Patents by Inventor Chandra S. Namuduri
Chandra S. Namuduri 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: 20190103797Abstract: 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: ApplicationFiled: October 3, 2017Publication date: April 4, 2019Applicant: 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: 10207699Abstract: 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: GrantFiled: October 2, 2017Date of Patent: February 19, 2019Inventors: 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
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Patent number: 10205358Abstract: An electric machine is provided that includes a rotor assembly having a rotor core configured to support permanent magnets spaced around the rotor core to define a number of rotor poles. The rotor core has multiple rotor slots arranged as multiple barrier layers at each of the rotor poles. The rotor core is configured so that the electric machine satisfies predetermined operating parameters. In one embodiment, the electric machine is coupled with an engine through a belt drive train and provides cranking (engine starting), regeneration and torque assist modes.Type: GrantFiled: August 1, 2014Date of Patent: February 12, 2019Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Chandra S. Namuduri, Murali Pandi, Thomas Wolfgang Nehl, Avoki M. Omekanda
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Patent number: 10190559Abstract: A system includes an electric machine coupled to an engine and configured to start the engine from an inactive state. A controller executes a first control algorithm while output speed of the electric machine is less than a first speed threshold, and also executes a second control algorithm while the output speed is greater than the first speed threshold and less than a second speed threshold. Additionally, the controller is programmed to execute a third control algorithm while the output speed is greater than the second speed threshold. The first control algorithm includes operating the electric machine using trapezoidal current control with pulse width modulation. The second control algorithm includes operating the electric machine using six-step voltage control with a variable phase advance angle. The third control algorithm includes operating the electric machine using six-step voltage control with a predetermined fixed phase advance angle.Type: GrantFiled: May 22, 2018Date of Patent: January 29, 2019Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Chandra S. Namuduri, Thomas W. Nehl
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Patent number: 10189469Abstract: A method of controlling a powertrain of a vehicle includes opening and/or closing one or more of a first switching device, a second switching device, a third switching device, and engaging and/or disengaging at least one of a pair of actuators for a starter mechanism or a motor/generator clutch. Many different control modes are provided for the powertrain by changing the operation of a motor-generator between a motor or a generator, and changing the electrical connections between a first energy storage device, a second energy storage device, an auxiliary electric system, the starter mechanism, and the motor-generator.Type: GrantFiled: March 20, 2015Date of Patent: January 29, 2019Assignee: GM Global Technology Operations LLCInventors: Venkata Prasad Atluri, Suresh Gopalakrishnan, Michael G. Reynolds, Chandra S. Namuduri, Kenneth J. Shoemaker, David W. Walters
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Patent number: 10190526Abstract: A method for providing consistent actuator events for each of a plurality of consecutive actuator events of an electromagnetic actuator, includes applying a first bi-directional current waveform for a first actuator event and applying a second bi-directional current waveform for a second actuator event immediately subsequent to the first actuator event. The first bi-directional current waveform includes applying current in a first direction when the actuator is commanded to an actuated position and applying current in a reversed second direction when the actuator is commanded to a rest position. The second bi-directional current waveform includes applying current in the reversed second direction when the actuator is commanded to an actuated position and applying current in the first direction when the actuator is commanded to a rest position.Type: GrantFiled: March 19, 2015Date of Patent: January 29, 2019Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Thomas W. Nehl, Suresh Gopalakrishnan, Avoki M. Omekanda, Chandra S. Namuduri
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Patent number: 10189470Abstract: 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: GrantFiled: August 17, 2016Date of Patent: January 29, 2019Assignee: GM Global Technology Operations LLCInventors: 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
