Patents by Inventor Tsutomu Omae

Tsutomu Omae 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).

  • Patent number: 5357181
    Abstract: 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: Grant
    Filed: October 8, 1993
    Date of Patent: October 18, 1994
    Assignee: Hitachi, Ltd.
    Inventors: Nobuyoshi Mutoh, Ryoso Masaki, Tsutomu Omae, Sanshiro Obara, Shotaro Naito
  • Patent number: 5033565
    Abstract: A generator generates two voltage outputs which have different voltage levels. One voltage output from the generator is used for operating a power steering apparatus. Another voltage output from the generator is used for charging a battery which supplies current to other loads.
    Type: Grant
    Filed: October 18, 1989
    Date of Patent: July 23, 1991
    Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.
    Inventors: Toshimi Abukawa, Toshiaki Okuyama, Kazuo Tahara, Katsuji Marumoto, Toshiyuki Koterazawa, Mitsuyuki Hombu, Tadashi Takahashi, Hisatugu Ishikura, Hiroshisa Yamamura, Toru Tatsuzaki, Tsutomu Omae, Shuichi Takamatsu
  • Patent number: 4960178
    Abstract: A generator generates two voltage outputs which have different voltage levels. One voltage output from the generator is used for operating a power steering apparatus. Another voltage output from the generator is used for charging a battery which supplies current to other loads.
    Type: Grant
    Filed: September 22, 1988
    Date of Patent: October 2, 1990
    Assignees: Hitachi, Ltd., Hitachi Automotive Engineering Co., Ltd.
    Inventors: Toshimi Abukawa, Toshiaki Okuyama, Kazuo Tahara, Katsuji Marumoto, Toshiyuki Koterazawa, Mitsuyuki Hombu, Tadashi Takahashi, Hisatugu Ishikura, Hirohisa Yamamura, Toru Tatsuzaki, Tsutomu Omae, Shuichi Takamatsu
  • Patent number: 4839834
    Abstract: In a speed detecting apparatus for detecting the rotational speed of a rotating body mechanically coupled thereto, an encoder generates one cycle of a sine-wave signal each time its angular position of rotation changes by a predetermined unit amount. A zero-crossing pulse is generated at each zero-crossing point of the sine-wave signal generated from the encoder, and the phase angle of the sine-wave signal is detected on the basis of the zero-crossing point of the sine-wave signal generated from the encoder. In a high speed range, the rotational speed is detected on the basis of the ratio between the number of zero-crossing pulses and the time interval between a first one and a last one of the plural zero-crossing pulses. On the other hand, in a low speed range, the rotational speed is detected on the basis of the combination of the number of the zero-crossing pulses appearing within a predetermined period of time and the phase angle of the sine-wave signal.
    Type: Grant
    Filed: January 12, 1987
    Date of Patent: June 13, 1989
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Omae, Toshihiko Matsuda, Youjirou Miyahara, Kenzo Kamiyama
  • Patent number: 4814678
    Abstract: A speed control apparatus for a motor comprising a motor model formed of a motor current model and a motor speed model connected in cascade, a basic torque instruction signal being applied to the motor model, and first and second control loops comparing output signals from the motor current model and the motor speed model with an instantaneous actual motor current signal and an instantaneous actual motor speed signal respectively and generating first and second correction signal to be added to the basic torque instruction signal to form a corrected torque instruction signal which is applied to a motor current control circuit, whereby a speed oscillation is suppressed even when the motor is driving an oscillatory load.
    Type: Grant
    Filed: July 7, 1987
    Date of Patent: March 21, 1989
    Assignee: Hitachi, Ltd
    Inventors: Tsutomu Omae, Toshihiko Matsuda, Takashi Sukegawa, Masahiro Tobise
  • Patent number: 4772996
    Abstract: A PWM inverter includes a plurality of arms connected in parallel with a d.c. power source. Each arm is constituted by an upper arm and a lower arm each having a switching element. A plurality of switching control signals are continuously and alternately applied to one and the other of the two switching elements constituting the same arm respectively. In the PWM inverter, shunt resistors are connected between a minus terminal of the d.c. power source and the lower arms respectively. The PWM inverter further comprises a waveform command generating circuit generating commands representative of current waveforms to be supplied to a load, a carrier wave generating circuit and sample-hold circuits. Each of the sample-hold circuits samples and holds a terminal voltage of the associated shunt resistor in synchronism with the period of the carrier wave generated from the carrier wave generating circuit and at specific timing in a conduction period of the associated switching element.
    Type: Grant
    Filed: April 9, 1987
    Date of Patent: September 20, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Hiroyuki Hanei, Takeshi Hanada, Kenji Kubo, Masahiko Watanabe, Tsutomu Omae, Toshihiko Matsuda
  • Patent number: 4753309
    Abstract: An electric power assistance steering apparatus provides a differential compensating circuit (54) in which a command current signal is added with a derivative of the command signal to provide a compensated current signal to a control circuit for varying the current to an electric motor (11) arranged to provide power assistance to a steering rack (6). The apparatus preferbly provides signals representative of torque and vehicle speed to a function generator to provide a first command signal which is added with a self-centering command current and the output is provided to give a second command current which is effectively the first command current limited in dependence upon the vehicle speed. The second command current is operated upon by the differential compensating circuit (54) to the compensated current signal.
