Patents by Inventor Isao Kezobo
Isao Kezobo 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: 11005402Abstract: A control device for a motor, comprising: a power converter for performing ON/OFF control on an upper switching element and a lower switching element in accordance with a drive command from a current controller, and thereby supplying power to a motor; a current sensor provided to the lower switching element; and a fault determining unit for determining a fault in the current sensor. When the lower switching element for each phase is OFF, the current sensor detects the current error in each phase. The fault determining unit obtains a current error determination value on the basis of the value obtained by converting, to Cartesian coordinates, the current error for each phase or the magnitude of the sum of current error vectors for each phase in which the value for the current error for each phase is held as the magnitude, and determines a fault.Type: GrantFiled: May 2, 2017Date of Patent: May 11, 2021Assignee: Mitsubishi Electric CorporationInventors: Yuya Tsuchimoto, Isao Kezobo, Shunsuke Nakajima, Akira Furukawa
-
Publication number: 20210058018Abstract: A control device includes: a first power converter applying a voltage to a first winding; a second power converter applying a voltage to a second winding; a first power supply circuit supplying power to the first power converter; a second power supply circuit supplying power to the second power converter; a current command calculator; a first current controller; and a second current controller. The second power supply circuit supplies power at a voltage higher than a voltage of the first power supply circuit. The current command calculator calculates a first voltage usage state, which is an indicator value correlated with a magnitude of the output voltage of the first power converter with respect to a power supply voltage output at a time of supply of power by the first power supply circuit, and calculates the second current command based on the first voltage usage state.Type: ApplicationFiled: March 13, 2018Publication date: February 25, 2021Applicant: Mitsubishi Electric CorporationInventors: Yuya TSUCHIMOTO, Isao KEZOBO, Akira FURUKAWA
-
Publication number: 20200412277Abstract: To provide a power converter which can distribute heat generation of the switching devices with good accuracy, even when the maximum heating phase of the positive electrode side and the maximum heating phase of the negative electrode side are different phases, and even when the maximum heating phase of the positive electrode side and the maximum heating phase of the negative electrode side changes before and after combining the offset voltage. The power converter calculates the offset voltage that makes the positive electrode side maximum heating evaluation value and the negative electrode side maximum heating evaluation value coincide with each other, in a state of controlling on/off the switching devices based on the combined AC voltage commands of the offset voltage.Type: ApplicationFiled: April 18, 2018Publication date: December 31, 2020Applicant: Mitsubishi Electric CorporationInventors: Hiroya NATSUHARA, Yoshihiko KIMPARA, Isao KEZOBO, Tatsuya MORI, Akira FURKAWA
-
Publication number: 20200300601Abstract: An angle detection device including: an angle sensor AGSE outputting first and second sine wave signals SINWS1, SINWS2 having phases that are different from each other by 90 degrees in accordance with rotation of a detection target; an angle calculator calculating an angle signal corresponding to a rotation angle of the detection target based on SINWS1 and SINWS2; and an angle sensor AGSE abnormality determiner ASAD determining an abnormality of AGSE based on SINWS1 and SINWS2. The ASAD includes: an amplitude signal calculator calculating an amplitude signal MALS based on a square root of a sum of squares of SINWS1 and SINWS2; a first angle signal ANGS1 calculation processor calculating ANGS1 based on SINWS1 and MALS; a second angle signal ANGS2 calculation processor calculating ANGS2 based on SINWS2 and MALS; and an abnormality determination processor determining the abnormality of AGSE based on an error between ANGS1 and ANGS2.Type: ApplicationFiled: April 28, 2016Publication date: September 24, 2020Applicant: Mitsubishi Electric CorporationInventors: Tatsuya MORI, Isao KEZOBO, Munenori YAMAMOTO, Akira FURUKAWA
-
Publication number: 20200300671Abstract: Provided are a failure determination device and method for a rotating machine control device, which are capable of detecting failure of a sensor configured to detect a rotational position of a rotating machine while the rotating machine is in operation. A rotation angle estimator calculates a rotation angle estimation value. A relationship between the rotation angle estimation value (?est), and a first angle detection value (?1) and a second angle detection value (?2), which are obtained from output signals of angle sensors configured to detect a rotational position of a rotating machine, is monitored while the rotating machine is in operation. In this manner, failure of the angle sensors, which are configured to detect the rotational position of the rotating machine, can be always detected even while the rotating machine is in operation.Type: ApplicationFiled: April 28, 2016Publication date: September 24, 2020Applicant: Mitsubishi Electric CorporationInventors: Tatsuya MORI, Isao KEZOBO, Munenori YAMAMOTO, Akira FURUKAWA
