Patents by Inventor Sanshiro Obara
Sanshiro Obara 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: 5495908Abstract: A control system for an electric car includes a motor connected to a battery as a main power source for driving the electric car, a strong electricity unit having high voltage devices including an inverter for driving the motor based on power supplied thereto from the battery, a weak electricity unit having low voltage circuits including a microcomputer for data processing, and connection devices for connecting the strong and weak electricity units in such a relationship that a signal path is connected between the units as electrically isolated therefrom, wherein signal transmission between the strong and weak electricity units is carried out with use of the signals isolated between the units.Type: GrantFiled: October 5, 1993Date of Patent: March 5, 1996Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.Inventors: Sanshiro Obara, Hiroyuki Yamada, Shigeyuki Yoshihara, Nobunori Matsudaira
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Patent number: 5481168Abstract: An electric vehicle torque controller has a torque calculating unit and an actuate torque detecting unit. The calculated torque signal is compared with the actual torque to generate a torque compensation value, which is converted to a torque current signal. The torque current signal is used to a slip frequency, which is added to the output of an angular speed detector and used to set a secondary magnetic flux value. A secondary magnetic flux signal is generated according to the secondary magnetic flux value and the torque current signal. A secondary magnetic flux estimating unit generates an estimated secondary magnetic flux value, which is used to determine the exciting current. Primary motor current is controlled in response to the exciting current, the torque current, motor speed and slip value.Type: GrantFiled: January 28, 1994Date of Patent: January 2, 1996Assignee: Hitachi, Ltd.Inventors: Nobuyoshi Mutoh, Taizou Miyazaki, Ryoso Masaki, Tsutomu Ohmae, Sanshiro Obara
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Patent number: 5467275Abstract: An electric vehicle control unit capable of position control so that the vehicle can be held in its stop position without vibration, even if an operator does not keep the brake pressed. The control circuit of the electric vehicle comprises a speed/torque instruction generation circuit, a position control selection circuit, a position instruction generation circuit and a motor control circuit. When the vehicle stops, control of the motor is changed from speed or torque control to position control.Type: GrantFiled: March 19, 1993Date of Patent: November 14, 1995Assignee: Hitachi, Ltd.Inventors: Yuusuke Takamoto, Ryoso Masaki, Sanshiro Obara, Satoru Kaneko
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Patent number: 5418932Abstract: A pulse generating device according to the present invention is operated in accordance with a pulse control command including output time data about output pulse given from external equipment such as a CPU. The pulse control command including the output time data about the output pulses is transferred to a master memory of a contents addressable memory at an optional timing from outside. The contents of that master memory are copied to a slave memory in response to copy enable signals transmitted from a copy enable device. The copy enable signals are transmitted whenever a predetermined number synchronizing signals showing an end of the pulse period are generated from the interval timer. The contents addressable memory reads out the output control command of the output pulse from a slave memory when the timer value of the interval timer coincides with the time data of the slave memory. The output control circuit transmits output pulses which correspond to the control command read out as described above.Type: GrantFiled: February 1, 1991Date of Patent: May 23, 1995Assignee: Hitachi, Ltd.Inventors: Mitsuru Watabe, Sanshiro Obara, Rika Oue, Shigeki Morinaga
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Patent number: 5357181Abstract: An object of the present invention is to secure safe driving of electric vehicles by enabling torque control regardless of sensor disorder. In the present invention, the mode of current sensor disorder is detected by a sensor disorder detection means. If it is found as a result that only 1 out of 3 current sensors is failing, the current of the failing current sensor is estimated by 2 normal current sensors and the torque control of the motor is continued by the ordinary torque control system. If 2 or more current sensors are found to be failing, a torque control system based on an AC current reference operation means is formed to control the motor torque based on the AC current reference. If a sensor failure detection means determines that only 1 phase is failing in the speed sensor, the motor torque is controlled by using the remaining 1 phase to detect the rotating angular speed of the motor.Type: GrantFiled: October 8, 1993Date of Patent: October 18, 1994Assignee: Hitachi, Ltd.Inventors: Nobuyoshi Mutoh, Ryoso Masaki, Tsutomu Omae, Sanshiro Obara, Shotaro Naito
