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).
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Publication number: 20200235440Abstract: Presented are battery pack voltage-switching (“V-switch”) systems, methods for making/operating such systems, and multi-pack, electric-drive motor vehicles with battery pack V-switch capabilities. A method for controlling operation of a vehicle includes a vehicle controller receiving a voltage switch signal to change a voltage output of the vehicle's battery system. The vehicle controller determines if a speed of a traction motor is less than a calibrated base speed; if so, the controller transmits a pack isolation signal to a power inverter to electrically disconnect the traction battery packs from the traction motor. The vehicle controller determines if a bus current of a DC bus is less than a calibrated bus current threshold; if so, the controller transmits an open signal to open one or more pack contactor switches and a close signal to close one or more pack contactor switches thereby causing the vehicle battery system to output the second voltage.Type: ApplicationFiled: January 18, 2019Publication date: July 23, 2020Applicant: GM Global Technology Operations LLCInventors: Lei Hao, Yue-Yun Wang, Chandra S. Namuduri, Suresh Gopalakrishnan, Thomas W. Nehl, Dongxu Li
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Publication number: 20200226049Abstract: A system for and method of analyzing user tools to detect and remediate those tools posing a high risk to an organization. The system and method involve calculating user tool complexity to predict potential tool failures and displaying the potential failures to a user for further analysis. Remediation tools are provided to permit the user to correct or minimize the potential failures. The user can identify high risk tools and mark potential risks in those tools as mitigated, pending mitigation, or no mitigation action required.Type: ApplicationFiled: January 10, 2019Publication date: July 16, 2020Inventors: Julie Cowan, Disha DUA, Liang Sun, Felix Shamis, Suresh Gopalakrishnan, Meshraj Khatiwada
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Publication number: 20200220364Abstract: System and method of dynamically balancing a rechargeable energy storage assembly having two or more respective units, a respective switch for each of the respective units and at least one sensor. The system includes a controller configured to control operation of the respective switch. The respective switch is configured to enable a respective circuit connection to the respective units when in an ON state and disable the respective circuit connection when in an OFF state. The respective units are characterized by a respective state of charge obtained based in part on the at least one sensor. A controller is configured to selectively employ at least one of a plurality of charging modes to charge one or more of the respective units, through operation of the respective switch. The plurality of charging modes includes a rest charging mode, a rapid initial charging mode and a rapid final charging mode.Type: ApplicationFiled: January 8, 2019Publication date: July 9, 2020Applicant: GM Global Technology Operations LLCInventors: Yue-Yun Wang, Lei Hao, Suresh Gopalakrishnan
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Patent number: 10677212Abstract: A method of controlled stopping an internal combustion engine having a stop-start mode and starter assembly includes detecting when the stop-start mode is active. The method also includes monitoring current rotational speed and position of the engine. The method additionally includes determining when the current rotational position is within a predetermined range of a target stop rotational position and the current rotational speed is less than a threshold rotational speed, and afterward energizing the starter assembly to engage the engine. The method also includes establishing a time delay following energizing the starter assembly to confirm engagement of the starter assembly with the engine. Furthermore, the method includes applying a torque by the starter assembly to stop the engine at the target stop position. A vehicle powertrain employing the engine equipped with the stop-start mode, the starter assembly, and an electronic controller configured to execute the method is also provided.Type: GrantFiled: May 1, 2018Date of Patent: June 9, 2020Assignee: GM Global Technology Operations LLCInventors: Suresh Gopalakrishnan, Lei Hao, Chandra S. Namuduri, Paul S. Lombardo, Chunhao J. Lee, Alexandru Rajala, Neeraj S. Shidore, Farzad Samie, Norman K. Bucknor, Dongxu Li
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Patent number: 10655583Abstract: A method for operating an electromagnetic actuator includes an actuation event utilizing a current waveform for the actuator characterized by an initial peak pull-in current in a first direction of current flow when the actuator is commanded to an actuated position; and a reversed peak current in a second opposite direction of current flow applied after the actuator is commanded to a rest position. The reversed peak current has a magnitude that is greater than the magnitude of the initial peak pull-in current.Type: GrantFiled: March 19, 2015Date of Patent: May 19, 2020Assignee: GM Global Technology Operations LLCInventors: Avoki M. Omekanda, Chandra S. Namuduri, Suresh Gopalakrishnan, Thomas W. Nehl
