Responsive To Rotor Speed Or Rotor Driven Member Patents (Class 318/715)
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Patent number: 6876170Abstract: A controller monitoring an operating state and performing a suitable process when detecting a magnetic pole position by means of a sensor for detecting a position and velocity of a movable part (rotor or movable member) of a synchronous motor. If tandem control is not employed, PWM of the motor is made enable to commence the operation of detecting the magnetic pole position, thus detecting an operation abnormality based on feedback of the position. In the case of tandem control including two position detectors, either a master or slave motor is brought into a free state, and the other is caused to perform the operation of detecting the magnetic pole position, thus detecting an operation abnormality based on the feedback of the position.Type: GrantFiled: January 28, 2004Date of Patent: April 5, 2005Assignee: Fanuc LTDInventors: Tadashi Okita, Naoto Sonoda
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Patent number: 6856114Abstract: The present invention relates to a method for the sensorless electric measurement of the position of a rotor of a permanently excited synchronous machine that is fed by a converter, by means of measuring signals which are sent to an evaluation device that calculates the electric position of the rotor from the angular dependence of the current space vector at an impressed stator flux pattern, wherein the distribution of absolute values of the differential current space vector varies in approximation in sinusoidal manner with twice the value of the electric rotor position angle sought.Type: GrantFiled: May 28, 2002Date of Patent: February 15, 2005Assignee: Continental Teves AG & Co., OHGInventors: Achim Netz, Sighard Schräbler, Holger Lüdtke, Peter Stauder, Marcus Schulz
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Publication number: 20040245960Abstract: Electric motor for driving members that rotate at speeds of greater than 40 000 revolutions per minute, includes a stator housing induction coils, a rotor supporting multiple permanent magnets and located coaxially inside the stator, and multiple Hall sensors integral with the stator and capable of detecting the position of one or more points on the rotor as it rotates in order appropriately to time the injection of the induction currents into the coils as a function of the position of the permanent magnets.Type: ApplicationFiled: December 16, 2003Publication date: December 9, 2004Inventor: Michael Bartolotti
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Patent number: 6822416Abstract: A device for monitoring a measuring system of an electric drive is described, including a measuring system (12) for detecting at least one measured quantity of an electric drive (10), at least one controller (78) which receives at least the measured quantity detected by the measuring system (12) and generates at least one manipulated variable for controlling the drive (10), where at least one signal acquisition (34, 73, 79, 89, 91, 93) is provided for detecting errors in the measuring system (12).Type: GrantFiled: July 9, 2001Date of Patent: November 23, 2004Assignee: Robert Bosch GmbHInventors: Olaf Kunz, Alfred Punzet, Gerhard Froehlich, Siegfried Melzer
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Patent number: 6803735Abstract: A method of starting a brushless DC motor 12 at any initial speed (A) establishes a initial stator-field speed and setting a counter of synchronization, (B) measures a speed of a rotor of the motor, (C) compares the speed of the rotor with the stator-field speed to determine if the rotor is synchronized with the stator-field. If the rotor is not synchronized with the stator-field, the method includes (a) re-setting the counter of synchronization, (b) increasing an acceleration portion of motor current (Iacc) to enhance torque, (c) setting the stator-field speed higher than the rotor speed, (d) calculating a period of an open-loop timer, (e) calculating a value for a load portion of the motor current (Ild), where total motor current I=Iacc+Ild, (f) performing commutation based on the open-loop timer and returning to step (B) until the rotor is synchronized with the stator-field.Type: GrantFiled: October 1, 2002Date of Patent: October 12, 2004Assignee: Siemens VDO Automotive Inc.Inventors: Ke Liu, John Makaran
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Patent number: 6803739Abstract: A method and apparatus of controlling a synchronous motor having a rotor, and a stator which produces a magnetic flux for rotating the rotor about an axis thereof, the method including the steps of detecting an angular position and a rotating speed of the rotor; estimating a phase difference between a voltage and an electric current of the synchronous motor, on the basis of the detected rotating speed of the rotor; and adjusting an advance angle of the rotor upon excitation of the synchronous motor, as a result of comparison of the detected rotating speed of the rotor with a target value, to thereby control the rotating speed and direction of the rotor.Type: GrantFiled: August 30, 2002Date of Patent: October 12, 2004Assignees: Toyota Jidosha Kabushiki Kaisha, Nippon Soken, Inc., Denso CorporationInventors: Hideki Miyata, Akira Hoshino, Hideo Tomomatsu, Masashi Hori, Hiromichi Yamazaki, Hitoshi Tanaka
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Patent number: 6801012Abstract: A system and methodology for control of a switched reluctance electric machine comprising: a switched reluctance electric machine including a sensor generating and transmitting a sensor signal indicative of an operating characteristic; a controller operatively coupled to the switched reluctance motor and the sensor; and the controller executing a method.Type: GrantFiled: March 31, 2003Date of Patent: October 5, 2004Assignees: Delphi Technologies, Inc., The University of AkronInventors: Mohammad S. Islam, Sayeed A. Mir, Tomy Sebastian, Iqbal Husain
