024
    Assignee: XEROX CORPORATION
    Inventors: Ajay Raghavan, Peter Kiesel
  • Patent number: 11823567
    Abstract: A system includes a sensor network comprising at least two optical fibers coupled to a pavement. Each optical fiber includes one or more optical sensors installed a predetermined distance from one or more adjacent optical fibers. The one or more optical sensors are configured to produce a wavelength shift signal. A processor is configured to determine one or both of one or more attributes of one or more objects travelling on the pavement and a traffic condition of the pavement based on the wavelength shift signal. A transmitter is configured to transmit the one or more attributes to a predetermined location.
    Type: Grant
    Filed: August 4, 2021
    Date of Patent: November 21, 2023
    Assignee: XEROX CORPORATION
    Inventors: Hong Yu, Qiushu Chen, Peter Kiesel, Ajay Raghavan, Jin Yan, Kyle Arakaki
  • Patent number: 11802901
    Abstract: A partial discharge (PD) transducer that includes a PD sensor configured to sense a PD event of an electrical system. At least one light emitting device (LED) is arranged in series with the PD sensor. The LED is configured to receive the electrical sensor signal from the PD sensor and to generate a light signal in response to the electrical sensor signal.
    Type: Grant
    Filed: November 30, 2021
    Date of Patent: October 31, 2023
    Assignee: XEROX CORPORATION
    Inventors: Todd Karin, Peter Kiesel, Ajay Raghavan
  • Patent number: 11782231
    Abstract: One or more spacers for installing an optical cable are disposed in a trench that extends along an axis. The optical cable includes one or more optical sensors. Each spacer includes a base configured to rest in a bottom of the trench. A first arm extends from the base. The first arm is adjacent to a first wall of the trench. An opposing second arm extends from the base. The second arm is adjacent to an opposing second wall of the trench. The optical cable is configured to extend along the axis.
    Type: Grant
    Filed: August 4, 2021
    Date of Patent: October 10, 2023
    Assignee: Xerox Corporation
    Inventors: Ajay Raghavan, Peter Kiesel, Hong Yu, Kyle Arakaki, Qiushu Chen, Jin Yan, Colin Campbell
  • Patent number: 11719559
    Abstract: A sensor system includes a sensor network comprising at least one optical fiber having one or more optical sensors. At least one of the optical sensors is arranged to sense vibration of an electrical device and to produce a time variation in light output in response to the vibration. A detector generates an electrical time domain signal in response to the time variation in light output. An analyzer acquires a snapshot frequency component signal which comprises one or more time varying signals of frequency components of the time domain signal over a data acquisition time period. The analyzer detects a condition of the electrical device based on the snapshot frequency component signal.
    Type: Grant
    Filed: October 28, 2019
    Date of Patent: August 8, 2023
    Assignee: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Peter Kiesel, Ajay Raghavan, Todd Karin, Qiushu Chen
  • Patent number: 11698323
    Abstract: A set of load responses of an asset for a sample of traffic loading events caused by objects of unknown weight is measured. At least one statistical parameter is determined from the set of load responses. A corresponding statistical parameter of known object weights loading the asset is determined. An object weight is assigned to a load response of the set of load responses based on correlation of the extracted statistical parameter to the corresponding statistical parameter.
    Type: Grant
    Filed: March 17, 2020
    Date of Patent: July 11, 2023
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Spenser Anderson, Hong Yu, Peter Kiesel, Ajay Raghavan
  • Patent number: 11693789
    Abstract: An illustrative embodiment disclosed herein is an apparatus including a processor and a memory. In some embodiments, the memory includes programmed instructions that, when executed by the processor, cause the apparatus to store a first object and a second object in a first region based on the first object and the second object having a first policy. In some embodiments, the memory includes programmed instructions that, when executed by the processor, cause the apparatus to store a third object in a second region based on the third object having a second policy. In some embodiments, a virtual disk includes the first region and the second region.
    Type: Grant
    Filed: December 1, 2021
    Date of Patent: July 4, 2023
    Assignee: Nutanix, Inc.
    Inventors: Karan Gupta, Gowtham Alluri, Dheer Moghe, Anshul Purohit, Arth Patel, Ajay Raghavan, Roger Liao
  • Patent number: 11585692
    Abstract: A sensor system includes a sensor network comprising at least one optical fiber having one or more optical sensors. At least one of the optical sensors is arranged to sense vibration of an electrical device and to produce a time variation in light output in response to the vibration. A detector generates an electrical time domain signal in response to the time variation in light output. An analyzer acquires a snapshot frequency component signal which comprises one or more time varying signals of frequency components of the time domain signal over a data acquisition time period. The analyzer detects a condition of the electrical device based on the snapshot frequency component signal.