-
Publication number: 20200255067Abstract: To provide a motor controller and an electric power steering apparatus which can suppress torque fluctuation resulting from low detection resolution of angle, with simple calculation, even in condition where the rotational speed of motor is low. A motor controller estimates an angle error correlation value correlated with the angle detection error based on the current command value when a change frequency of the angle detection value is lower than a cutoff frequency of feedback control system which controls a rotation state; corrects the current command value or the angle detection value based on the estimation value of angle error correlation value; and changes the estimation value of angle error correlation value so that the absolute value of angle detection error increases with respect to increase in the current command value, and the absolute value of angle detection error decreases with respect to decrease in the current command value.Type: ApplicationFiled: November 7, 2017Publication date: August 13, 2020Applicant: Mitsubishi Electric CorporationInventors: Kenta TANAKA, Isao KEZOBO, Akira FURUKAWA, Seiji SAWADA
-
Publication number: 20200153375Abstract: An inverter device includes: an inverter, a power supply current detection sensor, a phase current detection sensor, a three-phase voltage command calculator, and an inverter on/off signal generation unit. The phase current detection sensor detects a phase current in one phase of the inverter. The inverter on/off signal generation unit generates on/off signals based on the phase voltage commands. The three-phase voltage command calculator uses the power supply current and the phase current detected by the power supply current detection sensor and the phase current detection sensor, respectively, so as to calculate phase voltage commands directed to the inverter, and at a center time point of a period in which an upper arm switching element corresponding to one phase out of two phases for which the phase current detection sensor is not provided is on, and lower arm switching elements corresponding to the other two phases are on.Type: ApplicationFiled: July 4, 2017Publication date: May 14, 2020Applicant: Mitsubishi Electric CorporationInventors: Tatsuya MORI, Akira FURUKAWA, Isao KEZOBO
-
Publication number: 20200119674Abstract: A control device for a motor, comprising: a power converter for performing ON/OFF control on an upper switching element and a lower switching element in accordance with a drive command from a current controller, and thereby supplying power to a motor; a current sensor provided to the lower switching element; and a fault determining unit for determining a fault in the current sensor. When the lower switching element for each phase is OFF, the current sensor detects the current error in each phase. The fault determining unit obtains a current error determination value on the basis of the value obtained by converting, to Cartesian coordinates, the current error for each phase or the magnitude of the sum of current error vectors for each phase in which the value for the current error for each phase is held as the magnitude, and determines a fault.Type: ApplicationFiled: May 2, 2017Publication date: April 16, 2020Applicant: Mitsubishi Electric CorporationInventors: Yuya TSUCHIMOTO, Isao KEZOBO, Shunsuke NAKAJIMA
-
Patent number: 10583859Abstract: When the state where steering torque detected by a torque detection unit is normal and the value of the steering torque is the same as or larger than a threshold value continues, an assist command generation unit that generates an assist command corresponding to steering torque produced by a driver limits the assist command; a failure determination unit includes a first failure determination unit that performs determination on a failure regardless of the limitation of the assist command and a second failure determination unit that performs determination on a failure while the assist command is limited, and stops driving of a motor when the second failure determination unit determines that there exists a failure.Type: GrantFiled: December 2, 2015Date of Patent: March 10, 2020Assignee: Mitsubishi Electric CorporationInventors: Yuya Tsuchimoto, Isao Kezobo, Shunsuke Nakajima
-
