Patents by Inventor Sadahiro Akama
Sadahiro Akama 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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Publication number: 20240239208Abstract: This vehicle comprises a first dynamo-electric machine that imparts torque to a first drive wheel, a second dynamo-electric machine that applies torque to a second drive wheel, a rotation speed sensor that acquires a first rotation speed of the first drive wheel, a rotation speed sensor that acquires a second rotation speed of the second drive wheel, and a control device. The control device includes a basic setting unit that sets a basic rotation speed, a differential setting unit that sets a differential rotation speed, and an action control unit that controls the operation of the first dynamo-electric machine and the second dynamo-electric machine so that an average value of the first rotation speed and the second rotation speed becomes the basic rotation speed, and a difference between the first rotation speed and the second rotation speed reaches the differential rotation speed.Type: ApplicationFiled: March 28, 2024Publication date: July 18, 2024Applicant: DENSO CORPORATIONInventors: Shigeru KAMIO, Haibo LIU, Keisuke KAWAI, Tatsuya TAKAGI, Sadahiro AKAMA, Harumi HORIHATA, Masaru KUBOTA, Youichi KUROYANAGI
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Publication number: 20240239331Abstract: A mobile object includes: a first braking/driving torque application unit that applies first braking/driving torque to a right driving wheel; a second braking/driving torque application unit that applies second braking/driving torque to a left driving wheel; a right driven wheel and a left driven wheel each of which is constituted of a caster wheel; and a control unit that controls the first braking/driving torque application unit and the second braking/driving torque application unit. Moreover, the control unit is configured to perform turning, advancing/reversing and braking of the mobile object by controlling the first braking/driving torque and the second braking/driving torque or by controlling rotational speed of the right driving wheel and rotational speed of the left driving wheel.Type: ApplicationFiled: March 8, 2024Publication date: July 18, 2024Applicant: DENSO CORPORATIONInventors: Shigeru KAMIO, Haibo LIU, Keisuke KAWAI, Tatsuya TAKAGI, Sadahiro AKAMA, Harumi HORIHATA, Masaru KUBOTA, Youichi KUROYANAGI
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Patent number: 11183933Abstract: A control device has a first control part and a second control part. The control device is applied to a DC-DC converter. The control device selects a first switch turning-on instruction or a first switch turning-off instruction generated by the first control part during a voltage boost control period, and transmits the selected first switch turning-on instruction or the selected first switch turning-off instruction to a first switch in the DC-DC converter. The control device selects a second switch turning-on instruction or a second switch turning-off instruction generated by the second control part during a voltage step-down control period, and transmits the selected second switch turning-on instruction or the selected second switch turning-off instruction to a second switch in the DC-DC converter.Type: GrantFiled: January 16, 2020Date of Patent: November 23, 2021Assignee: DENSO CORPORATIONInventors: Mitsutaka Ito, Sadahiro Akama
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Publication number: 20200235665Abstract: A control device has a first control part and a second control part. The control device is applied to a DC-DC converter. The control device selects a first switch turning-on instruction or a first switch turning-off instruction generated by the first control part during a voltage boost control period, and transmits the selected first switch turning-on instruction or the selected first switch turning-off instruction to a first switch in the DC-DC converter. The control device selects a second switch turning-on instruction or a second switch turning-off instruction generated by the second control part during a voltage step-down control period, and transmits the selected second switch turning-on instruction or the selected second switch turning-off instruction to a second switch in the DC-DC converter.Type: ApplicationFiled: January 16, 2020Publication date: July 23, 2020Applicant: DENSO CORPORATIONInventors: Mitsutaka ITO, Sadahiro AKAMA
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Publication number: 20190113563Abstract: A semiconductor device includes a main switching element, a sense switching element, a sense resistor and an operational amplifier. The main switching element has a first terminal and a second terminal between which a load current flows. The sense switching element is connected to the main switching element to form a current mirror, and has a third terminal and a fourth terminal between which a sense current correlated with the load current flows. The sense resistor is arranged in a feedback path of the operational amplifier. A direction of the sense current flowing through the sense resistor is switchable according to a magnitude relationship between a potential of the first terminal and a potential of the second terminal or a magnitude relationship between the potential of the first terminal and the potential of the fourth terminal.Type: ApplicationFiled: December 21, 2018Publication date: April 18, 2019Inventors: Sadahiro AKAMA, Hidekazu ONO
