Patents by Inventor Theerawat Limpibunterng
Theerawat Limpibunterng 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: 20120197496Abstract: A vehicle control apparatus that controls a vehicle provided with a steering force applying device capable of applying steering force to induce a change in a steering angle of a steered wheel to the steered wheel, includes a difference detecting device that detects a positional difference that determines a relative positional relationship between a target running path to be maintained and the vehicle; a determining device that determines a control amount of the steering force applying device based on the detected positional difference; a controller that maintains a running path of the vehicle on the target running path by controlling the steering force applying device according to the determined control amount; a steering input detecting device that detects a steering input to a steering input device by a driver; and a correcting device that corrects a determining reference of the control amount of the steering force applying device such that, when a steering input is detected while the running path is maintaType: ApplicationFiled: October 5, 2010Publication date: August 2, 2012Applicants: AISIN SEIKI KABUSHIKI KAISHA, TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Theerawat Limpibunterng, Yoshiaki Tsuchiya, Hirofumi Nitta, Shoji Asai
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Patent number: 8229629Abstract: 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: GrantFiled: September 14, 2007Date of Patent: July 24, 2012Assignee: Toyota Jidosha Kabushiki KaishaInventors: Theerawat Limpibunterng, Takahiro Kojo
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Publication number: 20120029772Abstract: A steering control apparatus (100) controls a steering mechanism to limit a behavior of a vehicle in the vehicle (10) equipped with the steering mechanism (200) which can independently steer front wheels and rear wheels. The steering control apparatus is provided with: a controlling device for controlling the steering mechanism such that a rudder angle of the front wheels and a rudder angle of the rear wheels are reverse-phased and such that a rudder angle speed of the front wheels is higher than a rudder angle speed of the rear wheels.Type: ApplicationFiled: August 25, 2009Publication date: February 2, 2012Applicant: TOYOTA JIDOSHA KABUSHIKI KAISHAInventors: Yoshitaka Fujita, Taro Hirose, Theerawat Limpibunterng
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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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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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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: 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
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Patent number: 6983818Abstract: In the control of an electric power steering apparatus, where so-called lead steering control is performed in which a steering wheel angle signal is output through a lead filter to correct reaction delay of a driver and a vehicle, a delay in control response occurs due to feedback of a road surface reaction force torque. When road surface reaction force torque is fed back to the steering wheel, it is added through a low-pass filter having a time constant equal to a reaction delay time constant of a driver. A sum signal is output through a lead filter to a second motor for controlling a steering shaft.Type: GrantFiled: February 10, 2005Date of Patent: January 10, 2006Assignees: Mitsubishi Denki Kabushiki Kaisha, Fuji Jukogyo Kabushiki KaishaInventors: Takehiko Fujioka, Theerawat Limpibunterng, Hajime Oyama, Noriyuki Inoue, Masaya Endo
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Patent number: 6938725Abstract: In the control of an electric power steering apparatus, where so-called lead steering control is performed in which a steering wheel angle signal is output through a lead filter to correct reaction delay of a driver and a vehicle, a delay in control response occurs due to feedback of a road surface reaction force torque. When road surface reaction force torque is fed back to the steering wheel, it is added through a low-pass filter having a time constant equal to a reaction delay time constant of a driver. A sum signal is output through a lead filter to a second motor for controlling a steering shaft.Type: GrantFiled: March 10, 2004Date of Patent: September 6, 2005Assignees: Mitsubishi Denki Kabushiki Kaisha, Fuji Jukogyo Kabushiki KaishaInventors: Takehiko Fujioka, Theerawat Limpibunterng, Hajime Oyama, Noriyuki Inoue, Masaya Endo
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Publication number: 20050149241Abstract: In the control of an electric power steering apparatus, where so-called lead steering control is performed in which a steering wheel angle signal is output through a lead filter to correct reaction delay of a driver and a vehicle, a delay in control response occurs due to feedback of a road surface reaction force torque. When road surface reaction force torque is fed back to the steering wheel, it is added through a low-pass filter having a time constant equal to a reaction delay time constant of a driver. A sum signal is output through a lead filter to a second motor for controlling a steering shaft.Type: ApplicationFiled: February 10, 2005Publication date: July 7, 2005Applicants: Mitsubishi Denki Kabushiki Kaisha, Fuji Jukogyo Kabushiki KaishaInventors: Takehiko Fujioka, Theerawat Limpibunterng, Hajime Oyama, Noriyuki Inoue, Masaya Endo
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Patent number: 6886656Abstract: An electric power steering apparatus having a steering system capable of flexibly setting a relationship between a steering angle of a steering wheel and a wheel angle of a tire. The first motor controls steering reaction force exerted on the steering wheel. The on-center region determination section determines whether the steering wheel is in a position of an on-center region. The tire reaction force torque detection section detects tire reaction force torque transferred from the tire. The control section calculates a steering torque based on the tire reaction force torque and a torque gain. This torque is detected by the tire reaction force torque detection section. And the control section controls the first motor to exert the steering reaction force corresponding to the above calculated steering torque on the steering wheel. This control section also sets the torque gain in case of determining of on-center region larger than that in case of determining of non-on-center region.Type: GrantFiled: August 26, 2003Date of Patent: May 3, 2005Assignees: Fuji Jukogyo Kabushiki Kaisha, Mitsubishi Denki Kabushiki KaishaInventors: Takehiko Fujioka, Theerawat Limpibunterng, Masahiko Kurishige, Hideyuki Tanaka, Hajime Oyama
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Publication number: 20050039971Abstract: In the control of an electric power steering apparatus, in the case where so-called lead steering control is performed in which a handle angle signal is outputted through a lead filter in order to correct a reaction delay of a driver and a vehicle, there has been a problem that a delay of control response occurs due to the feedback of a road surface reaction force torque. When a road surface reaction force torque SAT is fed back to a handle 105 and is added, it is added through a low-pass filter 202c having a time constant equal to a reaction delay time constant t1 of a driver. An added signal is outputted through a lead filter 202b to a second motor for controlling a steering shaft.Type: ApplicationFiled: March 10, 2004Publication date: February 24, 2005Applicants: Mitsubishi Denki Kabushiki Kaisha, Fuji Jukogyo Kabushiki KaishaInventors: Takehiko Fujioka, Theerawat Limpibunterng, Hajime Oyama, Noriyuki Inoue, Masaya Endo
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Publication number: 20040040781Abstract: An electric power steering apparatus having a steering system capable of flexibly setting a relationship between a steering angle of a steering wheel and a wheel angle of a tire. The first motor controls steering reaction force exerted on the steering wheel. The on-center region determination section determines whether the steering wheel is in a position of an on-center region. The tire reaction force torque detection section detects tire reaction force torque transferred from the tire. The control section calculates a steering torque based on the tire reaction force torque and a torque gain. This torque is detected by the tire reaction force torque detection section. And the control section controls the first motor to exert the steering reaction force corresponding to the above calculated steering torque on the steering wheel. This control section also sets the torque gain in case of determining of on-center region larger than that in case of determining of non-on-center region.Type: ApplicationFiled: August 26, 2003Publication date: March 4, 2004Applicants: Fuji Jukogyo Kabushiki Kaisha, Mitsubishi Denki Kabushiki KaishaInventors: Takehiko Fujioka, Theerawat Limpibunterng, Masahiko Kurishige, Hideyuki Tanaka, Hajime Oyama