Analogue Comparison Patents (Class 318/604)
  • Patent number: 10075604
    Abstract: According to an embodiment of the present invention, a rotation-angle detection device for detecting a rotation angle of a rotor includes: plural rotation detectors that output detection signals which vary with the rotation angle of the rotor; a rotation calculator that outputs a rotated vector by rotating a vector expressed by the detection signals; an amplitude detector that outputs an amplitude signal indicating amplitude of the detection signals by performing computation on at least one of signals expressing the rotated vector using a predetermined target amplitude; a drive-power adjuster that adjusts the amplitude of the detection signals by changing drive power applied to the rotation detectors according to the amplitude signal; a corrector that corrects the amplitude based on the amplitude signal and outputs a corrected detection signal; and a rotation angle detector that detects a rotation angle of the rotor based on the corrected detection signal.
    Type: Grant
    Filed: June 26, 2014
    Date of Patent: September 11, 2018
    Assignee: RICOH COMPANY, LTD.
    Inventor: Fumihiro Shimizu
  • Patent number: 8456126
    Abstract: There is provided a motor control system and motor control method which can shorten settling time by restraining vibration and deviation relative to an advancing direction during operation. Moreover, according to the present invention, it is possible to cause a motor to be operated with an ideal track and, since it is possible to always monitor a present position, it is made easy to cause a plurality of axes to be synchronously operated. The motor control system is provided with a unit generating command waveforms from a jerk data which has significant effects on the vibration relative to the advancing direction, and a unit performing a real time real position control of regenerating future command waveforms according to a deviation amount, while always performing jerk-limit, whereby the vibration and the deviation relative to the advancing direction when the motor operates at high speed are restrained.
    Type: Grant
    Filed: March 9, 2011
    Date of Patent: June 4, 2013
    Assignee: Hitachi High-Tech Instruments Co., Ltd.
    Inventors: Mitsuaki Tate, Yasushi Ishii, Masamichi Kihara
  • Patent number: 8159173
    Abstract: A control device for a travel motor mounted to a vehicle has a resolver which works as a rotation-angle sensor. The control device has a RDC which calculates a rotation-angle output value ? based on rotation detection signals Sa, Sb transferred from the resolver. The control device supplies electric power to the travel motor based on the rotation angle output value ?. The RDC calculates “sin(???)” as an error deviation ? based on the signals Sa and Sb and the rotation-angle output value ?. The RDC calculates an angular acceleration by multiplying the error deviation ? with a gain (=Ka·Kb), and integrates the angular acceleration two times in order to obtain a next rotation-angle output value. A gain control part of the RDC decreases the gain when the judgment means judges that the travel motor rotates at a constant rotation speed.
    Type: Grant
    Filed: August 6, 2010
    Date of Patent: April 17, 2012
    Assignee: Denso Corporation
    Inventors: Shigenori Mori, Eiichiro Kawakami
  • Patent number: 7973503
    Abstract: A system has a sensor assembly mounted adjacent to a moving magnetic member such as a motor rotor to sense its position. The sensor assembly includes Hall-effect sensors each having a binary output, configured such that distinct positions of the moving magnetic member correspond to distinct digital patterns of the outputs of the Hall-effect sensors. Encoding circuitry is coupled to the outputs of the Hall-effect sensors to generate a multi-valued analog output, distinct values of the multi-valued analog output representing corresponding distinct digital patterns of the outputs of the Hall-effect sensors. The encoding circuitry may employ a ladder network with weighted-value resistors contributing different components of an analog current sensed by the controller. The sensed current can be converted to digital position information using suitable analog-to-digital conversion circuitry.
    Type: Grant
    Filed: June 26, 2007
    Date of Patent: July 5, 2011
    Assignee: Wooward HRT, Inc.
    Inventors: Raymond Y. Liu, Estella C. Chung
  • Patent number: 7148647
    Abstract: An analog amplifier performs control of a motor at the speed in proportion to a speed instruction (analog voltage) outputted from a numerical control device. The speed instruction (analog value) is converted into a digital value by an A/D converter and is then sent to a CPU. When the CPU judges that the received digital value corresponding to the speed instruction deviates from a predetermined range, the CPU stops sending out an enable signal, and sends out an emergency stop signal. As a result, the CPU stops electric power supply to the analog amplifier, and also invalidates the speed instruction sent to the analog amplifier 20, thereby performing control to make the speed of the motor become “0”.
