Patents by Inventor Junichi Hirata
Junichi Hirata 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: 20230256957Abstract: Provided is a vehicle posture control device configured to be installed in a vehicle provided with an actuator configured to generate a roll moment. The device includes a roll moment calculator (24) and an actuator controller (25). The roll moment calculator (24) is configured to calculate a roll moment command value to control the actuator such that a roll motion is generated in conjunction with a yaw motion in the vehicle (1) during turning thereof. The roll moment calculator (24) is configured to calculate the roll moment command value for output, on the basis of a sideslip angular velocity and a vehicle velocity of the vehicle. The actuator controller (25) is configured to control the actuator by using the calculated roll moment command value.Type: ApplicationFiled: April 13, 2023Publication date: August 17, 2023Applicants: NTN CORPORATION, SCHOOL JUDICIAL PERSON IKUTOKU GAKUENInventors: Junichi HIRATA, Makoto YAMAKADO
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Patent number: 11207984Abstract: Provided is a drive source control device (67) for controlling two drive sources (2L, 2R) of a vehicle. The vehicle including the two drive sources (2L, 2R), left and right drive wheels (61L, 61R), and a power transmission device (3) disposed among the two drive sources (2L, 2R) and the drive wheels (61L, 61R). The device (3) distributes powers from the two drive sources (2L, 2R) to the wheels (61L, 61R) to drive the wheels (61L, 61R). The drive source control device (67) includes: an angular acceleration calculation (71) to calculate angular accelerations of the drive wheels (61L, 61R) and/or angular accelerations of the drive sources (2L, 2R); and a torque correction (68) to, using the angular accelerations calculated by the angular acceleration calculation (71), correct command values for respective outputs of the drive sources (2L, 2R).Type: GrantFiled: April 1, 2019Date of Patent: December 28, 2021Assignee: NTN CORPORATIONInventor: Junichi Hirata
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Patent number: 11110805Abstract: The control device (67) includes a rotational speed calculator (68), a bearing torque estimator (69), a torque difference calculator (70) and a drive source torque calculator (71). The rotational speed calculator (68) calculates rotational speeds of first and second connection members. The bearing torque estimator (69) estimates a bearing torque, from the calculated, two rotational speeds. The torque difference calculator (70) calculates a target torque difference between torques to be generated by respective drive sources, from the estimated bearing torque, a torque difference amplification factor (?), and a difference between drive wheel torque command values for respective left and right drive wheels. The drive source torque calculation module (71) calculates drive source torque command values, which are torques to be generated by the respective, left and right drive sources, using the calculated, target torque difference and the drive wheel torque command values for the respective wheels.Type: GrantFiled: March 6, 2019Date of Patent: September 7, 2021Assignee: NTN CORPORATIONInventor: Junichi Hirata
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Patent number: 10780878Abstract: The vehicle turning control device for a vehicle includes a first road surface frictional coefficient calculator (22), a second road surface frictional coefficient calculator (25), a control gain calculator (23), a target yaw rate calculator (21), a target yaw rate corrector (27), a first braking/driving force calculator (24), and a second braking/driving force calculator (28). A second road surface frictional coefficient ?2 is obtained without braking/driving forces for respective wheels (2) being taken into consideration, and thus has a magnitude smaller than or equal to the magnitude of a first road surface frictional coefficient ?1. A braking/driving force command value calculator (29) calculates a braking/driving force command value from a braking/driving force (FA) and a braking/driving force (FB) which are respectively calculated with use of the first and second road surface frictional coefficients ?1 and ?2.Type: GrantFiled: May 17, 2017Date of Patent: September 22, 2020Assignee: NTN CORPORATIONInventor: Junichi Hirata
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Patent number: 10773599Abstract: Provided is a drive source control device that can suppress increase in the rotation speed of a drive source. This drive source control device (67) includes: an overspeed determination module (68) to determine whether the rotation speed of each of two drive sources (2L, 2R) is overspeed; and a correction module (69) to, when the overspeed determination module (68) determines that the rotation speed of at least one of the drive sources is overspeed, correct command values for outputs of the two drive sources, supplied from a command module (66a). The correction module (69) corrects the command values of the outputs of the two drive sources (2L, 2R) so that the torque of the drive wheel having greater rotation speed decreases from the torque before the correction, and the torque of the drive wheel having smaller rotation speed maintains or decreases from the torque before the correction.Type: GrantFiled: April 4, 2019Date of Patent: September 15, 2020Assignee: NTN CORPORATIONInventor: Junichi Hirata
