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).
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Patent number: 11874644Abstract: 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: GrantFiled: January 11, 2021Date of Patent: January 16, 2024Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Patent number: 11705834Abstract: 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: GrantFiled: December 27, 2019Date of Patent: July 18, 2023Assignee: Texas Instruments IncorporatedInventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Publication number: 20210203257Abstract: 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: ApplicationFiled: December 27, 2019Publication date: July 1, 2021Inventors: RAJAN LAKSHMI NARASIMHA, DAVID PATRICK MAGEE
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Publication number: 20210132585Abstract: 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: ApplicationFiled: January 11, 2021Publication date: May 6, 2021Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Patent number: 10890895Abstract: 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: GrantFiled: December 14, 2017Date of Patent: January 12, 2021Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Patent number: 10879821Abstract: 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: GrantFiled: June 28, 2019Date of Patent: December 29, 2020Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Patent number: 10797629Abstract: 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: GrantFiled: November 23, 2018Date of Patent: October 6, 2020Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Publication number: 20200169204Abstract: 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: ApplicationFiled: November 23, 2018Publication date: May 28, 2020Inventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Patent number: 10591548Abstract: 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: GrantFiled: October 8, 2018Date of Patent: March 17, 2020Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Publication number: 20200021214Abstract: 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: ApplicationFiled: June 28, 2019Publication date: January 16, 2020Inventors: Rajan LAKSHMI NARASIMHA, David Patrick MAGEE
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Publication number: 20190187668Abstract: 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: ApplicationFiled: December 14, 2017Publication date: June 20, 2019Applicant: Texas Instruments IncorporatedInventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Publication number: 20190041462Abstract: 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: ApplicationFiled: October 8, 2018Publication date: February 7, 2019Inventors: Rajan Lakshmi NARASIMHA, David Patrick MAGEE
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Patent number: 10094878Abstract: 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: GrantFiled: June 23, 2017Date of Patent: October 9, 2018Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Patent number: 9581649Abstract: 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: GrantFiled: August 26, 2015Date of Patent: February 28, 2017Assignee: TEXAS INSTRUMENTS INCORPORATEDInventors: Rajan Lakshmi Narasimha, David Patrick Magee
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Publication number: 20160238660Abstract: 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: ApplicationFiled: August 26, 2015Publication date: August 18, 2016Applicant: Texas Instruments IncorporatedInventors: Rajan Lakshmi Narasimha, David Patrick Magee