Patents by Inventor Masaki Okamura

Masaki Okamura 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: 20090179602
    Abstract: A rotary electric device control device is formed substantially by three signal process flows. A first component is a part generating a 3-phase drive signal supplied from a torque instruction value to an inverter circuit. This is the part from d,q current map to a PWM conversion. A second component detects a drive current value from a motor/generator and feeds back it to the current instruction. This corresponds to a loop for performing coordinate conversion of the drive current and inputting it as a current instruction value to a subtractor. A third component calculates a drive power and rpm of the motor/generator, acquires an estimated torque value, compensates the current instruction value according to the estimated value, and compensates a torque change. This corresponds to a power calculation, an rpm calculation, a torque estimation, and a current instruction compensation unit.
    Type: Application
    Filed: July 18, 2007
    Publication date: July 16, 2009
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kazuhito Hayashi, Masaki Okamura
  • Publication number: 20090173555
    Abstract: An object of the present invention is to provide a motive power output apparatus including a motor with a permanent magnet and a motor without a permanent magnet. A boost device (10) is connected to a power storage device (B). A first drive device (30) is connected to the boost device (10). A first rotating electric machine (35) with a permanent magnet is connected to the first drive device (30). A second drive device (40) is connected to the power storage device (B). A second rotating electric machine (45) without a permanent magnet is connected to the second drive device (40). A third drive device (20) is connected in parallel to the first drive device (30). A third rotating electric machine (25) with a permanent magnet is connected to the third drive device (20). The second rotating electric machine (45) is formed of a reluctance motor or an induction motor. The first rotating electric machine (35) and the second rotating electric machine (45) of the present invention may be linked to wheels of a vehicle.
    Type: Application
    Filed: May 22, 2007
    Publication date: July 9, 2009
    Applicant: Toyota Jidosha Kabushiki Kaisha
    Inventor: Masaki Okamura
  • Publication number: 20090146588
    Abstract: An object of the invention is to limit a current flowing in a booster converter circuit for a vehicle within a predetermined range. In the booster converter circuit for a vehicle including a battery that outputs a DC voltage; a switching unit having a switching element to be controlled to ON or OFF; an inductive element unit being connected between the battery and the switching unit and including an inductive element; a switching control unit that controls the switching element, an output voltage measuring unit that measures an output voltage of the booster converter circuit for a vehicle is provided, and the duty ratio determining device obtains a control duty ratio with respect to the switching element on the basis of a measured output voltage value so that a value of a converter current flowing through a path from the battery to the switching unit falls within a predetermined range.
    Type: Application
    Filed: November 18, 2008
    Publication date: June 11, 2009
    Inventor: Masaki OKAMURA
  • Publication number: 20090128117
    Abstract: A voltage transformer, which is placed between a DC power source (B) and a motor (M1), includes: a voltage sensor (10) and an electric current sensor (11), which senses input and output of electric power to and from the DC power source (B); a buck-boost converter (12) having power control elements, which is placed in a path connecting between power lines (PL1) and (PL2) that establish the connection to the DC power source (B) and the connection to the motor (M1), respectively; and a controller (30) for controlling the buck-boost converter (12). The controller (30) monitors the change in the regenerated power that is supplied to the DC power source (B), based on the outputs from the voltage sensor (10) and the electric current sensor (11), and, if the amount of change in the regenerated power is greater than a predetermined amount, the controller (30) changes the operation mode of the buck-boost converter (12) from a rapid operation mode to a slow operation mode.
    Type: Application
    Filed: December 14, 2006
    Publication date: May 21, 2009
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Kiyoe Ochiai, Masaki Okamura, Sojiro Yokoyama
  • Patent number: 7531982
    Abstract: A map holding unit holds, in the form of a map, a voltage control amount of the q axis in a case where no demagnetization of a permanent magnet motor occurs. Based on a motor revolution number, namely the number of revolutions of the motor provided from a revolution number detection unit, a demagnetized state calculation unit calculates a rotational angular velocity. Then, based on the voltage control amount from the map holding unit, a voltage control amount to be controlled that is provided from a PI control unit and the rotational angular velocity, the demagnetized state calculation unit calculates an amount of demagnetization and outputs, if the amount of demagnetization is greater than a predetermined value, an operation signal for controlling the operation of the permanent magnet motor.