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Publication number: 20040183496Abstract: A 3-phase AC current flowing to a 3-phase synchronous motor is converted through coordinate conversion to a d-axis current id and a q-axis current iq in a dq-axis coordinate system which rotates in synchronization with the motor rotation and a phase &dgr; of a rectangular wave voltage is calculated based upon the current deviation between a q-axis current command value iq* and the q-axis current iq. A 3-phase rectangular wave voltage is generated from a DC source based upon the calculated phase &dgr; and is applied to the 3-phase synchronous motor.Type: ApplicationFiled: February 18, 2004Publication date: September 23, 2004Applicant: NISSAN MOTOR CO., LTDInventor: Kantaro Yoshimoto
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Patent number: 6774599Abstract: In an actuator having an integrated drive circuit, a switching current flowing in a coil within the actuator is included in a position sensor signal of the actuator. According to the present invention, by arranging a detection circuit which performs sampling in synchronization with noise, a rotational position which does not include higher harmonic waves can be detected even if the switching noise in a motor coil current in the actuator itself is generated. Consequently, elimination of the influence of the noise allows posture and position control with less vibration to be realized.Type: GrantFiled: January 10, 2003Date of Patent: August 10, 2004Assignee: Sony CorporationInventor: Shinji Ishii
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Patent number: 6771039Abstract: A motor control apparatus includes an inverter for applying voltage to a synchronous motor and a control apparatus 4 for calculating a voltage instruction value to be applied by a PWM signal. There are provided a current difference sensing unit of the synchronous motor, a current difference calculation unit for calculating a current change attributed to the voltage applied, and a position sensing unit for estimating a counter electromotive force direction according to the current change sensed by the current change sensing unit and the current change calculated by the current difference calculation unit. The magnetic pole position of the rotor of the synchronous motor is estimated according to the counter electromotive force direction estimated by the position sensing unit and the voltage applied to the synchronous motor is controlled according to the estimated magnetic pole position.Type: GrantFiled: December 27, 2002Date of Patent: August 3, 2004Assignee: Hitachi, Ltd.Inventors: Yoshimi Sakurai, Yoshitaka Iwaji, Ryoso Masaki
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Publication number: 20040145335Abstract: A method for correcting speed feedback in a synchronous permanent-magnet motor by calculating the averages of speed reference and speed measurement for both downward and upward constant-speed travel and then identifying the gain and zero factors and correcting the measured speed measurement value to the correct value.Type: ApplicationFiled: January 14, 2004Publication date: July 29, 2004Inventor: Jyrki Laaksonheimo
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Patent number: 6696812Abstract: A control apparatus controls a voltage applied to an AC motor from a power converter with a PWM signal, and has two different magnetic pole position-estimating units which estimate a rotor magnetic pole position of the AC motor, and has a switching unit which selects any one of these two kinds of magnetic pole position-estimating units.Type: GrantFiled: September 20, 2001Date of Patent: February 24, 2004Assignee: Hitachi, Ltd.Inventors: Satoru Kaneko, Ryoso Masaki, Yasuo Morooka, Mitsuyuki Hombu, Hiroshi Katayama
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Patent number: 6686715Abstract: The present invention provides a motor control device, which comprises a signal control circuit having an input pin to output different motor drive signals according to input electronic signals. The signal control circuit is also protected for over current and over voltage. Two switch circuits of brake before make configuration are connected to the signal control circuit. An inverter is arranged between the two switch circuits. The inverter switches the motor drive signal among the two switch circuits and transmits it to a driver, which is connected to a motor drive circuit. A power source circuit is connected to the motor drive circuit to provide electricity for the motor drive circuit. A back electromotive force (back EMF) component for detection and control of the rotation speed of motor is disposed in the driver. The motor control device of the present invention has the advantages of reduced number of pins and shrunk volume.Type: GrantFiled: June 14, 2002Date of Patent: February 3, 2004Assignee: Champion Microelectronic Corp.Inventor: Davis Fan
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Patent number: 6674261Abstract: A sensorless detector 25 uses a rotor angle finally detected by a sensor interpolation detector 24 as an estimated value (&thgr;{circumflex over ( )}) of the rotor angle of a motor 3 in a first control cycle upon changing from a rotor angle detecting process carried out by the sensor interpolation detector 24. In subsequent control cycles, the sensorless detector 25 uses estimated values (&thgr;{circumflex over ( )}, &ohgr;{circumflex over ( )}) of the rotor angle and a rotor angular velocity in a preceding control cycle as calculation parameters, updates the calculation parameters with an observer which sequentially updates the calculation parameters depending on a phase difference (&thgr;−&thgr;{circumflex over ( )}) calculated in the preceding control cycle in order to eliminate the phase difference, for thereby calculating the estimated value (&thgr;{circumflex over ( )}) of the rotor angle of the motor 3 in the present control cycle.Type: GrantFiled: April 25, 2002Date of Patent: January 6, 2004Assignee: Honda Giken Kogyo Kabushiki KaishaInventors: Yutaka Takahashi, Nobuyuki Imai