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Publication number: 20190232799Abstract: Provided is a drive source control device (67) for controlling two drive sources (2L, 2R) of a vehicle. The vehicle including the two drive sources (2L, 2R), left and right drive wheels (61L, 61R), and a power transmission device (3) disposed among the two drive sources (2L, 2R) and the drive wheels (61L, 61R). The device (3) distributes powers from the two drive sources (2L, 2R) to the wheels (61L, 61R) to drive the wheels (61L, 61R). The drive source control device (67) includes: an angular acceleration calculation (71) to calculate angular accelerations of the drive wheels (61L, 61R) and/or angular accelerations of the drive sources (2L, 2R); and a torque correction (68) to, using the angular accelerations calculated by the angular acceleration calculation (71), correct command values for respective outputs of the drive sources (2L, 2R).Type: ApplicationFiled: April 1, 2019Publication date: August 1, 2019Applicant: NTN CORPORATIONInventor: Junichi HIRATA
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Publication number: 20190225094Abstract: Provided is a drive source control device that can suppress increase in the rotation speed of a drive source. This drive source control device (67) includes: an overspeed determination module (68) to determine whether the rotation speed of each of two drive sources (2L, 2R) is overspeed; and a correction module (69) to, when the overspeed determination module (68) determines that the rotation speed of at least one of the drive sources is overspeed, correct command values for outputs of the two drive sources, supplied from a command module (66a). The correction module (69) corrects the command values of the outputs of the two drive sources (2L, 2R) so that the torque of the drive wheel having greater rotation speed decreases from the torque before the correction, and the torque of the drive wheel having smaller rotation speed maintains or decreases from the torque before the correction.Type: ApplicationFiled: April 4, 2019Publication date: July 25, 2019Applicant: NTN CORPORATIONInventor: Junichi HIRATA
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Publication number: 20190202309Abstract: The control device (67) includes a rotational speed calculator (68), a bearing torque estimator (69), a torque difference calculator (70) and a drive source torque calculator (71). The rotational speed calculator (68) calculates rotational speeds of first and second connection members. The bearing torque estimator (69) estimates a bearing torque, from the calculated, two rotational speeds. The torque difference calculator (70) calculates a target torque difference between torques to be generated by respective drive sources, from the estimated bearing torque, a torque difference amplification factor (?), and a difference between drive wheel torque command values for respective left and right drive wheels. The drive source torque calculation module (71) calculates drive source torque command values, which are torques to be generated by the respective, left and right drive sources, using the calculated, target torque difference and the drive wheel torque command values for the respective wheels.Type: ApplicationFiled: March 6, 2019Publication date: July 4, 2019Applicant: NTN CORPORATIONInventor: Junichi HIRATA
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Publication number: 20190176812Abstract: The vehicle turning control device for a vehicle includes a first road surface frictional coefficient calculator (22), a second road surface frictional coefficient calculator (25), a control gain calculator (23), a target yaw rate calculator (21), a target yaw rate corrector (27), a first braking/driving force calculator (24), and a second braking/driving force calculator (28). A second road surface frictional coefficient ?2 is obtained without braking/driving forces for respective wheels (2) being taken into consideration, and thus has a magnitude smaller than or equal to the magnitude of a first road surface frictional coefficient ?1. A braking/driving force command value calculator (29) calculates a braking/driving force command value from a braking/driving force (FA) and a braking/driving force (FB) which are respectively calculated with use of the first and second road surface frictional coefficients ?1 and ?2.Type: ApplicationFiled: May 17, 2017Publication date: June 13, 2019Applicant: NTN CorporationInventor: Junichi HIRATA
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Patent number: 9555721Abstract: A slip control device for an electric automobile includes a maximum rotation frequency calculator to calculate a drive wheel maximum rotation frequency Nmax on the basis of a rotation frequency N1 of a driven wheel and an ideal slip ratio ?min according to the formula (Nmax?N1)/N1=?min. It is determined whether a drive wheel rotation frequency N2 exceeds the frequency Nmax. If it is determined that the frequency N2 exceeds the frequency Nmax, a torque command value to a motor unit is made to be zero.Type: GrantFiled: November 24, 2015Date of Patent: January 31, 2017Assignee: NTN CORPORATIONInventors: Yingjie Zhang, Junichi Hirata