    Type: Grant
    Filed: July 8, 2004
    Date of Patent: May 12, 2009
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Masaki Okamura, Takashi Yamashita
  • Publication number: 20090108794
    Abstract: A boost converter boosts a DC voltage of a DC power supply. An inverter converts the output voltage of the boost converter into an AC voltage. An AC motor is driven by the output voltage of the inverter. A control device which controls the boost converter reduces an output voltage instruction value of the boost converter in the case where the rotation speed of the AC motor is decreased and an absolute value of a variation rate of the rotation speed is not less than a predetermined value. The inverter is controlled in the control mode selected from a plurality of control modes including three modes of a sine wave PWM control mode, an overmodulation PWM control mode and a rectangular wave control mode. The control device of the boost converter reduces the output voltage instruction value of the boost converter only in the case where the control mode of the inverter is the rectangular wave control mode or the overmodulation control mode.
    Type: Application
    Filed: November 1, 2006
    Publication date: April 30, 2009
    Applicant: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kiyoe Ochiai, Masaki Okamura, Hiroyuki Oyanagi
  • Publication number: 20090025992
    Abstract: In response to a starting instruction of an engine 22 at a gearshift position of a gearshift lever 81 set to a parking position, the engine 22 and motors MG1 and MG2 are controlled to motor and start the engine 22 with output of a torque from the motor MG2 to keep a rotational position of a rotor in the motor MG2 at a preset reference position. This arrangement enables the engine 22 to be motored and started even in the state of separation of a ring gear shaft 32a from a driveshaft 36 by means of a transmission 60 and locking of drive wheels 39a and 39b by means of a parking lock mechanism 90.
    Type: Application
    Filed: February 23, 2007
    Publication date: January 29, 2009
    Applicant: Toyota Jidosha Kabushiki Kaisha
    Inventors: Kazuhito Hayashi, Masaki Okamura, Hideto Hanada
  • Patent number: 7482769
    Abstract: A high-level ECU generates a torque command value T1 according to an output request to an electric motor. A low-level ECU calculates a torque command value T2 for correcting the original torque command value T1 according to the operational state of the electric motor and, according to a final torque command value Tf that is set by combining the torque command values T1 and T2, the electric motor is controlled. The high-level ECU receives from the low-level ECU the torque command value T2 and a motor state quantity transmitted thereto and, by a comparison between an actual torque value Tj determined from the motor state quantity and the final torque command value Tf determined with the torque command value T2 reflected thereto, abnormality in electric motor control is detected.
    Type: Grant
    Filed: December 12, 2006
    Date of Patent: January 27, 2009
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Masaki Kutsuna, Masaki Okamura, Kenji Yamada
  • Publication number: 20090021198
    Abstract: In a motor drive control system configured to include a converter capable of stepping up the voltage, when the locked state of MG2 operating as an electric motor does not occur (NO in S130), a voltage command value VHref for the converter output voltage is set according to respective required voltages of MG1 operating as an electric generator and MG2 (S140). In contrast, when the locked state of MG2 occurs (YES in S130), the voltage command value VHref is set to a limit voltage Vlmt or less for limiting the voltage step-up by the converter (S150, S180). When the locked state occurs, the converter output voltage is decreased and accordingly the DC voltage switched by the inverter is lowered, so that a switching loss at the switching device forming a part of the inverter is reduced and the temperature increase due to the heat generation can be suppressed.
    Type: Application
    Filed: March 16, 2007
    Publication date: January 22, 2009
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaki Okamura, Hideaki Yaguchi
  • Publication number: 20090001925
    Abstract: A desired current is caused to flow through a coil by controlling switching of switching elements by a PWM controller. For a voltage sensor, a value of Vo??V, which is a difference between a midpoint voltage Vo of the switching elements and a predetermined threshold voltage ?V, and a value of Vo?(Vc??V), which is a difference between the midpoint voltage Vo and a value obtained by subtracting the threshold voltage ?V from a voltage Vc of an upper line, are determined. Then, the determined results obtained from the voltage sensor are input to the PWM controller through flip-flops and a dead time compensator to compensate for dead time, such as, for example, for a command for PWM control signal generation.