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Patent number: 10190561Abstract: A method of rapid starting an internal combustion engine includes determining that the engine is stopped and detecting an engine start request. The method also includes enabling a starter assembly having a brushless electric motor including a stator and a rotor and configured to drive a pinion gear, and engaging the pinion gear with the engine flywheel. The method also includes determining a present angular position of the rotor relative to the stator configured to generate a first rotor torque. The method additionally includes applying an electrical current to the motor, in response to the determined angular position of the rotor, to turn the rotor to a predetermined starting angular position configured to provide a second torque that is greater than the first torque. Furthermore, the method includes commanding the motor to spin the rotor and thereby apply the second torque via the pinion gear to start the engine.Type: GrantFiled: September 28, 2017Date of Patent: January 29, 2019Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Chandra S. Namuduri
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Publication number: 20190023255Abstract: A system includes an engine, a generator assembly, a direct current voltage bus, and a controller. The assembly is coupled to and driven via the engine, and has an electric generator, field windings, and a voltage rectifier collectively producing a generator output voltage. An inner control loop of the controller provides a field duty cycle signal to the field windings in response to an adjusted voltage control signal. An outer control loop of the controller provides a torque-based voltage control signal as an input to the inner control loop in response to a commanded engine torque and an estimated generator torque. An output torque of the generator is directly controlled via the outer control loop. The inner control loop calculates the adjusted voltage control signal as a difference between the torque-based voltage control signal and the output voltage.Type: ApplicationFiled: July 18, 2017Publication date: January 24, 2019Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Chandra S. Namuduri, Suresh Gopalakrishnan
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Patent number: 10184442Abstract: An interior permanent magnet electric machine includes a stator having a plurality of teeth disposed around a circumference oriented radially towards a center defining slots interposed between each of the teeth, and a conductive winding wrapped around each of the teeth of the stator to receive an electrical current. The electric machine also includes a rotor which is rotatable relative to the stator. The rotor defines a plurality of openings to receive permanent magnets near an outer portion of the rotor and a number of spokes interposed between mass reduction cutouts located closer to the center relative to the permanent magnets. Each of the permanent magnets defines a magnetic pole and each of the spokes is circumferentially aligned with one of the magnetic poles.Type: GrantFiled: May 19, 2016Date of Patent: January 22, 2019Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Chandra S. Namuduri, Murali Pandi, Thomas W. Nehl
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Publication number: 20180362075Abstract: Vehicles and steering systems for vehicles are provided. An exemplary steering system is provided for an automotive vehicle that includes road wheels and a rack mechanically coupled to the road wheels and laterally displaceable to change an orientation of the road wheels. The steering system includes a steering wheel mounted on a steering column and rotatable by a driver for inputting a steering command. The steering system also includes a lower column coupled to the rack. In the steering system, lateral displacement of the rack causes a rotational torque on the lower column. The steering system further includes a magneto-rheological coupling interconnected between the steering column and the lower column. The magneto-rheological coupling selectively communicates a desired portion of the rotational torque on the lower column to the steering column to provide haptic feedback to the steering column.Type: ApplicationFiled: June 19, 2017Publication date: December 20, 2018Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: JIN-WOO LEE, BAKHTIAR B. LITKOUHI, CHANDRA S. NAMUDURI
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Publication number: 20180358876Abstract: An IPM electric machine includes a rotor, rotor shaft stator, and permanent magnets. The rotor includes rare earth permanent magnets disposed within pockets. The rotor, the pockets and the permanent magnets conform to a first set of geometric design parameters. The stator includes radially-inwardly projecting teeth that form slots between pairs of the teeth. Electrical windings are disposed within slots of the laminate stack. The teeth and slots conform to a second set of geometric design parameters. The quantity of slots is between 60 and 96, the quantity of electrical poles is between 6 and 12, the quantity of electrical phases is between 3 and 6 and the electrical windings include a quantity of turns per phase that is between 8 and 20. A ratio of an outer diameter of the stator to an active length of the rotor is between 2 and 3.5.Type: ApplicationFiled: June 7, 2017Publication date: December 13, 2018Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Alireza Fatemi, Lei Hao, Thomas W. Nehl, Chandra S. Namuduri, Norman K. Bucknor
