Patents by Inventor Suresh Gopalakrishnan

Suresh Gopalakrishnan 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: 20180292005
    Abstract: A method for retracting an extended pin of a sliding camshaft actuator wherein the actuator includes a magnetic field generating coil, a magnetic piston in connection with the extended pin operable to be actuated by the magnetic field generating coil, and a pin stop plate. The method comprises creating an air gap between the magnetic piston and the pin stop plate and reversing voltage on the magnetic field generating coil to retract the extended pin.
    Type: Application
    Filed: April 6, 2017
    Publication date: October 11, 2018
    Inventors: Vijay A. Neelakantan, Suresh Gopalakrishnan, Christopher G. Benson
  • Publication number: 20180291859
    Abstract: A powertrain includes a motor-generator that is coupled to an engine. A starter mechanism is coupled to the engine. A first energy storage device is disposed in a parallel electrical relationship with the starter mechanism. A second energy storage device is disposed in a parallel electrical relationship with the motor-generator. The electrical circuit exhibits a first electrical resistance between the first energy storage device and the motor-generator, and a second electrical resistance between the second energy storage device and the motor-generator. The first electrical resistance is greater than the second electrical resistance so that electrical energy from the motor-generator more easily flows to the second energy storage device than the first energy storage device, and the motor-generator more easily draws electrical energy from the second energy storage device than from the first energy storage device.
    Type: Application
    Filed: April 11, 2017
    Publication date: October 11, 2018
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Venkata Prasad Atluri, Suresh Gopalakrishnan
  • Patent number: 10060399
    Abstract: An electromagnetically-activated actuator includes an electrical coil, an armature moveable between rest and actuated positions, and a bi-directional driver. A method for controlling an actuator event includes applying a supply voltage at a first polarity across the coil for a first duration to drive a forward current through the coil effective to move the armature away from the rest position. The forward current has a forward current peak at the end of the first duration. After the first duration, the supply voltage is applied at a second polarity across the coil for a second duration to drive a reverse current through the coil. The second duration terminates when the reverse current attains a predetermined reverse current peak, wherein the predetermined reverse current peak is coincident with the armature returning to the rest position.
    Type: Grant
    Filed: April 22, 2016
    Date of Patent: August 28, 2018
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan, Avoki M. Omekanda, Thomas W. Nehl
  • Publication number: 20180231611
    Abstract: A machine control system and a method of detecting a current sensor malfunction include obtaining a first current signal from a first current sensor corresponding with a first phase of a multi-phase machine, obtaining a second current signal from a second current sensor corresponding with a second phase of the multi-phase machine, and obtaining a position signal indicating an angular position of a rotor of the multi-phase machine corresponding with values of the first current signal and the second current signal. A determination is made of whether the current sensor malfunction occurred in the first current sensor or the second current sensor based only on the values of the first current signal and the second current signal at four of the angular positions of the rotor.
    Type: Application
    Filed: February 15, 2017
    Publication date: August 16, 2018
    Inventors: Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan
  • Patent number: 10008342
    Abstract: A device for supplying electric power includes a rectifier, an adaptive voltage clamping circuit, and a DC-DC voltage regulator. The rectifier receives electrical power, and is electrically connected to an input line of the adaptive voltage clamping circuit. The adaptive voltage clamping circuit includes a power transistor, a voltage feedback circuit, and a controller. The DC-DC voltage regulator is electrically connected to the adaptive voltage clamping circuit and, in one embodiment an actuator. The controller monitors the voltage feedback circuit and controls the power transistor to a fully open state to transfer electric power to the DC-DC voltage regulator when the voltage level supplied to the DC-DC voltage regulator is less than a threshold. The controller controls the power transistor in a linear state to regulate the voltage transferred to the DC-DC voltage regulator when the voltage level supplied to the DC-DC voltage regulator is greater than the threshold.