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Patent number: 6646408Abstract: A method for controlling driving of a Switched Reluctance Motor (SRM) is capable of operating the SRM normally according to a phase under the normal state in case a noise is inputted to a position sensor in the SRM. In order to achieve the advantage, the method for controlling driving of a three phase SRM using a position sensor having a rate of a rotor and a stator is 6/4 or 12/8 includes the steps of generating a sensor signal according to the position of a rotor in the SRM and operating the SRM by turning on respective phases in the SRM at the point of detecting a rising edge of the sensor signal and turning off the phase at the point of detecting a falling edge of the next sensor signal.Type: GrantFiled: December 13, 2001Date of Patent: November 11, 2003Assignee: LG Electronics Inc.Inventors: Sang Young Kim, Jun Young Lim
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Patent number: 6605917Abstract: A method of regulating a rotating electrical machine includes a preparatory step of determining a discrete voltage control law for the machine. The discrete control voltage to be applied at each sampling time is determined in the form of a first term corresponding to free evolution of the state of the machine in the absence of control, between the preceding sampling time and the current sampling time, and a second term dependent on the set point torque and a set point for the magnetic energy consumed by the machine. The method further includes, at each sampling time, a step of determining, with the aid of the discrete control law, the control voltage to be applied to the machine for the torque of the machine to reach the set point torque and the magnetic energy consumed by the machine to correspond to the set point magnetic energy.Type: GrantFiled: January 28, 2002Date of Patent: August 12, 2003Assignee: AlstomInventors: Jean-Luc Thomas, Jean-Claude Alacoque, Serge Poullain, Abdelkrim Benchaib
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Patent number: 6518718Abstract: Three-phase/d-q converters convert an output voltage V outputted from a power converter and a coil current flowing through a propulsion coil to a voltage and a current in a dq rotary coordinate system, respectively. A speed electromotive force observer estimates speed electromotive force based on these voltage and current, and a vehicle angular speed &ohgr;, and a speed electromotive force phase generator calculates a speed electromotive force phase &thgr;e based on the estimated speed electromotive force Zd, Zq. A phase synchronization controller constituted as a secondary PI control system stabilizes the speed electromotive force phase &thgr;e and outputs it as a phase reference &thgr;*. Accordingly, it is possible in a system of an LSM vehicle to obtain the stable phase reference &thgr;* with a minimum deviation even when the vehicle is running at low speed.Type: GrantFiled: March 23, 2001Date of Patent: February 11, 2003Assignees: Central Japan Railway Company, Railway Technical Research InstituteInventors: Syunsaku Koga, Junichi Kitano
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Patent number: 6515440Abstract: In the control system, a propulsion force is computed by a propulsion force computing unit based on a current command value outputted from a speed controller, an acceleration is computed by an acceleration computing unit based on the propulsion force and a running resistance outputted from a running resistance computing unit, a speed is computed by a speed computing unit based on the acceleration, and a simulated phase reference value is computed by a phase computing unit. Then, the simulated phase is computed by adding, at a simulated phase computing unit, a predetermined phase delay (e.g. 30 degrees) to the simulated phase reference value. The addition of the phase delay results in generation of synchronizing force in the LSM and thus little deviation between the simulated phase and the actual phase.Type: GrantFiled: March 23, 2001Date of Patent: February 4, 2003Assignees: Central Japan Railway Company, Railway Technical Research InstituteInventors: Syunsaku Koga, Junichi Kitano
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Patent number: 6498451Abstract: Disclosed is an electric motor system with reduced torque ripple comprising a sinusoidally magnetized permanent magnet, a sinusoidal inverter, a higher resolution position sensor, a composite iron stator yoke, a composite reinforced plastic rotor core and shaft; and a high gear ratio gear reduction box. The novel combination of magnet, inverter, sensor, plastic rotor core and shaft and high gear ratio gear box substantially reduces the torque ripple on the shaft of said motor system.Type: GrantFiled: September 6, 2000Date of Patent: December 24, 2002Assignee: Delphi Technologies, Inc.Inventors: Nady Boules, Rassem Ragheb Henry, Chandra Sekhar Namuduri, Thomas Wolfgang Nehl, Bruno Patrice Bernard, Shaotang Chen