    Type: Grant
    Filed: September 30, 2005
    Date of Patent: December 12, 2006
    Assignee: Fanuc Ltd
    Inventors: Kazunari Aoyama, Kunitaka Komaki, Yasuharu Aizawa
  • Patent number: 7062159
    Abstract: A device for correcting a digital estimate of an electric signal is described. The device includes a comparator that generates a current proportional to the difference between an analog estimate signal, which derives from the digital estimate, and the electric signal. The device also includes a capacitor positioned to be charged by the current, a transistor that discharges the capacitor, and a comparator that compares the voltage at the terminal of the capacitor with a reference voltage. The device also includes a controller that drives the transistor in response to the output signal of the comparator and a logic device that generates a correction digital signal to be added to or subtracted from the digital estimate of the electric signal in correspondence of an ascending or descending waveform of the electric signal.
    Type: Grant
    Filed: December 7, 2004
    Date of Patent: June 13, 2006
    Assignee: STMicroelectronics S.r.l.
    Inventors: Antonio Borrello, Stefano Saggini, Aldo Novelli, Ignazio Bellomo
  • Patent number: 7049776
    Abstract: An electric motor has a stator and an external rotor (40). Its external rotor (40) has a sensor magnet (54) having a plurality SP of sensor poles (55). The motor also has: at least one rotor position sensor (42, 44) for generating a rotor position signal and a rotor position evaluation arrangement for generating an absolute value for the rotor position, which apparatus comprises an A/D converter (144) having a resolution of at least two bits, the at least one rotor position sensor (42, 44) being connected to the A/D converter. In order to enable obtaining different digital values, even at rotational positions within the angle range of one sensor pole, each analog rotor position sensor signal is converted by the A/D converter into a digital value having at least two bits.
    Type: Grant
    Filed: December 13, 2003
    Date of Patent: May 23, 2006
    Assignee: ebm-papst St. Georgen GmbH & Co. KG
    Inventors: Jörg Hornberger, Hermann Rappenecker, Christian Rudel, Siegfried Schreiner
  • Patent number: 7049778
    Abstract: An interrupt signal is generated at each of rising timings of PWM signals which are produced on the basis of phase-shifted triangular wave carrier signals for phases, and voltage command values for the phases. At timings of the interrupt signals, A/D conversion of motor currents of the phases detected by a shunt is started. Interrupt signals are also produced at timings of valleys of the triangular wave carrier signals. Additionally, peak interrupt signals and valley interrupt signals are respectively produced at timings of peaks and valleys of triangular wave carrier signals for phases. Based on each of the peak interrupt signals, normality/abnormality of a switching element of an upper side of the phase corresponding to the interrupt signal is checked, and, based on each of the valley interrupt signals, normality/abnormality of a switching element of a lower side of the phase corresponding to the interrupt signal is checked.
    Type: Grant
    Filed: February 9, 2005
    Date of Patent: May 23, 2006
    Assignee: Nippon Yusoki Co., Ltd.
    Inventor: Ikuya Katanaya
  • Patent number: 7038420
    Abstract: A method of regulating an electric motor, regulation being implemented with a loop of gain less than unity as a function of a divergence between a setpoint signal for an operating parameter of the motor and a measured value of the same operating parameter of the electric motor, the divergence being taken into account only if said divergence is greater than a predetermined threshold whenever the measured value is greater than the setpoint signal.
    Type: Grant
    Filed: October 9, 2002
    Date of Patent: May 2, 2006
    Assignee: Johnson Controls Automotive Electronics
    Inventor: Valéry Becquet
  • Patent number: 7026773
    Abstract: System, method and apparatus for commutating a multiphase motor utilizing a single sensor. Commutation is carried out by employing a sensible system which incorporates phase commutating transition attributes. A motor is started by assigning a starting phase for a given direction of motor direction. An aligning phase initially is energized to orient the rotor so as to provide adequate starting phase start-up torque. Following such alignment and start-up, the motor is operated in response to transitions of the sensible system. In one aspect, a reference phase attribute may be incorporated in the sensible system to provide a mandated reference phase energization when the rotor is oriented for reference phase activation. Further described is a sensible system magnetic region configuration which is combined with a single package Hall effect sensor to provide three-phase unipolar and four-phase commutation with absolute phase defining information.