    Type: Grant
    Filed: February 29, 2016
    Date of Patent: June 26, 2018
    Assignee: GM Global Technology Operations LLC
    Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan, Nicholas W. Pinto, Nancy L. Johnson
  • Patent number: 9979336
    Abstract: A generator system includes an AC machine including a plurality of armature coils and a rectifier circuit electrically coupled to the armature coils. The rectifier circuit includes a plurality of switches. The generator system additionally includes a sensor device electrically coupled to a control circuit. The sensor device is configured to determine a rotor position of the AC machine. The control circuit determines a desired phase angle between a phase current and an induced voltage of the AC machine and provides a control signal to the rectifier circuit to switch the switches on and off to convert an AC signal to a DC signal and to control the rotor position of the AC machine to achieve the desired phase angle.
    Type: Grant
    Filed: July 28, 2015
    Date of Patent: May 22, 2018
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan
  • Patent number: 9973134
    Abstract: An electrical system includes a direct current (DC) voltage bus, a power supply providing a supply voltage to the DC voltage bus, an electric machine connected to the power supply, a reverse current protection (RCP) circuit positioned between the power supply and the electric machine, the RCP circuit including an energy dissipating element, and a controller. As part of an associated method, the controller detects a reverse current condition in which a current flows from the electric machine toward the power supply when an induced voltage of the electric machine exceeds a voltage level of the voltage bus. The controller transmits a control signal to the RCP circuit to direct the electrical current through the energy dissipating element for a duration of the reverse current condition or for a predetermined duration equal to or greater than that of the reverse current condition.
    Type: Grant
    Filed: March 7, 2017
    Date of Patent: May 15, 2018
    Assignee: GM Global Technology Operations LLC
    Inventors: Chandra S. Namuduri, Rajeev Vyas, Suresh Gopalakrishnan, Mark J. Rychlinski, Markus Demmerle, Varsha K. Sadekar
  • Publication number: 20180105158
    Abstract: A vehicle propulsion system includes a combustion engine configured to output a propulsion torque to satisfy a propulsion demand, and a traction electric machine to generate a supplemental torque to selectively supplement the propulsion torque. The propulsion system also includes a controller programmed to forecast an acceleration demand based on at least one estimation model. The controller is also programmed to issue a command indicative of a required axle torque corresponding to the acceleration demand. The controller is further programmed to engage at least one fuel conservation action in response to the required axle torque being within a first predetermined torque threshold range.
    Type: Application
    Filed: October 2, 2017
    Publication date: April 19, 2018
    Inventors: Chandra S. Namuduri, Venkata Prasad Atluri, Suresh Gopalakrishnan, Jin-Woo Lee, Kevin J. Robinet, Sai Rajagopalan, Chen-fang Chang, Michael Livshiz, Patrick J. O'leary
  • Publication number: 20180102952
    Abstract: An access data analytics system including a processor and a memory is provided. The processor stores an electronic report in the memory. The electronic report is generated based on an electronic report query include a plurality of parameters. The processor also collects access profile data including metadata associated with a user accessing the report, stores the access profile data within the memory, receives an access analytics data request requesting access analytics data associated with the stored report, retrieves the stored access profile data, generates an access analysis table including the access analytics data associated with the stored report based on the retrieved access profile data, and provides an extract including at least a portion of the access analytics data associated with the stored report from the access analysis table to a requestor of the access analytics data request.
    Type: Application
    Filed: October 7, 2016
    Publication date: April 12, 2018
    Inventors: Suresh Gopalakrishnan, Kim J. Murphy, Probal Ghosh
  • Patent number: 9932947
    Abstract: An electromagnetic actuation system includes an electrical coil, a magnetic core, an armature, a controllable bi-directional drive circuit for selectively driving current through the coil in either of two directions, and a control module providing an actuator command to the drive circuit. Current is driven though the electrical coil in a first direction when an actuation is desired. When the actuation is not desired current is driven through the electrical coil including in a second direction sufficient to reduce residual flux within the actuator below a level passively attained within the actuator at zero coil current.
