Patents by Inventor Keiji Kaita
Keiji Kaita 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: 20130049973Abstract: The calculation unit converts into a battery age each parameter calculated for a different factor of degradation of a battery. If at least one of the battery ages has reached an upper limit age, the determination unit determines that it is necessary to conduct a battery diagnosis. Once it has been determined that it is necessary to conduct the battery diagnosis, the display control unit causes a display device to display a diagnosis request message. After displaying the diagnosis request message has started if there is no result of the battery diagnosis received the electric power limiter unit limits electric power charged to and discharged from the battery. After the electric power charged to/discharged from the battery is limited if there is no result of the battery diagnosis received the start-up prohibition unit prohibits starting a system driving the vehicle.Type: ApplicationFiled: May 14, 2010Publication date: February 28, 2013Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Junichi Matsumoto, Keiji Kaita, Takayoshi Tezuka, Teruo Ishishita
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Publication number: 20120276440Abstract: A battery pack has a plurality of assembled batteries connected in parallel. Each of the assembled batteries has a plurality of cells connected electrically. A circulating current in each of the assembled batteries is calculated from an open circuit voltage of the assembled battery that varies according to the number of the cells connected in series, a value indicating a charge state of the assembled battery that varies according to the number of the cells connected in parallel, and an internal resistance of the assembled battery. The number of the cells connected in parallel and the number of the cells connected in series in each of the assembled batteries are numbers determined under the condition that the circulating current should not exceed an allowable current value for the assembled battery.Type: ApplicationFiled: April 25, 2011Publication date: November 1, 2012Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Teruo Ishishita, Yuji Nishi, Keiji Kaita, Masaru Takagi
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Publication number: 20120226406Abstract: When the gearshift position SP is the N position and the accumulated charge ratio SOC of the battery is less than or equal to the threshold value Slow (step S120), the engine is cranked by a first motor (the motor MG1) and started in the case that the vehicle stop is held (steps S140 and s150). After the engine is started, the shutoff of the inverter for driving the motor MG1 is performed and the self-sustained operation of the engine is performed at the rotation speed N1 at which the back electromotive force generated on the motor MG1 is more than the voltage applied to the inverters (steps S180 to S200).Type: ApplicationFiled: November 13, 2009Publication date: September 6, 2012Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Keiji Kaita, Takahiko Hirasawa
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Patent number: 8229614Abstract: During use of a secondary battery, a concentration change ratio estimating unit estimates a ratio of change in electrolytic solution concentration based on a charging/discharging current. According to the estimated ratio of change, a concentration estimated value calculating unit sequentially calculates an electrolytic solution concentration estimated value during the use of the secondary battery. Based on the estimated electrolytic solution concentration estimated value, a determining unit determines whether or not the electrolytic solution concentration is within a normal range. When the electrolytic solution concentration is outside the normal range, a charging/discharging condition modifying unit modifies a charging/discharging condition of the secondary battery to bring the electrolytic solution concentration back to the normal range, thus avoiding a tendency of overcharge or a tendency of overdischarge.Type: GrantFiled: September 25, 2008Date of Patent: July 24, 2012Assignees: Toyota Jidosha Kabushiki Kaisha, Denso CorporationInventors: Keiji Kaita, Teruo Ishishita, Shinobu Okayama, Yuji Nishi, Daisuke Kuroda
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Patent number: 8215424Abstract: In requirement of catalyst degradation control with setting of a catalyst degradation control flag Fc to 1, the braking control of the invention sets torque commands Tm1* and Tm2* of two motors and controls the operations of an engine and the two motors to shift a drive point of the engine on an optimum fuel consumption operation curve by a preset rotation speed variation Nrt1 in a specific range of rotation speed that ensures no occurrence of a misfire in the engine within an input limit Win of a battery and to ensure output of a braking torque demand Tr* to a ring gear shaft or driveshaft (steps S200 to S250). Such braking control stably lowers a rotation speed Ne of the engine to a target rotation speed Ne* and desirably enhances the fuel consumption under the catalyst degradation control.Type: GrantFiled: August 24, 2006Date of Patent: July 10, 2012Assignee: Toyota Jidosha Kabushiki KaishaInventor: Keiji Kaita
