Patents by Inventor Takahiro Kojo
Takahiro Kojo 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: 20120123642Abstract: A vehicle driving control apparatus is provided at least with: a rudder angle varying device capable of changing a relation between a steering angle, which is a rotation angle of a steering input shaft, and a rudder angle, which is a rotation angle of steered wheels; and a trajectory controlling device for controlling the rudder angle varying device such that a trajectory of a vehicle approaches a target driving route of the vehicle. The vehicle driving control apparatus is further provided with a changing device for changing responsiveness of control by the trajectory controlling device when there is a steering input given to the steering input shaft through a steering wheel by a driver of the vehicle.Type: ApplicationFiled: June 23, 2010Publication date: May 17, 2012Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventor: Takahiro Kojo
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Publication number: 20120029773Abstract: Lane keeping control is ended in accurate timing which does not give an uncomfortable feeling to a driver. In a vehicle 10 which is provided with a steering mechanism 200, an EPS actuator 300, and a VGRS actuator 500 and which can change a rudder angle regardless of a driver's steering input due to the cooperative control of the aforementioned mechanism and actuators, an ECU 100 performs LKA end control. In the control, in cases where a winker lever 16 is operated in a period of performing LKA control for making the vehicle 10 follow a target driving route, if the indicated direction of the winker lever 16 is different from a generation direction of generating an assist steering torque TA of the EPS actuator 300 in the LKA control, the LKA control is promptly ended. In cases where the indicated direction is equal to the generation direction, if a steering angle MAdrv corresponding to the driver's steering input exceeds a steering angle MAlka generated by the LKA control, the LKA control is ended.Type: ApplicationFiled: April 10, 2009Publication date: February 2, 2012Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Yoshitaka Fujita, Takahiro Kojo
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Publication number: 20110264329Abstract: A vehicle is provided with: an EPS a VGRS actuator as a rudder angle varying device; and an EPS actuator as a steering torque assisting device. In following a target driving route, a LKA target assist torque TLK is outputted from the EPS actuator on the basis of target lateral acceleration GYTG. On the other hand, in order to suppress the steering of a steering wheel by the assist torque, which is against a driver's will, steered wheels are steered by the VGRS actuator, excessively by a LKA correction target angle ?LK. At this time, it does not influence a relation between a steering angle and the rotation angle of a lower steering shaft. Thus, the following for the target driving route is realized without reducing the robustness of the vehicle with respect to the driver's steering.Type: ApplicationFiled: December 26, 2008Publication date: October 27, 2011Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Theerawat Limpibunterng, Takahiro Kojo
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Publication number: 20110036660Abstract: An object of the present invention is to reduce the possibility of a power assistance failure because of the phenomenon that steering assisting power which an electric power steering unit can generate is lower than the steering assisting power which is required for the electric power steering unit. A vehicle steering control device comprises an electric power steering unit, a steering ratio varying unit which drives an output member relative to an input member driven by steering operation of a driver to vary a steering ratio, and a control means which controls the steering ratio varying unit.Type: ApplicationFiled: November 19, 2008Publication date: February 17, 2011Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Takahiro Kojo, Theerawat Limpibunterng
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Patent number: 7885741Abstract: In a vehicle equipped with a power steering device for assisting the steering of the steered wheels by the steering wheel, when the steering angle of the steered wheels reaches the maximum steering angle, a steering control device restricts a target steering angle for operating the power steering device so that the steering angle or a reaction force acting against the power steering device does not exceed a value determined therefor, so to maintain the steering condition of the steered wheels stably without applying an excessive load on the power steering device. The target steering angle may be calculated as a value based upon rotational angle of the steering wheel and turning behavior control of the vehicle.Type: GrantFiled: October 18, 2005Date of Patent: February 8, 2011Assignees: Toyota Jidosha Kabushiki Kaisha, Advics Co., Ltd.Inventors: Yoshitaka Fujita, Yoshiaki Tsuchiya, Takahiro Kojo, Masato Suzumura, Kenji Asano
