Patents by Inventor Madhusudan Raghavan

Madhusudan 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).

  • Patent number: 11235662
    Abstract: A gearbox having a power take-off for an electrically propelled vehicle. The gearbox includes a housing; at least one planetary gear set; an input shaft in continuous connection with at least one sun gear; a first output shaft in continuous connection with a carrier; a second output shaft in continuous connection with a ring gear; and a plurality of brake clutches grounded to the housing and are selectively engageable in combinations to transfer a torque from the input shaft to at least one of the first output shaft and the second output shaft.
    Type: Grant
    Filed: November 2, 2020
    Date of Patent: February 1, 2022
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Neeraj S. Shidore, Madhusudan Raghavan
  • Patent number: 11220172
    Abstract: A vehicle powertrain includes a first power-source configured to generate a first power-source torque and a multiple speed-ratio transmission configured to transmit the first power-source torque to power the vehicle. The powertrain also includes a fluid coupling having a fluid pump shaft operatively connected to the first power-source and a turbine shaft operatively connected to the multi-speed transmission. The fluid coupling is configured to multiply the first power-source torque, and transfer the multiplied first power-source torque to the multiple speed-ratio transmission. The powertrain additionally includes a second power-source configured to generate a second power-source torque and a first torque transfer system configured to connect the second power-source to the first power-source. The powertrain further includes a second torque transfer system configured to connect the second power-source to the multi-speed transmission. A motor vehicle having such a powertrain is also envisioned.
    Type: Grant
    Filed: October 9, 2019
    Date of Patent: January 11, 2022
    Assignee: GM Global Technology Operations LLC
    Inventors: Neeraj S. Shidore, Derek F. Lahr, Lei Hao, Madhusudan Raghavan, Suresh Gopalakrishnan
  • Patent number: 11155153
    Abstract: A vehicle including a hybrid battery pack includes a first battery pack and a second battery pack. The first battery pack has a higher energy density than the second battery pack. The second battery pack has a higher power density than the first battery pack. A power inverter module is connected between the hybrid battery pack and a motor generator unit (MGU) that is connected to a powertrain of the vehicle. The power inverter module is configured to regulate power flow between the hybrid battery pack and the MGU. A battery management module is configured to: control switching of the power inverter module; selectively charge and discharge at least one of the first battery pack and the second battery pack; and selectively charge the first battery pack with power from the second battery pack.
    Type: Grant
    Filed: June 1, 2018
    Date of Patent: October 26, 2021
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: John A. Cafeo, Madhusudan Raghavan, Wei Li, Anil Bika, Azeem Sarwar, Ran Y. Gazit, Winson Ng, Ryan C. Sekol, Thomas A. Yersak
  • Publication number: 20210245603
    Abstract: An electrified drivetrain for a vehicle includes a first electric machine, a second electric machine, a clutch, an HVAC compressor, and a controller. The second electric machine is rotatably coupled to a geartrain, the first electric machine is rotatably coupled to the HVAC compressor, and is rotatably couplable to the geartrain via the clutch, and the clutch is operative in a first state and a second state. The first electric machine is rotatably coupled to the geartrain when the clutch is controlled to the first state, and is decoupled from the geartrain when the clutch is controlled to the second state. The controller is operatively connected to the first and second electric machines, the clutch, and the HVAC compressor to control operation of the electrified drivetrain. The first electric machine can be used as a heater element and to provide mechanical power to the drivetrain.
    Type: Application
    Filed: February 11, 2020
    Publication date: August 12, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Neeraj S. Shidore, Madhusudan Raghavan, Norman K. Bucknor, Vicente Domenech-Llopis
  • Publication number: 20210242691
    Abstract: A system for use with a direct current fast-charging (DCFC) station includes a controller and battery system. The battery system includes first and second battery packs, and first, second, and third switches. The switches have ON/OFF conductive states commanded by the controller to connect the battery packs in a parallel-connected (P-connected) or series-connected (S-connected) configuration. An electric powertrain with one or more electric machines is powered via the battery system. First and second charge ports of the system are connectable to the station via a corresponding charging cable. The first charge port receives a low or high charging voltage from the station. The second charge port receives a low charging voltage. When the station can supply the high charging voltage to the first charge port, the controller establishes the S-connected configuration via the switches, and thereafter charges the battery system solely via the first charge port.