    Type: Grant
    Filed: April 26, 2005
    Date of Patent: April 11, 2006
    Assignee: Petersen Technology Corporation
    Inventor: Christian C. Petersen
  • Patent number: 6967459
    Abstract: The invention concerns a method of regulating the current in a direct current machine with which are associated an arrangement for generating a current target value signal, as well as a PWM generator (FIG.
    Type: Grant
    Filed: August 14, 2001
    Date of Patent: November 22, 2005
    Assignee: ebm-papst St. Georgen GmbH & Co. KG
    Inventors: Alexander Hahn, Hermann Rappenecker
  • Patent number: 6912427
    Abstract: A programmable limit switch includes output channels for receiving position data, each position value of the position data representing an incremental advance of a workpiece through a production field, and for producing actuation signals. The channels are connectable to respective output devices responsive to the respective actuation signals and located in the field. Each output channel has an output controller, which is individually programmable to change the state of respective actuation signals in response to reaching selected position values. Preferably, the PLS includes input connectors coupled to a respective channel and connectable to respective input devices located within the production field. Each channel operates its own inputs and outputs according to a variety of programmed functions depending upon system conditions seen by the output controller.
    Type: Grant
    Filed: March 22, 2002
    Date of Patent: June 28, 2005
    Assignee: Ametek, Inc.
    Inventors: Jack Pattee, Sheila F. Champagne
  • Patent number: 6798859
    Abstract: A branch amplifier card for a nuclear reactor control rod drive control system is provided. The control system includes a control processor, a plurality of transponder cards arranged in clusters with each cluster under the control of a branch amplifier card. The branch amplifier card is configured to receive commands from the control processor, send the converted commands to transponder cards under the control of the branch amplifier card and to a downstream branch amplifier card, receive an acknowledge word from transponder cards under the control of the branch amplifier card, add AC voltage threshold level information about the transponder cards under the control of the branch amplifier card to the acknowledge word, permit transponder trouble information attached to the acknowledge word to remain in the acknowledge word, and resend the acknowledge word including the transponder trouble information to an upstream branch amplifier card.
    Type: Grant
    Filed: August 18, 2003
    Date of Patent: September 28, 2004
    Assignee: General Electric Company
    Inventors: William Michael Steiner, Craig Miles Smith, Leonid Boris Sheikman, Craig Ernest Leighty
  • Patent number: 6166501
    Abstract: An index signal generating circuit for generating a precise index signal free from time shifting even under ambient temperature changes. An index signal generating circuit includes a magnet attached onto the circumference of the rotor of a spindle motor, a magnetic flux detecting device for detecting magnetic flux of the magnet when the magnet moves past the magnetic flux detecting device, a Hall effect device for switching a current in the driving coil of the spindle motor, a first waveform shaping circuit for shaping the detected output of the magnetic flux detecting device into a rectangular-wave signal, a second waveform shaping circuit for shaping the output of the Hall effect device into a rectangular-wave signal, and a logic circuit for ANDing the output rectangular-wave signals from the first and second waveform shaping circuits, wherein an index signal is generated at the timing of a transition of the AND output of the logic circuit.
    Type: Grant
    Filed: February 8, 1999
    Date of Patent: December 26, 2000
    Assignee: Alps Electric Co., Ltd.
    Inventors: Shigeru Furuki, Mikio Sekine
  • Patent number: 5856733
    Abstract: The upper limit value and lower limit value of a control target value are alternately supplied to a single D/A converter in synchronism with a clock, an analog output from the D/A converter is compared with an output from a PBR serving as a position detector, and a motor is driven by the difference voltage, thereby positioning the control object. In this case, control of the moving direction and drive/stop of the motor is performed by a combination between the setting states of the upper and lower limit values and the polarity of the difference voltage, and the switching operation of the selector is stopped during a control operation, thereby making it possible to smoothly perform the control operation at a high speed. The control system can be digitized as a whole by detecting a position by an encoder, and integration of the system can be enhanced, thereby realizing a compact and stable control system.
    Type: Grant
    Filed: October 28, 1996
    Date of Patent: January 5, 1999
    Assignees: Nissan Motor Co., Ltd., Calsonic Corp.