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Patent number: 5355749Abstract: A control apparatus of a motor drive vehicle includes a unit for generating a target vehicle speed; a speed instruction unit for generating a target motor rotational speed of the motor based upon a preset motor control pattern in response to the target vehicle speed; a power circuit for operating the motor at the target motor rotational speed upon receipt of the target motor rotational speed; a variable transmission unit for converting a drive output from the motor into a transmission ratio for instructing a rotational speed of the drive output, and transferring the converted transmission ratio to a drive shaft of the motor drive vehicle; and a transmission ratio calculating unit for determining the transmission gear ratio based on the target vehicle speed and the target motor rotational speed thereby to instruct the determined transmission gear ratio to the variable transmission unit.Type: GrantFiled: December 17, 1992Date of Patent: October 18, 1994Assignee: Hitachi, Ltd.Inventors: Sanshiro Obara, Ryoso Masaki, Toshiaki Okuyama, Tsutomu Ohmae, Keigo Naoi, Makoto Shioya
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Patent number: 5349351Abstract: An analog-digital converting device is designed such that when an operation of converting a special analog signal into a digital signal and an operation of converting another analog signal into a digital signal are instructed concurrently, priority is given to the conversion operation of the special analog signal, The analog-digital converting device includes an analog multiplexer having a main channel and a sub channel, a sample holder, an AD converter, a conversion result register having a plurality of storage areas, and an AD control circuit for controlling the drive of the individual components according to an instruction of a CPU. When the analog signals input to the channels are converted into digital signals in sequence, priority is given to AD conversion of the analog signal input to the main channel over AD conversion of the analog signal input to the sub channel.Type: GrantFiled: September 3, 1992Date of Patent: September 20, 1994Assignee: Hitachi, Ltd.Inventors: Sanshiro Obara, Mitsuru Watabe, Rika Minami, Shigeki Morinaga
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Patent number: 5345155Abstract: An electric vehicle control system, according to the present invention, comprises at least two electric motors for independently driving left and right wheels of the vehicle, power supply unit for supplying power to the motors, unit for detecting command entered by a driver of the vehicle and driving operational amount provided for the vehicle, unit for detecting output torques of the two motors, unit for calculating a motor speed difference command signal for making the two output torques consistent with each other, unit for calculating a vehicle speed command signal for the vehicle on the basis of detected command and the driving operational amount, unit for calculating motor speed command signals for respective of the motors on the basis of calculated motor speed difference command signal and the vehicle speed command signal, unit for detecting actual speeds of the two motors, and control unit for voltage controlling supply power from the power supply unit to the motors so that the detected actual speeds oType: GrantFiled: March 25, 1992Date of Patent: September 6, 1994Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.Inventors: Ryoso Masaki, Yuusuke Takamoto, Sanshiro Obara, Hirohisa Yamamura, Hiroyuki Yamada
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Patent number: 5309073Abstract: An electric vehicle control device is disclosed, which includes an AC motor for driving a vehicle; a main electric power conversion unit for supplying an AC voltage to the AC motor; a battery for supplying a DC voltage to the main electric power conversion unit; an auxiliary electric power conversion unit connected to the battery and adapted to be connected to a load or a power supply; a controller for controlling the main and auxiliary electric power conversion units so as to act selectively as an inverter or a converter; and a switching unit for giving selectively the AC motor the AC voltage from the main and auxiliary electric power conversion units under control of the controller. In the running mode of the electric vehicle, the controller described above makes the main electric power conversion unit act as an inverter and controls the switching unit so that the AC voltage from the main electric power conversion unit is given to the AC motor.Type: GrantFiled: October 20, 1992Date of Patent: May 3, 1994Assignee: Hitachi, Ltd.Inventors: Satoru Kaneko, Ryoso Masaki, Sanshiro Obara, Tsutomu Ohmae, Yuusuke Takamoto, Hirohisa Yamamura
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Patent number: 5289517Abstract: A digital pulse processing device is capable of selecting desired precision. The digital pulse processing device includes a counter group for counting pulses output from a pulse output device, the counter group having a plurality of counters A and B that can be separated from and coupled with each other, a mode control circuit for instructing separation and coupling of the counters A and B, and a control circuit for separating and coupling the counters A and B in accordance with the instruction of the mode control circuit. An overflow condition of the free-run counter B is detected using an overflow flag. Detection of an overflow is conducted by setting the flag when an overflow condition has occurred twice or more. The flag is reset by rewriting the state of the flag by a software. An overflow condition which has occurred for the first time is detected in the conventional manner and is treated as carry or borrow.Type: GrantFiled: September 10, 1991Date of Patent: February 22, 1994Assignee: Hitachi, Ltd.Inventors: Mamoru Ohba, Mitsuru Watabe, Rika Minami, Sanshiro Obara