    Type: Grant
    Filed: March 10, 2015
    Date of Patent: April 3, 2018
    Assignee: GM Global Technology Operations LLC
    Inventors: Thomas Wolfgang Nehl, Suresh Gopalakrishnan, Chandra S. Namuduri, Avoki M. Omekanda
  • Publication number: 20180050686
    Abstract: A hybrid vehicle propulsion includes an engine and a first electric machine, where each is configured to selectively provide torque to propel the vehicle. The propulsion system also includes a second electric machine coupled to the engine to provide torque to start the engine from an inactive state. A high-voltage power source is configured to power both of the first electric machine and the second electric machine over a high-voltage bus. The propulsion system further includes a controller programmed to deactivate the engine and propel the vehicle using the first electric machine in response to the vehicle being driven at a steady-state speed for a predetermined duration of time. The controller is also programmed to restart the engine using the second electric machine powered by the high-voltage power source.
    Type: Application
    Filed: August 17, 2016
    Publication date: February 22, 2018
    Inventors: Venkata Prasad Atluri, Norman K. Bucknor, Robert S. Conell, Suresh Gopalakrishnan, Lei Hao, Chunhao J. Lee, Derek F. Lahr, Dongxu Li, Shifang Li, Chandra S. Namuduri, Thomas W. Nehl, Avoki M. Omekanda, Bob R. Powell, JR., Rashmi Prasad, Farzad Samie, Neeraj S. Shidore, Aaron M. Sullivan
  • Publication number: 20180038356
    Abstract: A device for supplying electric power includes a rectifier, an adaptive voltage clamping circuit, and a DC-DC voltage regulator. The rectifier receives electrical power, and is electrically connected to an input line of the adaptive voltage clamping circuit. The adaptive voltage clamping circuit includes a power transistor, a voltage feedback circuit, and a controller. The DC-DC voltage regulator is electrically connected to the adaptive voltage clamping circuit and, in one embodiment an actuator. The controller monitors the voltage feedback circuit and controls the power transistor to a fully open state to transfer electric power to the DC-DC voltage regulator when the voltage level supplied to the DC-DC voltage regulator is less than a threshold. The controller controls the power transistor in a linear state to regulate the voltage transferred to the DC-DC voltage regulator when the voltage level supplied to the DC-DC voltage regulator is greater than the threshold.
    Type: Application
    Filed: February 29, 2016
    Publication date: February 8, 2018
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan, Nicholas W. Pinto, Nancy L. Johnson
  • Patent number: 9868410
    Abstract: An electric power management system for a vehicle includes a first power bus arranged in parallel with a second power bus between first and second nodes. A third power bus couples a first battery and an auxiliary load at the second node. The second power bus couples a starter, a second battery and a generator at the first node, and selectively couples the first node to the second node when a first switch is activated. The second battery couples to the first node when a second switch is activated and the engine starter couples to the first node when a starter switch is activated. The second power bus couples the first node to the second node when a third switch is activated. A controller monitors states of charge of the first battery and the second battery and controls activations of the first switch, the second switch and the third switch.
    Type: Grant
    Filed: March 30, 2015
    Date of Patent: January 16, 2018
    Assignee: GM Global Technology Operations LLC
    Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan, Venkata Prasad Atluri
  • Patent number: 9866157
    Abstract: A transmission assembly has an integrated torque machine including a torque machine stator and a torque machine rotor. The torque machine rotor includes at least one set of rotor magnets. An integrated rotational position sensor is configured to monitor rotational position of the torque machine rotor in relation to the torque machine stator. The integrated rotational position sensor includes a sensor rotor element and a sensor stator element. The sensor rotor element includes at least one set of sensor rotor magnets. The sensor rotor element is positioned such that the at least one set of sensor rotor magnets are aligned with respect to a rotor pole of the at least one set of rotor magnets of the torque machine rotor. The sensor stator element is positioned such that the sensor stator element is aligned with a magnetic axis of the torque machine stator.