    Inventors: Takashi Matsumoto, Yoshinori Satoh, Hiroyuki Ureshino, Eiji Takahashi, Kouji Iwahashi
  • Patent number: 5361025
    Abstract: The interface circuit has a single input terminal for receiving an analog or digital control signal indicative of the required speed of rotation of the motor. The type of input signal is recognised by means of comparator circuits. The input signal is processed differently according to its nature in order, in any case, to output an analog signal acceptable by the regulation and control circuit which pilots the motor.
    Type: Grant
    Filed: March 26, 1993
    Date of Patent: November 1, 1994
    Assignee: Industrie Magneti Marelli SpA
    Inventors: Pietro De Filippis, Franco Salerno, Paolo Mastella
  • Patent number: 5245262
    Abstract: A digitally programmable integrated-circuit analog-signal servo co-processor has digital programming contact pads to which an external microprocessor may be connected, has analog-signal input pads and analog-signal output pads, and includes a plurality of programmable analog-signal-manipulating circuits (ASMC's). Each of the ASMC's has input and output terminals connected to an input programmable-switch matrix so that one or a combination of the ASMC blocks may be connected between the analog-signal input and output contact pads of the integrated circuit. Certain ASMC blocks have microprocessor programmable transfer functions, e.g. ASMC integrator, notch filter, low pass filter, PD compensator and voltage divider. Key ones of those ASMC blocks are discrete-time circuits including switched-capacitor resistors and have transfer functions wherein the parameters are ratios of capacitances and the switching rate frequency to provide accurate and stable performance.
    Type: Grant
    Filed: July 13, 1992
    Date of Patent: September 14, 1993
    Assignee: Allegro Microsystems, Inc.
    Inventors: Kristaan L. Moody, Paul W. Latham, II
  • Patent number: 5214364
    Abstract: Apparatus and method for automatically controlling the rotation of an angularly positionable antenna from one angular position to a desired new angular position. The disclosed technique provides the user with a list of destination indicia, each of which corresponds to a geographic location. The user is also provided with a selector for choosing one or more of the available destination indicia. Once the user selects a destination index, a retrieval system automatically retrieves the appropriate geographic reference location from a destination indicia table stored in memory. A calculation is then automatically performed to determine the desired angular position of the antenna with respect to an arbitrary reference angle. The antenna rotor shaft is then energized to rotate the shaft to the desired angular position.
    Type: Grant
    Filed: May 21, 1991
    Date of Patent: May 25, 1993
    Assignee: Zenith Data Systems Corporation
    Inventors: Terry A. Perdue, David Poplewski
  • Patent number: 5081408
    Abstract: The present invention relates to a digital servo-control system whose purpose is to control very high precision equipment. The system includes two digital-to-analog converters, one of which is followed by a divider, with the two converters contributing to producing a control signal. A processor responds to a measurement signal and to a reference value to generate the digital values that are delivered to the converters. The system is particularly suitable for application to servo-controlling a voltage-controlled oscillator.
    Type: Grant
    Filed: October 15, 1990
    Date of Patent: January 14, 1992
    Assignee: Alcatel Cit
    Inventor: Andre Lankar
  • Patent number: 4672550
    Abstract: A control system is provided for allowing complex shapes to be machined on a workpiece at high speed. The control system is computer controlled and receives workpiece profile data which are converted into a succession of tool position signals during machining. Not all the digital signals are calculated at one time, a number of future digital signals are calculated during a succession of time intervals. In each time interval, a tool position signal is outputted which is of a constant amplitude corresponding to the required tool position and which is fed to a signal processor where it is converted into a continuous signal which so changes progressively that at successive time intervals, equal to the time intervals of the tool position signals, the amplitude of the continuous signal is related to the successive values of the tool position signals. This continuous signal is fed to a closed-loop control system which controls the movement of the tool holder in accordance with the continuous signal.
    Type: Grant
    Filed: April 6, 1984
    Date of Patent: June 9, 1987
    Assignee: AE PLC
    Inventors: Robert J. H. Winterbottom, Walter G. Edwards
  • Patent number: 4636959
    Abstract: In combination with a postage meter which includes a plurality of loads, a source of supply of motive power for driving the respective loads and instrumentalities for selectively coupling the source of motive power to the respective loads, there is provided an improvement which comprises: the motive power source including a d.c.