    Type: Grant
    Filed: July 2, 1986
    Date of Patent: June 28, 1988
    Assignee: Hitachi, Ltd.
    Inventors: Katsuji Marumoto, Tsutomu Omae
  • Patent number: 4712052
    Abstract: 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: Grant
    Filed: October 3, 1985
    Date of Patent: December 8, 1987
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Omae, Sanshiro Obara, Kenji Kubo, Masahiko Watanabe
  • Patent number: 4580083
    Abstract: A chopper controller for a D.C. motor controls currents flowing in an armature winding and a field winding of the D.C. motor by controlling an armature chopper and a field chopper in accordance with a command from a command generator such as an accelerator pedal. The armature chopper and the field chopper are controlled by chopper control signals from an armature chopper control circuit and a field chopper control circuit, respectively. Those chopper control signals are in a predetermined phase relationship and an interruption request signal is issued in phase-synchronism with one of the chopper control signals. In response to the interruption request signal, computing means computes an armature chopper duty factor and a field chopper duty factor in accordance with the command from the command generator and supplies them to the chopper control circuits.
    Type: Grant
    Filed: September 19, 1984
    Date of Patent: April 1, 1986
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Omae, Katsuji Marumoto, Shotaro Naito
  • Patent number: 4468724
    Abstract: A load DC motor is supplied with a DC current through a converter principally consisting of thyristors controlled by an ON-state control signal. The load current is detected both as to the mean value and the variation in time thereof. The mean value of the load current is calculated based on the load current values detected at the time of the present On-signal and the preceding ON-signal. The difference between the reference value and the mean value of the load current is calculated, and the difference between this differential signal and the variation of the load current is further calculated, so that the timing for providing the ON-signal is calculated based on the resultant differential signal.
    Type: Grant
    Filed: April 2, 1982
    Date of Patent: August 28, 1984
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Omae, Toshihiko Matsuda, Makoto Tachikawa
  • Patent number: 4366420
    Abstract: A control device for an electromobile provided with a shunt motor includes a pattern generating means for storing, as patterns, armature and field currents capable of generating an output torque with a minimum loss in the driving system of the electromobile to deliver an armature current command and a field current command for generating a specified output torque on the basis of the patterns, an armature control circuit for supplying the shunt motor with an armature current corresponding to the armature current command, and a field control circuit for supplying the shunt motor with a field current corresponding to the field current command. Thus, the torque control of the shunt motor is conducted on the basis of the patterns, and a computer control is applicable to the above control device.
    Type: Grant
    Filed: January 7, 1980
    Date of Patent: December 28, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Omae, Katsuji Marumoto, Shotaro Naito
  • Patent number: 4337509
    Abstract: A digital control system for controlling firing pulses supplied to thyristors for power conversion to desired phases, wherein data necessary for obtaining desired phase control signals is set in a counter which normally counts clock pulses having a predetermined period and the firing pulses are generated in synchronism with the generation of overflow pulses from the counter. The data setting to the counter, which is repeated at a period shorter than that of the source voltage, is performed by reading out the actual count value of the counter by a digital arithmetic processor circuit, by correcting the read value by the use of the value corresponding to a desired phase and by setting the corrected value again in the counter.
    Type: Grant
    Filed: July 22, 1980
    Date of Patent: June 29, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Omae, Toshihiko Matsuda
  • Patent number: 4311556
    Abstract: In a method and a system for inspection of the inside of a nuclear reactor vessel in which an inspection device for inspecting a defect in a nuclear reactor vessel is so moved by a drive/control device as to permit inspection of a part to be inspected in the reactor vessel, and the presence or absence of defect in the reactor vessel is judged based upon information from the inspection device in the course of the above-mentioned movement of the inspection device; the movement of the inspection device is pursued and monitored by monitor means, and the movement of the inspection device is suppressed when an abnormality in the movement of the inspection device is judged based upon information from the monitor means, to avoid the abnormal movement.
    Type: Grant
    Filed: July 18, 1979
    Date of Patent: January 19, 1982
    Assignee: Hitachi, Ltd.
    Inventors: Taro Iwamoto, Shimon Ando, Sho Kusumoto, Tsutomu Omae, Toshitaka Suzuki, Masatake Takidera, Takaichi Koyama, Kunio Hamada, Kazuhiro Yoshida
  • Patent number: 4249236
    Abstract: The firing phase of the power converter which can change power to be supplied to a load is determined by the firing angle instruction produced from the current control circuit in accordance with the magnitude of the current difference between the current target value and the current actual value flowing through the load. The nonlinear compensating circuit produces a correction angle instruction predetermined in accordance with the magnitude of the current actual value in the current intermittent region in which the load current becomes intermittent. In the current intermittent region, the sum of the firing angle instruction from the current control circuit and the correction angle instruction is used to determine the firing phase of the power converter and thereby to compensate for nonlinear response. The nonlinear compensation in the current intermittent region is made only in the transient state when the difference between the current target value and the current actual value exceeds a preset value.
