Patents by Inventor Abraham Gebregergis
Abraham Gebregergis 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: 9461574Abstract: A motor control system for determining a reference d-axis current and a reference q-axis current is provided. The motor control system includes a motor, a DC power source and DC input lines, and a current command controller. The DC power source generates a bridge voltage across the DC input lines. The current command controller is configured to monitor the bridge voltage and a torque reference command. The current command controller is configured to calculate the reference q-axis current based on a torque reference command. The current command controller is configured to calculate the reference d-axis current based on a magnitude of the reference q-axis current.Type: GrantFiled: March 12, 2013Date of Patent: October 4, 2016Assignee: STEERING SOLUTIONS IP HOLDING CORPORATIONInventors: Abraham Gebregergis, Ramakrishnan RajaVenkitasubramony, Tomy Sebastian, Siddharth Ballal
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Patent number: 9172318Abstract: A motor control system for determining an offset correction value is provided. The motor control system includes a motor, an inverter, an inverter controller, and a dynamic offset compensation control module. The inverter is configured to transmit the phase current to the motor. The inverter controller determines the phase current to the motor. The dynamic offset compensation control module is in communication with the inverter controller and the motor, and is configured to perform a method at a fixed periodic interval to determine the offset correction value.Type: GrantFiled: March 5, 2013Date of Patent: October 27, 2015Assignee: Steering Solutions IP Holding CorporationInventors: Abraham Gebregergis, Ramakrishnan RajaVenkitasubramony, Tomy Sebastian
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Patent number: 9143081Abstract: A motor control system for determining a ripple compensating current is provided. The motor control system includes a motor having a plurality of motor harmonics and a motor frequency, and a bandwidth compensation controller that is in communication with the motor. The bandwidth compensation controller is configured to determine a magnitude response compensation value and a phase compensation value for each of the plurality of motor harmonics. The magnitude response compensation value and the phase compensation value are both based on the motor frequency. The bandwidth compensation controller is configured to determine the ripple compensating current based on the magnitude response compensation value and the phase compensation value.Type: GrantFiled: March 14, 2013Date of Patent: September 22, 2015Assignee: Steering Solutions IP Holding CorporationInventors: Abraham Gebregergis, Ramakrishnan RajaVenkitasubramony, Tomy Sebastian, Niharika P. Popy
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Patent number: 9136785Abstract: A motor control system is provided. The motor control system includes a motor having plurality of motor harmonics, and a torque ripple compensation controller in communication with the motor. The torque ripple compensation controller is configured to determine a harmonic ripple current for a corresponding one of the plurality of motor harmonics. The harmonic ripple current is based on a reference q-axis current and a reference d-axis current. The torque ripple compensation controller is configured to add the harmonic ripple current for each of the plurality of motor harmonics together to determine the ripple compensating current.Type: GrantFiled: March 12, 2013Date of Patent: September 15, 2015Assignee: Steering Solutions IP Holding CorporationInventors: Abraham Gebregergis, Mohammad S. Islam, Tomy Sebastian, Mazharul H. Chowdhury, Shakil Hossain, Ramakrishnan RajaVenkitasubramony, Niharika P. Popy
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Patent number: 9054612Abstract: A motor control system is provided. The motor control system includes a motor having plurality of motor harmonics, and a torque ripple compensation controller in communication with the motor. The torque ripple compensation controller is configured to determine a harmonic ripple current for a corresponding one of the plurality of motor harmonics. The harmonic ripple current is based on a reference q-axis current and a reference d-axis current. The torque ripple compensation controller is configured to add the harmonic ripple current for each of the plurality of motor harmonics together to determine the ripple compensating current.Type: GrantFiled: March 12, 2013Date of Patent: June 9, 2015Assignee: Steering Solutions IP Holding CorporationInventors: Abraham Gebregergis, Mohammad S. Islam, Tomy Sebastian, Mazharul H. Chowdhury, Shakil Hossain, Ramakrishnan RajaVenkitasubramony, Niharika P. Popy
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Patent number: 8924082Abstract: A method for controlling operation of a torque-assist motor includes determining a rotational position of the torque-assist motor and producing a motor speed signal that is indicative of a rotational speed of the motor. One or more gain factors are produced based on the rotational speed of the torque-assist motor. An electrical current applied to the torque-assist motor is detected, and a current error is calculated based on a commanded electrical current and the electrical current applied to the torque-assist motor. A quadrature axis voltage is calculated based on the current error and the one or more gain factors. An inverter is driven with a direct voltage signal that is phased with the rotational position of the torque-assist motor so as to produce the electrical current applied to the torque-assist motor. The electrical current exhibits a characteristic that is affected by the quadrature axis voltage.Type: GrantFiled: March 30, 2012Date of Patent: December 30, 2014Assignee: Steering Solutions IP Holding CorporationInventors: Abraham Gebregergis, Ramakrishnan RajaVenkitasubramony, Tomy Sebastian, Niharika P. Popy
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Patent number: 8862328Abstract: A system and a method for determining an absolute position of a motor shaft in an electric power steering system during an ignition off state are provided. The system includes a microprocessor that energizes first and second position sensors to generate first and second signals, respectively, at a first time, and third and fourth signals, respectively, at a second time. The microprocessor determines a first relative position value based on the first and second signals, and a second relative position value based on the third and fourth signals. The microprocessor determines an amount of relative rotation of the shaft during the ignition off state based on the first and second relative position values, and determines a current absolute position value based on a previously stored absolute position value and the amount of relative rotation of the rotatable shaft.Type: GrantFiled: May 12, 2011Date of Patent: October 14, 2014Assignee: Steering Solutions IP Holding CorporationInventors: Abraham Gebregergis, Paul Fisher, Christian E. Ross