    Type: Application
    Filed: February 3, 2020
    Publication date: August 5, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Lei Hao, Yue-Yun Wang, Suresh Gopalakrishnan, Chandra S. Namuduri, Rashmi Prasad, Madhusudan Raghavan
  • Publication number: 20210107348
    Abstract: A vehicle powertrain includes a first power-source configured to generate a first power-source torque and a multiple speed-ratio transmission configured to transmit the first power-source torque to power the vehicle. The powertrain also includes a fluid coupling having a fluid pump shaft operatively connected to the first power-source and a turbine shaft operatively connected to the multi-speed transmission. The fluid coupling is configured to multiply the first power-source torque, and transfer the multiplied first power-source torque to the multiple speed-ratio transmission. The powertrain additionally includes a second power-source configured to generate a second power-source torque and a first torque transfer system configured to connect the second power-source to the first power-source. The powertrain further includes a second torque transfer system configured to connect the second power-source to the multi-speed transmission. A motor vehicle having such a powertrain is also envisioned.
    Type: Application
    Filed: October 9, 2019
    Publication date: April 15, 2021
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Neeraj S. Shidore, Derek F. Lahr, Lei Hao, Madhusudan Raghavan, Suresh Gopalakrishnan
  • Patent number: 10940748
    Abstract: A hybrid transmission for use with a vehicle having an engine has an electric-only mode where the engine is off and a hybrid mode where the engine is on. The hybrid transmission includes an engine connection member configured for connection with the engine, a motor/generator unit configured to selectively operate as a motor, a transmission gearing arrangement, and a transmission input member connected with the transmission gearing arrangement. A torque transfer device is controllable to transfer torque from the motor to the transmission input member upstream in power flow from the transmission gearing arrangement, and a starter gear set includes a planetary gear set positioned in power flow between the engine connection member and the motor. The starter gear set is selectively engageable with the transmission input member and the engine connection member.
    Type: Grant
    Filed: June 17, 2019
    Date of Patent: March 9, 2021
    Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Madhusudan Raghavan, Neeraj S. Shidore
  • Publication number: 20200391584
    Abstract: A hybrid transmission for use with a vehicle having an engine has an electric-only mode where the engine is off and a hybrid mode where the engine is on. The hybrid transmission includes an engine connection member configured for connection with the engine, a motor/generator unit configured to selectively operate as a motor, a transmission gearing arrangement, and a transmission input member connected with the transmission gearing arrangement. A torque transfer device is controllable to transfer torque from the motor to the transmission input member upstream in power flow from the transmission gearing arrangement, and a starter gear set includes a planetary gear set positioned in power flow between the engine connection member and the motor. The starter gear set is selectively engageable with the transmission input member and the engine connection member.
    Type: Application
    Filed: June 17, 2019
    Publication date: December 17, 2020
    Inventors: Madhusudan Raghavan, Neeraj S. Shidore
  • Patent number: 10760624
    Abstract: Presented are wedge-type engine disconnect devices, methods for making/using such disconnect devices, and motor vehicles equipped with such disconnect devices. An engine disconnect device includes an outer race that attaches to a torque converter's pump cover. The outer race's inner diameter (ID) surface has circumferentially spaced grooves. An inner race is concentrically aligned within the outer race and attaches to an engine's output shaft. The inner race's outer diameter (OD) surface has circumferentially spaced pockets. A wedge plate interposed between the inner and outer races has multiple circumferentially spaced ramps. Each ramp slidably mounts within one groove and one pocket. The wedge plate moves between an engaged position, whereat the ramps wedge between the ID and OD surfaces to thereby transfer torque between the inner and outer races, and a disengaged position, whereat the ramps unwedge to thereby free the inner race to rotate with respect to the outer race.
    Type: Grant
    Filed: April 12, 2019
    Date of Patent: September 1, 2020
    Assignee: GM Global Technology Operations LLC
    Inventors: Farzad Samie, Derek F. Lahr, Dmitriy Bruder, Madhusudan Raghavan, Chunhao J. Lee, Dongxu Li
  • Publication number: 20200180596
    Abstract: A hybrid electric powertrain system includes a transmission, engine, e-accessory, primary and secondary electric machines, and controller. The e-accessory is powered by the secondary electric machine in response to an accessory torque demand. The engine and primary electric machine are connected to the transmission and configured, alone or in combination, to provide input drive torque to the transmission. The secondary electric machine is connected to the e-accessory and satisfies the accessory torque demand. A first clutch between the secondary electric machine and a transmission input member connects the secondary electric machine to the input member. The controller, in response to an output torque request, executes a power-sharing strategy using an objective cost function that allocates engine torque, primary motor torque, and secondary motor torque to the input member to satisfy the output torque request, while satisfying the accessory torque demand via the secondary electric machine.