Publication number: 20200062297Abstract: An electric power steering apparatus including: a steering torque detector to detect a steering torque of a driver; a motor to assist a steering force of the driver; an estimated speed calculator to calculate an estimated speed, which is an estimated value of a rotation speed of the motor; an estimated speed corrector to correct the estimated speed based on the steering torque; an estimated angle calculator to calculate an estimated angle of the motor by integrating the estimated speed after the correction; and an electric power supply to supply electric power to the motor based on the estimated angle, wherein the estimated speed corrector corrects the estimated speed when a determination signal, which is based on a value obtained by removing a frequency component of steering of the driver from a derivative of the steering torque, the steering torque, and the estimated speed have the same signs.Type: ApplicationFiled: May 18, 2017Publication date: February 27, 2020Applicant: Mitsubishi Electric CorporationInventors: Yuya TSUCHIMOTO, Isao KEZOBO, Akira FURUKAWA, Yuji TAKATSUKA
-
Publication number: 20200031385Abstract: There is provided an electric power steering device, including: a reverse steering detection unit configured to determine start of reverse steering when a magnitude of a rotational speed of a motor is equal to or smaller than a set speed, a rotational acceleration of the motor is in a direction of causing the rotational speed of the motor to become 0, and a magnitude of the rotational acceleration of the motor is equal to or larger than a set acceleration; and a current command control unit configured to output a current command for the motor based on the steering torque or the rotational speed of the motor, in which the current command control unit is configured to increase a transfer gain from input to output by the current command control unit when the reverse steering detection unit determines start of the reverse steering.Type: ApplicationFiled: March 27, 2017Publication date: January 30, 2020Applicant: Mitsubishi Electric CorporationInventors: Isao KEZOBO, Kenta TANAKA, Akira FURUKAWA, Masaharu TANAKA, Akiyoshi TAKASHIMA
-
Patent number: 10543868Abstract: When an AC rotary machine having a rotor structure for generating saliency, and including first three-phase windings and second three-phase windings is controlled, a first position estimation command to be superimposed on a voltage command or a current command directed to each of the first three-phase windings and a second position estimation command to be superimposed on a voltage command or a current command directed to each of the second three-phase windings are set to have the same frequency, and caused to have a phase difference, thereby increasing an estimation accuracy of a rotation position of the AC rotary machine.Type: GrantFiled: May 27, 2015Date of Patent: January 28, 2020Assignee: Mitsubishi Electric CorporationInventors: Tatsuya Mori, Shunsuke Nakajima, Isao Kezobo
-
Publication number: 20190389506Abstract: An electric power steering apparatus includes: a torque sensor configured to detect a steering torque of a driver; a motor configured to assist in a steering force of the driver; a rotation angle estimation unit configured to estimate a rotation angle of the motor to output an estimated angle; a correction signal calculation unit configured to calculate a correction signal based on the steering torque; a frequency separation unit configured to separate the estimated angle into a first frequency component and a second frequency component; an estimated angle correction unit configured to calculate, as a control angle, a value obtained by adding a second-frequency-component corrected signal, which is obtained by correcting the second frequency component based on the correction signal, to the first frequency component; and an electric power supply unit configured to supply electric power to the motor based on the control angle.Type: ApplicationFiled: March 7, 2017Publication date: December 26, 2019Applicant: Mitsubishi Electric CorporationInventors: Yuya TSUCHIMOTO, Isao KEZOBO, Yuji TAKATSUKA, Akira FURUKAWA
-
Patent number: 10439535Abstract: This invention is concerning a control device of an AC rotating machine that estimates, as an estimated rotational position, a rotational position of an AC rotating machine having N sets of three-phase windings where N is a natural number equal to or greater than 2, the device being made up of: a voltage sum calculator that calculates a voltage sum from N sets of voltage commands for applying AC voltage to the N sets of three-phase windings; a current sum calculator that calculates a current sum from N sets of currents respectively flowing in the N sets of three-phase windings; and a rotational position estimator that calculates an estimated rotational position on the basis of calculation results of the voltage sum calculator and the current sum calculator.Type: GrantFiled: April 27, 2015Date of Patent: October 8, 2019Assignee: Mitsubishi Electric CorporationInventors: Tatsuya Mori, Shunsuke Nakajima, Isao Kezobo
-
