Patents Examined by Saul M. Bergmann
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Patent number: 4904912Abstract: A control mechanism employing an internal model coordination method according to the present invention is arranged to obtain a manipulation variable by comparing a desired value or a reference value with a feedback variable into which a controlled variable is transformed to provide an error, sequentially transmitting the error to an internal model which is composed of the same number of elements as its order, adding the outputs of a plurality of gain controllers into which the state variables of the respective elements are input, and comparing the result of the addition with another feedback variable supplied from a conventional regulator. The control mechanism is characterized by a new regulator arranged to receive as its input a branched signal of the desired value or the reference value and a path arranged to cause a signal obtained by addition of the output of the new regulator to the final state variable of the internal model to be input to a corresponding one of the gain controllers.Type: GrantFiled: October 6, 1988Date of Patent: February 27, 1990Inventor: Nobuo Yamamoto
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Patent number: 4902949Abstract: A resistor is provided in parallel with the capacitor of a phase compensating circuit in order that a rapid transition may be made to a steady velocity state when a motor is started, a target velocity (reference velocity) is changed, or a large fluctuation in load occurs. When the steady velocity state does not prevail, the capacitor is isolated from the circuit and the resistor is connected into the circuit in its place.Type: GrantFiled: June 22, 1988Date of Patent: February 20, 1990Assignee: Fuji Photo Film Co., Ltd.Inventor: Masafumi Hirata
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Patent number: 4902947Abstract: A servo circuit with a failure detection mechanism comprising: a servo circuit for servo controlling on the basis of a control signal an actuator which is connected through a hydraulic circuit with a source of oil pressure and is operated by the hydraulic circuit which is changed over by a servo valve; a monitor circuit arranged in parallel relationship with the servo circuit and generating a monitor control signal; and a failure detection circuit in which the control signal of the servo circuit and the monitor control signal of the monitor circuit are inputted and which detects a failure of the servo circuit on the basis of the control signal and the monitor control signal; wherein the hydraulic circuit is provided with pressure detecting means for detecting a pressure thereof; and the monitor circuit includes a correction circuit in which a pressure signal from the pressure detecting means is inputted and which corrects a loop gain of the monitor circuit in correspondence with a value of the pressure signalType: GrantFiled: January 12, 1989Date of Patent: February 20, 1990Assignee: Teijin Seiki Company LimitedInventor: Hidenobu Ako
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Patent number: 4902950Abstract: A numerical control method is provided, which is capable of compensating for a response delay of a servo system to command pulses to thereby make it possible to repetitively effect reciprocal movement of a controlling object at a high speed over the entirety between target positions inclusive of these positions, without the need of increasing a time period for execution of a desired operation.Type: GrantFiled: August 11, 1988Date of Patent: February 20, 1990Assignee: Fanuc Ltd.Inventors: Hideaki Kawamura, Kentaro Fujibayashi, Haruhiko Kozai
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Patent number: 4901000Abstract: A circuit inserted between a microprocessor controller and a stepper motor driver uses a detector to detect single peak or double peak pulses from the controller and selectively produce one or two motor steps for each controller program loop, and a time delay circuit to regulate the time of the second step to yield a substantially regular stepping rate.Type: GrantFiled: February 23, 1989Date of Patent: February 13, 1990Assignee: General Motors CorporationInventors: Marc B. Center, Norman Maasshoff
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Patent number: 4900999Abstract: A control system for a reciprocating linear motion or intermittent motion device. The system includes e.g. programmable control for setting an extent of stroke for an operation member of the device, for setting a period of stroke time for the operation member, and a memory for storing therein in the order of addresses items of velocity data at stroke positions at a specified spacing, the items of velocity data being obtained from a predetermined operation member velocity diagram. When the extent of stroke and time are specified by, the velocities of the operation member are determined based on the specified values and the velocity data in the memory, permitting the operation member to perform a stroke motion by the specified amount for the specified time period at the velocities determined.Type: GrantFiled: February 3, 1989Date of Patent: February 13, 1990Assignee: Shikoku Kakoki Co., Ltd.Inventors: Masato Shibata, Yoshitaka Yamane