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Publication number: 20120099618Abstract: An alternating current impedance-estimating section (106) estimates an alternating current impedance (Rh) of the secondary battery based on electric current (I) and voltage (V) of the secondary battery detected when a ripple generating section causes a ripple current to flow in the secondary battery. A temperature estimating section (108) estimates the temperature (T) of the secondary battery based on the alternating current impedance (Rh) estimated by the alternating current impedance-estimating section (106) with the use of the relation, obtained in advance, between the temperature (T) of the secondary battery and the alternating current impedance (Rh) of the secondary battery at a ripple frequency.Type: ApplicationFiled: July 7, 2010Publication date: April 26, 2012Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Yuji Nishi, Hidenori Takahashi, Masatoshi Tazawa, Masanobu Matsusaka, Keiji Kaita
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Patent number: 7957862Abstract: A plurality of electronic control units (ECU) are classified under a plurality of ECU groups. A relay is provided for each ECU group, and connected between each ECU in a corresponding group and a power supply. Connection is established between respective ECUs by a communication network. When power is turned ON, each ECU outputs a flag indicating its own communication enabled state as long as there is no error in the communication function. A relay error detection portion detects, based on communication state information indicating whether each ECU is in a communication enabled state or communication disabled state, an error of the relay when the communication state information between ECU groups is inconsistent. Thus, an error in a relay that is provided for each group can be detected with a simple configuration.Type: GrantFiled: April 25, 2006Date of Patent: June 7, 2011Assignee: Toyota Jidosha Kabushiki KaishaInventors: Keiji Kaita, Katsuhiro Suzuki
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Publication number: 20100204861Abstract: During use of a secondary battery, a concentration change ratio estimating unit estimates a ratio of change in electrolytic solution concentration based on a charging/discharging current. According to the estimated ratio of change, a concentration estimated value calculating unit sequentially calculates an electrolytic solution concentration estimated value during the use of the secondary battery. Based on the estimated electrolytic solution concentration estimated value, a determining unit determines whether or not the electrolytic solution concentration is within a normal range. When the electrolytic solution concentration is outside the normal range, a charging/discharging condition modifying unit modifies a charging/discharging condition of the secondary battery to bring the electrolytic solution concentration back to the normal range, thus avoiding a tendency of overcharge or a tendency of overdischarge.Type: ApplicationFiled: September 25, 2008Publication date: August 12, 2010Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, DENSO CORPORATIONInventors: Keiji Kaita, Teruo Ishishita, Shinobu Okayama, Yuji Nishi, Daisuke Kuroda
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Publication number: 20100087973Abstract: An HV_ECU executes a program including the steps of: determining whether or not an EV switch is turned on until a monitoring timer expires when a system startup switch is turned on, latching the ON state of the EV switch if the EV switch is turned on and confirming an EV mode request on system startup, detecting various state quantities of a vehicle, and starting up a system in an EV mode without starting an engine if an EV mode prohibiting condition is unsatisfied.Type: ApplicationFiled: August 27, 2007Publication date: April 8, 2010Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, AISIN AW CO., LTD.Inventors: Keiji Kaita, Shinobu Nishiyama
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Patent number: 7689335Abstract: Start/stop decision circuit receives main and sub IG instruction signals from a hold circuit and a sub line, respectively, and if the signals match in logic, the start/stop decision circuit follows the main IG instruction signal's logic to determine whether an ignition switch is turned on/off. If the main and sub IG instruction signals attain the high and low levels, respectively, and a logic discrepancy is thus caused, and a condition is established for speculating that the vehicle is parked and therefrom a decision is made that the vehicle system will be stopped with high probability, then the start/stop decision circuit determines that the ignition switch is turned off, and start/stop decision circuit detects that the hold circuit has an ON failure and subsequently the start/stop decision circuit stops the vehicle system.Type: GrantFiled: February 16, 2006Date of Patent: March 30, 2010Assignee: Toyota Jidosha Kabushik KaishaInventors: Keiji Kaita, Masaya Amano