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Publication number: 20140265962Abstract: A motor control system for determining a ripple compensating current is provided. The motor control system includes a motor having a plurality of motor harmonics and a motor frequency, and a bandwidth compensation controller that is in communication with the motor. The bandwidth compensation controller is configured to determine a magnitude response compensation value and a phase compensation value for each of the plurality of motor harmonics. The magnitude response compensation value and the phase compensation value are both based on the motor frequency. The bandwidth compensation controller is configured to determine the ripple compensating current based on the magnitude response compensation value and the phase compensation value.Type: ApplicationFiled: March 14, 2013Publication date: September 18, 2014Applicant: STEERING SOLUTIONS IP HOLDING CORPORATIONInventors: Abraham Gebregergis, Ramakrishnan RajaVenkitasubramony, Tomy Sebastian, Niharika P. Popy
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Publication number: 20140265951Abstract: A motor control system for determining a reference d-axis current and a reference q-axis current is provided. The motor control system includes a motor, a DC power source and DC input lines, and a current command controller. The DC power source generates a bridge voltage across the DC input lines. The current command controller is configured to monitor the bridge voltage and a torque reference command. The current command controller is configured to calculate the reference q-axis current based on a torque reference command. The current command controller is configured to calculate the reference d-axis current based on a magnitude of the reference q-axis current.Type: ApplicationFiled: March 12, 2013Publication date: September 18, 2014Applicant: Steering Solutions IP Holding CorporationInventors: Abraham Gebregergis, Ramakrishnan RajaVenkitasubramony, Tomy Sebastian, Siddharth Ballal
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Publication number: 20140265961Abstract: A motor control system is provided. The motor control system includes a motor having plurality of motor harmonics, and a torque ripple compensation controller in communication with the motor. The torque ripple compensation controller is configured to determine a harmonic ripple current for a corresponding one of the plurality of motor harmonics. The harmonic ripple current is based on a reference q-axis current and a reference d-axis current. The torque ripple compensation controller is configured to add the harmonic ripple current for each of the plurality of motor harmonics together to determine the ripple compensating current.Type: ApplicationFiled: March 12, 2013Publication date: September 18, 2014Applicant: Steering Solutions IP Holding CorporationInventors: Abraham Gebregergis, Mohammad S. Islam, Tomy Sebastian, Mazharul H. Chowdhury, Shakil Hossain, Ramakrishnan RajaVenkitasubramony, Niharika P. Popy
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Publication number: 20140253004Abstract: A motor control system for determining an offset correction value is provided. The motor control system includes a motor, an inverter, an inverter controller, and a dynamic offset compensation control module. The inverter is configured to transmit the phase current to the motor. The inverter controller determines the phase current to the motor. The dynamic offset compensation control module is in communication with the inverter controller and the motor, and is configured to perform a method at a fixed periodic interval to determine the offset correction value.Type: ApplicationFiled: March 5, 2013Publication date: September 11, 2014Applicant: Steering Solutions IP Holding CorporationInventors: Abraham Gebregergis, Ramakrishnan RajaVenkitasubramony, Tomy Sebastian
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Publication number: 20130261896Abstract: A method for controlling operation of a torque-assist motor includes determining a rotational position of the torque-assist motor and producing a motor speed signal that is indicative of a rotational speed of the motor. One or more gain factors are produced based on the rotational speed of the torque-assist motor. An electrical current applied to the torque-assist motor is detected, and a current error is calculated based on a commanded electrical current and the electrical current applied to the torque-assist motor. A quadrature axis voltage is calculated based on the current error and the one or more gain factors. An inverter is driven with a direct voltage signal that is phased with the rotational position of the torque-assist motor so as to produce the electrical current applied to the torque-assist motor. The electrical current exhibits a characteristic that is affected by the quadrature axis voltage.Type: ApplicationFiled: March 30, 2012Publication date: October 3, 2013Applicant: STEERING SOLUTIONS IP HOLDING CORPORATIONInventors: Abraham Gebregergis, Ramakrishnan RajaVenkitasubramony, Tomy Sebastian, Niharika P. Popy
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Publication number: 20110282552Abstract: A system and a method for determining an absolute position of a motor shaft in an electric power steering system during an ignition off state are provided. The system includes a microprocessor that energizes first and second position sensors to generate first and second signals, respectively, at a first time, and third and fourth signals, respectively, at a second time. The microprocessor determines a first relative position value based on the first and second signals, and a second relative position value based on the third and fourth signals. The microprocessor determines an amount of relative rotation of the shaft during the ignition off state based on the first and second relative position values, and determines a current absolute position value based on a previously stored absolute position value and the amount of relative rotation of the rotatable shaft.Type: ApplicationFiled: May 12, 2011Publication date: November 17, 2011Inventors: Abraham Gebregergis, Paul Fisher, Christian E. Ross