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Patent number: 9475396Abstract: A slip control device for an electric vehicle which determines without error slippage occurrence with only a rotation angle sensor for motor rotation control and perform rapid control to eliminate the slippage. A threshold calculator calculates a normal angular acceleration of a motor depending on a manipulation amount of an accelerator to obtain a threshold, and an angular acceleration calculator differentiates a detection value from a rotation angle sensor twice to calculate an angular acceleration. A slip determination determines whether a wheel driven by a motor has slipped, and a torque limitation limits a torque when determining a slippage. The determination compares the calculated acceleration to the threshold, counts a number of times it is consecutively determined that the calculated acceleration exceeds the threshold, and determines a slippage if the number of times has reached a set value.Type: GrantFiled: November 24, 2015Date of Patent: October 25, 2016Assignee: NTN CORPORATIONInventors: Yingjie Zhang, Junichi Hirata
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Patent number: 9423290Abstract: An effective value operation unit calculates an effective value of a vibration waveform of a bearing, the vibration waveform being measured by using a vibration sensor. An envelope processing unit performs envelope processing on the vibration waveform measured by using the vibration sensor, thereby generating an envelope waveform of the vibration waveform. An effective value operation unit calculates an effective value of an AC component of the envelope waveform generated by the envelope processing unit. A diagnostic unit diagnoses an abnormality of the bearing based on the effective value of the vibration waveform calculated by the effective value operation unit and the effective value of the AC component of the envelope waveform calculated by the effective value operation unit.Type: GrantFiled: December 24, 2010Date of Patent: August 23, 2016Assignee: NTN CORPORATIONInventors: Tomoya Sakaguchi, Nobuyuki Ninoyu, Junichi Hirata, Yasuhiko Sakakibara
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Publication number: 20160075256Abstract: A slip control device for an electric automobile which assuredly eliminates a slippage with a simple configuration without involving a wasted decrease in running performance, is provided. A maximum rotation frequency calculator 22 calculates a drive wheel maximum rotation frequency Nmax on the basis of a rotation frequency N1 of a driven wheel and an ideal slip ratio ?min according to the following formula, (Nmax?N1)/N1=?min. It is determined whether a drive wheel rotation frequency N2 exceeds the frequency Nmax. If it is determined that the frequency N2 exceeds the frequency Nmax, a torque command value to a motor unit 3 is made to be zero.Type: ApplicationFiled: November 24, 2015Publication date: March 17, 2016Applicant: NTN CORPORATIONInventors: Yingjie ZHANG, Junichi HIRATA
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Publication number: 20160075237Abstract: A slip control device for an electric vehicle which errorlessly determines slippage occurrence with only a rotation angle sensor for motor rotation control and perform rapid control to eliminate the slippage, is provided. A threshold calculator 21 calculates a normal angular acceleration of a motor depending on a manipulation amount of an accelerator to obtain a threshold, and an angular acceleration calculator 22 differentiates a detection value from a rotation angle sensor 3a twice to calculate an angular acceleration. A slip determination 23 determines whether a wheel 7 driven by a motor 3 has slipped, and a torque limitation 25 limits a torque when determining a slippage. The determination 23 compares the calculated acceleration to the threshold, counts a number of times it is consecutively determined that the calculated acceleration exceeds the threshold, and determines a slippage if the number of times has reached a set value.Type: ApplicationFiled: November 24, 2015Publication date: March 17, 2016Applicant: NTN CORPORATIONInventors: Yingjie ZHANG, Junichi HIRATA
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Publication number: 20140284122Abstract: Included are an elastic support mechanism (10) and a shock absorber (11) in a suspension (3) interposed between an in-wheel motor device (1) and a vehicle body structure (2). The elastic support mechanism (10) can change a modulus of elasticity and the shock absorber (11) can change a damping force. The provision is made of a resonance monitoring unit (21) to monitor whether or not a rotational speed of a motor (7) falls within a predetermined resonance frequency range. When the rotational speed of the motor (7) is determined as falling within the resonance frequency range, an elastic modulus control unit (22) changes the modulus of elasticity, and a damping force control unit (23) changes the damping force of the shock absorber (11).Type: ApplicationFiled: October 25, 2012Publication date: September 25, 2014Inventor: Junichi Hirata