Patent number: 10421483Abstract: An input/output device is connected, via an in-vehicle communication network, to a control device for controlling a motor provided in an electric power steering apparatus that is provided in a vehicle. The input/output device generates an excitation start instruction signal for starting excitation in the motor on the basis of an externally input excitation start instruction, transmits the generated excitation start instruction signal to the control device over the in-vehicle communication network, and receives response data relating to the excitation of the electric power steering apparatus, the response data being detected by the control device while the excitation is underway, from the control device over the in-vehicle communication network.Type: GrantFiled: April 9, 2015Date of Patent: September 24, 2019Assignee: MITSUBISHI ELECTRIC CORPORATIONInventors: Isao Kezobo, Yoshihiko Kinpara, Hidetoshi Ikeda
-
Publication number: 20190256131Abstract: When a voltage application command is outputted to a three-phase winding of one system, a d-axis proportionality constant and a q-axis proportionality constant are set with Ld and Lq, respectively, as parameters; when voltage application commands are outputted to three-phase windings of two systems, a d-axis proportionality constant and a q-axis proportionality constant are set with [Ld+Md] and [Lq+Mq], respectively, as parameters.Type: ApplicationFiled: November 14, 2016Publication date: August 22, 2019Applicant: Mitsubishi Electric CorporationInventors: Tatsuya MORI, Akira FURUKAWA, Isao KEZOBO
-
Patent number: 10333311Abstract: A control unit of an electric motor control device includes an inverter circuit 6 that supplies power to an electric motor, a current control unit that outputs a voltage command value as a drive command of the inverter circuit, a current detecting unit that detects current flowing to each phase of the electric motor, and a failed phase identifying unit that identifies a location of a failure in the current detecting unit. The failed phase identifying unit determines whether or not a magnitude or a phase of a frequency component of the test voltage command included in a detected current value when the inverter circuit is driven with a test voltage command having a frequency higher than a rotational frequency of the electric motor as a drive command is within a predetermined range, and determines that a failure has occurred in a phase that is not within the predetermined range.Type: GrantFiled: January 14, 2016Date of Patent: June 25, 2019Assignee: Mitsubishi Electric CorporationInventors: Chiaki Fujimoto, Kenta Tanaka, Tatsuya Mori, Isao Kezobo
-
Patent number: 10315692Abstract: Provided is a control device for a rotary machine including: a power feed unit configured to feed electric power in accordance with a power feed command to a rotary machine; a rotation-state detecting unit configured to detect a rotation state of the rotary machine; a torque detecting unit configured to detect an output torque output from the rotary machine; an abnormality determining unit configured to determine an abnormality in the rotation-state detecting unit or the torque detecting unit; and an excitation-command generating unit configured to generate an excitation command for oscillating the rotary machine, in which the power feed command is generated based at least on the excitation command, and the abnormality determining unit is configured to determine the abnormality in the detecting units based on a response of the rotation state and a response of the output torque to the excitation command.Type: GrantFiled: November 13, 2013Date of Patent: June 11, 2019Assignee: Mitsubishi Electric CorporationInventors: Isao Kezobo, Yoshihiko Kimpara, Akira Furukawa
-
Patent number: 10259492Abstract: An inverter system failure is detected on the basis of the currents of respective phases detected by a current detection unit when carrying out switching control in accordance with a first drive mode in which all switching elements on a lower-side arm are switched on and all switching elements on an upper-side arm are switched off, and the currents of respective phases detected by the current detection unit when carrying out switching control in accordance with a second drive mode in which all of the switching elements on the upper-side arm are switched on and all of the switching elements on the lower-side arm are switched off.Type: GrantFiled: November 4, 2014Date of Patent: April 16, 2019Assignee: Mitsubishi Electric CorporationInventors: Isao Kezobo, Yoshihiko Kimpara, Shunsuke Nakajima
-
Publication number: 20190100234Abstract: An electric power steering apparatus includes a high-frequency compensation unit that outputs a high-frequency compensation signal obtained by filtering the high-frequency components of an assist torque command signal and multiplying the filtered high-frequency components by a gain; a corrected steering torque signal obtained by negatively or positively feeding back the high-frequency compensation signal to a steering torque signal is inputted to an assist torque command calculation unit; the assist torque command calculation unit outputs the assist torque command signal in accordance with the corrected steering torque signal.Type: ApplicationFiled: May 24, 2016Publication date: April 4, 2019Applicant: Mitsubishi Electric CorporationInventors: Isao KEZOBO, Kenta TANAKA, Masaharu TANAKA, Akiyoshi TAKASHIMA