    Type: Application
    Filed: August 2, 2007
    Publication date: January 1, 2009
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Hiroki Ohtani, Masaki Okamura
  • Publication number: 20080218111
    Abstract: A square wave voltage having an amplitude equal to an output voltage of a converter is applied to an AC motor by a square wave control block. Torque control of the AC motor is performed basically by changing the voltage phase of the square wave voltage according to the torque deviation. When the motor revolution is suddenly changed, a instruction value correction unit sets a voltage instruction value of the output voltage of the converter according to a change ratio of the motor revolutions. This improves control of the motor current by changing the voltage applied to the motor in accordance with the sudden change of the motor revolutions without waiting for torque feedback control having a low control response.
    Type: Application
    Filed: May 1, 2006
    Publication date: September 11, 2008
    Applicant: Toyota Jidosha Kabushiki Kaisha
    Inventor: Masaki Okamura
  • Patent number: 7417393
    Abstract: A control device determines whether a motor generator is controlled in a PWM control mode, an overmodulation control mode or a rectangular-wave control mode. If a command to perform a boosting operation by a voltage step-up converter is issued while the motor generator is controlled in the rectangular-wave control mode, the control device controls an inverter to drive the motor generator by switching the control mode to the overmodulation or PWM control mode. Further, the control device controls the inverter to drive the motor generator by suppressing increase of a torque command value.
    Type: Grant
    Filed: July 12, 2004
    Date of Patent: August 26, 2008
    Assignees: Toyota Jidosha Kabushiki Kaisha, Denso Corporation
    Inventors: Masaki Okamura, Takashi Yamashita
  • Patent number: 7355869
    Abstract: In a case where the deviation between a target voltage (Vdc_com1) and an output voltage (Vm) is larger than a specified value (A), a voltage command (Vdc_com2) of a voltage step-up converter (12) is calculated by adding the specified value (A) to the output voltage (Vm). When the output voltage (Vm) having been decreasing starts to increase, the voltage command (Vdc_com2) is calculated in such a manner that the rate of change of the voltage command (Vdc_com2) is equal to or smaller than a standard value. Using the calculated voltage command (Vdc_com2), feedback control of the voltage step-up converter is conducted in such a manner that the output voltage (Vm) is equal to the target voltage (Vdc_com1).
    Type: Grant
    Filed: May 25, 2004
    Date of Patent: April 8, 2008
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventor: Masaki Okamura
  • Patent number: 7337525
    Abstract: An electric rotating machine has a rotor having N and S poles and includes a stator with an annular stator core and slots. Multiple-phase stator windings are embedded in the slots, and are formed by winding continuous wires such that straight parts of the stator windings pressed in a flat shape are wound in rings around a grooved cylindrical member. The cylindrical member is inserted into a bore defined by the annular stator core so that the grooves of the cylindrical member are arranged opposite to the slots. The sets of the windings are folded back alternately outside the slots of the stator core and are wound so the sets of the windings are embedded alternately in the direction of the depth of the slots. Leading and trailing ends of the continuous wires are superposed after being wound at least one turn around the circumferentially arranged slots of the stator.
    Type: Grant
    Filed: April 11, 2007
    Date of Patent: March 4, 2008
    Assignee: Hitachi, Ltd.
    Inventors: Toshiaki Ueda, Yoshimi Mori, Masaki Okamura, Sakae Ishida, Toshinori Watanabe
  • Publication number: 20070278986
    Abstract: A voltage command value of a converter is set by executing the step of determining a candidate voltage of a system voltage VH as a converter output voltage in a voltage range from the minimum necessary voltage corresponding to induction voltage of a motor generator and a maximum output voltage of the converter; the step of estimating power loss at the battery, converter, inverter and motor generator, at each candidate voltage, and calculating total sum of estimated power loss of the overall system; and the step of setting the voltage command value VH# based on the candidate voltage that minimizes the total sum of estimated power losses among the candidate voltages.