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Patent number: 4712052Abstract: A digital servo-control system used for driving a machine with a plurality of drive shafts having a digital type multi-axis position control unit, provided in common to all of the drive shafts, for computing a torque command value for each drive shaft on the basis of a position detection value detected by a position detector provided for each drive shaft and a position command value for each drive shaft, and torque control units, respectively provided in correspondence to a plurality of motors adapted to drive the respective drive shafts, for controlling output torque of a corresponding motor in accordance with the computed torque command value.Type: GrantFiled: October 3, 1985Date of Patent: December 8, 1987Assignee: Hitachi, Ltd.Inventors: Tsutomu Omae, Sanshiro Obara, Kenji Kubo, Masahiko Watanabe
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Patent number: 4481819Abstract: A method and apparatus for detecting metal wipe damages of plane bearings with the metal wipe generating an ultrasonic signal as an acoustic emission signal when it occurs. The ultrasonic signal has a periodic appearance therefore, the metal wipe damages, can be detected by monitoring the periodic nature of the ultrasonic signal. The ultrasonic signal is received by a transducer fixed to the plane bearing with the periodic nature of the received ultrasonic signal being computed by a processing unit so as to provide a output signal of the occurrence of a metal wipe when the received ultrasonic signal is periodic.Type: GrantFiled: February 9, 1983Date of Patent: November 13, 1984Assignee: Hitachi, Ltd.Inventors: Takao Yoneyama, Ichiya Satoh, Sanshiro Obara, Tomoaki Inoue, Tsuguaki Koga
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Patent number: 4373379Abstract: Presented are a method and apparatus for detecting defect in the water cooling system, e.g. cracking, of a hydrogen-cooled dynamic electric machine. The stator core of the hydrogen-cooled dynamic electric machine is cooled from its inside by cooling water circulated therethrough. When a defect such as crack is caused in the water cooling system, the hydrogen gas leaks into the cooling water. The hydrogen gas is then conveyed by the cooling water to a cooling water supply tank to which the water is recirculated and is accumulated in the upper free space in the water supply tank. Carrier air is forcibly blown into the upper free space of the water supply pipe to prevent the hydrogen concentration from being increased to a dangerous level of explosion threshold. The hydrogen concentration is measured in this state and the defect in the water cooling system is known from the measured concentration of the hydrogen gas.Type: GrantFiled: November 25, 1980Date of Patent: February 15, 1983Assignee: Hitachi, Ltd.Inventors: Sanshiro Obara, Ikuro Miyashita
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Patent number: 4367530Abstract: A control apparatus for an internal combustion engine includes a plurality of sensors for producing signals indicative of operating conditions of the engine, an input/output unit adapted to receive sensed signals and to deliver control signals to actuators which control an energy conversion function of the engine and a central-processor unit coupled with the input/output unit and adapted to execute an arithmetic operation for producing data to be sent to the input/output unit. The input/output unit includes a first register file having a plurality of registers for storing constants and data produced by the central processor unit and a second register file having a plurality of registers for storing signals indicative of conditions of the engine as of a selected instant in time during which the engine is operative.Type: GrantFiled: January 19, 1981Date of Patent: January 4, 1983Assignee: Hitachi, Ltd.Inventors: Shigeki Morinaga, Sanshiro Obara, Hiroastu Tokuda, Hideo Nakamura
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Patent number: 4276602Abstract: An electronic control apparatus for an internal combustion engine having engine sensors, actuators, and a signal processor, contains an improved interface unit for coupling signals to the actuators in response to an output from the processor based upon sensor signals. The interface unit includes a scheme for generating event timing signals in accordance with the prescribed timing signal pattern generated by a stage pulse generator. Depending upon the operational conditions of the engine, the processor supplies a control code through which the timing signals that are produced are altered. This control code is used to alter the rate of occurrence or frequency of generation of the timing signals so that specific actuator control functions may be varied depending upon the engine operation conditions.Type: GrantFiled: July 19, 1979Date of Patent: June 30, 1981Assignee: Hitachi, Ltd.Inventors: Sanshiro Obara, Hiroatsu Tokuda, Akihiko Konno, Hideo Nakamura
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Patent number: 4058755Abstract: A speed control system for an induction motor controlled by a converting arrangement coupled with a commutatorless motor which operates without commutation failure notwithstanding wide variations in the speed of the commutatorless motor. The speed control system includes an arrangement for maintaining the value of a direct current signal of the converting arrangement less than the maximum current value for ensuring proper operation of the converting arrangement.Type: GrantFiled: January 20, 1976Date of Patent: November 15, 1977Assignee: Hitachi, Ltd.Inventors: Mitsuyuki Honbu, Sanshiro Obara, Takamasa Hori