Patents by Inventor Minoru Kurosawa
Minoru Kurosawa 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).
-
Patent number: 8258732Abstract: A drive system of a permanent magnet motor is constituted of a mode switching trigger generator which monitors a state of a permanent magnet motor and issues a mode switching trigger, a conduction mode determining unit which receives the mode switching trigger and switches the mode of the permanent magnet motor, and a PWM generator which outputs a PWM signal to an inverter in accordance with the output of the conduction mode determining unit. The mode switching trigger is generated on condition that the speed electromotive force of the permanent magnet motor exceeds a constant or variable threshold value.Type: GrantFiled: February 6, 2009Date of Patent: September 4, 2012Assignee: Renesas Electronics CorporationInventors: Yoshitaka Iwaji, Yasuhiko Kokami, Minoru Kurosawa
-
Patent number: 8232751Abstract: A position sensorless drive method capable of driving a permanent magnet motor by an ideal sine-wave current and enabling the driving from an extremely low-speed range in the vicinity of zero-speed is provided. A neutral-point potential of the permanent magnet motor is detected in synchronization with a PWM waveform of an inverter. The position of a rotor of the permanent magnet motor is estimated from the variation of the neutral-point potential. Since the neutral-point potential is varied in accordance with the magnetic circuit characteristics of an individual permanent magnet motor, the position can be detected regardless of the presence of saliency of the permanent magnet motor.Type: GrantFiled: August 26, 2009Date of Patent: July 31, 2012Assignee: Renesas Electronics CorporationInventors: Yoshitaka Iwaji, Yasuhiko Kokami, Minoru Kurosawa
-
Patent number: 8089232Abstract: The disclosed invention achieves a significant reduction in the noise and vibration of a brushless motor from a startup up to the number of steady revolutions. To drive the brushless motor from stop up to the number of steady revolutions, when the arithmetic sequencer detects a rise of a clock signal CARYCLK, current control arithmetic is executed. On detecting a fall of the clock signal, the arithmetic sequence determines whether a division control signal DIVCNT has changed. If this signal has changed, soft switch arithmetic is executed. When the division control signal has not changed or after the completion of soft switching arithmetic, the arithmetic sequencer determines whether a rise of a mask signal MASK has occurred during one cycle of the PWM carrier signal CARYCLK. If a rise of the mask signal has not occurred, the operation returns to the first step. If a rise of the mask signal has occurred, PLL control arithmetic is executed, then the operation returns to the first step.Type: GrantFiled: November 25, 2008Date of Patent: January 3, 2012Assignee: Renesas Electronics CorporationInventors: Kichiya Itagaki, Minoru Kurosawa
-
Publication number: 20110156625Abstract: This invention provides a motor driving apparatus that made it possible to reduce torque ripples including those attributed to load variation of the motor and an associated method for control of motor revolution. An output stage to a multiphase DC motor is comprised of power elements to supply output voltages to multiphase coils and a predriver to supply drive voltages to the power elements. A resistor means detects a current flowing through the power elements. A supply current detector detects a voltage signal produced across the resistor means as a supply current, using a high-speed ADC and a moving average filter. An output controller generates a PWM signal with a frequency lower than the frequency of the high-speed ADC so that the current detected by the supply current detector conforms to a current signal indicating a motor revolving speed and transfers the PWM signal to the output stage.Type: ApplicationFiled: March 9, 2011Publication date: June 30, 2011Applicant: RENESAS ELECTRONICS CORPORATIONInventors: Minoru KUROSAWA, Yasuhiko KOKAMI
-
Publication number: 20110074324Abstract: A control technology for a synchronous motor for suppressing rotational pulsation caused by variation in individuals without making a control algorithm complex is provided. In a motor drive system which is a control device for a synchronous motor, in order to suppress the pulsation component of N times as high as the AC frequency for driving the synchronous motor, a controller in which the phase property of the disturbance response of the controller with respect to the pulsation frequency is within ±45° is arranged. Therefore, the torque pulsation component generated from distortion in induction voltage or variation between phases is suppressed.Type: ApplicationFiled: December 8, 2010Publication date: March 31, 2011Applicant: Renesas Electronics CorporationInventors: Yoshitaka Iwaji, Yasuhiko Kokami, Minoru Kurosawa, Junnosuke Nakatsugawa
