Patents by Inventor Rajan Lakshmi Narasimha

Rajan Lakshmi Narasimha 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).

  • Patent number: 11874644
    Abstract: In described examples of methods and control systems to control a position and/or velocity of a machine, control circuitry is coupled to receive and dither a control signal, and to compute a control output value according to the dithered control signal and a control function. An inverter is coupled to the control circuitry, to control the position and/or velocity according to the control output value.
    Type: Grant
    Filed: January 11, 2021
    Date of Patent: January 16, 2024
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Patent number: 11705834
    Abstract: Systems and methods for sensorless trapezoidal control of brushless DC motors provide effective high-torque startup and low speed operation without the use of Hall effect sensors or encoders during motor operation. The systems and methods also provide the ability to boost signal-to-noise ratio for motor startup and low speed operation via an augmenting supply voltage. Sampling architectures and current-dependent inductance modeling architectures for the control systems are also described.
    Type: Grant
    Filed: December 27, 2019
    Date of Patent: July 18, 2023
    Assignee: Texas Instruments Incorporated
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Publication number: 20210203257
    Abstract: Systems and methods for sensorless trapezoidal control of brushless DC motors provide effective high-torque startup and low speed operation without the use of Hall effect sensors or encoders during motor operation. The systems and methods also provide the ability to boost signal-to-noise ratio for motor startup and low speed operation via an augmenting supply voltage. Sampling architectures and current-dependent inductance modeling architectures for the control systems are also described.
    Type: Application
    Filed: December 27, 2019
    Publication date: July 1, 2021
    Inventors: RAJAN LAKSHMI NARASIMHA, DAVID PATRICK MAGEE
  • Publication number: 20210132585
    Abstract: In described examples of methods and control systems to control a position and/or velocity of a machine, control circuitry is coupled to receive and dither a control signal, and to compute a control output value according to the dithered control signal and a control function. An inverter is coupled to the control circuitry, to control the position and/or velocity according to the control output value.
    Type: Application
    Filed: January 11, 2021
    Publication date: May 6, 2021
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Patent number: 10890895
    Abstract: In described examples of methods and control systems to control a position and/or velocity of a machine, control circuitry is coupled to receive and dither a control signal, and to compute a control output value according to the dithered control signal and a control function. An inverter is coupled to the control circuitry, to control the position and/or velocity according to the control output value.
    Type: Grant
    Filed: December 14, 2017
    Date of Patent: January 12, 2021
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Patent number: 10879821
    Abstract: A motor controller includes current measurement circuitry and estimation circuitry. The current measurement circuitry is adapted to be coupled to a motor, and configured to measure current in the motor. The estimation circuitry is coupled to the current measurement circuitry, and includes a memory, current computation circuitry, and summation circuitry. The memory stores coefficients of a function for estimating current related to variation of inductance of the motor. The current computation circuitry is coupled to the memory, and is configured to compute a compensation current value based on the coefficients. The summation circuitry is coupled to the current compensation circuitry, and is configured to generate a position error signal by subtracting the compensation current value from a measured current value generated by the current measurement circuitry.
    Type: Grant
    Filed: June 28, 2019
    Date of Patent: December 29, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Patent number: 10797629
    Abstract: A permanent magnet motor controller injects a periodic signal into a field oriented controller of the brushless motor. Phase currents in stator windings of the brushless motor are measured. A d-axis current and a q-axis current are determined with a transform of the phase currents. The d-axis current and the q-axis current are demodulated to extract an angle dependent current signature that includes a sine component of a rotor angle estimate and a cosine component of the rotor angle estimate. The rotor angle estimate is determined by processing the sine component and cosine component.
    Type: Grant
    Filed: November 23, 2018
    Date of Patent: October 6, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Publication number: 20200169204
    Abstract: A permanent magnet motor controller injects a periodic signal into a field oriented controller of the brushless motor. Phase currents in stator windings of the brushless motor are measured. A d-axis current and a q-axis current are determined with a transform of the phase currents. The d-axis current and the q-axis current are demodulated to extract an angle dependent current signature that includes a sine component of a rotor angle estimate and a cosine component of the rotor angle estimate. The rotor angle estimate is determined by processing the sine component and cosine component.