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Patent number: 6456031Abstract: Method and system for estimating rotor position of a switched reluctance machine is provided. The method allows for estimating flux linkage across a respective phase of the machine. The method allows for measuring of magnetization curves at aligned and unaligned positions of the machine. The method further allows for computing magnetization reference data between the aligned and unaligned positions. A storing step allows for storing rotor position data based on the magnetization reference data. The stored rotor position data is indicative of rotor position variation as a function of phase current. A relating step allows to relate the estimated flux linkage to the magnetization reference data to determine, for a respective phase current, correspondence of the estimated flux linkage relative to the magnetization reference data. A retrieving step allows for retrieving stored rotor position data when said correspondence is determined.Type: GrantFiled: January 19, 2001Date of Patent: September 24, 2002Assignee: Delphi Technologies, Inc.Inventors: Gabriel Gallegos-Lopez, Kaushik Rajashekara, James E. Walters
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Patent number: 6414462Abstract: A speed control apparatus for a synchronous reluctance motor is disclosed. The speed control apparatus includes a voltage detector for detecting a voltage applied to the motor, a first phase converter for receiving voltages in three phases from the voltage detector and converting the three-phase voltages into equivalent voltages in two phases, a current detector for detecting a current applied to the motor, a second phase converter for receiving currents in three phases from the current detector and converting the three-phase currents into equivalent currents in two phases, and a rotor speed operator for receiving the two-phase voltages thereby computing a speed of a rotor included in the motor. A speed controller for receiving a deviation between a speed command externally inputted and an output value from the rotor speed operator is provided for generating a torque-related current command.Type: GrantFiled: March 23, 2001Date of Patent: July 2, 2002Assignee: LG Electronics, Inc.Inventor: Dal-Ho Chong
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Patent number: 6404161Abstract: A circuit for the measurement of time intervals includes a generator providing primary periodic pulses, a frequency divider capable of transmitting secondary periodic pulses for scaling down the frequency of the primary periodic pulses, and a counter for counting the secondary periodic pulses transmitted during the measured time interval. The frequency divider is programmable by a digital factor which determines the frequency division. The circuit further includes a self-calibration circuit for modifying the digital factor as a function of the number of pulses counted by the counter during a previous time interval measurement.Type: GrantFiled: August 13, 1999Date of Patent: June 11, 2002Assignee: STMicroelectronics S.A.Inventors: David Roubinet, Stéphane Guilhot
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Patent number: 6310450Abstract: A method is for decoding three logic signals produced by three Hall effect sensors installed in an electronically-switched three-phase brushless motor according to a sequence of six driving phases to be switched synchronously with a rotor position. The method includes determining a real phasing of the three Hall effect sensors at 60, 120, 300 or 240 electrical degrees. The determining is accomplished by decoding a whole set of eight possible combinations of the three logic signals produced by the three Hall effect sensors. The real phasing of the three Hall effect sensors is discriminated based upon two dissimilar combinations from among six valid combinations, the six valid combinations from among the eight possible combinations. The method further includes determining the rotor position based upon the real phasing of the three Hall effect sensors and generating logic driving signals synchronous with the rotor position.Type: GrantFiled: April 21, 2000Date of Patent: October 30, 2001Assignee: STMicroelectronics S.r.l.Inventor: Domenico Arrigo
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Patent number: 6288514Abstract: A method for commutation of a switched reluctance motor (SRM) is disclosed that requires no rotor position sensor or detailed prior knowledge of the motor's magnetic characteristics. The apparatus and method employs a calibration routine to learn the flux-current characteristics of each SRM phase in its aligned position. From these characteristics, the flux-current characteristics at other appropriate switching angles are approximated. Commutation is accomplished by estimating the flux in an active phase and comparing the estimate to the flux approximated for the switching angle. The apparatus and method is particularly well suited for relatively heavy duty loading applications, such as a fan.Type: GrantFiled: October 1, 1999Date of Patent: September 11, 2001Assignee: Texas Instruments IncorporatedInventors: Michael T. Direnzo, Wasim Khan
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Patent number: 6232739Abstract: An apparatus for determining an incremental angular position of a rotating member of an induction motor. A sensor assembly is positioned adjacent a target wheel attached to the rotating member, the target wheel having a plurality of teeth, separated by slots, angularly spaced around the periphery of the target wheel. The sensor assembly is located proximate the periphery of the target wheel, and includes a plurality of sensors each configured to generate a respective output signal that transitions between first and second states at the passage thereby of each leading and trailing edge of the teeth. The apparatus also includes a processing circuit configured to generate an incremental position signal in response to the output signals. Each sensor is spaced from an adjacent sensor by a predetermined distance equal to 180 degrees divided by n, where n is the number of sensors, and 360 degrees is a tooth-to-tooth distance.Type: GrantFiled: February 11, 2000Date of Patent: May 15, 2001Assignee: Delphi Technologies, Inc.Inventors: Ronald John Krefta, James E. Walters