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Publication number: 20110022268Abstract: In a vehicle including a VGRS actuator capable of changing the steering transmission ratio by rotating an upper steering shaft and a lower steering shaft relative to each other, an ECU performs a lock releasing process when the VGRS motor is locked. In the process, an actual steering angle is calculated, and is compared with a lock release threshold value that is set in advance in view of the axial force applied to the lower steering shaft during steering. If the actual steering angle is equal to or smaller than the lock release threshold value, the ECU performs driving control of a lock mechanism so as to release the locked state of the VGRS motor.Type: ApplicationFiled: April 6, 2009Publication date: January 27, 2011Applicant: Toyota Jidosha Kabushiki KaishaInventor: Takahiro Kojo
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Publication number: 20110010052Abstract: An ECU executes steering control in a vehicle including an electronic control power steering apparatus. In the steering control, it is determined that an assist motor is in a power generating state when a motor rotation speed ? which is the rotation speed of the assist motor is greater than an upper limit rotation speed ?1 set according to a motor command voltage Vq that is the driving voltage of the assist motor. When the assist motor is in the power generating state, the ECU interrupts the supply of current to the assist motor by controlling a relay portion of a drive apparatus that drives the assist motor so that it is open, thereby reducing the amount of power that is generated to zero. Also, when returning to an assist possible state, assist torque Tm is changed gradually with zero as the initial value in order to prevent it from changing suddenly.Type: ApplicationFiled: April 1, 2009Publication date: January 13, 2011Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Theerawat Limpibunterng, Takahiro Kojo
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Publication number: 20100228444Abstract: An object of the present invention is to cover a drop in turning responsiveness of a vehicle to a driver's steering operation caused by a limit on the operating speed of a steerable wheel turning unit by a turn assist yaw moment independent of turn lateral forces of steerable wheels to thereby prevent the drop in turning responsiveness of the vehicle when the operating speed of the steerable wheel turning unit is limited. A vehicle travel control device comprises a steerable wheel turning unit capable of turning steerable wheels to steer independently of steering of a driver and a braking unit as a turn assist yaw moment generating means capable of generating a turn assist yaw moment independently of turn lateral forces of the steerable wheels.Type: ApplicationFiled: November 19, 2008Publication date: September 9, 2010Applicant: Toyota Jidosha Kabushiki KaishaInventors: Takahiro Kojo, Theerawat Limpibunterng
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Patent number: 7743875Abstract: A power steering apparatus has a steering power assisting system coupled to tire wheels and a variable gear transfer system coupled to a steering wheel. The steering power assisting system includes a torsion bar rotation sensor and a first actuator rotation sensor to calculate a first pinion angle and a second pinion angle based on the detected rotation angles, respectively. The variable gear transfer system includes a steering sensor and a second actuator rotation sensor to calculate a third pinion angle based on the detected rotation angles. Sensor failure is detected by comparing the calculated first, second and third pinion angles.Type: GrantFiled: July 25, 2008Date of Patent: June 29, 2010Assignees: Denso Corporation, Toyota Jidosha Kabushiki KaishaInventors: Kenichirou Hidaka, Junko Hidaka, legal representative, Nobuhiko Makino, Takahiro Kojo, Theerawat Limpibunterng
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Patent number: 7711465Abstract: An operation torque estimating portion estimates an operation torque Th of a driver based on an input angle ?h and an input torque T output from a torque sensor. A non-holding state detecting portion determines whether the driver is holding a steering wheel by comparing an absolute value of the operation torque Th and a predetermined value ?1. An equilibrium detecting portion determines whether an equilibrium point is reached by comparing the absolute value of the input torque T with a predetermined value ?2. When it is determined that the driver is not holding the steering wheel and the equilibrium point is reached, a switching portion switches to such a position that causes a target steering adjusting portion to multiply a target output angle ?pm by a predetermined gain G according to the input torque T so that the target steering angle is made smaller.Type: GrantFiled: March 30, 2009Date of Patent: May 4, 2010Assignee: Toyota Jidosha Kabushiki KaishaInventors: Theerawat Limpibunterng, Takahiro Kojo