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Publication number: 20200070679Abstract: Presented are intelligent vehicle systems and control logic for predictive charge planning and powertrain control of electric-drive vehicles, methods for manufacturing/operating such systems, and electric-drive vehicles with smart charge planning and powertrain control capabilities. Systems and methods of AI-based predictive charge planning for smart electric vehicles use machine-learning (ML) driver models that draws on available traffic, location, and roadway map information to estimate vehicle speed and propulsion torque requirements to derive a total energy consumption for a given trip. Systems and methods of AI-based predictive powertrain control for smart hybrid vehicles use ML driver models with deep learning techniques to derive a drive cycle profile defined by a preview route with available traffic, geopositional, geospatial, and map data.Type: ApplicationFiled: August 29, 2018Publication date: March 5, 2020Applicant: GM Global Technology Operations LLCInventors: Yue-Yun Wang, Junfeng Zhao, Suresh Gopalakrishnan, Yiran HU, Norman K. Bucknor
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Publication number: 20200070667Abstract: An electrical system includes a rechargeable energy storage system (RESS) and a controller. The RESS includes first and second battery packs connected to a voltage bus, each pack having a respective plurality of battery cells and a corresponding cell balancing circuit. The RESS further includes switches that selectively connect or disconnect the packs to or from each other to achieve series and parallel modes. The controller executes a method by detecting a requested series to parallel mode transition. Responsive to a threshold imbalance being present in a state of charge or pack voltage of the packs relative to each other, the controller balances the state of charge/voltage using open/closed state control of the cell balancing circuits, and possibly a switching block having PWM-controlled switches and a circuit element. The controller may execute the requested mode transition upon balancing.Type: ApplicationFiled: September 4, 2018Publication date: March 5, 2020Applicant: GM Global Technology Operations LLCInventors: Yue-Yun Wang, Suresh Gopalakrishnan, Lei Hao
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Patent number: 10574116Abstract: A starter includes a three-phase switched reluctance electric motor including a rotor and a stator, a pinion gear, a power inverter that is connected to the stator, and a rotational position sensor. The rotor includes a quantity of rotor poles that is between 6 and 16, and the stator includes a quantity of stator poles that is between 8 and 24. An outer diameter of the electric motor is less than 85 mm. An active length of the motor is less than 50 mm. An airgap distance between the rotor and the stator is between 0.1 mm and 0.5 mm. A ratio between a rotor pole arc and a stator pole arc is at least 1.0:1. A ratio between a stator diameter and a rotor diameter is at least 2.0:1, and a ratio between a stator pole height and a rotor pole height is at least 2.5:1.Type: GrantFiled: April 24, 2018Date of Patent: February 25, 2020Assignee: GM Global Technology Operations LLCInventors: Avoki M. Omekanda, Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan, Thomas W. Nehl
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Patent number: 10544772Abstract: An electric starter system is usable with an engine and a power inverter module (PIM), e.g., of a powertrain. The starter system includes a poly phase/AC brushless starter motor connected to the PIM via an AC voltage bus and selectively connected to the engine during a requested engine start event. A sensor on the DC voltage bus outputs a signal indicative of a voltage level of the DC voltage bus. The controller executes a method using voltage stabilization logic having a proportional-integral (PI) torque control loop. Logic execution in response to the requested engine starting event causes the controller to control the starter motor, when the bus voltage exceeds a calibrated minimum voltage, using a starting torque determined via the control loop. The commanded starting torque limits inrush current to the starter motor such that the DC voltage bus remains above the minimum voltage.Type: GrantFiled: April 24, 2018Date of Patent: January 28, 2020Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan
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Patent number: 10511213Abstract: A solenoid assembly includes a solenoid actuator having a core. A coil is configured to be wound at least partially around the core such that a magnetic flux (?) is generated when an electric current flows through the coil. An armature is configured to be movable based on the magnetic flux (?). A controller has a processor and tangible, non-transitory memory on which is recorded instructions for controlling the solenoid assembly. The controller is configured to obtain a plurality of model matrices, a coil current (i1) and an eddy current (i2). The magnetic flux (?) is obtained based at least partially on a third model matrix (C0), the coil current (i1) and the eddy current (i2). Operation of the solenoid actuator is controlled based at least partially on the magnetic flux (?). In one example, the solenoid actuator is an injector.Type: GrantFiled: October 3, 2017Date of Patent: December 17, 2019Assignee: GM Global Technology Operations LLCInventors: Shifang Li, Thomas W. Nehl, Suresh Gopalakrishnan, Avoki Omekanda, Rashmi Prasad, Chandra S. Namuduri