    Type: Grant
    Filed: January 27, 2020
    Date of Patent: February 21, 2023
    Assignees: Palo Alto Research Center Incorporated, General Electric Company
    Inventors: Peter Kiesel, Ajay Raghavan, Todd Karin, Qiushu Chen, Malcolm G. Smith, Jr., Robert T. Stinson, IV
  • Publication number: 20230039117
    Abstract: A system includes a sensor network comprising at least two optical fibers coupled to a pavement. Each optical fiber includes one or more optical sensors installed a predetermined distance from one or more adjacent optical fibers. The one or more optical sensors are configured to produce a wavelength shift signal. A processor is configured to determine one or both of one or more attributes of one or more objects travelling on the pavement and a traffic condition of the pavement based on the wavelength shift signal. A transmitter is configured to transmit the one or more attributes to a predetermined location.
    Type: Application
    Filed: August 4, 2021
    Publication date: February 9, 2023
    Inventors: Hong Yu, Qiushu Chen, Peter Kiesel, Ajay Raghavan, Jin Yan, Kyle Arakaki
  • Publication number: 20230038939
    Abstract: One or more spacers for installing an optical cable are disposed in a trench that extends along an axis. The optical cable includes one or more optical sensors. Each spacer includes a base configured to rest in a bottom of the trench. A first arm extends from the base. The first arm is adjacent to a first wall of the trench. An opposing second arm extends from the base. The second arm is adjacent to an opposing second wall of the trench. The optical cable is configured to extend along the axis.
    Type: Application
    Filed: August 4, 2021
    Publication date: February 9, 2023
    Inventors: Ajay Raghavan, Peter Kiesel, Hong Yu, Kyle Arakaki, Qiushu Chen, Jin Yan, Colin Campbell
  • Publication number: 20230039656
    Abstract: A sensor network comprises at least one lateral optical fiber and at least one longitudinal optical fiber. The lateral fiber comprises optical sensors coupled to a pavement in a transverse orientation relative to a direction of vehicle travel along the pavement. The longitudinal fiber comprises optical sensors coupled to the pavement in a longitudinal orientation relative to the direction of vehicle travel. The optical sensors are configured to produce wavelength shift signals comprising one or more lateral strain signals associated with the lateral fiber and one or more tangential strain signals associated with the longitudinal fiber. A processor is operatively coupled to the sensor network and configured to determine a weight of vehicles moving along the pavement based on the lateral and tangential strain signals. A transmitter is operatively coupled to the processor and configured to transmit the weight of vehicles to a predetermined location.
    Type: Application
    Filed: July 26, 2022
    Publication date: February 9, 2023
    Inventors: Jin Yan, Qiushu Chen, Ajay Raghavan, Peter Kiesel, Jingxiao Liu
  • Patent number: 11555864
    Abstract: A monitoring system includes an array of optical sensors disposed within a transformer tank. Each optical sensor is configured to have an optical output that changes in response to a temperature within the transformer tank. An analyzer is coupled to the array of optical sensors. The analyzer is configured to determine a sensed temperature distribution based on the sensed temperature. The sensed temperature distribution is compared to an expected distribution. Exterior contamination of the transformer tank is detected based on the comparison.
    Type: Grant
    Filed: October 28, 2021
    Date of Patent: January 17, 2023
    Assignee: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Saman Mostafavi, Hong Yu, Ajay Raghavan, Peter Kiesel
  • Patent number: 11519894
    Abstract: A corrosion monitoring system includes one or more objects coupled to respective portions of a transformer tank. The one or more objects are configured to corrode before the respective portions of the transformer tank. At least one optical sensor is coupled to each of the objects. The at least one optical sensor has an optical output that changes in response to strain of the object. An analyzer is coupled to the at least one optical sensor. The analyzer is configured to perform one or more of detecting and predicting corrosion of the transformer tank based on the output of the at least one optical sensor.
    Type: Grant
    Filed: January 18, 2021
    Date of Patent: December 6, 2022
    Assignees: Palo Alto Research Company Incorporated, Consolidated Edison Company of New York, Inc.