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Publication number: 20090276121Abstract: A vehicle steering control system that controls the operation of an electric vehicle steering device, which applies a steering assist force to a steering mechanism via a gear mechanism and includes: a temperature estimating section for estimating the temperature of or around the gear mechanism; and a correcting section for correcting the steering assist force according to the estimated gear temperature.Type: ApplicationFiled: September 14, 2007Publication date: November 5, 2009Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Theerawat Limpibunterng, Takahiro Kojo
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Publication number: 20090198417Abstract: An operation torque estimating portion estimates an operation torque Th of a driver based on an input angle ?h and an input torque T output from a torque sensor. A non-holding state detecting portion determines whether the driver is holding a steering wheel by comparing an absolute value of the operation torque Th and a predetermined value ?1. An equilibrium detecting portion determines whether an equilibrium point is reached by comparing the absolute value of the input torque T with a predetermined value ?2. When it is determined that the driver is not holding the steering wheel and the equilibrium point is reached, a switching portion switches to such a position that causes a target steering adjusting portion to multiply a target output angle ?pm by a predetermined gain G according to the input torque T so that the target steering angle is made smaller.Type: ApplicationFiled: March 30, 2009Publication date: August 6, 2009Applicant: Toyota Jidosha Kabushiki KaishaInventors: Theerawat Limpibunterng, Takahiro Kojo
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Patent number: 7530423Abstract: An operation torque estimating portion estimates an operation torque Th of a driver based on an input angle ?h and an input torque T output from a torque sensor. A non-holding state detecting portion determines whether the driver is holding a steering wheel by comparing an absolute value of the operation torque Th and a predetermined value ?1. An equilibrium detecting portion determines whether an equilibrium point is reached by comparing the absolute value of the input torque T with a predetermined value ?2. When it is determined that the driver is not holding the steering wheel and the equilibrium point is reached, a switching portion switches to such a position that causes a target steering adjusting portion to multiply a target output angle ? pm by a predetermined gain G according to the input torque T so that the target steering angle is made smaller.Type: GrantFiled: October 17, 2006Date of Patent: May 12, 2009Assignee: Toyota Jidosha Kabushiki KaishaInventors: Theerawat Limpibunterng, Takahiro Kojo
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Patent number: 7528569Abstract: An inverter circuit includes a bridge circuit constituted of a plurality of pairs of a high-side switching element and a low-side switching element, a command signal processing section, a pulse generating section for generating pulse signals to control the inverter bridge circuit according to the command signal to have a dead time to prevent short circuiting of the dc power source and a command signal compensation section. The compensation section modifies the command signal according to a current voltage level of the dc power source to control the dead zone, thereby preventing deformation of ac output power of the bridge circuit.Type: GrantFiled: September 1, 2006Date of Patent: May 5, 2009Assignees: Denso Corporation, Toyota Jidosha Kabushiki KaishaInventors: Kenichiro Hidaka, Hisashi Kameya, Mitsutomo Iwase, Yasuo Ito, Masahiro Miyata, Takahiro Kojo
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Publication number: 20090026004Abstract: A power steering apparatus has a steering power assisting system coupled to tire wheels and a variable gear transfer system coupled to a steering wheel. The steering power assisting system includes a torsion bar rotation sensor and a first actuator rotation sensor to calculate a first pinion angle and a second pinion angle based on the detected rotation angles, respectively. The variable gear transfer system includes a steering sensor and a second actuator rotation sensor to calculate a third pinion angle based on the detected rotation angles. Sensor failure is detected by comparing the calculated first, second and third pinion angles.Type: ApplicationFiled: July 25, 2008Publication date: January 29, 2009Applicants: DENSO CORPORATION, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Kenichirou Hidaka, Nobuhiko Makino, Takahiro Kojo, Theerawat Limpibunterng, Junko Hidaka