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Publication number: 20100019729Abstract: A vehicle includes a charging unit receiving electric power from an external power source and externally charging a power storage unit. When a connector unit is coupled to the vehicle and a state ready for charging by the external power source is attained, a controller predicts degradation ratio of the power storage unit at the time point of completion of external charging based on degradation characteristic of the power storage unit in connection with SOC and battery temperature obtained in advance, and sets target state of charge of each power storage unit based on the battery temperatures so that the predicted degradation ratio does not exceed tolerable degradation ratio at the time point of completion of external charging. Then, the controller controls corresponding converters such that SOCs of power storage units attain the target states of charge.Type: ApplicationFiled: July 21, 2009Publication date: January 28, 2010Applicant: Toyota Jidosha Kabushiki KaishaInventors: Keiji Kaita, Junta Izumi
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Patent number: 7628125Abstract: A cooling system includes a first cooling system in which coolant is supplied from a radiator to a motor so as to cool the motor, and then the coolant is supplied to banks of an engine through a circulation passage and split flow passages so as to cool the engine; and a second cooling system in which the coolant delivered from the radiator through a branch passage is further cooled by a radiator, and the cooled coolant is supplied to a drive circuit so as to cool the drive circuit. With this configuration, it is possible to efficiently cool the motor, the engine, and the drive circuit whose suitable operating temperatures are different from each other, and to make the configuration of the cooling system simple.Type: GrantFiled: January 31, 2005Date of Patent: December 8, 2009Assignee: Toyota Jidosha Kabushiki KaishaInventors: Keiji Kaita, Shinichi Abe
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Patent number: 7559871Abstract: In a reverse drive with power output from an engine, the control procedure of the invention selects a drive point of the higher rotation speed corresponding to the higher accelerator opening among available drive points that ensure output of a target engine power, and controls the engine to be driven at the selected drive point and ensure output of a torque demand corresponding to the accelerator opening to a drive shaft. A required torque level output from a motor MG2 increases with an increase in engine torque under the conditions of a fixed torque demand of the drive shaft and a fixed output power level of the engine 22. Setting a drive point of the higher rotation speed and the lower torque corresponding to a higher level of the accelerator opening ensures output of the torque demand to the drive shaft. Setting a drive point of the lower rotation speed and the higher torque corresponding to a lower level of the accelerator opening improves the drive feeling of the engine.Type: GrantFiled: July 19, 2005Date of Patent: July 14, 2009Assignee: Toyota Jidosha Kabushiki KaishaInventors: Masaya Amano, Keiji Kaita
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Publication number: 20090145375Abstract: A cooling system includes a first cooling system in which coolant is supplied from a radiator to a motor so as to cool the motor, and then the coolant is supplied to banks of an engine through a circulation passage and split flow passages so as to cool the engine; and a second cooling system in which the coolant delivered from the radiator through a branch passage is further cooled by a radiator, and the cooled coolant is supplied to a drive circuit so as to cool the drive circuit. With this configuration, it is possible to efficiently cool the motor, the engine, and the drive circuit whose suitable operating temperatures are different from each other, and to make the configuration of the cooling system simple.Type: ApplicationFiled: January 31, 2005Publication date: June 11, 2009Inventors: Keiji Kaita, Shinichi Abe
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Publication number: 20090130538Abstract: The high-voltage battery unit 400, for each of the plurality of areas A1 to AN grouped by the temperature distribution pattern set in step S110, the reference internal resistance Rrc(n) indicating an internal resistance of the battery cell 450 based on the correlation to the temperature is acquired based on the area representative temperature Ta(n) detected by any one of the temperature sensors 44k in the individual area An (step S140); the detected internal resistance Rdm(m) based on the detected voltage V(x) and the detected current value I is acquired for each battery module 40x; the presence or absence of an abnormal cell in an individual battery module 40x is determined based on the reference internal resistance Rrm(n) of the battery module 40x based on the reference internal resistance Rrc(n) and the detected internal resistance Rdm(m) (steps S180 to S210).Type: ApplicationFiled: May 10, 2007Publication date: May 21, 2009Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Keiji Kaita, Teruo Ishishita