    Type: Grant
    Filed: October 4, 1984
    Date of Patent: January 13, 1987
    Assignee: Pitney Bowes Inc.
    Inventors: Edilberto I. Salazar, Wallace Kirschner
  • Patent number: 4636701
    Abstract: A control system for controlling the rotation of a rotary mechanism such as a propeller housing in a Z-type propulsion apparatus is provided. A command signal and a feedback signal both relating to the rotation of the rotary mechanism are compared with each other. And a control signal which varies at a predetermined inclination is generated when the command and feedback signals differ in amplitude from each other. And a drive unit rotates the rotary mechanism in accordance with the control signal.
    Type: Grant
    Filed: April 12, 1984
    Date of Patent: January 13, 1987
    Assignee: Niigata Engineering Co., Ltd.
    Inventors: Masanori Kodera, Yasuo Aizawa, Kohji Ichijo
  • Patent number: 4635205
    Abstract: An improvement in combination with a postage meter including a rotary postage printing drum having apparatus for changing respective postage values to be printed, and including apparatus for actuating the changing apparatus, there is provided an improvement for indexing the changing apparatus into engagement with the actuating apparatus. The improvement comprises: a d.c. motor coupled to the drum for rotation of the drum; a device for sensing angular displacement of the drum; and a computer coupled to the sensing device and to the d.c. motor; wherein the computer provides respective amounts representative of desired angular displacements of the drum during successive sampling time periods, responds to the sensing device for providing respective amounts representative of actual angular displacements of the drum during successive sampling time periods, compensates for the difference between desired and actual angular displacements and generates a d.c.
    Type: Grant
    Filed: October 4, 1984
    Date of Patent: January 6, 1987
    Assignee: Pitney Bowes Inc.
    Inventors: Alton B. Eckert, Jr., Wallace Kirschner, Edilberto I. Salazar
  • Patent number: 4631681
    Abstract: An improvement in combination with a postage meter including a rotary drum having a periphery adapted for feeding a sheet in a path of travel. The improvement comprises: a first device for sensing a time interval during which a sheet is linearly displaced a predetermined distance in the path of travel; a d.c. motor coupled to the drum for rotation of the drum; a second device for sensing angular displacement of the drum; and a computer coupled to the first and second sensing devices and to the d.c. motor; wherein the computer responds to the first sensing device for providing respective amounts representative of desired angular displacements of the drum during successive sampling time periods, responds to the second sensing device for providing respective amounts representative of actual angular displacements of the drum during successive sampling time periods, compensates for the difference between desired and actual angular displacements and generates a d.c.
    Type: Grant
    Filed: October 4, 1984
    Date of Patent: December 23, 1986
    Assignee: Pitney Bowes Inc.
    Inventors: Edilberto I. Salazar, Wallace Kirschner, John L. Lorenzo, Keith E. Schubert, Philip Pollak, Jr.
  • Patent number: 4630210
    Abstract: Apparatus is provided for controlling the velocity of a portion of a load in accordance with a trapazoidal-shaped velocity versus time profile. The apparatus includes a d.c.
    Type: Grant
    Filed: October 4, 1984
    Date of Patent: December 16, 1986
    Assignee: Pitney Bowes Inc.
    Inventors: Edilberto I. Salazar, Wallace Kirschner
  • Patent number: 4594538
    Abstract: A speed monitoring circuit is disclosed for an automatic positioning system. This speed monitoring circuit composes a measurement of the actually present speed determined from measurement signals generated by an incremental position measuring device with the desired speed commanded by the positioning system. The difference between the actual and commanded speed is detected and, in the event of an excessive deviation, a warning or an automatic termination of operation of the positioning system is provided. In the disclosed system, the desired speed is determined by a controller in which a digital computer calculates the difference between the instantaneous position of one relatively movable machine component and the desired position of the movable component as established by programmed data.