-
Patent number: 7915844Abstract: This invention provides a motor driving apparatus that made it possible to reduce torque ripples including those attributed to load variation of the motor and an associated method for control of motor revolution. An output stage to a multiphase DC motor is comprised of power elements to supply output voltages to multiphase coils and a predriver to supply drive voltages to the power elements. A resistor means detects a current flowing through the power elements. A supply current detector detects a voltage signal produced across the resistor means as a supply current, using a high-speed ADC and a moving average filter. An output controller generates a PWM signal with a frequency lower than the frequency of the high-speed ADC so that the current detected by the supply current detector conforms to a current signal indicating a motor revolving speed and transfers the PWM signal to the output stage.Type: GrantFiled: June 12, 2008Date of Patent: March 29, 2011Assignee: Renesas Electronics CorporationInventors: Minoru Kurosawa, Yasuhiko Kokami
-
Patent number: 7859209Abstract: A control technology for a synchronous motor for suppressing rotational pulsation caused by variation in individuals without making a control algorithm complex is provided. In a motor drive system which is a control device for a synchronous motor, in order to suppress the pulsation component of N times as high as the AC frequency for driving the synchronous motor, a controller in which the phase property of the disturbance response of the controller with respect to the pulsation frequency is within ±45° is arranged. Therefore, the torque pulsation component generated from distortion in induction voltage or variation between phases is suppressed.Type: GrantFiled: August 23, 2007Date of Patent: December 28, 2010Assignee: Renesas Electronics CorporationInventors: Yoshitaka Iwaji, Yasuhiko Kokami, Minoru Kurosawa, Junnosuke Nakatsugawa
-
Patent number: 7847500Abstract: Control technique of a synchronous motor capable of suppressing rotation pulsation caused by individual difference without complicating control algorithm is provided. A pulsation generator superimposing a pulsation component anticipated in advance to a current command for the synchronous motor and a correction current generator superimposing a correction signal substantially having an average value of zero to the current command are provided in a synchronous motor control device. By this configuration, the correction signal suppressing a distortion component is superimposed to a value of the current command with a simplified control configuration. Torque pulsation is suppressed by determining the correction signal from difference between a detection current and a command current.Type: GrantFiled: December 12, 2007Date of Patent: December 7, 2010Assignee: Renesas Technology CorporationInventors: Yoshitaka Iwaji, Junnosuke Nakatsugawa, Yasuhiko Kokami, Minoru Kurosawa
-
Patent number: 7750586Abstract: A drive control device of motor capable of starting up even a motor of such a type that the polarity of induced voltage does not switch every 180° of electrical angle or the polarity, positive or negative, does not occur with accuracy without causing a reverse rotation is provided. In a start-up control of motor, the following operation is performed: a current is passed through any coils in two phases, and the polarity of voltage induced in the non-conducting phase is detected. A conducting phase at start-up is determined based on the detected polarity of induced voltage. The average value of induced voltages in non-conducting phase detected with respect to the coils in respective phases is determined. The average value and the detected induced voltages are compared with each other, and relative polarities are determined from the magnitude relation with the average value to determine a conducting phase at start-up.Type: GrantFiled: August 4, 2008Date of Patent: July 6, 2010Assignee: Renesas Technology Corp.Inventors: Minoru Kurosawa, Yasuhiko Kokami
-