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Patent number: 9979384Abstract: A timing adjustment method for a drive circuit, including: a rise detector for a rise start when a voltage-driven semiconductor element is turned off; a timing signal output unit outputting a speed change timing signal after a set delay time has elapsed from the rise start; and a conduction controller for a conduction control terminal of the semiconductor element using the timing signal, comprises: defining an estimated terminal voltage of the conduction control terminal when a rise completion time elapses; increasing a delay time by a predetermined unit time, and changing the drive signal to a turning off level again, when the conduction control terminal doesn't fall below the estimated terminal voltage after the drive signal is changed to a turning off level before the level is inverted; and determining a delay time, when the conduction control terminal falls below the estimated terminal voltage initially, as a set value.Type: GrantFiled: April 2, 2015Date of Patent: May 22, 2018Assignee: DENSO CORPORATIONInventors: Atsushi Kobayashi, Kiyoshi Yamamoto, Atsushi Kanamori, Sadahiro Akama
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Patent number: 9900000Abstract: A drive device for controlling a power switching element to turn on and off includes: an on-side circuit performing an on operation of the power switching element; an off-side circuit performing an off operation of the power switching element; and a temperature detector detecting a temperature. At least one of the on-side and off-side circuits includes a current path for supplying or drawing a gate current of the power switching element and a switch circuit for switching the gate current. The switch circuit transitionally changes the gate current based on the temperature of the power switching element when the switching circuit switches the gate current.Type: GrantFiled: March 12, 2015Date of Patent: February 20, 2018Assignee: DENSO CORPORATIONInventors: Atsushi Kanamori, Sadahiro Akama, Kiyoshi Yamamoto, Atsushi Kobayashi
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Patent number: 9800237Abstract: A drive device for controlling a power switching element includes: an on-side circuit that performs an on operation of the power switching element; and an off-side circuit that performs an off operation of the power switching element. The on-side circuit or the off-side circuit includes: multiple main MOS transistors; a sense MOS transistor that define a drain current of each main MOS transistor; and a sense current control circuit that controls a drain current of the sense MOS transistor to be constant; and a switch circuit that is connected to the gate of each main MOS transistor, and controls each main MOS transistor to turn on and off so as to switch a gate current in the power switching element.Type: GrantFiled: March 12, 2015Date of Patent: October 24, 2017Assignee: DENSO CORPORATIONInventors: Sadahiro Akama, Kiyoshi Yamamoto, Atsushi Kobayashi, Atsushi Kanamori
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Publication number: 20170104479Abstract: A drive device for controlling a power switching element to turn on and off includes: an on-side circuit performing an on operation of the power switching element; an off-side circuit performing an off operation of the power switching element; and a temperature detector detecting a temperature. At least one of the on-side and off-side circuits includes a current path for supplying or drawing a gate current of the power switching element and a switch circuit for switching the gate current. The switch circuit transitionally changes the gate current based on the temperature of the power switching element when the switching circuit switches the gate current.Type: ApplicationFiled: March 12, 2015Publication date: April 13, 2017Inventors: Atsushi KANAMORI, Sadahiro AKAMA, Kiyoshi YAMAMOTO, Atsushi KOBAYASHI
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Publication number: 20170093392Abstract: A timing adjustment method for a drive circuit, including: a rise detector for a rise start when a voltage-driven semiconductor element is turned off; a timing signal output unit outputting a speed change timing signal after a set delay time has elapsed from the rise start; and a conduction controller for a conduction control terminal of the semiconductor element using the timing signal, comprises: defining an estimated terminal voltage of the conduction control terminal when a rise completion time elapses; increasing a delay time by a predetermined unit time, and changing the drive signal to a turning off level again, when the conduction control terminal doesn't fall below the estimated terminal voltage after the drive signal is changed to a turning off level before the level is inverted; and determining a delay time, when the conduction control terminal falls below the estimated terminal voltage initially, as a set value.Type: ApplicationFiled: April 2, 2015Publication date: March 30, 2017Inventors: Atsushi KOBAYASHI, Kiyoshi YAMAMOTO, Atsushi KANAMORI, Sadahiro AKAMA
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Publication number: 20160352316Abstract: A drive device for controlling a power switching element includes: an on-side circuit that performs an on operation of the power switching element; and an off-side circuit that performs an off operation of the power switching element. The on-side circuit or the off-side circuit includes: multiple main MOS transistors; a sense MOS transistor that define a drain current of each main MOS transistor; and a sense current control circuit that controls a drain current of the sense MOS transistor to be constant; and a switch circuit that is connected to the gate of each main MOS transistor, and controls each main MOS transistor to turn on and off so as to switch a gate current in the power switching element.Type: ApplicationFiled: March 12, 2015Publication date: December 1, 2016Inventors: Sadahiro AKAMA, Kiyoshi YAMAMOTO, Atsushi KOBAYASHI, Atsushi KANAMORI