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Patent number: 6163127Abstract: A position sensorless interior permanent magnet drive system and methods for use in electric and hybrid electric vehicles. The interior permanent magnet drive system and method use two rotor position estimation techniques for low and high speed operation and an initial rotor magnet polarity detection technique used at stand-still conditions. The use of the two different rotor position estimation techniques in combination enhances system efficiency and accuracy.Type: GrantFiled: November 22, 1999Date of Patent: December 19, 2000Assignee: General Motors CorporationInventors: Nitinkumar Ratilal Patel, Thomas P. O'Meara
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Patent number: 6140791Abstract: A sinusoidal acceleration trajectory controller is used in positioning a transducer at high speed to minimize vibration and acoustic noise. The controller reduces vibration and acoustic noise without sacrifice of seeking time by using a sinusoidal waveform as the actuator input. This sinusoidal waveform is a function of target track position and the seeking terminal time. When the velocity of the read/write head on the transducer reaches a maximum velocity, the sinusoidal waveform becomes a segment sinusoidal waveform, including a zero value waveform between two half sinusoidal waveforms. The amplitude of the sinusoidal waveforms and the coast period are minimized to obtain the minimum harmonic content in the segment sinusoidal waveform.Type: GrantFiled: June 10, 1999Date of Patent: October 31, 2000Assignee: Samsung Information Systems AmericaInventor: Xiao (John) Zhang
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Patent number: 5969496Abstract: At the time of starting a synchronous motor (40), one method of the present invention assumes that the synchronous motor (40) rotates at a revolving speed of not less than a predetermined level, and detects an electrical angle of a rotor (50) according to a first detection process, which has a practical accuracy when the revolving speed of the rotor (50) is not less than the predetermined level (step S120). In case that the electrical angle has not been detected successfully, the method detects the electrical angle of the rotor (50) according to a second detection process, which has a practical accuracy when the revolving speed of the rotor (50) is less than the predetermined level (step S160). Another method first detects the revolving speed of the rotor (50).Type: GrantFiled: June 23, 1998Date of Patent: October 19, 1999Assignee: Toyota Jidosha Kabushiki KaishaInventors: Eiji Yamada, Yasutomo Kawabata
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Patent number: 5936372Abstract: In an armature current limit value calculator section, limitation is applied to a pre-limitation torque command ST in correspondence with a presently detected speed SPD, to calculate a torque command STC. Meanwhile, in a field current calculator section 12, a pre-correction field current command value SF is decreased in correspondence with the detected speed SPD when the speed is large. In addition, a coefficient K.tau. which increases when the torque command is large is calculated on the basis of the pre-limitation torque command ST at this time. Further, a field current command is calculated from an equation SFC=K.tau.*SF. A current command calculator section 3 prepares a current command on the basis of the torque command STC and the field current command SFC supplied, and drives an electric motor 5 via a current control section 4.Type: GrantFiled: June 2, 1997Date of Patent: August 10, 1999Assignee: Okuma CorporationInventors: Masayuki Nashiki, Akiyoshi Satake
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Patent number: 5905355Abstract: A pump-motor apparatus comprising: a pump having an input shaft for receiving motive force to operate the pump, wherein during rotation of the input shaft, the pump exhibits repeating cyclical first torque variations on the input shaft, said first torque variations including cyclical torque peaks and torque dips and occurring in substantially evenly spaced increments in angular position of the input shaft; and an electric drive motor having an output shaft coupled to and driving the input shaft, wherein the electric drive motor exhibits on the output shaft repeating cyclical second torque variations, said second torque variations including cyclical torque peaks and torque dips and occurring in substantially evenly spaced increments in angular position of the output shaft, wherein the substantially evenly spaced increments in angular position of the output shaft are equal to the substantially evenly spaced angular increments in position of the input shaft, wherein torque peaks and dips of the output shaft secoType: GrantFiled: April 7, 1997Date of Patent: May 18, 1999Assignee: General Motors CorporationInventors: Gary Chris Fulks, Michael Anthony Dimatteo, William Charles Kruckemeyer
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Patent number: 5864217Abstract: An apparatus and method for estimating rotor position in and commutating a switched reluctance motor (SRM), using both a flux/current SRM angle estimator and a toothed wheel generating a magnetic pickup. Commutation is based on the flux/current SRM at startup and lower speeds. At higher speeds, when magnetic pickup sensed from the toothed wheel is sufficiently large in amplitude to create frequent reliable interrupts, commutation is based on signals from the toothed wheel magnetic pickup. Phase errors can be compensated by adjusting the angle input to the commutator as a function of estimated speed. Alternatively, the flux/current SRM angle estimator can be run in a background mode to tune the toothed wheel interrupt angle signal at different speeds.Type: GrantFiled: May 8, 1997Date of Patent: January 26, 1999Assignee: General Electric CompanyInventors: James Patrick Lyons, Mark Alan Preston
