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).
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Patent number: 9035594Abstract: A boost converter control apparatus for controlling a motor drive system which is provided with a boost converter disposed between an electric power converter and a direct current power supply, the boost converter boosting a direct current voltage of the direct current power supply and supplying it to the electric power converter, is provided with: an operating device provided with a proportional element, an integral element and a derivative element, the derivative element being configured as a bandpass filter, the operating device calculating a PID controlled variable corresponding to an electric current command value of the boost converter for maintaining an output voltage of the boost converter at a command value of an inter-terminal voltage VH of a smoothing condenser; and a controlling device which is configured to control the output voltage of the boost converter on the basis of the calculated PID controlled variable.Type: GrantFiled: April 19, 2011Date of Patent: May 19, 2015Assignee: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Naoyoshi Takamatsu, Masaki Okamura
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Publication number: 20150084422Abstract: A magnetic component has a core on which windings are wound. The windings are electrically connected in series to constitute a coil of a first reactor. The winding constitutes a coil of a second reactor. The core has a leg portion on which the winding is wound, a leg portion on which the winding is wound, and a leg portion on which the winding is wound. When a current flows through the windings, magnetic fluxes produced from the windings, respectively, and flowing through the winding counteract each other. Furthermore, when a current flows through the winding, induced voltages produced from the windings, respectively, by the magnetic flux produced by the winding counteract each other.Type: ApplicationFiled: March 18, 2013Publication date: March 26, 2015Inventors: Masanori Ishigaki, Shuji Tomura, Takaji Umeno, Masaki Okamura, Daigo Nobe
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Publication number: 20140321182Abstract: A control apparatus for a voltage conversion apparatus includes: duty command signal generation means for generating a duty command signal corresponding to a duty ratio of switching elements carrier signal generation means for generating carrier signals corresponding to respective switching frequencies of the switching elements; switching control signal generation means for generating respective switching control signals of switching ON and OFF states of the switching elements, by comparing the duty command signal with the carrier signals; one arm driving control means for implementing one arm driving by alternatively turning on the first and second switching elements; and phase inverting means for bringing phases of portions, of the carrier signals, corresponding to switching at least right after arm switching, into a state where the phases are shifted from each other by 180 degrees between the first and second switching elements, at the time of the arm switching.Type: ApplicationFiled: October 7, 2011Publication date: October 30, 2014Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Naoyoshi Takamatsu, Masaki Okamura
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Patent number: 8866430Abstract: An apparatus for controlling a boost converter is provided with: an operating device provided with a proportional element, an integral element and a derivative element, the derivative element being configured as a bandpass filter, the operating device calculating a PID controlled variable; a controlling device for controlling the output voltage of the boost converter on the basis of the calculated PID controlled variable; a judging device for judging whether or not loss suppression on the direct current power supply is to be prioritized; and a switching device for switching an operation mode of the operating device from a variation suppression mode to a loss suppression mode if it is judged that the loss suppression is to be prioritized. In the loss suppression mode, a cutoff frequency of the bandpass filter is corrected to a lower frequency side at a lower rotational speed of the three-phase alternating current motor.Type: GrantFiled: April 19, 2011Date of Patent: October 21, 2014Assignee: Toyota Jidosha Kabushiki KaishaInventors: Naoyoshi Takamatsu, Masaki Okamura
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Publication number: 20140265605Abstract: The power converter includes a first operation mode in which each of switching elements is controlled on or off independently so as to perform a power conversion between a load and both a first DC power source and a second DC power source and a second operation mode in which every two of the switching elements are controlled on or off concurrently so as to perform the power conversion between the load and the first DC power source or the second DC power source. A switching speed at which when each of the switching elements is turned on or turned off is controlled in accordance with the operation mode. Specifically, the switching speed in the second operation mode is higher than the switching speed in the first operation mode.Type: ApplicationFiled: October 2, 2012Publication date: September 18, 2014Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Masanori Ishigaki, Shuji Tomura, Takaji Umeno, Masaki Okamura, Daigo Nobe
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Patent number: 8796960Abstract: A control device for a motor drive system including an AC motor having a magnet in a rotor, a converter, and an inverter generates a step-up command value for the converter based on a torque command value for the AC motor. The control device determines whether or not to carry out field-weakening control for increasing a current in a direction weakening force of a magnet that is supplied from the inverter to the AC motor, based on the step-up command value and a state of drive of the AC motor. When field-weakening control should be carried out and when an absolute value of the torque command value is smaller than a threshold value, the control device further increases the generated step-up command value. By doing so, an amount of a field-weakening current can be decreased and therefore efficiency of the motor drive system can be improved.Type: GrantFiled: April 21, 2010Date of Patent: August 5, 2014Assignee: Toyota Jidosha Kabushiki KaishaInventors: Masaki Okamura, Naoyoshi Takamatsu