    Type: Grant
    Filed: September 14, 1984
    Date of Patent: June 10, 1986
    Assignee: Dr. Johannes Heidenhain GmbH
    Inventor: Walter Schmitt
  • Patent number: 4570112
    Abstract: A numerically controlled motor provides a drive at a rate which is proportional to rotation of an independently driven shaft. In addition, the ratio of such rate to such rotation can be varied by a control circuit by which, in response to each pulse supplied by an encoder on said shaft, an incremental value, corresponding to an analogue signal supplied by a potentiometer to an A-D converter, which converts said signal to said value, is supplied to an accumulator, which sums the successively supplied increment values and, at a predetermined cumulative value, "overflows", such "overflow" supplying a drive signal to the n.c. motor. The potentiometer is manually set by an operator to vary the increment value and thus the frequency of "overflow" in relation to shaft rotation. The control circuit also enables "reverse" and "fast forward" drive to the motor independently of the shaft.
    Type: Grant
    Filed: November 23, 1983
    Date of Patent: February 11, 1986
    Assignee: USM Corporation
    Inventors: Robert Yardley, Ewen R. Cameron, Joseph A. Shutt, Andrew G. N. Walter
  • Patent number: 4523137
    Abstract: In a dual mode servo for a rotary printer control system for controlling the velocity and position of a rotary print wheel and a print wheel carriage, the analog counterpart of a digital desired velocity multibit character is generated by a bidirectional digital to analog converter so that the analog desired velocity signal has a maximum value range lying both above and below a zero reference level, thereby eliminating the need for additional analog level converting circuitry.
    Type: Grant
    Filed: September 27, 1983
    Date of Patent: June 11, 1985
    Assignee: Mechatron Systems, Inc.
    Inventor: Harvey C. Wong
  • Patent number: 4483260
    Abstract: A needle bar shifter for a textile tufting machine having an operating rod connected to the needle bar and extending into an hydraulic cylinder for manipulation by movement of a spool in a bore in the rod, the rod having passages to permit flow of hydraulic fluid from one side to the other of the end of the rod by opening of different passages by movement of the spool, which is manipulated by light hydraulic pressure independent of the high pressure needed for manipulation of the rod and needle bar.
    Type: Grant
    Filed: August 27, 1981
    Date of Patent: November 20, 1984
    Inventor: Donald A. Gallant
  • Patent number: 4446408
    Abstract: A control apparatus for machine tools is provided which comprises a pulsed digital difference detector having one input connected to a digital branch and having a second input connected to a follower drive and having an output, an adding register having its input connected to the output of the pulsed digital difference detector, an analog nominal value source having its control input connected to the output of the adding register, and an analog branch having an input connected to the analog nominal value source and having its output connected to the input of the follower drive. A drive motor for the tool provides a signal to the digital branch and a drive motor for the blank forms part of the follower drive. The drive motor for the tool is a d.c. motor coupled to a velocity pickup, and cooperating with means for withdrawing the tool and a distance pickup coupled to the drive motor for the blank.
    Type: Grant
    Filed: October 28, 1981
    Date of Patent: May 1, 1984
    Assignee: Veb Werkzeugmaschinenkombinat "7 Oktober" Berlin
    Inventors: Joachim Ebermann, Heinz Graf, Siegfried Schleicher, Jurgen Uhlig
  • Patent number: 4358721
    Abstract: A control for the motor of a mechanism which adjusts the position of the distal end of a passenger loading bridge, which control, when actuated, causes the motor to operate and the adjustment mechanism to move the end of the bridge to a preset position.
    Type: Grant
    Filed: May 20, 1980
    Date of Patent: November 9, 1982
    Assignee: Abex Corporation
    Inventor: Aaron V. Farr
  • Patent number: 4341986
    Abstract: A servo control system for the positioning of a projector comprising a dit current motor having the projector connected to the shaft of the motor, and a digital computer for providing command signals to move the projector to a programmed position at a programmed velocity within a predetermined time period. A potentiometer produced an electrical signal indicative of the actual position of the projector, and a tachometer produces an electrical signal indicative of the actual velocity of the projector. Feedback means, in turn, provides a position error signal indicative of the difference between the programmed position and the actual position of the projector, provides a velocity error signal indicative of the difference between the programmed velocity and the actual velocity of the projector, and varies, in response to the position and velocity error signals, the voltage level of the command signal such that the projector will attain the programmed position within the predetermined time period.