    Type: Application
    Filed: May 23, 2007
    Publication date: December 6, 2007
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventor: Masaki Okamura
  • Publication number: 20070180682
    Abstract: An electric rotating machine has a rotor having N and S poles and includes a stator with an annular stator core and slots. Multiple-phase stator windings are embedded in the slots, and are formed by winding continuous wires such that straight parts of the stator windings pressed in a flat shape are wound in rings around a grooved cylindrical member. The cylindrical member is inserted into a bore defined by the annular stator core so that the grooves of the cylindrical member are arranged opposite to the slots. The sets of the windings are folded back alternately outside the slots of the stator core and are wound so the sets of the windings are embedded alternately in the direction of the depth of the slots. Leading and trailing ends of the continuous wires are superposed after being wound at least one turn around the circumferentially arranged slots of the stator.
    Type: Application
    Filed: April 11, 2007
    Publication date: August 9, 2007
    Applicant: HITACHI LTD.
    Inventors: Toshiaki Ueda, Yoshimi Mori, Masaki Okamura, Sakae Ishida, Toshinori Watanabe
  • Publication number: 20070165432
    Abstract: A control device calculates a voltage command value of a voltage step-up converter based on a torque command value and a motor revolution number and calculates an on-duty of an NPN transistor based on the calculated voltage command value and a DC voltage from a voltage sensor. When the on-duty is influenced by a dead time of NPN transistors, control device fixes the on-duty at 1.0 to control the NPN transistors in such a manner that the voltage is increased or decreased.
    Type: Application
    Filed: July 12, 2004
    Publication date: July 19, 2007
    Applicant: Denso Corporation
    Inventors: Masaki Okamura, Takashi Yamashita
  • Publication number: 20070138986
    Abstract: A high-level ECU generates a torque command value T1 according to an output request to an electric motor. A low-level ECU calculates a torque command value T2 for correcting the original torque command value T1 according to the operational state of the electric motor and, according to a final torque command value Tf that is set by combining the torque command values T1 and T2, the electric motor is controlled. The high-level ECU receives from the low-level ECU the torque command value T2 and a motor state quantity transmitted thereto and, by a comparison between an actual torque value Tj determined from the motor state quantity and the final torque command value Tf determined with the torque command value T2 reflected thereto, abnormality in electric motor control is detected.
    Type: Application
    Filed: December 12, 2006
    Publication date: June 21, 2007
    Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHA
    Inventors: Masaki Kutsuna, Masaki Okamura, Kenji Yamada
  • Patent number: 7208903
    Abstract: In one coordinate system of arbitrary rectangular coordinate systems including a coordinate system in which the position of a stator is fixed, a coordinate system in which the position of a rotor is fixed, and a coordinate system which rotates at a rotational frequency which is n times (n is an integer which is not 0 or 1) that of the rotor, a filter on any other coordinate system is defined. Further, driving of a motor is controlled by utilizing this filter. As a result, a coordinate transformation operation need not be individually performed with respect to control variables.
    Type: Grant
    Filed: May 31, 2006
    Date of Patent: April 24, 2007
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Hideo Nakai, Hiroki Ohtani, Yukio Inaguma, Katsuhiro Asano, Hideto Hanada, Masaki Okamura
  • Patent number: 7199537
    Abstract: By using a target voltage Vc* of a capacitor connected to the output side of a DC/DC converter and a voltage Vb of a battery connected to the input side of the DC/DC converter, a duty ratio D as a drive instruction of the DC/DC converter is calculated. By using the voltage Vb, the electromotive force Vbo of the battery, and the charge/discharge current Ib of the battery, an internal resistance Rb is calculated. According to the internal resistance Rb and the electromotive force Vbo, the current value when the battery output becomes maximum is set as the upper limit value of the optimal current range IR, the DC/DC converter is driven/controlled by limiting the duty ratio D so that the current Ib is within the range of the optimal current range IR. Thus, it is possible to appropriately convert the battery input voltage.
    Type: Grant
    Filed: January 14, 2003
    Date of Patent: April 3, 2007
    Assignee: Toyota Jidosha Kabushiki Kaisha
    Inventors: Masaki Okamura, Eiji Sato