    Type: Grant
    Filed: September 15, 2015
    Date of Patent: January 9, 2018
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Suresh Gopalakrishnan, Chandra S. Namuduri, Lei Hao, Alexandru Rajala
  • Patent number: 9863355
    Abstract: An electromagnetic actuation system includes an actuator having an electrical coil, a magnetic core, and an armature. The system further includes a controllable drive circuit for selectively driving current through the electrical coil. A control module provides an actuator command to the drive circuit effective to drive current through the electrical coil to actuate the armature. The control module includes a magnetic force control module configured to adapt the actuator command to converge magnetic force within the actuator to a preferred force level.
    Type: Grant
    Filed: March 10, 2015
    Date of Patent: January 9, 2018
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Suresh Gopalakrishnan, Thomas Wolfgang Nehl, Chandra S. Namuduri, Avoki M. Omekanda
  • Publication number: 20170334422
    Abstract: A vehicle propulsion system includes an engine and a first electric machine each configured to selectively provide torque to propel the vehicle. The propulsion system also includes a second electric machine coupled to the engine and configured to start the engine from an inactive state. A high-voltage battery powers both of the first electric machine and the second electric machine over a high-voltage bus. The vehicle further includes a controller programmed to issue a command to start the engine using the second electric machine in response to a threshold acceleration demand following a period of reduced acceleration demand.
    Type: Application
    Filed: May 19, 2016
    Publication date: November 23, 2017
    Inventors: Chandra S. Namuduri, Lei Hao, Suresh Gopalakrishnan, Thomas W. Nehl
  • Publication number: 20170306907
    Abstract: An electromagnetically-activated actuator includes an electrical coil, an armature moveable between rest and actuated positions, and a bi-directional driver. A method for controlling an actuator event includes applying a supply voltage at a first polarity across the coil for a first duration to drive a forward current through the coil effective to move the armature away from the rest position. The forward current has a forward current peak at the end of the first duration. After the first duration, the supply voltage is applied at a second polarity across the coil for a second duration to drive a reverse current through the coil. The second duration terminates when the reverse current attains a predetermined reverse current peak, wherein the predetermined reverse current peak is coincident with the armature returning to the rest position.
    Type: Application
    Filed: April 22, 2016
    Publication date: October 26, 2017
    Inventors: CHANDRA S. NAMUDURI, Suresh Gopalakrishnan, Avoki M. Omekanda, Thomas W. Nehl
  • Publication number: 20170284556
    Abstract: A core structure for an electromagnetic actuator includes an electrically conductive magnetic core component having a magnetic axis, an outer surface between axially opposite ends and at least one slit arranged between said axially opposite ends through the outer surface.
    Type: Application
    Filed: March 19, 2015
    Publication date: October 5, 2017
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: AVOKI M. OMEKANDA, THOMAS W. NEHL, CHANDRA S. NAMUDURI, SURESH GOPALAKRISHNAN
  • Patent number: 9777660
    Abstract: A method for parameter estimation in an electromagnetic actuator having an electrical coil and an armature includes applying a voltage pulse to the electrical coil of the actuator prior to an actuator event and of sufficient duration to ensure that a resulting electrical current achieves steady state. At least one parameter of the actuator is estimated based upon the voltage pulse and the steady state current.
    Type: Grant
    Filed: March 16, 2015
    Date of Patent: October 3, 2017
    Assignee: GM Global Technology Operations LLC
    Inventors: Chandra S. Namuduri, Suresh Gopalakrishnan, Thomas Wolfgang Nehl, Avoki M. Omekanda
  • Patent number: 9777686
    Abstract: A system for controlling actuation of an electromagnetic actuator includes an actuator having an electrical coil, a magnetic core, and an armature. A controllable drive circuit is responsive to an electric power flow signal for driving current through the electrical coil to actuate the armature. A control module includes an armature motion observer configured to determine an armature motion parameter in the actuator based upon a magnetic flux within the actuator and a predetermined mechanical equation of motion corresponding to the actuator and adapt the electric power flow signal based on the armature motion parameter.
    Type: Grant
    Filed: March 17, 2015
    Date of Patent: October 3, 2017
    Assignee: GM Global Technology Operations LLC
    Inventors: Thomas Wolfgang Nehl, Suresh Gopalakrishnan, Avoki M. Omekanda, Chandra S. Namuduri