Patent number: 7723937Abstract: A motor drive control device and motor startup method prevent startup noise and reduce startup time. At startup, a current to which a rotor does not react is passed through two phase coils of a polyphase DC motor in succession, and a voltage polarity induced in a non-conducting phase is detected. A first operation decodes the detected signal, and determines phase coils of the motor through which a current should pass to rotate the rotor and the energization direction. A second operation forms a control signal for passing a current according to the determination to drive the motor, detects a voltage peak induced in the non-conducting phase during the drive, and performs switching control of a conducting phase. In normal operation, the position of the rotor is detected based on a back EMF in each phase, and rotation control is performed.Type: GrantFiled: October 12, 2007Date of Patent: May 25, 2010Assignee: Renesas Technology Corp.Inventors: Minoru Kurosawa, Yasuhiko Kokami
-
Publication number: 20100066284Abstract: A position sensorless drive method capable of driving a permanent magnet motor by an ideal sine-wave current and enabling the driving from an extremely low-speed range in the vicinity of zero-speed is provided. A neutral-point potential of the permanent magnet motor is detected in synchronization with a PWM waveform of an inverter. The position of a rotor of the permanent magnet motor is estimated from the variation of the neutral-point potential. Since the neutral-point potential is varied in accordance with the magnetic circuit characteristics of an individual permanent magnet motor, the position can be detected regardless of the presence of saliency of the permanent magnet motor.Type: ApplicationFiled: August 26, 2009Publication date: March 18, 2010Applicant: RENESAS TECHNOLOGY CORP.Inventors: Yoshitaka IWAJI, Yasuhiko KOKAMI, Minoru KUROSAWA
-
Patent number: 7615909Abstract: In an energy recovery type surface acoustic wave motor, an increase in energy efficiency at the time of energy recovery and supply is achieved by adjusting phase change.Type: GrantFiled: March 27, 2006Date of Patent: November 10, 2009Assignees: Panasonic Electric Works Co., Ltd, Tokyo Institute of TechnologyInventors: Masahiro Kirigaya, Masahiro Sato, Youhei Ishigami, Kazuo Sawada, Minoru Kurosawa
-
Publication number: 20090200971Abstract: A drive system of a permanent magnet motor is constituted of a mode switching trigger generator which monitors a state of a permanent magnet motor and issues a mode switching trigger, a conduction mode determining unit which receives the mode switching trigger and switches the mode of the permanent magnet motor, and a PWM generator which outputs a PWM signal to an inverter in accordance with the output of the conduction mode determining unit. The mode switching trigger is generated on condition that the speed electromotive force of the permanent magnet motor exceeds a constant or variable threshold value.Type: ApplicationFiled: February 6, 2009Publication date: August 13, 2009Inventors: Yoshitaka IWAJI, Yasuhiko Kokami, Minoru Kurosawa
-
Publication number: 20090189556Abstract: The disclosed invention achieves a significant reduction in the noise and vibration of a brushless motor from a startup up to the number of steady revolutions. To drive the brushless motor from stop up to the number of steady revolutions, when the arithmetic sequencer detects a rise of a clock signal CARYCLK, current control arithmetic is executed. On detecting a fall of the clock signal, the arithmetic sequence determines whether a division control signal DIVCNT has changed. If this signal has changed, soft switch arithmetic is executed. When the division control signal has not changed or after the completion of soft switching arithmetic, the arithmetic sequencer determines whether a rise of a mask signal MASK has occurred during one cycle of the PWM carrier signal CARYCLK. If a rise of the mask signal has not occurred, the operation returns to the first step. If a rise of the mask signal has occurred, PLL control arithmetic is executed, then the operation returns to the first step.Type: ApplicationFiled: November 25, 2008Publication date: July 30, 2009Inventors: Kichiya ITAGAKI, Minoru Kurosawa
-
Publication number: 20090072773Abstract: This invention provides a motor driving apparatus that made it possible to reduce torque ripples including those attributed to load variation of the motor and an associated method for control of motor revolution. An output stage to a multiphase DC motor is comprised of power elements to supply output voltages to multiphase coils and a predriver to supply drive voltages to the power elements. A resistor means detects a current flowing through the power elements. A supply current detector detects a voltage signal produced across the resistor means as a supply current, using a high-speed ADC and a moving average filter. An output controller generates a PWM signal with a frequency lower than the frequency of the high-speed ADC so that the current detected by the supply current detector conforms to a current signal indicating a motor revolving speed and transfers the PWM signal to the output stage.Type: ApplicationFiled: June 12, 2008Publication date: March 19, 2009Inventors: Minoru KUROSAWA, Yasuhiko Kokami