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Patent number: 8593092Abstract: A control system controls a multiphase rotating machine by a 120° energization process and a PWM process. In the 120° energization process, respective ones of switching elements of a high side arm and switching elements of a low side arm of a power conversion circuit are turned on. In the PWM process, the switching elements of the power conversion circuit turn on/off so that two phases that are connected to the switching elements that are in the on-state are alternately rendered conductive to the high potential side input terminal and the low potential side input terminal of the power conversion circuit.Type: GrantFiled: February 6, 2013Date of Patent: November 26, 2013Assignee: DENSO CORPORATIONInventors: Masahiro Kuroda, Nobumasa Ueda, Kiyoshi Nagata, Masaya Ootake, Sadahiro Akama
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Patent number: 8217603Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.Type: GrantFiled: November 24, 2010Date of Patent: July 10, 2012Assignee: DENSO CORPORATIONInventors: Sadahiro Akama, Shuji Agatsuma, Nobumasa Ueda, Masahiro Kuroda, Kiyoshi Nagata, Masaya Ootake
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Patent number: 8179688Abstract: An electric device includes: a first electric element; a second electric element capable of flowing large current therethrough so that heat is generated in the second electric element; a heat sink; and a first wiring board and a second wiring board, which are disposed on one side of the heat sink. The large current in the second electric element is larger than that in the first electric element. The first wiring board and the second wiring board are separated each other. The first electric element is disposed on the first wiring board, and the second electric element is disposed on the second wiring board.Type: GrantFiled: October 19, 2010Date of Patent: May 15, 2012Assignee: DENSO CORPORATIONInventors: Yutaka Fukuda, Mitsuhiro Saitou, Toshihiro Nagaya, Kan Kinouchi, Sadahiro Akama, Koji Numazaki, Norihisa Imaizumi
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Publication number: 20110080127Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.Type: ApplicationFiled: November 24, 2010Publication date: April 7, 2011Applicant: DENSO CORPORATIONInventors: Sadahiro Akama, Shuji Agatsuma, Nobumasa Ueda, Masahiro Kuroda, Kiyoshi Nagata, Masaya Ootake
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Publication number: 20110044009Abstract: An electric device includes: a first electric element; a second electric element capable of flowing large current therethrough so that heat is generated in the second electric element; a heat sink; and a first wiring board and a second wiring board, which are disposed on one side of the heat sink. The large current in the second electric element is larger than that in the first electric element. The first wiring board and the second wiring board are separated each other. The first electric element is disposed on the first wiring board, and the second electric element is disposed on the second wiring board.Type: ApplicationFiled: October 19, 2010Publication date: February 24, 2011Applicant: DENSO CORPORATIONInventors: Yutaka Fukuda, Mitsuhiro Saitou, Toshihiro Nagaya, Kan Kinouchi, Sadahiro Akama, Koji Numazaki, Norihisa Imaizumi
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Patent number: 7893638Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.Type: GrantFiled: October 31, 2007Date of Patent: February 22, 2011Assignee: DENSO CORPORATIONInventors: Sadahiro Akama, Shuji Agatsuma, Nobumasa Ueda, Masahiro Kuroda, Kiyoshi Nagata, Masaya Ootake
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Patent number: 7843700Abstract: An electric device includes: a first electric element; a second electric element capable of flowing large current therethrough so that heat is generated in the second electric element; a heat sink; and a first wiring board and a second wiring board, which are disposed on one side of the heat sink. The large current in the second electric element is larger than that in the first electric element. The first wiring board and the second wiring board are separated each other. The first electric element is disposed on the first wiring board, and the second electric element is disposed on the second wiring board.Type: GrantFiled: April 14, 2005Date of Patent: November 30, 2010Assignee: DENSO CORPORATIONInventors: Yutaka Fukuda, Mitsuhiro Saitou, Toshihiro Nagaya, Kan Kinouchi, Sadahiro Akama, Koji Numazaki, Norihisa Imaizumi
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Publication number: 20090174350Abstract: A control system controls a multiphase rotating machine by a 120° energization process and a PWM process. In the 120° energization process, respective ones of switching elements of a high side arm and switching elements of a low side arm of a power conversion circuit are turned on. In the PWM process, the switching elements of the power conversion circuit turn on/off so that two phases that are connected to the switching elements that are in the on-state are alternately rendered conductive to the high potential side input terminal and the low potential side input terminal of the power conversion circuit.Type: ApplicationFiled: December 16, 2008Publication date: July 9, 2009Applicant: DENSO CORPORATIONInventors: Masahiro Kuroda, Hiroshi Taki, Nobumasa Ueda, Sadahiro Akama, Kiyoshi Nagata, Masaya Ootake
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Publication number: 20080252242Abstract: A motor driving apparatus has a loss-of-synchronism monitoring circuit that monitors the rotation of a rotary machine such as a brushless DC motor to detect a sign of transition to a state of loss of synchronism. When the sign is detected, an energization control circuit temporarily stops driving of the rotary machine to bring it into a free running state, and thereafter carries out control so as to resume driving of the rotary machine. Further, the motor driving apparatus has an inverter and a drive control circuit that controls switching operation of the inverter based on rotation of the rotary machine.Type: ApplicationFiled: October 31, 2007Publication date: October 16, 2008Applicant: DENSO CORPORATIONInventors: Sadahiro Akama, Shuji Agatsuma, Nobumasa Ueda, Masahiro Kuroda, Kiyoshi Nagata, Masaya Ootake