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Patent number: 8760097Abstract: A voltage control operation unit receives, from a subtraction unit, a value obtained by subtracting a detection value of a voltage from a voltage command value, and performs a control operation for setting the voltage to be equal to the voltage command value. The voltage control operation unit outputs the calculated control amount as a current command value. A current control operation unit receives, from a subtraction unit, a value obtained by subtracting a detection value of a current from a current command value, and performs a control operation for setting the current to be equal to the current command value. A driving signal generation unit generates a signal for driving a boost converter based on a duty command value received from the current control operation unit.Type: GrantFiled: May 27, 2009Date of Patent: June 24, 2014Assignee: Toyota Jidosha Kabushiki KaishaInventors: Naoyoshi Takamatsu, Masaki Okamura, Daigo Nobe
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Publication number: 20140145694Abstract: A power source system (5) includes a direct current power source (10), a direct current power source (20), and a power converter (50) having a plurality of switching elements (S1-S4) and reactors (L1, L2). The power converter (50) performs a direct current voltage conversion between the direct current power sources (10, 20) and a power source line (PL) in parallel by controlling the switching elements (S1-S4). Each of the switching elements (S1-S4) is disposed to be included in both a power conversion path formed between the direct current power source (10) and the power source line (PL), and a power conversion path formed between the direct current power source (20) and the power source line (PL).Type: ApplicationFiled: June 5, 2012Publication date: May 29, 2014Inventors: Masanori Ishigaki, Shuji Tomura, Naoki Yanagizawa, Takaji Umeno, Masaki Okamura, Daigo Nobe
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Publication number: 20140090107Abstract: This invention is intended to allow accumulation of large quantities of soluble sugars in tissue other than plant seeds. A plant is modified so as to suppress a gene encoding a subunit exhibiting the highest sequence similarity with the subunit encoded by the AGPL1 gene of rice among subunits constituting.Type: ApplicationFiled: March 22, 2012Publication date: March 27, 2014Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, NATIONAL INSTITUTE OF AGROBIOLOGICAL SCIENCES, THE UNIVERSITY OF TOKYOInventors: Madoka Yonekura, Naohiro Aoki, Ryu Ohsugi, Masaki Okamura, Tatsuro Hirose, Chikara Ohto, Akio Miyao
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Patent number: 8653772Abstract: In a voltage conversion device of a motor drive control device, switching-control is performed so as to enlarge an output allowable voltage range of the voltage conversion device restricted by a dead time in a switching operation for an upper arm and a lower arm performing power conversion by a switching operation. Accordingly, restriction in the output voltage from the voltage conversion device, caused by the dead time, can be suppressed.Type: GrantFiled: June 2, 2009Date of Patent: February 18, 2014Assignees: Toyota Jidosha Kabushiki Kaisha, Kabushiki Kaisha Toyota JidoshokkiInventors: Naoyoshi Takamatsu, Masaki Okamura, Yasuhiro Koike
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Publication number: 20140028225Abstract: A boost converter control apparatus for controlling a motor drive system which is provided with a boost converter disposed between an electric power converter and a direct current power supply, the boost converter boosting a direct current voltage of the direct current power supply and supplying it to the electric power converter, is provided with: an operating device provided with a proportional element, an integral element and a derivative element, the derivative element being configured as a bandpass filter, the operating device calculating a PID controlled variable corresponding to an electric current command value of the boost converter for maintaining an output voltage of the boost converter at a command value of an inter-terminal voltage VH of a smoothing condenser; and a controlling device which is configured to control the output voltage of the boost converter on the basis of the calculated PID controlled variable.Type: ApplicationFiled: April 19, 2011Publication date: January 30, 2014Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Naoyoshi Takamatsu, Masaki Okamura
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Publication number: 20140001990Abstract: A motor drive system control apparatus includes: a direct current power supply; a three-phase alternating current motor; a first power converter including switching circuits corresponding to each of three phases of the three-phase alternating current motor and a smoothing condenser disposed electrically in parallel with the switching circuits; an estimating device for estimating peak generation timing in which a peak is generated in an inter-terminal voltage VH of the smoothing condenser on the basis of at least one of an operating condition of the three-phase alternating current motor; a switching condition of the switching circuits corresponding to each of the three phases; and a controlling device for controlling a drive condition of the first power converter so the inter-terminal voltage VH (or a VH peak) in the peak generation timing decreases, for a predetermined period from start timing set in a time domain before the estimated peak generation timing.Type: ApplicationFiled: January 11, 2011Publication date: January 2, 2014Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Naoyoshi Takamatsu, Masaki Okamura
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Patent number: 8600597Abstract: An electric vehicle includes a synchronous motor that outputs torque to a first driving wheel; an induction motor that outputs torque to a second driving wheel; and an output torque changing portion that makes the synchronous motor torque smaller than the induction motor torque when torque is output to the first or second driving wheel and the vehicle speed is close to zero, and makes the synchronous motor torque larger than the induction motor torque when torque is output to the first or second driving wheel and the vehicle is moving at or greater than a predetermined speed in a direction opposite a direction in which the vehicle is being operated to move, by the torque output to the first and second driving wheels.Type: GrantFiled: May 20, 2011Date of Patent: December 3, 2013Assignee: Toyota Jidosha Kabushiki KaishaInventor: Masaki Okamura
