Patents by Inventor Takayuki Itoh
Takayuki Itoh 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: 20020042697Abstract: It is one object of the present invention to form a conventional mesh as a sample in order to efficiently generate a high-quality mesh for a predetermined shape model.Type: ApplicationFiled: May 11, 2001Publication date: April 11, 2002Inventors: Atsushi Yamada, Keisuke Inoue, Takayuki Itoh
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Patent number: 6349995Abstract: The present invention is directed to a brake control system for a vehicle, which includes a cut-off valve for opening or closing a main passage, which communicates a master cylinder with a wheel brake cylinder, and a pump for discharging the pressurized brake fluid to the wheel brake cylinder, with an outlet of the pump connected to a position between the cut-off valve and the wheel brake cylinder. An inlet valve is provided for opening or closing an auxiliary passage which communicates an inlet of the pump with the master cylinder. And, a controller is adapted to place the cut-off valve in a closed position thereof, place the inlet valve in an open position thereof, and actuate the pump to supply the pressurized brake fluid discharged from the pump into the wheel brake cylinder, when a brake-assist control is to be performed.Type: GrantFiled: December 22, 1999Date of Patent: February 26, 2002Assignee: Aisin Seiki Kabushiki KaishaInventors: Takayuki Itoh, Satoshi Yokoyama, Masanobu Fukami, Toshihisa Kato, Kenji Tanaka
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Patent number: 6328390Abstract: The present invention is directed to a brake control system for a vehicle, wherein a first valve device for opening or closing a main passage, a hydraulic pressure pump, and a second valve device for opening or closing an auxiliary passage are disposed in each hydraulic pressure circuit of a dual hydraulic pressure circuit system. At least one of the first and second valve devices is controlled to equalize the slip rates of a pair of wheels, with the wheel brake cylinders operatively mounted thereon and disposed in different hydraulic circuits, and placed at the left side and right side of the vehicle, respectively, when a difference between the slip rates of the wheels placed at the left side and right side exceeds a predetermined value.Type: GrantFiled: November 19, 1998Date of Patent: December 11, 2001Assignee: Aisin Seiki Kabushiki KaishaInventors: Kenji Tozu, Takayuki Itoh, Masanobu Fukami, Satoshi Yokoyama
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Patent number: 6317704Abstract: A method is provided for generating a quadrilateral mesh and a hexahedral mesh. First, a geometric model, which is an object of meshing, is input. The model is either two-dimensional or three-dimensional. Multiple bubbles of a plurality of types are generated in a region of the geometric model. The bubbles are moved according to an interbubble force defined by a predetermined rule, and the bubble count is controlled to adjust a neighboring relationship between the bubbles, so that the stable allocation of the bubbles are determined. By connecting the centers of bubbles of a specific type, a mesh is generated.Type: GrantFiled: September 5, 1998Date of Patent: November 13, 2001Assignee: International Business Machines CorporationInventors: Tomotake Furuhata, Takayuki Itoh, Keisuke Inoue, Atsuski Yamada
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Patent number: 6308115Abstract: A vehicle running condition judgment device for accurately detecting a change in a road surface condition and a vehicle's limit running condition. With substitution of respective tire characteristics and a detected state quantity into a vehicle motion model, vehicle slip angles are estimated for respective assumed road surface conditions. Based on the current state quantity and the last estimated vehicle slip angle, currently estimated vehicle slip angles for the respective assumed road surface conditions are compensated. A differential operation section calculates an estimation value of a vehicle slip angular velocity for each of the assumed road surface conditions based on the compensated vehicle slip angles for the respective assumed road surface conditions. Meanwhile, an operation section calculates a detection value of a vehicle slip angular velocity based on the detected state quantity.Type: GrantFiled: July 28, 1999Date of Patent: October 23, 2001Assignees: Kabushiki Kaisha Toyota Chuo Kenkyusho, Aishin Seiki Kabushiki KaishaInventors: Hiroyuki Yamaguchi, Katsuhiro Asano, Kenji Tozu, Takayuki Itoh, Akitaka Nishio