-
Publication number: 20080297082Abstract: A drive control device of motor capable of starting up even a motor of such a type that the polarity of induced voltage does not switch every 180° of electrical angle or the polarity, positive or negative, does not occur with accuracy without causing a reverse rotation is provided. In a start-up control of motor, the following operation is performed: a current is passed through any coils in two phases, and the polarity of voltage induced in the non-conducting phase is detected. A conducting phase at start-up is determined based on the detected polarity of induced voltage. The average value of induced voltages in non-conducting phase detected with respect to the coils in respective phases is determined. The average value and the detected induced voltages are compared with each other, and relative polarities are determined from the magnitude relation with the average value to determine a conducting phase at start-up.Type: ApplicationFiled: August 4, 2008Publication date: December 4, 2008Inventors: Minoru Kurosawa, Yasuhiko Kokami
-
Publication number: 20080252171Abstract: In an energy recovery type surface acoustic wave motor, an increase in energy efficiency at the time of energy recovery and supply is achieved by adjusting phase change.Type: ApplicationFiled: March 27, 2006Publication date: October 16, 2008Applicants: Matsushita Electric Works, Ltd., Tokyo Institute of TechnologyInventors: Masahiro Kirigaya, Masahiro Sato, Youhei Ishigami, Kazuo Sawada, Minoru Kurosawa
-
Patent number: 7411365Abstract: A drive control device of motor capable of starting up even a motor of such a type that the polarity of induced voltage does not switch every 180° of electrical angle or the polarity, positive or negative, does not occur with accuracy without causing a reverse rotation is provided. In a start-up control of motor, the following operation is performed: a current is passed through any coils in two phases, and the polarity of voltage induced in the non-conducting phase is detected. A conducting phase at start-up is determined based on the detected polarity of induced voltage. The average value of induced voltages in non-conducting phase detected with respect to the coils in respective phases is determined. The average value and the detected induced voltages are compared with each other, and relative polarities are determined from the magnitude relation with the average value to determine a conducting phase at start-up.Type: GrantFiled: October 13, 2005Date of Patent: August 12, 2008Assignee: Renesas Technology Corp.Inventors: Minoru Kurosawa, Yasuhiko Kokami
-
Publication number: 20080143288Abstract: Control technique of a synchronous motor capable of suppressing rotation pulsation caused by individual difference without complicating control algorithm is provided. A pulsation generator superimposing a pulsation component anticipated in advance to a current command for the synchronous motor and a correction current generator superimposing a correction signal substantially having an average value of zero to the current command are provided in a synchronous motor control device. By this configuration, the correction signal suppressing a distortion component is superimposed to a value of the current command with a simplified control configuration. Torque pulsation is suppressed by determining the correction signal from difference between a detection current and a command current.Type: ApplicationFiled: December 12, 2007Publication date: June 19, 2008Applicant: Renesas Technology Corp.,Inventors: Yoshitaka Iwaji, Junnosuke Nakatsugawa, Yasuhiko Kokami, Minoru Kurosawa
-
Publication number: 20080100243Abstract: A motor drive control device and motor startup method prevent startup noise and reduce startup time. At startup, a current to which a rotor does not react is passed through two phase coils of a polyphase DC motor in succession, and a voltage polarity induced in a non-conducting phase is detected. A first operation decodes the detected signal, and determines phase coils of the motor through which a current should pass to rotate the rotor and the energization direction. A second operation forms a control signal for passing a current according to the determination to drive the motor, detects a voltage peak induced in the non-conducting phase during the drive, and performs switching control of a conducting phase. In normal operation, the position of the rotor is detected based on a back EMF in each phase, and rotation control is performed.Type: ApplicationFiled: October 12, 2007Publication date: May 1, 2008Inventors: Minoru KUROSAWA, Yasuhiko KOKAMI