    Inventors: Mark Teepe, Todd Karin, Peter Kiesel, Ajay Raghavan, Jane Shin, Bradley Kittrell, Serena Lee
  • Patent number: 11486919
    Abstract: An approach to detecting partial discharge events involves retrofitting an electrical system to include a capacitive sensor configured to capacitively sense partial discharge events of a component of the electrical system. The capacitive sensor has a first electrical conductor that forms a first terminal of the capacitive sensor, a second electrical conductor that forms a second terminal of the capacitive sensor, and a dielectric that separates the first electrical conductor and the second electrical conductor. The capacitive sensor generates an electrical sensor signal at an output of the capacitive sensor in response to the partial discharge event. The electrical sensor signal is converted to an optical signal and the optical signal is processed to detect an occurrence of the partial discharge event.
    Type: Grant
    Filed: October 24, 2019
    Date of Patent: November 1, 2022
    Assignees: Palo Alto Research Center Incorporated, General Electric Company, Consolidated Edison Company of New York, Inc.
    Inventors: Todd Karin, Peter Kiesel, Ajay Raghavan, Robert T. Stinson, IV, Malcolm G. Smith, Jr., Jane Shin, Serena Lee, Bradley Kittrell
  • Patent number: 11474509
    Abstract: A system and method are provided for determining a causal inference in a manufacturing process. During operation, the system can receive data associated with a processing system which includes a set of interconnected machines and an associated set of processes. The system can generate, based on the data, a graph indicating flows of outputs between the machines as part of the processes. The system can determine, based on a set of variables, one or more candidate clusters in the graph. The system can perform, based on one or more variables of interest, root cause analysis on the one or more candidate clusters by: applying an additive noise model to prune the one or more candidate clusters from the graph; and determining, based on the pruned graph, a candidate pathway likely to cause an issue in at least one process, thereby facilitating improved efficiency in the processing system.
    Type: Grant
    Filed: May 20, 2021
    Date of Patent: October 18, 2022
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Saman Mostafavi, Ajay Raghavan, Hong Yu, Deokwoo Jung
  • Patent number: 11448570
    Abstract: One embodiment can provide a system for detecting anomaly for high-dimensional sensor data associated with one or more machines. During operation, the system can obtain sensor data from a set of sensor associated with one or machines, apply data exploration techniques on the sensor data to automatically process sensor data to identify a subset of feature sensors from the available set of feature sensors, apply an unsupervised machine-learning technique to the identified subset of feature sensors and the target sensor to learn a set of pair-wise univariate models, and determine whether and how an anomaly occurs in the operation of the one or more machines based on the set of pair-wise univariate models.
    Type: Grant
    Filed: June 4, 2019
    Date of Patent: September 20, 2022
    Assignees: Palo Alto Research Center Incorporated, Panasonic Holdings Corporation
    Inventors: Deokwoo Jung, Fangzhou Cheng, Ajay Raghavan, Yukinori Sasaki, Akira Minegishi, Tetsuyoshi Ogura, Yosuke Tajika
  • Patent number: 11404728
    Abstract: A system includes a first optical sensor sensitive to both a parameter of interest, Parameter1, and at least one confounding parameter, Parameter2 and a second optical sensor sensitive only to the confounding parameter. Measurement circuitry measures M1 in response to light scattered by the first optical sensor, where M1=value of Parameter1+K*value of Parameter2. The measurement circuitry also measures M2 in response to light scattered by the second optical sensor, where M2=value of Parameter2. Compensation circuitry determines a compensation factor, K, for the confounding parameter based on measurements of M1 and M2 taken over multiple load/unload cycles or over one or more thermal cycles. The compensation factor is used to determine the parameter of interest.
    Type: Grant
    Filed: November 30, 2020
    Date of Patent: August 2, 2022
    Assignee: PALO ALTO RESEARCH CENTER INCORPORATED
    Inventors: Anurag Ganguli, Julian Schwartz, Ajay Raghavan, Peter Kiesel, Bhaskar Saha, Saroj Sahu, Lars Wilko Sommer
  • Patent number: 11314577
    Abstract: A system is provided for determining causes of faults in a manufacturing system. The system stores data associated with a processing system which includes machines and associated processes, wherein the data includes timestamp information, machine status information, and product-batch information. The system determines, based on the data, a topology of the processing system, wherein the topology indicates flows of outputs between the machines as part of the processes. The system determines information of machine faults in association with the topology. The system generates, based on the machine-fault information, one or more fault parameters which indicates frequency and severity of a respective fault. The system constructs, based on the topology and the machine-fault information, a system model which includes the one or more fault parameters, thereby facilitating diagnosis of the processing system.
    Type: Grant
    Filed: October 12, 2020
    Date of Patent: April 26, 2022
    Assignee: Palo Alto Research Center Incorporated
    Inventors: Hong Yu, Ajay Raghavan, Saman Mostafavi, Deokwoo Jung