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Patent number: 10487791Abstract: An electric starter system is usable with a powertrain having an engine with a flywheel. The starter system includes a brushless starter motor having a machine temperature, and a solenoid operable for translating a pinion gear into meshed engagement with the flywheel and the starter motor in response to a requested engine start event. A controller has temperature regulation logic that includes a proportional-integral torque control loop. Execution of a method embodied by the logic, in response to the requested engine start event when the machine temperature exceeds a first temperature, causes the controller to determine a required starting torque of the starter motor using the control loop. The controller causes the starter motor to transmit the required starting torque to the engine at a level that reduces the machine temperature below the first temperature.Type: GrantFiled: May 1, 2018Date of Patent: November 26, 2019Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Suresh Gopalakrishnan, Chandra S. Namuduri
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Publication number: 20190356257Abstract: A multi-phase switched reluctance motor including a rotor and a stator, an electronic commutator subassembly, and a controller. The electronic commutator subassembly includes an electronic motor control unit, a power inverter, and a rotational position sensor, with the power inverter being electrically connected to the stator of the switched reluctance motor. The controller is in communication with the electronic motor control unit, the power inverter, and the rotational position sensor. The controller includes an instruction set that is executable to characterize operation of the switched reluctance motor, dynamically determine inductance of the switched reluctance motor based upon the characterized operation, and execute a closed-loop torque control routine to control the switched reluctance motor based upon the dynamically determined inductance of the switched reluctance motor.Type: ApplicationFiled: May 16, 2018Publication date: November 21, 2019Applicant: GM Global Technology Operations LLCInventors: Suresh Gopalakrishnan, Avoki M. Omekanda, Thomas W. Nehl, Chandra S. Namuduri, Lei Hao
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Patent number: 10480674Abstract: 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: GrantFiled: March 19, 2015Date of Patent: November 19, 2019Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Avoki M. Omekanda, Thomas W. Nehl, Chandra S. Namuduri, Suresh Gopalakrishnan
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Patent number: 10479220Abstract: 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: GrantFiled: April 11, 2017Date of Patent: November 19, 2019Assignee: GM Global Technology Operations LLCInventors: Chandra S. Namuduri, Venkata Prasad Atluri, Suresh Gopalakrishnan
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Patent number: 10473081Abstract: An electric starter system includes a brushless alternating current (AC) starter motor selectively coupled to an engine and having a rotor with a rotor position. A position sensor generates measured position signals indicative of rotor position. A controller is in communication with the sensor. The controller has sensorless logic, e.g., a BEMF, inductance, or high-frequency signal injection method, for generating an estimated rotor position. The controller executes a method in which, below a threshold speed of the starter motor, the controller calibrates the sensorless logic using the measured position signals and controls a torque operation of the starter motor using the measured position signals. Above the threshold speed, the torque operation is controlled solely using the estimated rotor position. A powertrain includes the engine, a transmission, a drive shaft, and a load, along with the electric starter system.Type: GrantFiled: April 24, 2018Date of Patent: November 12, 2019Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Suresh Gopalakrishnan, Chandra S. Namuduri
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Publication number: 20190338745Abstract: An electric starter system is usable with a powertrain having an engine with a flywheel. The starter system includes a brushless starter motor having a machine temperature, and a solenoid operable for translating a pinion gear into meshed engagement with the flywheel and the starter motor in response to a requested engine start event. A controller has temperature regulation logic that includes a proportional-integral torque control loop. Execution of a method embodied by the logic, in response to the requested engine start event when the machine temperature exceeds a first temperature, causes the controller to determine a required starting torque of the starter motor using the control loop. The controller causes the starter motor to transmit the required starting torque to the engine at a level that reduces the machine temperature below the first temperature.Type: ApplicationFiled: May 1, 2018Publication date: November 7, 2019Applicant: GM Global Technology Operations LLCInventors: Lei Hao, Suresh Gopalakrishnan, Chandra S. Namuduri