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Patent number: 7430469Abstract: In a motor vehicle, when an intake air temperature Ta is not lower than a preset reference temperature Tref, warm-up drive control selectively uses an evaporated fuel processing acceleration operation curve, which gives a high level of a negative pressure in an intake manifold, to set a target drive point of an engine and controls the operation of the engine. This ensures good emission of the engine. When the intake air temperature Ta is lower than the preset reference temperature Tref and when the setting of a heating demand Hq requires heating, on the other hand, the warm-up drive control increases an EGR quantity from an ordinary level and switches over an operation mode of a cooling system for the engine to a warm-up circulation mode for making the flow of a cooling medium bypass a radiator.Type: GrantFiled: September 17, 2004Date of Patent: September 30, 2008Assignee: Toyota Jidosha Kabushiki KaishaInventor: Keiji Kaita
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Publication number: 20080110684Abstract: In requirement of catalyst degradation control with setting of a catalyst degradation control flag Fc to 1, the braking control of the invention sets torque commands Tm1* and Tm2* of two motors and controls the operations of an engine and the two motors to shift a drive point of the engine on an optimum fuel consumption operation curve by a preset rotation speed variation Nrt1 in a specific range of rotation speed that ensures no occurrence of a misfire in the engine within an input limit Win of a battery and to ensure output of a braking torque demand Tr* to a ring gear shaft or driveshaft (steps S200 to S250). Such braking control stably lowers a rotation speed Ne of the engine to a target rotation speed Ne* and desirably enhances the fuel consumption under the catalyst degradation control.Type: ApplicationFiled: August 24, 2006Publication date: May 15, 2008Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Keiji Kaita
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Publication number: 20070255485Abstract: In a motor vehicle of the invention, when an intake air temperature Ta is not lower than a preset reference temperature Tref, warm-up drive control selectively uses an evaporated fuel processing acceleration operation curve, which gives a high level of a negative pressure in an intake manifold, to set a target drive point of an engine and controls the operation of the engine. This ensures good emission of the engine. When the intake air temperature Ta is lower than the preset reference temperature Tref and when the setting of a heating demand Hq requires heating, on the other hand, the warm-up drive control increases an EGR quantity from an ordinary level and switches over an operation mode of a cooling system for the engine to a warm-up circulation mode for making the flow of a cooling medium bypass a radiator. This introduces a greater amount of heat of exhaust into a heat exchanger to enable quick supply of the warm air to a passenger compartment.Type: ApplicationFiled: September 17, 2004Publication date: November 1, 2007Inventor: Keiji Kaita
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Publication number: 20070243970Abstract: In a reverse drive with power output from an engine, the control procedure of the invention selects a drive point of the higher rotation speed corresponding to the higher accelerator opening among available drive points that ensure output of a target engine power, and controls the engine to be driven at the selected drive point and ensure output of a torque demand corresponding to the accelerator opening to a drive shaft. A required torque level output from a motor MG2 increases with an increase in engine torque under the conditions of a fixed torque demand of the drive shaft and a fixed output power level of the engine 22. Setting a drive point of the higher rotation speed and the lower torque corresponding to a higher level of the accelerator opening ensures output of the torque demand to the drive shaft. Setting a drive point of the lower rotation speed and the higher torque corresponding to a lower level of the accelerator opening improves the drive feeling of the engine.Type: ApplicationFiled: July 19, 2005Publication date: October 18, 2007Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Masaya Amano, Keiji Kaita
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Publication number: 20060276947Abstract: A plurality of electronic control units (ECU) are classified under a plurality of ECU groups. A relay is provided for each ECU group, and connected between each ECU in a corresponding group and a power supply. Connection is established between respective ECUs by a communication network. When power is turned ON, each ECU outputs a flag indicating its own communication enabled state as long as there is no error in the communication function. A relay error detection portion detects, based on communication state information indicating whether each ECU is in a communication enabled state or communication disabled state, an error of the relay when the communication state information between ECU groups is inconsistent. Thus, an error in a relay that is provided for each group can be detected with a simple configuration.Type: ApplicationFiled: April 25, 2006Publication date: December 7, 2006Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Keiji Kaita, Katsuhiro Suzuki