    Type: Application
    Filed: December 6, 2018
    Publication date: June 11, 2020
    Applicant: GM Global Technology Operations LLC
    Inventors: Norman K. Bucknor, Madhusudan Raghavan
  • Patent number: 10676079
    Abstract: A hybrid electric powertrain system includes a transmission, engine, e-accessory, primary and secondary electric machines, and controller. The e-accessory is powered by the secondary electric machine in response to an accessory torque demand. The engine and primary electric machine are connected to the transmission and configured, alone or in combination, to provide input drive torque to the transmission. The secondary electric machine is connected to the e-accessory and satisfies the accessory torque demand. A first clutch between the secondary electric machine and a transmission input member connects the secondary electric machine to the input member. The controller, in response to an output torque request, executes a power-sharing strategy using an objective cost function that allocates engine torque, primary motor torque, and secondary motor torque to the input member to satisfy the output torque request, while satisfying the accessory torque demand via the secondary electric machine.
    Type: Grant
    Filed: December 6, 2018
    Date of Patent: June 9, 2020
    Assignee: GM Global Technology Operations LLC
    Inventors: Norman K. Bucknor, Madhusudan Raghavan
  • Publication number: 20190376484
    Abstract: A vehicle engine electric starter motor can bring a vehicle engine crankshaft up to a desired spinning speed prior to igniting the accompanying vehicle engine by way of multiple speed ratios. The vehicle engine electric starter motor includes a planetary gearset assembly. The planetary gearset assembly receives rotational drive input from an armature shaft, and transmits rotational drive output to an engine flywheel. Amid use of the vehicle engine electric starter motor, the vehicle engine electric starter motor can provide a first speed ratio by way of the planetary gearset assembly between the rotational drive input and the rotational drive output in a first mode of operation. And the vehicle engine electric starter motor can provide a second speed ratio by way of the planetary gearset assembly between the rotational drive input and the rotational drive output in a second mode of operation.
    Type: Application
    Filed: June 6, 2018
    Publication date: December 12, 2019
    Inventors: Madhusudan Raghavan, Neeraj S. Shidore, Shawn H. Swales
  • Publication number: 20190366831
    Abstract: An energy share system includes a first vehicle and a second vehicle. The first vehicle includes a first battery pack and a first battery management module configured to selectively charge and discharge the first battery pack. The second vehicle includes a second battery pack and a second battery management module configured to, in response to receipt of payment, selectively charge the second battery pack with power received from the first battery pack of the first vehicle.
    Type: Application
    Filed: August 8, 2018
    Publication date: December 5, 2019
    Applicant: GM Global Technology Operations LLC
    Inventors: John A. Cafeo, Madhusudan Raghavan, Wei Li, Anil Bika, Azeem Sarwar, Ran Y. Gazit, Winson Ng, Ryan C. Sekol, Thomas A. Yersak
  • Publication number: 20190366830
    Abstract: A vehicle including a hybrid battery pack includes a first battery pack and a second battery pack. The first battery pack has a higher energy density than the second battery pack. The second battery pack has a higher power density than the first battery pack. A power inverter module is connected between the hybrid battery pack and a motor generator unit (MGU) that is connected to a powertrain of the vehicle. The power inverter module is configured to regulate power flow between the hybrid battery pack and the MGU. A battery management module is configured to: control switching of the power inverter module; selectively charge and discharge at least one of the first battery pack and the second battery pack; and selectively charge the first battery pack with power from the second battery pack.
    Type: Application
    Filed: June 1, 2018
    Publication date: December 5, 2019
    Applicant: GM Global Technology Operations LLC
    Inventors: John A. CAFEO, Madhusudan RAGHAVAN, Wei LI, Anil BIKA, Azeem SARWAR, Ran Y. GAZIT, Winson NG, Ryan C. SEKOL, Thomas A. YERSAK
  • Publication number: 20190232950
    Abstract: A powertrain system for a vehicle operates in one of a plurality of powertrain propulsion modes including an engine-only drive mode, an electric-only (EV) drive mode, a regenerative braking mode, a coasting mode and an engine/electric-assist mode. The vehicle also includes a Global Positioning System (GPS) sensor, a vehicle navigation system, a telematics system, a vehicle spatial monitoring system and a controller. The controller includes an instruction set that is executable to determine a trajectory for the vehicle, and determine road conditions, traffic conditions and surface conditions based upon the trajectory for the vehicle and the road conditions, traffic conditions and surface conditions. One of the powertrain propulsion modes is selected based upon the trajectory for the vehicle and the road conditions, traffic conditions and surface conditions. Operation of the hybrid powertrain system is controlled in the selected propulsion mode.
    Type: Application
    Filed: January 30, 2018
    Publication date: August 1, 2019
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Venkata Prasad Atluri, Madhusudan Raghavan, Neeraj S. Shidore
  • Patent number: 10189470
    Abstract: A vehicle propulsion system includes an engine and a first electric machine each configured to selectively provide torque to propel the vehicle. A second electric machine is 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. A propulsion controller is programmed to start the engine using cranking torque output from the second electric machine powered by the high-voltage power source. The controller is also programmed to operate both of the first electric machine and the combustion engine to propel the vehicle in response to an acceleration demand greater than a threshold. The controller is further programmed to decouple the engine and propel the vehicle using the first electric machine in response to vehicle speed less than a speed threshold.