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Patent number: 5841262Abstract: A universal drive for a switched reluctance machine the drive obtaining a desired speed, the drive comprising means for automatically forming a magnetization table, said table containing information relating the magnetic flux, current, and rotor angle of said switched reluctance machine; means for automatically forming a rule table, the rule table containing information relating the torque of the SRM to turn-on and turn-off angles; sensors for sensing the dc bus voltage and currents of the phases of the machine; means for estimating a reference angle using information in the magnetization table and the sensed dc bus voltage and phase currents; means for obtaining the turn-on and turn-off angles from the self-tuned table based upon the desired speed; and means for turning the phase currents of the machine on at the turn-on angle in relation to the reference angle and turning the phase current off at the turn-off angle in relation to the reference angle.Type: GrantFiled: March 25, 1997Date of Patent: November 24, 1998Assignee: Emerson Electric Co.Inventor: Yifan Tang
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Patent number: 5821710Abstract: A brushless motor having permanent magnets that can be used as a prime mover for automobiles, in place of internal combustion engines, since the motor can yield high torque during low-speed rotation, as in the case of conventional types of brushless motors and can be used at high torque and with excellent motor efficiency at rotations three times as high as that of conventional types.Type: GrantFiled: September 19, 1997Date of Patent: October 13, 1998Assignee: Hitachi Metals, Ltd.Inventors: Masahiro Masuzawa, Noriyoshi Hirao, Takashi Sasaki, Masahiro Mita
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Patent number: 5652494Abstract: A circuit and method for controlling a switched reluctance drive having at least one phase winding and a rotor position encoder that provides a set of signals corresponding to the absolute position of the rotor relative to the stator. The circuit monitors the set of signals and generates a high frequency clock signal having a frequency substantially proportional to the frequency at which the set of signals changes state. The high frequency clock signal comprises a number of digital pulses for each rotor revolution that is an integral multiple of the number of digital pulses from the rotor position transducer for each rotor revolution and corresponds to the incremental position of the rotor. The high frequency clock signal is applied to a counter that is reset upon each change in state of the set of signals. The output of the counter is compared to predetermined values and the at least one phase winding is energized and de-energized in response to the results of the comparison.Type: GrantFiled: June 7, 1995Date of Patent: July 29, 1997Assignee: Switched Reluctance Drives, Ltd.Inventor: David Mark Sugden
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Patent number: 5485071Abstract: A method of establishing a reference current for use in operating a synchronous motor. A torque-angle profile of the motor is obtained, an excitation component and a reluctance component of the torque-angle profile are obtained, and the reference current is obtained from the excitation component and the reluctance component of the torque-angle profile.Type: GrantFiled: February 23, 1995Date of Patent: January 16, 1996Inventors: Chao Bi, Kuan-Teck Chang, Teck-Seng Low
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Patent number: 5428275Abstract: A method of controllably starting a prime mover, such as a gas turbine engine for an aircraft, in which the prime mover is coupled to a synchronous machine operable in a generating mode in which the synchronous machine converts motive power generated by the prime mover into electrical power and in a starting mode in which the synchronous machine provides motive power to the prime mover to accelerate the prime mover to self-sustaining speed includes three controlled phases: a pre-ignition phase, an ignition phase, and a torque augmentation phase. During each phase the prime mover is accelerated at a predetermined rate. When the motive power provided by the synchronous machine falls below a predetermined level, its operation is converted from its starting mode to its generating mode.Type: GrantFiled: May 12, 1993Date of Patent: June 27, 1995Assignee: Sundstrand CorporationInventors: Kenneth R. Carr, James A. Shippling, Leland E. Weber, Malcolm J. McArthur
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Patent number: 5315226Abstract: A method and apparatus for controlling a synchronous motor with an AC voltage. A rated value proportional to a desired frequency of the AC voltage and related to a rotational speed of the synchronous motor is provided. The rated value is continuously added up in an accumulator to provide added-up signal values. The added-up signal values are employed for addressing stored function values in a function value memory, the function values representing at least one AC voltage. The addressed function values are read out from the function value memory and are converted into at least one AC voltage having the frequency corresponding to the rated value. The AC voltage is supplied to the synchronous motor for generating a rotary field such that the frequency of the AC voltage defines the rotational speed of the synchronous motor.Type: GrantFiled: January 13, 1993Date of Patent: May 24, 1994Assignee: Linotype-Hell AGInventors: Ewald Fehlauer, Klaus Hofmann