    Type: Grant
    Filed: September 4, 1979
    Date of Patent: February 3, 1981
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Omae, Tosihiko Matuta
  • Patent number: 4211961
    Abstract: A control circuit for controlling supply of current for electric motor has a chopper circuit connected with a battery in series. The chopper circuit is constructed with such as power transistors or power thyristors, and the ON-OFF operation thereof is controlled by a driving pulse. A command signal is produced at a movable tap of a potentiometer, across which a D-C control voltage from the battery is applied. In order to determine the duty and the control frequency of the chopper circuit, a duty controlling oscillator circuit is provided, which generates an output signal on the basis of the command signal from the potentiometer. The duty controlling oscillator circuit includes an integrator composed of an operational amplifier having a negative feedback of a condenser, to the -input terminal of which the command signal is applied.
    Type: Grant
    Filed: June 15, 1978
    Date of Patent: July 8, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Katsuji Marumoto, Tsutomu Omae
  • Patent number: 4207478
    Abstract: A DC chopper device comprising a DC power source, a plurality of power transistors connected in series with a controlled unit driven by the DC power source and connected in parallel with each other to make chopping operation, a chopper control unit controlling the chopping operation of the power transistors, and a base drive circuit connected between the chopper control unit and each of the power transistors. Each base drive circuit includes impedance means for discharging the charge stored in the base region of the associated power transistor when the power transistor is turned off from its conducting state, and current flow blocking means for blocking current flow through the impedance means in the conducting state of the power transistor. The impedance values of the impedance means in the base drive circuits are selected so that all the power transistors can be substantially simultaneously turned on.
    Type: Grant
    Filed: May 8, 1978
    Date of Patent: June 10, 1980
    Assignee: Hitachi, Ltd.
    Inventors: Katsuji Marumoto, Schigeru Kuriyama, Tsutomu Omae
  • Patent number: 4163886
    Abstract: Disclosed is a control apparatus for an automatic pipe welder, for controlling the automatic pipe welder which continuously butt welds pipes while it is running along a welding line on the periphery of a pipe, in accordance with predetermined welding conditions for each of a plurality of welding areas sectioned along the welding line. All of the welding conditions for the welding areas are stored in a digital storage device while welding conditions on an area currently being welded are stored in another storage device. The contents of the second-mentioned digital storage device are converted by a digital-analog converter to analog signals, which are then held respectively in corresponding sample and hold circuits. Outputs of the sample and hold circuits are supplied as control commands to respective control units which control the welder in accordance with the welding conditions. In this manner, the construction of the control apparatus and a control panel thereof is simplified.
    Type: Grant
    Filed: September 15, 1977
    Date of Patent: August 7, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Omae, Keiziro Sakai
  • Patent number: 4144992
    Abstract: Method for controlling an automatic pipe welder is disclosed. In the automatic welder which requires remote control, welding conditions for butt welding pipes are stored and an actual joint geometry or groove shape is sensed. From signals relating to the stored welding conditions and the sensed groove shape, a control command signal in actual welding is produced to effect welding under an optimum condition. On the other hand, an arc condition at an actual welding point and a melting condition of a metal are monitored and displayed to modify the welding conditions in accordance with the monitored condition to control the automatic pipe welder.
    Type: Grant
    Filed: September 1, 1977
    Date of Patent: March 20, 1979
    Assignee: Hitachi, Ltd.
    Inventors: Tsutomu Omae, Takanori Shibata, Keiziro Sakai, Tomio Iizuka, Takaichi Koyama
  • Patent number: 4096418
    Abstract: An electromobile equipped with an automatic transmission which may detect a running condition of a vehicle and selects a gear ratio suited for the running condition. In this electromobile, a build-up characteristic of an electric motor current immediately after gear-change is improved, thereby minimizing delay in power transmission so as to shorten a gear-changing duration, in an attempt to improve an operational feeding of a driver at the time of gear change.
    Type: Grant
    Filed: March 30, 1977
    Date of Patent: June 20, 1978
    Assignee: The Agency of Industrial Science and Technology
    Inventors: Katsuji Marumoto, Tsutomu Omae, Toshio Suzuki, Takanori Shibata, Hirohisa Yamamura
  • Patent number: 4025860
    Abstract: An electric auto power supply has an energy battery which is capable of discharging a current for a comparatively long period of time and high in energy density, and a power battery which is capable of discharging a current of a comparatively high amperage and high in power density. The energy battery and the power battery are connected respectively by way of switching means in parallel relation to each other, so as to be used as a power source of an electromobile. The current discharged from these batteries is controlled, such that a current required for the travelling of the electromobile, which is dependent upon the travelling conditions thereof, is supplied simultaneously from both batteries, or separately from individual batteries, or otherwise only from one battery, while a current is being charged to the other battery, thus extending the possible mileage range of the electromobile.
    Type: Grant
    Filed: September 15, 1975
    Date of Patent: May 24, 1977
    Assignee: Agency of Industrial Science & Technology
    Inventors: Takanori Shibata, Tsutomu Omae