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Publication number: 20080195275Abstract: In the control device for vehicles which executes a control of the vehicle by one calculation control device based upon a target control amount generated by another calculation control device connected to the one calculation control device by way of a communication means, the other calculation control device calculates an estimated target control amount by itself to compare it with the target control amount generated by the one calculation control device and input thereto by way of the communication means, or a third calculation control device compares the target control amounts generated by the one and the other calculation control devices and input thereto by way of the communication means, thereby to judge if an abnormality has occurred in the communication means, and to rapidly modify the control to make a counter-measure against the abnormality.Type: ApplicationFiled: October 18, 2005Publication date: August 14, 2008Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Takahiro Kojo, Yoshiaki Tsuchiya, Masato Suzumura, Jun Sakugawa, Kenji Asano
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Publication number: 20080097671Abstract: In view of the matter that an abnormality occurred in an operating portion of a control system comes out in an early stage as a result of the control, while it takes a time for an abnormality occurred in the generation of a controlling amount for controlling the operation of an operating portion to come out, in ceasing the control when an abnormality has occurred in the control system the controlling amount is decreased at a higher speed when the abnormality of the controlling amount was judged than a speed at which the operation of the operating device is decreased when the abnormality of the operating device was judged.Type: ApplicationFiled: October 18, 2005Publication date: April 24, 2008Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, ADVICS CO., LTD.Inventors: Takahiro Kojo, Masato Suzumura, Yoshiaki Tsuchiya, Kenji Asano
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Publication number: 20070299583Abstract: In a vehicle equipped with a power steering device for assisting the steering of the steered wheels by the steering wheel, when the steering angle of the steered wheels reaches the maximum steering angle, a steering control device restricts a target steering angle for operating the power steering device so that the steering angle or a reaction force acting against the power steering device does not exceed a value determined therefor, so to maintain the steering condition of the steered wheels stably without applying an excessive load on the power steering device. The target steering angle may be calculated as a value based upon rotational angle of the steering wheel and turning behavior control of the vehicle.Type: ApplicationFiled: October 18, 2005Publication date: December 27, 2007Applicants: TOYOTA JIDOSHA KABUSHIKI KAISHA, ADVICS CO., LTD.Inventors: Yoshitaka Fujita, Yoshiaki Tsuchiya, Takahiro Kojo, Masato Suzumura, Kenji Asano
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Patent number: 7248016Abstract: A motor controller including an inverter including plural switching elements that are subjected to PWM control to generate sine waves of plural phases, a motor including a stator coil supplied with the sine waves thus generated so that rotational magnetic field is generated in the stator coil, and a rotor that is rotationally driven by the action of the rotational magnetic field generated by the stator coil, a storage unit for detecting the sine waves of the respective phases generated in the inverter and storing a correction amount for each phase that is calculated on the basis of the detection result so that the sine waves of the respective phases are coincident with one another and a correcting unit for correcting a PWM signal for carrying out the PWM control on the switching elements on the basis of the correction amount thus calculated.Type: GrantFiled: November 8, 2005Date of Patent: July 24, 2007Assignee: DENSO CORPORATIONInventors: Kenichiro Hidaka, Mikihiro Hiramine, Motoshi Kawai, Toshio Tsutsui, Masahiro Miyata, Takahiro Kojo
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Publication number: 20070107979Abstract: An operation torque estimating portion estimates an operation torque Th of a driver based on an input angle ?h and an input torque T output from a torque sensor. A non-holding state detecting portion determines whether the driver is holding a steering wheel by comparing an absolute value of the operation torque Th and a predetermined value ?1. An equilibrium detecting portion determines whether an equilibrium point is reached by comparing the absolute value of the input torque T with a predetermined value ?2. When it is determined that the driver is not holding the steering wheel and the equilibrium point is reached, a switching portion switches to such a position that causes a target steering adjusting portion to multiply a target output angle ? pm by a predetermined gain G according to the input torque T so that the target steering angle is made smaller.Type: ApplicationFiled: October 17, 2006Publication date: May 17, 2007Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Theerawat Limpibunterng, Takahiro Kojo