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Patent number: 10110103Abstract: An electric drive system includes bus rails carrying a bus voltage, an energy storage system (ESS), and a power inverter. The system includes a voltage converter connected to the bus rails and having an inductor coil, semiconductor switches, a bypass switch connected to a positive bus rail, and a capacitor. A polyphase electric machine is electrically connected to the power inverter. A controller executes a method in which operation of the converter is regulated based on power, torque, and speed values of the electric machine. The converter is selectively bypassed by closing the bypass switch under predetermined high-power/high-torque conditions, with the bus voltage adjusted until it is equal to the battery output voltage. The bypass switch is opened and the bus voltage thereafter regulated to a predetermined voltage.Type: GrantFiled: June 21, 2017Date of Patent: October 23, 2018Assignee: GM Global Technology Operations LLCInventors: Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan, Thomas W. Nehl
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Patent number: 10101396Abstract: 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: GrantFiled: February 15, 2017Date of Patent: October 16, 2018Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan
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Publication number: 20180291859Abstract: 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: ApplicationFiled: April 11, 2017Publication date: October 11, 2018Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Chandra S. Namuduri, Venkata Prasad Atluri, Suresh Gopalakrishnan
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Publication number: 20180266379Abstract: A system includes an electric machine coupled to an engine and configured to start the engine from an inactive state. A controller executes a first control algorithm while output speed of the electric machine is less than a first speed threshold, and also executes a second control algorithm while the output speed is greater than the first speed threshold and less than a second speed threshold. Additionally, the controller is programmed to execute a third control algorithm while the output speed is greater than the second speed threshold. The first control algorithm includes operating the electric machine using trapezoidal current control with pulse width modulation. The second control algorithm includes operating the electric machine using six-step voltage control with a variable phase advance angle. The third control algorithm includes operating the electric machine using six-step voltage control with a predetermined fixed phase advance angle.Type: ApplicationFiled: May 22, 2018Publication date: September 20, 2018Applicant: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Lei Hao, Chandra S. Namuduri, Thomas W. Nehl
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Publication number: 20180258900Abstract: A vehicle propulsion system includes an engine configured to be selectively activated to provide torque to propel the vehicle and a starter module coupled to the engine and configured to start the engine from an inactive state. The starter module includes a brushless electric machine to generate an output torque to crank start the engine. The starter motor also includes a pinion gear coupled to the electric machine, where the pinion gear is actuatable to selectively engage a cranking input of the engine. A controller assembly is programmed to cause actuation of the pinion gear to engage the cranking input of the engine and transfer a cranking torque to activate the engine.Type: ApplicationFiled: March 7, 2017Publication date: September 13, 2018Inventors: Chandra S. NAMUDURI, Lei HAO, Thomas W. NEHL
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Patent number: 10060399Abstract: 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: GrantFiled: April 22, 2016Date of Patent: August 28, 2018Assignee: GM GLOBAL TECHNOLOGY OPERATIONS LLCInventors: Chandra S. Namuduri, Suresh Gopalakrishnan, Avoki M. Omekanda, Thomas W. Nehl
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Publication number: 20180231611Abstract: 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: ApplicationFiled: February 15, 2017Publication date: August 16, 2018Inventors: Lei Hao, Chandra S. Namuduri, Suresh Gopalakrishnan
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Patent number: 10044297Abstract: A vehicle including a cooling fan that is rotatably coupled to an electric motor that is electrically powered by a DC power source via an inverter is described. A method for controlling the cooling fan includes monitoring, via a first controller, a vehicle speed, and selecting a preferred operating state for the electric motor based upon the vehicle speed. The preferred operating state includes one of a first command associated with controlling the cooling fan to force air through the cooling system, a second command associated with a fan brake request, and a third command associated with an energy recovery mode. A discrete message from the first controller is communicated to an inverter controller, wherein the discrete message is based upon the preferred operating state for the electric motor. The inverter controller controls the inverter to control the electric motor in response to the discrete message.Type: GrantFiled: November 22, 2016Date of Patent: August 7, 2018Assignee: GM Global Technology Operations LLCInventors: Chandra S. Namuduri, Rajeev Vyas, Fausto Eleazar Vazquez Flores, Mark J. Rychlinski, Varsha Sadekar