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Patent number: 6278929Abstract: The present invention is directed to a vehicle motion control system, which includes a hydraulic braking pressure control apparatus for controlling braking force applied to each wheel of a vehicle at least in response to depression of a brake pedal. A vehicle condition monitor is disposed in the vehicle for monitoring a condition of the vehicle in motion, and a vehicle condition determining device is provided for determining stability of the vehicle in motion, including a turning motion of the vehicle on the basis of the output of the monitor. A braking force controller is provided for controlling the pressure control apparatus in response to the result of determination of the vehicle condition determining device to control the braking force applied to each wheel of the vehicle.Type: GrantFiled: October 26, 1999Date of Patent: August 21, 2001Assignee: Aisin Seiki Kabushiki KaishaInventors: Kenji Tozu, Takayuki Itoh
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Patent number: 6259453Abstract: A method for automatically generating a mesh (e.g., a quadrilateral mesh, a hexahedral mesh, and the like) includes inputting a geometric model to be meshed, generating a plurality of bubbles within a region of the geometric model, determining a stable allocation of the bubbles by moving the bubbles using a force defined by a potential field provided for the bubbles and controlling a number of the bubbles, and generating the mesh by connecting centers of adjacent bubbles.Type: GrantFiled: October 13, 1998Date of Patent: July 10, 2001Assignee: International Business Machines CorporationInventors: Takayuki Itoh, Keisuke Inoue, Atsushi Yamada, Tomotake Furuhata
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Patent number: 6206490Abstract: The present invention is directed to a brake control system for a vehicle, wherein a first valve device for opening or closing a main passage, which communicates a master cylinder with wheel brake cylinders, a hydraulic pressure pump for supplying the hydraulic pressure to the main passage, and a second valve device for opening or closing an auxiliary passage, which communicates the inlet of the pressure pump with the master cylinder, are disposed in each hydraulic pressure circuit of a dual hydraulic pressure circuit system.Type: GrantFiled: November 25, 1998Date of Patent: March 27, 2001Assignee: Aisin Shiki Kabushiki KaishaInventors: Kenji Tozu, Takayuki Itoh, Masanobu Fukami, Satoshi Yokoyama
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Patent number: 6196643Abstract: A brake control apparatus includes a first valve to open and close a main line between a master cylinder and a wheel cylinder, a pump connected between a first valve and the wheel cylinder to supply pressurized brake fluid to the wheel cylinder, an auxiliary line connecting the inlet side of the pump to a master cylinder, a second valve to open and close the auxiliary line, a pressure sensor to detect the output pressure of the master cylinder and an electronic control unit which controls the first valve, the second valve, and the pump based upon the pressure detected by the pressure sensor so that the wheel cylinder receives a higher pressure than that of the master cylinder. The electronic control unit also closes the second valve while the pressure sensor detects the pressure over a certain pressure determined by the road surface condition.Type: GrantFiled: December 28, 1998Date of Patent: March 6, 2001Assignee: Aisin Seiki Kabushiki KaishaInventors: Satoshi Yokoyama, Kenji Tozu, Masanobu Fukami, Takayuki Itoh
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Patent number: 6179396Abstract: A brake control apparatus includes a first valve for opening and closing a main line, a pump having an inlet port and an outlet port to supply pressurized brake fluid to a point between the main line and the wheel cylinder, an auxiliary line Mfc connecting the inlet port of the pump to a master cylinder, a second valve for opening and closing the auxiliary line, a brake operation sensor for detecting the operation of a brake pedal, and an electronic controller which controls the first valve, the second valve, and the hydraulic pump. The electronic controller judges the need for brake assist control based on the detection by the brake operation sensor and controls the first valve, the second valve and the pump to perform the brake assist control. The electronic control unit also controls the duty ratio for the second valve based on the detection of the brake operation sensor.Type: GrantFiled: December 28, 1998Date of Patent: January 30, 2001Assignee: Aisin Seiki Kabushiki KaishaInventors: Masanobu Fukami, Kenji Tozu, Takayuki Itoh, Satoshi Yokoyama
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Patent number: 6124857Abstract: A quadrilateral or a hexahedron is used for a virtual object. If, for example, a quadrilateral mesh is composed of perfect squares and a voronoi diagram is dual to them, it is considered that the voronoi diagram comprises the perfect squares whose centers are connected to be a quadrilateral mesh. Accordingly, the quadrilateral mesh is generated by filling the object to be meshed with quadrilateral virtual objects corresponding to the voronoi diagram and connecting their centers.Type: GrantFiled: August 12, 1998Date of Patent: September 26, 2000Assignee: International Business Machines CorporationInventors: Takayuki Itoh, Keisuke Inoue, Atsushi Yamada, Kenji Shimada