    Type: Grant
    Filed: January 22, 1981
    Date of Patent: July 27, 1982
    Assignee: The United States of America as represented by the Secretary of the Navy
    Inventor: George B. Browder
  • Patent number: 4251760
    Abstract: A system for duplicating a master part includes a gauge for measuring changes in the dimension therein of a master part to be duplicated and for providing control signals representative of changes from a predetermined dimension. The control signals are applied to a control circuit for controlling an adjustable tool block associated with a machine tool for machining a workpiece in response to the control signals from the gauge to assure that the workpiece dimension conforms to that of the master part.
    Type: Grant
    Filed: June 30, 1978
    Date of Patent: February 17, 1981
    Assignee: Subco, Inc.
    Inventor: Richard C. Gersch
  • Patent number: 4245298
    Abstract: A system for creating a control reference signal for a remote electrical servo device having a movable output unit wherein the velocity and position of the output unit are controlled by the vector magnitude of the control reference signal. This system includes a digital circuit for creating a first fixed analog signal indicative of a known or desired velocity for the unit during a preselected controlled time interval and a second digital means for creating a desired time base positional profile during the preselected time interval. An encoder arrangement is employed for detecting the actual time base positional profile of the servo output unit during the given time interval so that an analog signal generally proportional to the algebraic difference between the actual and desired time base positional digital profile can be created at various times during the time interval.
    Type: Grant
    Filed: January 15, 1979
    Date of Patent: January 13, 1981
    Assignee: Magicam, Inc.
    Inventor: Dan Slater
  • Patent number: 4137487
    Abstract: A method and apparatus for automatically leveling a band of fibers such as sliver, roving and the like by varying the drafting speed of a drafting mechanism responsive to variations in the thickness of the band. Analogue signals are produced by variations in the thickness of the band and are converted to digital signals for being stored in a digital register. After a period of time, corresponding with the time for conveyance of the scanned point in the sliver up to and into the draft zone, the information is read out of the storage register and converted back to an analogue signal. The analogue signal is compared with another signal representing the actual drafting speed for producing a compared signal for controlling the drafting speed.
    Type: Grant
    Filed: September 27, 1976
    Date of Patent: January 30, 1979
    Assignee: Schubert & Salzer
    Inventors: Heinrich Niestroj, Peter Denz
  • Patent number: 4119958
    Abstract: A synchro to digital converter which has a programmable read only memory (prom) that operates under control of a feed back counter and register. The prom is programmed to generate a digital signal proportional to the converter's inherent systematic error. The data stored in the prom is empirically derived by running an error (input angle vs. output angle) curve on the uncompensated converter. The corrected error signal from the prom is converted to analog form by conventional digital to analog converter means and subtracted from the closed loop steering signal which is derived from an approximating network thereby increasing the converter output accuracy to within better than 2 arc minutes.
    Type: Grant
    Filed: October 23, 1975
    Date of Patent: October 10, 1978
    Assignee: The Singer Company
    Inventors: David Julian Simon, Alfred Douglas Gronner, Carl Cono Stella
  • Patent number: 4077000
    Abstract: A system for selectively aiming a directional receiving antenna in one of a plurality of different directions respectively associated with a plurality of broadcast transmitters differently located in azimuth relative to the antenna in response to the entry into a digital keyboard of the different identification numbers assigned to the different transmitters.
    Type: Grant
    Filed: January 13, 1977
    Date of Patent: February 28, 1978
    Inventor: Jerry A. Grubbs
  • Patent number: 4031531
    Abstract: Each output signal from a synchro device is applied to an individual voltage comparator through a step-down transformer. Each comparator is biased to a predetermined threshold level and produces an output signal whenever the magnitude of the associated synchro signal exceeds the threshold in the proper polarity. The comparator output voltages are applied to individual clocked flip-flops so as to produce binary output signals in a parallel format indicative of the rotor displacement of the synchro device.
    Type: Grant
    Filed: January 12, 1976
    Date of Patent: June 21, 1977
    Assignee: Sperry Rand Corporation
    Inventors: Jeffrey C. Rice, Terry A. Tucker
  • Patent number: 4016467
    Abstract: A servodrive apparatus is disclosed for a postage meter having a postage printing drum mounted for rotation from and to a home position in single revolution increments and a conveyor for transporting individual pieces of mail into operative engagement with the incrementally rotating drum to be printed with postage. The servodrive apparatus drives the printing drum and controls the angular velocity of the drum to be substantially equal to a preselected angular velocity so that noise generated by the meter is decreased and its operating life is increased. This servodrive apparatus includes a motor for driving the printing drum and means for sensing the angular displacement of the printing drum. A signal generator produces a signal proportional to the preselected angular velocity and a comparator compares the sensed angular velocity of the drum and the preselected angular velocity.