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Patent number: 8575875Abstract: In a converter of a motor drive control device, one of a first switching element and a second switching element is selected in accordance with a current command value of a current flowing through a reactor. The converter is then controlled so that a drive command for the selected switching element is generated. In this way, the efficiency of the converter is improved while a voltage step-up or step-down operation is performed by the converter.Type: GrantFiled: May 27, 2009Date of Patent: November 5, 2013Assignee: Toyota Jidosha Kabushiki KaishaInventors: Naoyoshi Takamatsu, Masaki Okamura
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Publication number: 20130264975Abstract: A converter is disposed between a first battery and a power line for transmitting power inputted to and outputted from a motor for traveling. A second battery, on the other hand, is connected to the power line with a relay being interposed therebetween. A control unit controls the relay to be turned on or off in accordance with an operating state of the motor.Type: ApplicationFiled: December 20, 2010Publication date: October 10, 2013Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Keiji Kaita, Teruo Ishishita, Yuji Nishi, Masaru Takagi, Masaki Okamura
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Patent number: 8525455Abstract: A triangle wave generator (4) measures the phase difference between a triangle wave (CA) and the rotor electrical angle (?m) during a first cycle in which the rotation rate of a rotor (7) is detected, and changes the frequency of the triangle wave (CA) when the value of the phase difference between the triangle wave (CA) and the rotor electrical angle (?m) exceeds a threshold value, thereby allowing rapid response to changes in rotor rotation when PWM control is performed.Type: GrantFiled: October 1, 2009Date of Patent: September 3, 2013Assignee: Toyota Jidosha Kabushiki KaishaInventors: Naoyoshi Takamatsu, Masaki Okamura
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Patent number: 8519653Abstract: A control device for performing PWM control of an inverter includes a synchronous PWM control circuit for generating a control command for the inverter by performing PWM control based on a comparison between a sinusoidal voltage command signal for operating the AC motor according to, an operation command and a carrier signal, and a carrier generating unit for keeping an integer as a synchronization number being a frequency ratio between the voltage command signal and the carrier signal, and producing the carrier signal by switching the synchronization number according to an operation state of the AC motor. The carrier generating unit adjusts a phase relationship between the voltage command signal and the carrier signal according to the synchronization number such that an AC current transmitted between the inverter and the AC motor according to the control command provided from the synchronous PWM control circuit is symmetrical with respect to a boundary between positive and negative portions.Type: GrantFiled: May 29, 2009Date of Patent: August 27, 2013Assignee: Toyota Jidosha Kabushiki KaishaInventors: Naoyoshi Takamatsu, Masaki Okamura, Takanori Degaki
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Publication number: 20130134786Abstract: The power supply system includes a first DC power source, a second DC power source, and a power converter having a plurality of switching elements and reactors. The power converter is configured to be switchable, by the control of the plurality of switching elements, between a parallel connection mode in which DC voltage conversion is executed with the DC power sources connected in parallel with a power line and a series connection mode in which DC voltage conversion is executed with the DC power sources connected in series with the power line. Each of the switching elements is arranged to be included both in a power conversion path between the first DC power source and the power line PL and a power conversion path between the second DC power source and the power line.Type: ApplicationFiled: September 21, 2011Publication date: May 30, 2013Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, KABUSHIKI KAISHA TOYOTA CHUO KENKYUSHOInventors: Masanori Ishigaki, Shuji Tomura, Takaji Umeno, Masaki Okamura, Daigo Nobe, Yoshiyuki Nakamura
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Publication number: 20130057188Abstract: An apparatus for controlling a boost converter is provided with: an operating device provided with a proportional element, an integral element and a derivative element, the derivative element being configured as a bandpass filter, the operating device calculating a PID controlled variable corresponding to an electric current command value of the boost converter; a controlling device for controlling the output voltage of the boost converter on the basis of the calculated PID controlled variable; a judging device for judging whether or not loss suppression on the direct current power supply is to be prioritized; and a switching device for switching an operation mode of the operating device from a variation suppression mode to a loss suppression mode if it is judged that the loss suppression is to be prioritized. In the loss suppression mode, a cutoff frequency of the bandpass filter is corrected to a lower frequency side at a lower rotational speed of the three-phase alternating current motor.Type: ApplicationFiled: April 19, 2011Publication date: March 7, 2013Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Naoyoshi Takamatsu, Masaki Okamura
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Patent number: 8387732Abstract: A power output apparatus including a power source, an electric motor and a connecting and disconnecting device, and a method of controlling the power output apparatus, are provided. When load driving force is applied from the power source to a power shaft in a condition where the power shaft and a driveshaft are disconnected from each other by the connecting and disconnecting device, lock control is executed to control the motor by fixing a direction of a magnetic field of a stator so as to restrict rotation of a rotor. When the rotor rotates during execution of the lock control, rotation retardation control is executed to control the motor by rotating the direction of the stator magnetic field in accordance with rotation of the rotor, so that driving force is applied from the motor to the power shaft in a direction opposite to that of the load driving force as driving force applied from the power source to the power shaft.Type: GrantFiled: June 18, 2009Date of Patent: March 5, 2013Assignee: Toyota Jidosha Kabushiki KaishaInventors: Masaki Okamura, Kazuhito Hayashi