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Patent number: 5304907Abstract: A servo system for a motor having a rotor that includes a phase detector circuit for detecting a rotational phase of the rotor and for defining a plurality of angular positions of the rotor, each angle between adjacent angular positions being of the same size, a rotating device for rotating the rotor at a predetermined constant rotational speed, a speed detector circuit for detecting a rotational speed of the rotor at each of the angular positions, an error detector circuit for detecting errors of the speed detector circuit at each of the angular positions when the rotor is rotated at the predetermined constant rotational speed, a memory for storing the detection errors at each of the angular positions, and a servo control circuit for controlling a rotational speed and/or phase of the rotor in accordance with the rotational speed detected by the speed detector circuit and the detection errors read from the memory.Type: GrantFiled: November 15, 1991Date of Patent: April 19, 1994Assignee: Sony CorporationInventors: Fumiyoshi Abe, Takayuki Horikoshi, Akira Hasegawa
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Patent number: 5296794Abstract: An identity state observer for a smooth-rotor permanent-magnet synchronous motor is derived which reconstructs the electrical and mechanical states of the motor from current and voltage measurements. The observer operates in the rotor frame and estimates direct and quadrature stator currents, rotor velocity, and rotor position. Since the rotor position is estimated, the rotor reference frame is approximated using the latest rotor position estimate. The motor dynamics and the transformation into the estimated rotor frame are nonlinear and thus the observer and observer error dynamics are nonlinear. Therefore, small signal stability is analyzed from a linearized model. Simulations including realistic measurement disturbances are used to investigate the global stabilitiy and accuracy of the observer.Type: GrantFiled: April 13, 1993Date of Patent: March 22, 1994Assignee: Massachusetts Institute of TechnologyInventors: Jeffrey H. Lang, Lawrence A. Jones
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Patent number: 5296793Abstract: A state observer driven by measurements of phase voltages and currents for estimating the angular orientation of a rotor of a synchronous motor such as a variable reluctance motor (VRM). Phase voltages and currents are detected and serve as inputs to a state observer. The state observer includes a mathematical model of the electromechanical operation of the synchronous motor. The characteristics of the state observer are selected so that the observer estimates converge to the actual rotor angular orientation and velocity, winding phase flux linkages or currents.Type: GrantFiled: November 5, 1986Date of Patent: March 22, 1994Assignee: Massachusetts Institute of TechnologyInventor: Jeffrey H. Lang
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Patent number: 5262709Abstract: A pulse motor control circuit for starting up and synchronizing a sync pulse motor (for use typically in factory automation or precise machining) with an external sync signal. The control circuit applies a starting drive pulse signal to start up and drive the motor to place it in synchronism with the external signal, and then switches the drive pulse signal to the external signal for the synchronous revolution of the motor. The starting drive pulse signal has a variable frequency which is varied from a frequency in the self-starting region to that of the external sync signal.Type: GrantFiled: February 6, 1992Date of Patent: November 16, 1993Assignee: Matsushita Electric Industrial Co. Ltd.Inventor: Akio Yasuda
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Patent number: 5095254Abstract: A disc record/reproduce apparatus with a brushless dc motor having no separate dedicated position sensor, controls rotation of the dc synchronous motor by back-electromotive force signals developed in windings of the brushless dc motor using a/d converter included in one-chip microprocessor in the first mode, and controls by position and index signals recorded on the disc in the second mode. During start-up, a start-up oscillator is used. The control with a back-electromotive force signal is provided to enable the microprocessor to write a position signal on a disc and provided for inspecting the brushless dc motor independently. In the second mode, functions for executing the back-electromotive force control in the microprocessor is disabled during recording and reproducing of data to prevent overload on the microprocessor which is busy because of communication with an external computer and control of head position.Type: GrantFiled: February 5, 1991Date of Patent: March 10, 1992Assignee: Victor Company of Japan, Ltd.Inventor: Yasuhiro Ueki
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Patent number: 4701839Abstract: The present invention provides a high response inexpensive microprocessor based digital control system. The digital control system uses only one detector that detects only one motion characteristic of the device controlled by the system. In the preferred embodiment, the digital control system controls the field orientation, the position and the velocity of a movable member of a brushless motor by creating commands that represent the desired position of the movable member 1024 times per second. The system also provides methods for improving the accuracy and precision of the system.Type: GrantFiled: November 9, 1984Date of Patent: October 20, 1987Assignee: International Cybernetic CorporationInventors: Paul F. McNally, Spencer W. Allen, Matthew G. Cimbala