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Patent number: 4897590Abstract: Disclosed is an apparatus for gaining high-speed random access to a track in a magnetic recording/playback system of the type in which a magnetic head is shifted to an adjacent track in response to a forward-feed/reverse-feed signal and the head is positioned at the center of this track by tracking control. When the track number of a track to be accessed is designated, the designated track number is compared with a track number at which the magnetic head is presently located. An apparatus is provided for fast-feeding the magnetic head to a track adjoining the designated track on the basis of the comparison, and for subsequently outputting the forward-feed/reverse-feed signal for the purpose of tracking control.Type: GrantFiled: November 17, 1988Date of Patent: January 30, 1990Assignee: Fuji Photo Film Co., Ltd.Inventors: Nobuo Minoura, Katsuo Nakadai, Toshikatsu Harase, Satoshi Iwamatsu
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Patent number: 4897589Abstract: Disclosed herein is an origin indexing apparatus applicable to a printer. A moving member, such as a printing head mounted on a carriage, is moved by a stepper motor which rotates in stepwise fashion by sequentially changing excited phase by a predetermined number K. An initially set origin of such a moving member is exactly indexed or identified in a later origin indexing operation according to the relationship between the phase difference between excited phases of the stepper motor at the time of initial setting of the origin and the origin indexing operation and the number of phases K of the stepper motor. One of three positions is indexed as the origin based upon this relationship, including a center position corresponding to a subsequent specified phase appearing in the same cycle following the indexed excited phase, and positions downstream and upstream of the center position.Type: GrantFiled: May 16, 1988Date of Patent: January 30, 1990Assignee: Brother Kogyo Kabushiki KaishaInventors: Takashi Fujiwara, Kiyotaka Ohara
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Patent number: 4897588Abstract: A double motor feed control system for controlling a relative linear feed motion between two objects, such as a rail and a table of a linear motion rolling contact bearing assembly. The double motor feed control system includes a first motor, a threaded feed shaft driven to rotate by the first motor, and a slider assembly threadably connected to the feed shaft. The slider assembly includes a nut which is fitted onto and in thread engagement with the feed shaft, an inner ring fixedly attached to the nut and provided with a rotor, and a motor housing rotatably supported on the rotor through a pair of ball bearings and provided with a stator in opposite arrangement with the rotor to thereby define a second motor. By controlling the direction of rotation of each of the first and second motors, the feed speed may be selectively set at a fast or slow speed.Type: GrantFiled: July 21, 1988Date of Patent: January 30, 1990Assignee: Nippon Thompson Co., Ltd.Inventor: Seiji Takei
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Patent number: 4896087Abstract: A control system is provided for a workcell having a plurality of electric robots and a plurality of workcell equipment items in turn having a plurality of control and sensor devices associated therewith.Respective electronic robot controllers are disposed at respective workcell locations to operate robots as a part of the workcell process. Each robot controller has a floppy disk or other means for loading program data for one of the robot controllers.A first input/output control module is disposed at another workcell location and it has connected thereto as inputs a first group of the sensor devices and as outputs a first group of the control devices. Second and third input/output control modules are disposed at additional workcell locations and have connected thereto as inputs second and third groups of the sensor devices and as outputs second and third groups of the control devices.Type: GrantFiled: January 31, 1989Date of Patent: January 23, 1990Assignee: Staubli International AG.Inventors: Eimei M. Onaga, Richard J. Casler, Jr., James A. Hart, Kim N. Trinh, Kenneth E. Daggett
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Patent number: 4896088Abstract: A switched reluctance motor drive or generator takes advantage of the characteristic independence of concentrated phase windings to optimize fault-tolerant operation. No "dead zones" in motor torque production or generator voltage output are created by faulted phases. One embodiment prevents unbalanced magnetic pull on the rotor despite deactivation of a faulted phase by employing multiple pairs of opposed stator pole windings in each phase.Type: GrantFiled: March 31, 1989Date of Patent: January 23, 1990Assignee: General Electric CompanyInventor: Thomas M. Jahns
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Patent number: 4894597Abstract: A deburring robot capable of adjusting the grinder position in response to detected data of the positions and shapes of the burrs on the workpiece as it carries out the deburring operation. A detector is provided at the robot position where the deburring is performed in order to detect the position and shape of the burr concerned. The detected data thus obtained is compared with the data on the predetermined taught positions of the grinder stored in a controller, so that the correction of the grinder position is effected simultaneously with the deburring operation.Type: GrantFiled: May 18, 1988Date of Patent: January 16, 1990Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Sadayuki Ohtomi