    Type: Grant
    Filed: March 10, 1975
    Date of Patent: April 5, 1977
    Assignee: Pitney-Bowes, Inc.
    Inventor: Richard A. Hallenbeck
  • Patent number: 3962620
    Abstract: A programmer or switching apparatus produces an ON and OFF valued control signal for turning an associated controlled component ON and OFF at preselected points in the variation range of a reference variable. The apparatus includes a reference transducer for converting the reference variable into a reference signal representing the variable. A pair of set-point devices provide a pair of set-point signals which are compared with the reference signal to define operating points at which the control signal switches between its ON and OFF values. The apparatus has the versatility of allowing, by merely setting the set-point devices and without making any circuit changes, the first transition of the control signal to be either from ON to OFF or from OFF to ON as the reference variable increases from its minimum to its maximum value.
    Type: Grant
    Filed: June 3, 1974
    Date of Patent: June 8, 1976
    Assignee: The Arthur G. Russell Company, Incorporated
    Inventor: Warren E. Dion
  • Patent number: 3949286
    Abstract: A digital position control for linearly moving apparatus driven by a motor includes a command signal generating loop coupled to a motor operative condition control loop. The command signal generating loop provides a digital pulse train signal having frequency characteristics corresponding to the desired accelerations and velocities of the apparatus and a total number of pulses proportional to the desired movement of the apparatus. The motor operative condition control loop employs the command signal to energize the motor in accordance with the frequency and pulse count characteristics of the command signal.
    Type: Grant
    Filed: November 5, 1974
    Date of Patent: April 6, 1976
    Assignee: Dynapar Corporation
    Inventor: James W. Appelgren
  • Patent number: 3939390
    Abstract: Numerical control means for controlling the position of a machine tool or the like by means of a servomotor are described. A position command signal is compared to the signal indicative of the servomotor position, and the resultant error signal is added to a speed command signal to control the speed of operation of the motor. A follow-up signal is generated whenever the amplitude of the error signal exceeds a predetermined level, and the latter is added to a digital position signal coupled to the system. A constant digital signal generated by said follow up signal is added to said error signal instead of said speed signal.
    Type: Grant
    Filed: November 14, 1972
    Date of Patent: February 17, 1976
    Assignee: Ing. C. Olivetti & C., S.p.A.
    Inventors: Piero Pomella, Luciano Lauro
  • Patent number: 3934186
    Abstract: A program control unit for industrial robots comprising programming means to check instructions from arm-position memory means in which the arm motions are set by means of an arm-position selecting circuit and generates arm-position setting signals and also instruction signals for the grip and the exterior through an instruction signal converter circuit, and a stepping circuit to which are led quick-feed or jumping instructions as well as instructions based on actual arm-position signals, grip and exterior motion signals, and confirmation signals from the programming means, so that the programming means can be allowed to proceed with the processes by said stepping circuit.
    Type: Grant
    Filed: October 19, 1973
    Date of Patent: January 20, 1976
    Assignee: Mitsubishi Jukogyo Kabushiki Kaisha
    Inventors: Kyohei Hayakawa, Hiroshi Maeda
  • Patent number: 3932796
    Abstract: A multi-axis machine tool or the like employing controls for an open loop stepping motor system of two or more axes in which variable frequency feedrate clock pulses are generated to ultimately control the speed of the various stepping motors. The frequency of the feedrate clock pulses is modified in accordance with programmed information; additional information defines the tool path which can either be straight line or circular arc segments and characteristically the feedrate clock pulse generation means increases pulse frequency at the beginning of a segment in such manner as to increase motor speed in accordance with system inertial limitations from a speed below to a speed above the slewing rate of the stepping motors. Thereafter upon sensing a predetermined distance from the end of the segment, pulse frequency is reduced to reduce the stepping motor speed below the slewing rate.
    Type: Grant
    Filed: January 31, 1973
    Date of Patent: January 13, 1976
    Assignee: Textron, Inc.
    Inventors: Marvin L. Kreithen, John J. Lawler, Jr.