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Publication number: 20190338742Abstract: A method of controlled stopping an internal combustion engine having a stop-start mode and starter assembly includes detecting when the stop-start mode is active. The method also includes monitoring current rotational speed and position of the engine. The method additionally includes determining when the current rotational position is within a predetermined range of a target stop rotational position and the current rotational speed is less than a threshold rotational speed, and afterward energizing the starter assembly to engage the engine. The method also includes establishing a time delay following energizing the starter assembly to confirm engagement of the starter assembly with the engine. Furthermore, the method includes applying a torque by the starter assembly to stop the engine at the target stop position. A vehicle powertrain employing the engine equipped with the stop-start mode, the starter assembly, and an electronic controller configured to execute the method is also provided.Type: ApplicationFiled: May 1, 2018Publication date: November 7, 2019Applicant: GM Global Technology Operations LLCInventors: Suresh Gopalakrishnan, Lei Hao, Chandra S. Namuduri, Paul S. Lombardo, Chunhao J. Lee, Alexandru Rajala, Neeraj S. Shidore, Farzad Samie, Norman K. Bucknor, Dongxu Li
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Publication number: 20190338744Abstract: An electric starter system is used with an engine. The starter system may include a solenoid device coupled to a pinion gear, a brushless starter motor connectable to the engine via the pinion gear during a requested engine start event, and a controller. In response to the start event, when the engine speed is less than a threshold speed, the controller delivers a control current to the solenoid device at a peak current level sufficient for translating the pinion gear into contact with the flywheel. The control current is reduced to a holding current level less than the peak current level after the pinion gear is engaged with the flywheel. Motor torque is commanded from the starter motor, through the pinion gear, and to the flywheel while maintaining the holding current level, and held for a duration sufficient for starting the engine.Type: ApplicationFiled: May 1, 2018Publication date: November 7, 2019Applicant: GM Global Technology Operations LLCInventors: Chandra S. Namuduri, Kenneth J. Shoemaker, Chunhao J. Lee, Lei Hao, Thomas W. Nehl, Suresh Gopalakrishnan
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Publication number: 20190338743Abstract: An engine starter system includes a starter including a multi-phase brushless electric motor and an electronic commutator assembly. A controller includes an instruction set that is executable in response to a command to execute an engine starting event. Operation includes determining a desired starting profile, controlling the starter to engage a rotatable member of the engine, and monitoring the rotational speed of the electric motor via a rotor position sensing circuit. The starter inverter is dynamically controlled to control the electric motor to spin the rotatable member of the internal combustion engine responsive to the desired starting profile, including dynamically controlling the starter inverter to control the electric motor to control the spin of the engine responsive to the desired starting profile to prevent occurrence of an engine speed flare event during the engine starting event.Type: ApplicationFiled: May 1, 2018Publication date: November 7, 2019Applicant: GM Global Technology Operations LLCInventors: Suresh Gopalakrishnan, Lei Hao, Chandra S. Namuduri, Paul S. Lombardo, Jeffrey R. Aldrich, Chunhao J. Lee, Neeraj S. Shidore
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Publication number: 20190323472Abstract: An electric starter system is usable with an engine and a power inverter module (PIM), e.g., of a powertrain. The starter system includes a polyphase/AC brushless starter motor connected to the PIM via an AC voltage bus and selectively connected to the engine during a requested engine start event. A sensor on the DC voltage bus outputs a signal indicative of a voltage level of the DC voltage bus. The controller executes a method using voltage stabilization logic having a proportional-integral (PI) torque control loop. Logic execution in response to the requested engine starting event causes the controller to control the starter motor, when the bus voltage exceeds a calibrated minimum voltage, using a starting torque determined via the control loop. The commanded starting torque limits inrush current to the starter motor such that the DC voltage bus remains above the minimum voltage.Type: ApplicationFiled: April 24, 2018Publication date: October 24, 2019Applicant: GM Global Technology Operations LLCInventors: Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan