Patents by Inventor Atsushi Yokoyama
Atsushi Yokoyama 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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Patent number: 7651426Abstract: A first common rotational axis of first and second shafts of a first differential is prevented from being coaxial with a second common rotational axis of first and second rotary members of a second differential so that each of the first and second shafts is prevented from extending through at least one of the first and second rotary members.Type: GrantFiled: November 15, 2006Date of Patent: January 26, 2010Assignee: Hitachi, Ltd.Inventors: Atsushi Yokoyama, Makoto Yamakado, Tatsuyuki Yamamoto
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Publication number: 20090218179Abstract: Provided is an electric brake capable of accurately estimating the brake pad temperature and securing a sufficient braking force and response. An electric brake has a disc rotor rotating with a wheel, an actuator for rectilinearly actuating a piston in the axial direction of the disc rotor by using an electric motor, a drive controller for controlling the drive of the actuator, a brake pad pressed by the piston to give a frictional resistance to the disc rotor in the direction of rotation, and a braking start position detector for detecting a braking start position of the piston where the disc rotor is brought into contact with the brake pad. The drive controller stores the braking start position detected by the braking start position detector as the maximum braking start position. When the braking start position shifts in the pressing force-increasing direction, the drive controller updates the value stored as the maximum braking-start position.Type: ApplicationFiled: February 8, 2006Publication date: September 3, 2009Applicant: HITACHI, LTD.Inventors: Atsushi Yokoyama, Yoshinari Kawahara, Satoru Kuragaki
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Publication number: 20090213727Abstract: A voice packet communications system which objectively evaluates the voice quality in real time. Voice packets received from a network are input into an adjustment circuit. The adjustment circuit evens out the periods of the voice packets, detects the drop-out of voice packets, and inserts substitute packets in the voice packet sequence. Furthermore, the adjustment circuit outputs the number of voice packets that have dropped out, the number of substitute packets that have been inserted, and the number of voice packets that have accumulated inside the circuit, as quality information in each monitoring period. A decoding circuit converts the voice packets adjusted by the adjustment circuit into voice information. A judgement circuit calculates an index that indicates the communications quality of the voice packets from the quality information using a specified calculation formula.Type: ApplicationFiled: January 5, 2009Publication date: August 27, 2009Applicant: Oki Electric Industry., Ltd.Inventors: Hiromi Aoyagi, Atsushi Yokoyama, Nobuyuki Yamaguchi, Kazuyoshi Akie
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Patent number: 7565954Abstract: A brake control apparatus for a vehicle having brake devices for generating pad-pressing forces at respective wheels includes brake control units for individually controlling the pad-pressing forces at the respective wheels; a storing unit for storing drive data required for controlling the pad-pressing force at each wheel; a vehicle-driving-state detector for detecting a driving state of the vehicle; and a vehicle controller for controlling a vehicle driving state using the brake control unit for each wheel. Memory data representing the relationship between a motor position and the pad-pressing force is updated using the state of brake actuators obtained when the driving state of the vehicle is stabilized by operating the brake devices during braking.Type: GrantFiled: December 15, 2006Date of Patent: July 28, 2009Assignee: Hitachi, Ltd.Inventors: Yoshinari Kawahara, Tadahiko Nogami, Takaomi Nishigaito, Atsushi Yokoyama
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Patent number: 7552978Abstract: A brake system that provides a good pedal feel, that assists stepping force of a driver by a small motor, and that can control braking force of wheels individually. The brake system comprises a first actuator (5) for increasing a liquid pressure in a master cylinder (2) by driving torque of a motor (51), and a second actuator (6) capable of driving a brake generating mechanism (3) without transmitting power to the master cylinder (2), wherein the actuators (5, 6) to be driven are switched depending on the operation of a brake pedal (1). The first and second actuators (5, 6) are connected to hydraulic piping (4f, 4r), and a pressurized oil is supplied to the brake generating mechanism (3) through hydraulic valve means (63f, 63r, . . . 65rr).Type: GrantFiled: October 29, 2004Date of Patent: June 30, 2009Assignee: Hitachi, Ltd.Inventors: Atsushi Yokoyama, Taisetsu Tanimichi, Satoru Kuragaki, Yukihiro Osawa, Jun Kubo, Yukihiko Inoue, Katsuya Iwasaki, Mitsuo Sasaki, Tsutomu Hibi
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Publication number: 20090143951Abstract: An object of the present invention is to provide a forward collision avoidance assistance system that attains the reduction of driver's uncomfortable feeling and the improvement in drivability while ensuring the collision avoidance performance during operation for avoiding contact with an object. A collision avoidance calculation unit 3 determines a risk of collision between a host vehicle and an object detected in the host vehicle traveling direction based on information about the host vehicle detected by a host vehicle information detection unit 1 and information about the object detected by an object information detection unit 2, and calculates control information for object avoidance to be output to an actuator 5 based on a result of collision risk judgment.Type: ApplicationFiled: November 13, 2008Publication date: June 4, 2009Applicant: HITACHI, LTD.Inventors: Junya Takahashi, Atsushi Yokoyama, Satoru Kuragaki
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Publication number: 20090112404Abstract: A vehicle control apparatus having a vehicle state quantity detection unit for detecting vehicle state quantity such as a roller angular velocity, a lateral jerk calculation unit for calculating lateral jerk of a vehicle based on the vehicle state quantity, and a control unit for carrying out the vehicle control based on the lateral jerk.Type: ApplicationFiled: October 28, 2008Publication date: April 30, 2009Applicant: HITACHI, Ltd.Inventors: Shinya IMURA, Atsushi Yokoyama, Junya Takahashi, Tatsuya Yoshida
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Publication number: 20090088925Abstract: A drive assist system includes an assist starting part starting assist, a detection part detecting relative distances and speeds between a vehicles, a calculation part calculating collision risks when changing a lane by the basis of the relative distances and speeds, a first judgment part judging whether the lane can be changed by the relative distances, speeds and the collision risks, a decision part deciding a target space for lane change by the relative distances and speeds when the lane cannot be changed, a second judgment part judging whether a lane changeable space is in the target space, a setting part setting a target speed for the vehicle go to a lane change waiting position when no space and to setting a target speed the vehicle enters a lane changeable position when there is the space, and a control part controlling a speed of the vehicle reaches the target speed.Type: ApplicationFiled: August 20, 2008Publication date: April 2, 2009Applicant: Hitachi, Ltd.Inventors: Toshiharu SUGAWARA, Atsushi Yokoyama, Takaomi Nishigaito, Masatoshi Hoshino, Tatsuya Yoshida, Jun Kubo, Shinjiro Saito
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Publication number: 20090088966Abstract: A driving support system includes a lane detecting unit for detecting lanes around a vehicle, a route correcting unit for correcting a route along which the vehicle is expected to travel taking into consideration an obstacle on the route after the route has been recognized by lanes detected by the lane detecting unit, and a control unit for controlling the vehicle on the basis of the positional relation between the corrected route determined by the route correcting unit and the vehicle.Type: ApplicationFiled: August 20, 2008Publication date: April 2, 2009Applicant: Hitachi, Ltd.Inventors: Atsushi YOKOYAMA, Shinjiro SAITO, Masatsugu ARAI, Tatsuya YOSHIDA
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Publication number: 20090054202Abstract: A right-and-left-wheel differential torque generator makes a deceleration acted on a vehicle body to be corrected in small even when a rotating electric machine for generating a right-and-left-wheel differential torque is operated to generate a yaw moment of the vehicle, for this purpose, a correcting throttle opening is added to a throttle operation by a driver to correct a torque amount of an engine brake causing a power supply, two power generators A, B coupled independently to each of the left and right wheels and a rotating electric machine C for generating a torsional torque are provided, the power generator A absorbs (brake) the torque from one wheel to generate a power, and this power is supplied so that a torsional torque is generated by the rotating electric machine C in a direction toward which the other wheel (coupled with the power generator B) is accelerated.Type: ApplicationFiled: February 8, 2006Publication date: February 26, 2009Applicant: Hitachi LtdInventors: Makoto Yamakado, Atsushi Yokoyama, Masaru Yamasaki
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Publication number: 20090038876Abstract: A steering system, comprising: an input cylinder having a first hydraulic chamber and a second hydraulic chamber; a transmission mechanism, wherein a transmission efficiency for converting and transmitting a linear motion of the input cylinder to a rotary motion of a steering wheel is less than a transmission efficiency for converting and transmitting the rotary motion of the steering wheel to the linear motion of the input cylinder; an output cylinder connected to a steerable vehicle wheel and having a third hydraulic chamber and a fourth hydraulic chamber; a first hydraulic passage for connecting the first hydraulic chamber to the third hydraulic chamber; a second hydraulic passage for connecting the second hydraulic chamber to the fourth hydraulic chamber; a flow rate control mechanism for exchanging hydraulic oil with: a first hydraulic circuit including the first and third hydraulic chambers and the first hydraulic passage; and a second hydraulic circuit including the second and fourth hydraulic chambersType: ApplicationFiled: October 11, 2007Publication date: February 12, 2009Applicant: Hitachi, Ltd.Inventors: Takahiro ITO, Atsushi Yokoyama, Mitsuo Sasaki
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Patent number: 7489678Abstract: A voice packet communications system which objectively evaluates the voice quality in real time. Voice packets received from a network are input into an adjustment circuit. The adjustment circuit evens out the periods of the voice packets, detects the drop-out of voice packets, and inserts substitute packets in the voice packet sequence. Furthermore, the adjustment circuit outputs the number of voice packets that have dropped out, the number of substitute packets that have been inserted, and the number of voice packets that have accumulated inside the circuit, as quality information in each monitoring period. A decoding circuit converts the voice packets adjusted by the adjustment circuit into voice information. A judgment circuit calculates an index that indicates the communications quality of the voice packets from the quality information using a specified calculation formula.Type: GrantFiled: January 24, 2005Date of Patent: February 10, 2009Assignee: Oki Electric Industry Co., Ltd.Inventors: Hiromi Aoyagi, Atsushi Yokoyama, Nobuyuki Yamaguchi, Kazuyoshi Akie
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Publication number: 20090030574Abstract: To provide a vehicle motion control system capable of defining clear guidelines on more specific control timing associated with accelerating, steering, and braking operations, and conducting motion control based on the defined guidelines. An ideal motion control unit 42 within a central controller 40 uses longitudinal jerk information of a vehicle to control the steering of the vehicle. Information for determining the initiation timing of steering is presented from a human-vehicle interface (HVI) 55 to a driver. In accordance with the information presented from the HVI 55, the driver controls the initiation timing of steering.Type: ApplicationFiled: July 26, 2007Publication date: January 29, 2009Applicant: Hitachi, Ltd.Inventors: Makoto Yamakado, Atsushi Yokoyama, Masato Abe
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Publication number: 20090026835Abstract: The first control is to displace the primary piston by the amount obtained by multiplying the input rod displacement quantity by a proportional gain. The second control is to propel the primary piston by a prescribed offset thereby executing the first control. The third control is to displace the primary piston by the amount obtained by multiplying the input rod displacement quantity by a proportional gain specifically at a pressure decrease request. The brake force control device properly selects a control method from the first to third control methods to control the primary piston based on the automatic braking release conditions and a driver's brake request when a driver executes a brake operation during the automatic braking.Type: ApplicationFiled: July 24, 2008Publication date: January 29, 2009Applicant: Hitachi, Ltd.Inventors: Kenichiro MATSUBARA, Toshiyuki Innami, Atsushi Yokoyama, Satoru Kuragaki, Kimio Nishino, Toshiharu Sugawara
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Publication number: 20080294321Abstract: In order to fit a driver's driving feeling, a vehicle speed control system includes a unit calculating the instantaneous curvature and a unit controlling a vehicle speed, and controls to reduce the vehicle speed when the instantaneous curvature tends to increase and to enhance the vehicle speed when the instantaneous curvature tends to decrease.Type: ApplicationFiled: May 21, 2008Publication date: November 27, 2008Applicant: Hitachi, Ltd.Inventors: Makoto YAMAKADO, Atsushi Yokoyama, Masato Abe