    Type: Application
    Filed: November 23, 2018
    Publication date: May 28, 2020
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Patent number: 10591548
    Abstract: A controller for driving a motor includes a multiphase driver, an analog-to-digital converter (ADC), impedance estimation circuitry, and fault detection circuitry. The multiphase driver is configured to generate drive signals for energizing each motor phase winding. The ADC is configured to digitize voltage and current from each motor phase winding. The impedance estimation circuitry is configured to determine a phasor value for the digitized voltages and for the digitized currents at a predetermined harmonic frequency, and to determine a sequence impedance value based on the phasor values. The fault detection circuitry is configured to identify a fault in the windings of the motor based on the sequence impedance value.
    Type: Grant
    Filed: October 8, 2018
    Date of Patent: March 17, 2020
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Publication number: 20200021214
    Abstract: A motor controller includes current measurement circuitry and estimation circuitry. The current measurement circuitry is adapted to be coupled to a motor, and configured to measure current in the motor. The estimation circuitry is coupled to the current measurement circuitry, and includes a memory, current computation circuitry, and summation circuitry. The memory stores coefficients of a function for estimating current related to variation of inductance of the motor. The current computation circuitry is coupled to the memory, and is configured to compute a compensation current value based on the coefficients. The summation circuitry is coupled to the current compensation circuitry, and is configured to generate a position error signal by subtracting the compensation current value from a measured current value generated by the current measurement circuitry.
    Type: Application
    Filed: June 28, 2019
    Publication date: January 16, 2020
    Inventors: Rajan LAKSHMI NARASIMHA, David Patrick MAGEE
  • Publication number: 20190187668
    Abstract: In described examples of methods and control systems to control a position and/or velocity of a machine, control circuitry is coupled to receive and dither a control signal, and to compute a control output value according to the dithered control signal and a control function. An inverter is coupled to the control circuitry, to control the position and/or velocity according to the control output value.
    Type: Application
    Filed: December 14, 2017
    Publication date: June 20, 2019
    Applicant: Texas Instruments Incorporated
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Publication number: 20190041462
    Abstract: A controller for driving a motor includes a multiphase driver, an analog-to-digital converter (ADC), impedance estimation circuitry, and fault detection circuitry. The multiphase driver is configured to generate drive signals for energizing each motor phase winding. The ADC is configured to digitize voltage and current from each motor phase winding. The impedance estimation circuitry is configured to determine a phasor value for the digitized voltages and for the digitized currents at a predetermined harmonic frequency, and to determine a sequence impedance value based on the phasor values. The fault detection circuitry is configured to identify a fault in the windings of the motor based on the sequence impedance value.
    Type: Application
    Filed: October 8, 2018
    Publication date: February 7, 2019
    Inventors: Rajan Lakshmi NARASIMHA, David Patrick MAGEE
  • Patent number: 10094878
    Abstract: A controller for driving a motor includes a multiphase driver, an analog-to-digital converter (ADC), impedance estimation circuitry, and fault detection circuitry. The multiphase driver is configured to generate drive signals for energizing each motor phase winding. The ADC is configured to digitize voltage and current from each motor phase winding. The impedance estimation circuitry is configured to determine a phasor value for the digitized voltages and for the digitized currents at a predetermined harmonic frequency, and to determine a sequence impedance value based on the phasor values. The fault detection circuitry is configured to identify a fault in the windings of the motor based on the sequence impedance value.
    Type: Grant
    Filed: June 23, 2017
    Date of Patent: October 9, 2018
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Patent number: 9581649
    Abstract: Described examples include controllers and methods for controlling an inverter to drive a load and for detecting load faults by determining phasor values representing voltages and currents associated with the individual load phases based on sets of input values, determining voltage and current sequence components according to the phasor values, determining a sequence impedance value by recursively solving a set of update equations at least partially according to the voltage and current sequence components, and detecting a load fault when the sequence impedance value exceeds a threshold value.
    Type: Grant
    Filed: August 26, 2015
    Date of Patent: February 28, 2017
    Assignee: TEXAS INSTRUMENTS INCORPORATED
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
  • Publication number: 20160238660
    Abstract: Described examples include controllers and methods for controlling an inverter to drive a load and for detecting load faults by determining phasor values representing voltages and currents associated with the individual load phases based on sets of input values, determining voltage and current sequence components according to the phasor values, determining a sequence impedance value by recursively solving a set of update equations at least partially according to the voltage and current sequence components, and detecting a load fault when the sequence impedance value exceeds a threshold value.
    Type: Application
    Filed: August 26, 2015
    Publication date: August 18, 2016
    Applicant: Texas Instruments Incorporated
    Inventors: Rajan Lakshmi Narasimha, David Patrick Magee