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Patent number: 4565956Abstract: To provide for fast response of a servo drive with a synchronous machine in which the same torque is available over the entire rotational range of the machine regardless of angular position of the rotor, phase currents to phase windings, preferably three-phase, are controlled in dependence on required torque, and steered to the respective phase windings by a rotor position transducer in such a manner that the sum of all the phase currents remains constant, and is connected to the respective phase windings, in pulses, during an electrical angular range when induced armature counter electromotive force voltages in the respective phase windings, which have an essentially trapezoidal shape, are in their flat or unvarying range within the voltage distribution during revolution of the rotor. Thus, currents are supplied to the phase windings only when the counter EMF voltages are essentially constant.Type: GrantFiled: October 9, 1984Date of Patent: January 21, 1986Assignee: Robert Bosch GmbHInventors: Peter Zimmermann, John W. Teape
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Patent number: 4527109Abstract: A control apparatus for thyristor motor comprises a voltage detector (27), a speed detecting circuit (600) and a correction circuit (800). The voltage detector (27) detects DC voltage (E.sub.d) supplied to an inverter circuit (200). The speed detecting circuit (600) detects the rotational speed of a synchronous motor (3) and provides speed voltage (E.omega.) proportional thereto. The correction circuit (800) detects a difference between the detected DC voltage (E.sub.d) and the speed voltage (E.omega.) and provides a correction signal to an excitation circuit (700) when a difference is detected. The excitation circuit (700) corrects field current in response to the correction signal so that the DC voltage (E.sub.d) and the speed voltage may be equal. Thus, a proportional relation can be maintained between the instructed torque and the generated torque.Type: GrantFiled: February 15, 1984Date of Patent: July 2, 1985Assignee: Mitsubishi Denki Kabushiki KaishaInventors: Yasuhiko Hosokawa, Naoki Morishima
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Patent number: 4496893Abstract: A synchronous motor is driven by a plurality of inverting circuits. The inverting circuits are controlled by signals from a position detecting circuit coupled to the shaft of the synchronous motor so as to produce output current signals from the inverting circuits which are shifted by a certain angle from each other.Type: GrantFiled: January 9, 1984Date of Patent: January 29, 1985Assignee: Tokyo Shibaura Denki Kabushiki KaishaInventors: Teruo Nakano, Akio Hirata
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Patent number: 4490661Abstract: In an improved motor control system for a pulse width modulated synchronous brushless motor, means for adaptively controlling the "torque angle", i.e. the angle between the rotating magnetic field created by the stator windings and the rotor field created by the permanent magnets on the rotor, is provided. The relationship between the two magnetic fields is controlled as a function of load and speed to provide the optimum operating point at all times. Controlling the torque angle effectively varies the back EMF constant K.sub.e (V/RPM), and the torque constant K.sub.+ (torque/ampere) of the motor.Type: GrantFiled: July 28, 1983Date of Patent: December 25, 1984Assignee: Kollmorgen Technologies CorporationInventors: Lynnie B. Brown, Charles J. Ford, III, Richard F. Dugan
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Patent number: 4450396Abstract: An electronically controlled rotating synchronous machine having armature and field windings on the same magnetically-permeable core. The rotor of the machine is an open tooth structure. The self inductance of the armature and field windings is substantially independent of relative position between the rotor and stator but mutual inductance between the armature and field windings varies with relative position. A rotor position detector senses the voltage in one of the machine windings and relates that voltage to said relative position. Switches are provided to control electric current flow in the armature winding on the basis of the voltage sensed by the detector.Type: GrantFiled: September 23, 1980Date of Patent: May 22, 1984Assignee: Massachusetts Institute of TechnologyInventor: Richard D. Thornton
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Patent number: 4447771Abstract: A motor control system wherein the motor windings are energized by sinusoidal excitation currents synthesized from prerecorded sine values. The frequency of the winding excitation currents is synchronous with the rotor movement and the phase is a function of the rotor position with respect to the stator. The phase of the winding excitation is additionally controllable as a function of speed or some other adequate system parameter. It has further been found that the total operational speed range of the system is substantially increased by further adjusting and controlling the phase of the excitation currents as a function of the desired speed.Type: GrantFiled: August 31, 1981Date of Patent: May 8, 1984Assignee: Kollmorgen Technologies CorporationInventor: James S. Whited
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Patent number: 4429056Abstract: Process of reacting carbon monoxide and hydrogen in the presence of halogen-containing ruthenium catalysts to produce acetaldehyde and ethanol.Type: GrantFiled: November 19, 1981Date of Patent: January 31, 1984Assignee: National Distillers and Chemical CorporationInventor: David W. Smith