    Type: Grant
    Filed: August 17, 2016
    Date of Patent: January 29, 2019
    Assignee: GM Global Technology Operations LLC
    Inventors: Venkata Prasad Atluri, Peter Beller, Norman K. Bucknor, Tito R. Huffman, Derek F. Lahr, Chunhao J. Lee, Dongxu Li, Chandra S. Namuduri, Thomas W. Nehl, Madhusudan Raghavan, Alexandru Rajala, Farzad Samie, Neeraj S. Shidore
  • Publication number: 20180050685
    Abstract: A vehicle propulsion system includes an engine and a first electric machine each configured to selectively provide torque to propel the vehicle. A second electric machine is 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. A propulsion controller is programmed to start the engine using cranking torque output from the second electric machine powered by the high-voltage power source. The controller is also programmed to operate both of the first electric machine and the combustion engine to propel the vehicle in response to an acceleration demand greater than a threshold. The controller is further programmed to decouple the engine and propel the vehicle using the first electric machine in response to vehicle speed less than a speed threshold.
    Type: Application
    Filed: August 17, 2016
    Publication date: February 22, 2018
    Inventors: Venkata Prasad Atluri, Peter Beller, Norman K. Bucknor, Tito R. Huffman, Derek F. Lahr, Chunhao J. Lee, Dongxu Li, Chandra S. Namuduri, Thomas W. Nehl, Madhusudan Raghavan, Alexandru Rajala, Farzad Samie, Neeraj S. Shidore
  • Patent number: 9586575
    Abstract: An electrical system includes an engine, a motor-generator and a starter mechanism, and engine systems also include the engine. The electrical system includes a first energy storage device having a first voltage level and a second energy storage device having a second voltage level less than the first voltage level. The electrical system further includes a controller configured to control the motor-generator, the starter mechanism and first and second switching devices. Current from at least one of the first and second energy storage devices is delivered to the motor-generator when at least one of the first switching device is in a first closed state and the second switching device is in a second closed state such that the motor-generator transfers torque to the starter mechanism and the starter mechanism uses the torque to start the engine.
    Type: Grant
    Filed: September 23, 2016
    Date of Patent: March 7, 2017
    Assignee: GM Global Technology Operations LLC
    Inventors: Alan G. Holmes, Venkata Prasad Atluri, Chandra S. Namuduri, Robert S. Conell, Michael G. Reynolds, Thomas Wolfgang Nehl, Bob R. Powell, Madhusudan Raghavan
  • Publication number: 20170008469
    Abstract: An electrical system includes an engine, a motor-generator and a starter mechanism, and engine systems also include the engine. The electrical system includes a first energy storage device having a first voltage level and a second energy storage device having a second voltage level less than the first voltage level. The electrical system further includes a controller configured to control the motor-generator, the starter mechanism and first and second switching devices. Current from at least one of the first and second energy storage devices is delivered to the motor-generator when at least one of the first switching device is in a first closed state and the second switching device is in a second closed state such that the motor-generator transfers torque to the starter mechanism and the starter mechanism uses the torque to start the engine.
    Type: Application
    Filed: September 23, 2016
    Publication date: January 12, 2017
    Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLC
    Inventors: Alan G. Holmes, Venkata Prasad Atluri, Chandra S. Namuduri, Robert S. Conell, Michael G. Reynolds, Thomas Wolfgang Nehl, Bob R. Powell, Madhusudan Raghavan
  • Patent number: 9481357
    Abstract: A powertrain includes an engine with a crankshaft rotating on a first axis, motor/generator unit (MGU), belted drive system, transmission, actuator assembly, and controller. An MGU rotor shaft rotates about a second axis. The belted drive assembly has a first pulley connected to the crankshaft, a second pulley selectively connected to the rotor shaft, and an endless rotatable drive element that connects the pulleys. The transmission is connected to the flywheel via an input clutch. The actuator assembly has a third axis parallel to the first and second axes, a linear actuator(s), pinion gears translatable along the third axis to selectively engage the first and second gear elements, and overrunning clutches to passively disengage the pinion gears from the first or second gear element. The controller transmits control signals to the MGU and linear actuators to command a control state via translation of the pinion gears.
    Type: Grant
    Filed: December 30, 2014
    Date of Patent: November 1, 2016
    Assignee: GM Global Technology Operations LLC
    Inventors: Chandra S. Namuduri, Alexandru Rajala, Alan G. Holmes, Thomas Wolfgang Nehl, Venkata Prasad Atluri, Madhusudan Raghavan