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Patent number: 7445091Abstract: An electrically operated brake device in which braking force differences between electrically operated brakes are reduced to prevent unstable vehicle traveling during braking. Motors 13 of electrically operated brakes are returned to standard positions during the stop of a vehicle and the motor 13 of each of the brakes is driven for a predetermined amount, pressing a brake pad 17 against a disc rotor 18 to produce a braking force. An electric current value of each motor 13 in the above operation is measured and differences between the values are calculated. Electric current of each motor is increased or decreased so that there is no current difference between the motors 13. Based on a drive amount of each motor in this operation, standard positions of the motors are determined and updated. Repeating the above operations reduces braking force differences between the brakes.Type: GrantFiled: June 21, 2004Date of Patent: November 4, 2008Assignee: Hitachi, Ltd.Inventors: Yoshinari Kawahara, Kousaku Ohno, Atsushi Yokoyama, Mitsuhide Sasaki
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Publication number: 20080155085Abstract: A server device that provides a client device with one or more data storage locations of one or more sets of information about one or more datasets. The one or more sets of information about the one or more datasets are to be provided by one or more network devices. Each of the sets of information about the datasets is described in a structured format. The server device includes a data storage location acquiring unit that acquires the data storage locations of the sets of information about the datasets from the corresponding network devices, a data storage location management unit that manages the acquired data storage locations of the sets of information about the datasets; and a data storage location providing unit that provides the client device with the acquired data storage locations of the sets of information about the datasets.Type: ApplicationFiled: December 17, 2007Publication date: June 26, 2008Applicant: Ricoh Company, Ltd.Inventors: Atsushi YOKOYAMA, Yukinari HIROSE, Shinichiro OZEKI
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Publication number: 20080120394Abstract: A network apparatus providing data-related information outside the network apparatus in accordance with a format of structured description, the data-related information being related to data to be provided, is disclosed that includes an external data storage location management part configured to manage the data storage location of the data-related information of an external network apparatus and a data storage location provision part configured to provide, outside the network apparatus, the data storage location of the data-related information of the network apparatus and the data storage location of the data-related information of the external network apparatus.Type: ApplicationFiled: October 15, 2007Publication date: May 22, 2008Inventors: Akira Yokoyama, Osamu Suzuki, Mitsuo Nakamura, Xiaojun Du, Shinichiro Ozeki, Yukinari Hirose, Atsushi Yokoyama
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Publication number: 20080116740Abstract: A brake system that provides a good pedal feel, that assists stepping force of a driver by a small motor, and that can control braking force of wheels individually. The brake system comprises a first actuator (5) for increasing a liquid pressure in a master cylinder (2) by driving torque of a motor (51), and a second actuator (6) capable of driving a brake generating mechanism (3) without transmitting power to the master cylinder (2), wherein the actuators (5, 6) to be driven are switched depending on the operation of a brake pedal (1). The first and second actuators (5, 6) are connected to hydraulic piping (4f, 4r), and a pressurized oil is supplied to the brake generating mechanism (3) through hydraulic valve means (63f, 63r, . . . 65rr).Type: ApplicationFiled: October 29, 2004Publication date: May 22, 2008Applicant: Hitachi, Lld.Inventors: Atsushi Yokoyama, Taisetsu Tanimichi, Satoru Kuragaki, Yukihiro Osawa, Jun Kubo, Yukihiko Inoue, Katsuya Iwasaki, Mitsuo Sasaki, Tsutomu Hibi
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Patent number: RE40502Abstract: A plasma display panel has a good productivity of partition formation and air exhaustion process and realizes a bright and stable display. A discharge gas is filled in a gap between two substrates. A mesh-patterned partition is arranged on the inner surface of one of the substrates for dividing the gap into plural squares corresponding to a cell arrangement. The partition has low portions forming a mesh-like air path that travels through all of the gas-filled space enclosed by the partition, in a plan view. A plasma display panel includes two spaced substrates defining a gap therebetween. The gap is divided by intersecting walls into columns and rows of discharge cells. Portions of a wall that are lower in height than remaining portions of the wall define a flow path. The plasma display panel realizes a bright and stable display.Type: GrantFiled: April 25, 2005Date of Patent: September 16, 2008Assignee: Fujitsu Hitachi Plasma Display LimitedInventors: Yasuhiko Kunii, Masayuki Shibata, Yoshimi Kawanami, Kenichi Yamamoto, Atsushi Yokoyama, Yusuke Yajima, Shinji Kanagu, Yasuhiro Wakabayashi, Akihiro Fujimoto, Toshiyuki Nanto