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Patent number: 6121973Abstract: A method and appatatus for generating a quadrilateral mesh comprising a plurality of quadrilateral elements from a triangular mesh comprising a plurality of triangular elements by performing the following operations: for each candidate quadrilateral element comprising a pair of adjacent triangular elements (also referred to as a pair of adjacent triangular elements in embodiments), calculating a first evaluation value which represents a relationship between the candidate quadrilateral element and an alignment direction of quadrilateral elements specified by a user and a second evaluation value which relates to the shape of the candidate quadrilateral element; and selecting, by using the first and the second evaluation values, a candidate quadrilateral element to be used as an element of the quadrilateral mesh among the candidate quadrilateral elements.Type: GrantFiled: August 12, 1998Date of Patent: September 19, 2000Assignee: International Business Machines CorporationInventors: Takayuki Itoh, Tomotake Furuhata, Kenji Shimada
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Patent number: 6120113Abstract: The present invention is directed to a hydraulic braking system for an automotive vehicle, wherein a first passage is provided for communicating a master cylinder with first and second wheel cylinders. First and second pressure control devices are disposed in the first passage to control the hydraulic pressure of the brake fluid in the first and second wheel cylinders, respectively. A second passage is provided for communicating the master cylinder with an inlet of an auxiliary pressure source, which introduces the brake fluid from the wheel cylinders, and discharges the pressurized brake fluid to the wheel cylinders through the pressure control devices.Type: GrantFiled: April 22, 1997Date of Patent: September 19, 2000Assignee: Aisin Seiki Kabushiki KaishaInventors: Norio Yamazaki, Yoshiyuki Yasui, Kenji Tozu, Masanobu Fukami, Takayuki Itoh, Seiichi Kojima
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Patent number: 6106080Abstract: The present invention is directed to a brake control system for a vehicle, which includes a master cylinder for pressurizing the brake fluid to discharge a master cylinder pressure in response to depression of a brake pedal, a modulator disposed between the master cylinder and a wheel brake cylinder for selecting a pressure control mode out of rapid pressure increase, pulse pressure increase, pulse pressure decrease, rapid pressure decrease and hold modes, a hydraulic pressure pump for discharging the pressurized brake fluid to the wheel brake cylinder through the modulator, and a reservoir for storing the brake fluid drained from the wheel brake cylinder through the modulator. A normally open first switching valve is disposed between the master cylinder and the modulator, and a normally closed second switching valve is disposed between the master cylinder and an inlet of the pressure pump.Type: GrantFiled: August 25, 1998Date of Patent: August 22, 2000Assignee: Aisin Seiki Kabushiki KaishaInventors: Kenji Tozu, Takayuki Itoh, Norio Yamazaki, Satoshi Yokoyama
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Patent number: 6078858Abstract: The present invention is directed to a vehicle motion control system for maintaining vehicle stability by controlling a braking force applied to each wheel of the vehicle. In the system, a control map setting unit is adapted to set plural control maps with an x-axis of a slip rate deviation between a desired slip rate and an actual slip rate, and a y-axis of a vehicle acceleration deviation between a vehicle acceleration and a wheel acceleration for each wheel, respectively. Each control map has an origin determined by the desired slip rate and the vehicle acceleration provided for each control mode. A pressure mode setting unit is adapted to set a pressure mode for a pressure control apparatus in each control mode. The pressure mode is set according to a location determined by the slip rate deviation and the vehicle acceleration deviation on the control map. A reference map setting unit is adapted to set a reference map with an x-axis of the slip rate and a y-axis of the vehicle acceleration.Type: GrantFiled: January 20, 1998Date of Patent: June 20, 2000Assignee: Aisin Seiki Kabushiki KaishaInventors: Kenji Tozu, Takayuki Itoh, Norio Yamazaki