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Publication number: 20130006540Abstract: An effective value operation unit calculates an effective value of a vibration waveform of a hearing, the vibration waveform being measured by using a vibration sensor. An envelope processing unit performs envelope processing on the vibration waveform measured by using the vibration sensor, thereby generating an envelope waveform of the vibration waveform. An effective value operation unit calculates an effective value of an AC component of the envelope waveform generated by the envelope processing unit. A diagnostic unit diagnoses an abnormality of the bearing based on the effective value of the vibration waveform calculated by the effective value operation unit and the effective value of the AC component of the envelope waveform calculated by the effective value operation unit.Type: ApplicationFiled: December 24, 2010Publication date: January 3, 2013Inventors: Tomoya Sakaguchi, Nobuyuki Ninoyu, Junichi Hirata, Yasuhiko Sakakibara
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Patent number: 8240919Abstract: A hydrostatic bearing pad in which separation between a housing and a pad member and entry of an adhesive into an air supply groove are prevented to obtain stable bearing performance is provided. The hydrostatic bearing pad includes the pad member having a bearing surface forming a hydrostatic bearing and having air supply holes formed therein, and the housing bonded to the pad member with the adhesive. The air supply groove for supplying compressed gas to the pad member is formed in a surface of the housing bonded to the pad member in a manner corresponding to arrangement of the air supply holes. An adhesive inflow groove, is formed between a bonded portion, where the housing and the pad member are bonded to each other with the adhesive interposed therebetween and the air supply groove. The adhesive inflow groove, is formed along the air supply groove in the surface of the housing bonded to the pad member.Type: GrantFiled: April 18, 2008Date of Patent: August 14, 2012Assignee: NTN CorporationInventor: Junichi Hirata
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Patent number: 8162544Abstract: A gas bearing spindle includes a rotation shaft, a sleeve, and a housing. The sleeve includes a bearing portion formed of a nonmetallic sintered body; and a retaining ring formed of a metal. Further, the retaining ring and the bearing portion are in contact with each other at a first fit surface that is a boundary surface between the outer circumferential surface of the bearing portion and the inner circumferential surface of the retaining ring, as well as at a second fit surface that is a boundary surface between the outer circumferential surface of the bearing portion and the inner circumferential surface of the retaining ring, is distant further away from the sleeve through hole relative to the first fit surface, and is formed adjacent to a center of the sleeve through hole in a direction in which the sleeve through hole extends, when viewed from the first fit surface.Type: GrantFiled: April 28, 2010Date of Patent: April 24, 2012Assignee: NTN CorporationInventor: Junichi Hirata
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Patent number: 8052327Abstract: A hydrostatic gas bearing capable of easily adjusting a clearance between a rotor and a radial bearing pad is provided. This hydrostatic gas bearing comprises a radial bearing pad radially supporting a rotor, a linear motion guide moving the radial bearing pad and a ball stud swingably coupling the radial bearing pad to the linear motion guide. The linear motion guide moves the radial bearing pad in a direction intersecting with a direction connecting the center of rotation of the rotor and the ball stud with each other. The quantity of adjustment in movement of the radial bearing pad caused by the linear motion guide is larger than the quantity of change in the clearance between the outer peripheral surface of the rotor and the radial bearing pad, whereby a small quantity of the bearing clearance can be precisely adjusted.Type: GrantFiled: June 4, 2008Date of Patent: November 8, 2011Assignee: NTN CorporationInventors: Yoshio Fujikawa, Junichi Hirata
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Publication number: 20100284638Abstract: A gas bearing spindle includes a rotation shaft, a sleeve, and a housing. The sleeve includes a bearing portion formed of a nonmetallic sintered body; and a retaining ring formed of a metal. Further, the retaining ring and the bearing portion are in contact with each other at a first fit surface that is a boundary surface between the outer circumferential surface of the bearing portion and the inner circumferential surface of the retaining ring, as well as at a second fit surface that is a boundary surface between the outer circumferential surface of the bearing portion and the inner circumferential surface of the retaining ring, is distant further away from the sleeve through hole relative to the first fit surface, and is formed adjacent to a center of the sleeve through hole in a direction in which the sleeve through hole extends, when viewed from the first fit surface.Type: ApplicationFiled: April 28, 2010Publication date: November 11, 2010Inventor: Junichi Hirata