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Patent number: 6070952Abstract: The present invention is directed to a braking force control system for an automotive vehicle having a hydraulic braking pressure control apparatus which is provided for applying the braking force to each of front and rear wheels of the vehicle at least in response to depression of a brake pedal. A desired yaw rate is set in accordance with a motion of the vehicle, and an actual yaw rate of the vehicle is measured. A varying rate of the desired yaw rate is calculated, and a varying rate of the actual yaw rate is calculated. Then, a deviation between the varying rate of the desired yaw rate and the varying rate of the actual yaw rate is calculated. And, a limitation unit is provided for actuating the hydraulic braking pressure control apparatus to limit the varying rate of the actual yaw rate by applying the braking force to at least one of the wheels, when the deviation exceeds a predetermined value.Type: GrantFiled: May 9, 1997Date of Patent: June 6, 2000Assignee: Aisin Seiki Kabushiki KaishaInventors: Kenji Tozu, Yoshiyuki Yasui, Masanobu Fukami, Takayuki Itoh, Norio Yamazaki
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Patent number: 6039411Abstract: The present invention is directed to a brake control system, which includes a first pressure circuit and a second pressure circuit for communicating a master cylinder with two sets of wheel cylinders, respectively. In each pressure circuit, a modulator is arranged to modulate the braking pressure in each wheel cylinder, a pressure pump is disposed to supply pressurized brake fluid to each wheel cylinder through each modulator, a normally open first valve is arranged to open or close a first passage for communicating the master cylinder with the modulator, and a normally closed second valve is arranged to open or close a second passage for communicating a reservoir directly with the inlet of each pump, or communicating the reservoir with it through the master cylinder. The pressurized brake fluid is supplied to each pressure circuit including the second valve at the inlet of the pump to perform an auxiliary pressurization.Type: GrantFiled: April 29, 1999Date of Patent: March 21, 2000Assignee: Aisin Seiki Kabushiki KaishaInventors: Kenji Tozu, Takayuki Itoh, Masanobu Fukami, Satoshi Yokoyama
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Patent number: 5935186Abstract: The present invention is directed to a monitor system for use in an automotive vehicle which includes wheel brake cylinders operatively mounted on wheels, respectively, and which includes a hydraulic pressure control apparatus for generating a hydraulic braking pressure in response to depression of a brake pedal. A difference calculating unit calculates a difference between a wheel speed of a wheel to be determined and a wheel speed of at least one reference wheel which is compared with a predetermined value, when a braking operation detection unit detects a braking operation. Then, a determination unit compares the difference with a predetermined value, and determines that the pressure circuit provided for the wheel to be determined is normal, when the difference is lower than the predetermined value. An output unit may be provided to produce an output signal when a period of time during which the difference continues to be equal to or greater than the predetermined value, exceeds a predetermined time.Type: GrantFiled: November 15, 1996Date of Patent: August 10, 1999Assignee: Aisin Seiki Kabushiki KaishaInventors: Norio Yamazaki, Kenji Tozu, Yoshiyuki Yasui, Masanobu Fukami, Takayuki Itoh
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Patent number: 5927830Abstract: The present invention is directed to a vehicle motion control system for maintaining vehicle stability by controlling the braking force applied to at least one wheel of a vehicle. A vehicle condition monitor is provided for monitoring a condition of the vehicle in motion. The braking force is applied by a braking apparatus to each wheel in response to depression of a brake pedal, and on the basis of an output of the monitor and irrespective of depression of the brake pedal. A control variable is provided for actuating the braking apparatus and set in accordance with at least a first parameter (e.g., wheel acceleration) and a second parameter (e.g., slip rate) which are provided on the basis of the output of the monitor, respectively, so that the control variable is varied in response to the output of the monitor. The control variable is integrated during the braking apparatus is actuated.Type: GrantFiled: November 27, 1996Date of Patent: July 27, 1999Assignee: Aisin Seiki Kabushiki KaishaInventors: Kenji Tozu, Yoshiyuki Yasui, Masanobu Fukami, Takayuki Itoh, Norio Yamazaki
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Patent number: 5913578Abstract: The present invention is directed to a vehicle motion control system for maintaining stability of an automotive vehicle when the vehicle is in motion, by controlling a hydraulic braking pressure control apparatus to control a hydraulic braking pressure in each of wheel brake cylinders operatively mounted on each wheel of the vehicle to control a braking force applied thereto. A steering control unit and an anti-skid control unit are provided for actuating the apparatus to control the braking force applied to at least one of the wheels, respectively.Type: GrantFiled: October 28, 1997Date of Patent: June 22, 1999Assignee: Aisin Seiki Kabushiki KaishaInventors: Kenji Tozu, Yoshiyuki Yasui, Takayuki Itoh, Norio Yamazaki