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Patent number: 4894599Abstract: In a servo controlled device such as a disk drive actuator or a robot that is driven by a DC motor and must seek from one position to another position and settle at the target position in a minimum time, a deadbeat control response can effect settling in a minimum number of servo sample times with no steady state error and no ripple between sampling instants. The device design, initial conditions entering the deadbeat controlled mode and the frequency of servo samples can be used to enable deadbeat control by limiting the control current to a value that will not saturate the motor coil or exceed the linear operating range of the controlled device.Type: GrantFiled: March 31, 1988Date of Patent: January 16, 1990Assignee: International Business Machines CorporationInventors: Hjalmar H. Ottesen, Yuzo Nakagawa, Shyunji Ono
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Patent number: 4894594Abstract: The designated speeds of a plurality of blocks are read beforehand, deceleration start positions are calculated to maintain the servo system at a speed below the designated speeds of the blocks read beforehand at the start positions of the previously read blocks, and the servo system is decelerated from the calculated deceleration start positions, whereby the servo system speed is kept below the designated speeds of all of the blocks and the deceleration of the speed of the servo system is controlled with a high degree of accuracy.Type: GrantFiled: September 21, 1988Date of Patent: January 16, 1990Assignee: Fanuc LtdInventors: Hideaki Kawamura, Kentaro Fujibayashi, Nozomu Arimoto
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Patent number: 4893066Abstract: A hybrid sample rate servo motor employing rate feedback compensation is disclosed. The system employs a shaft encoder having a predetermined resolution to provide position data which are pulses indicating the shaft has moved another resolution unit. Under high motor velocity conditions the rate compensation feedback loop is operated at a conventional constant sample rate. Under low velocity conditions, the sample rate at which the rate compensation feedback loop is operated is modified so that rate samples are taken and calculated only when new position data are available from the motor encoder. Rate quantization error is substantially reduced, thereby leading to more robust controller operation.Type: GrantFiled: September 19, 1988Date of Patent: January 9, 1990Assignee: Hewlett-Packard CompanyInventors: Lowell J. Stewart, Alfred H. Mebane IV
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Patent number: 4890048Abstract: A stepping motor controller supplies a pulsed input signal to a motor driver controlling rotation of a stepping motor. To accelerate or decelerate the motor, the controller linearly increases or decreases the frequency of the motor driver input signal at a rate proportional to a desired angular acceleration value conveyed in an input command. The controller includes a computer responding to a low frequency interrupt signal by periodicaly adding the acceleration value to an accumulated velocity value, adding the accumulated velocity value to an accumulated displacement value, and adjusting an output angular displacement value in accordance with the amount of overflow of the accumulated displacement value. A hardware accumulator responds to a high frequency clock signal by periodically incrementing an accumulated number by the output angular displacement value of the computer, the accumulator generating a pulse of the motor driver input signal whenever the accumulated number overflows.Type: GrantFiled: January 9, 1989Date of Patent: December 26, 1989Inventor: L. Wayne Hunter
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Patent number: 4890046Abstract: A numerical control apparatus according to the invention reliably eliminates the influence on positional accuracy of static resistance and dynamic resistance, which act as disturbance upon a servo loop, when a semi-closed loop forms a servo system for positioning, by numerical control, a machine tool or the like driven by a servomotor. The numerical control apparatus has a backlash correction function and supplies the servo system with a backlash correction data BL(i) distinguished from an ordinary move command BL(i). In order to eliminate a shift from a commanded position due to the aforementioned disturbance, an offset command corresponding to frictional torque Fa in the mechanical system of the machine tool or the like is applied to the servo system as a torque correction signal FR(i) in accordance with the backlash correction data BL(i).Type: GrantFiled: July 29, 1988Date of Patent: December 26, 1989Assignee: Fanuc LtdInventors: Mitsuo Kurakake, Keiji Sakamoto
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Patent number: 4890045Abstract: A disk apparatus spindle motor control system has a control circuit including a frequency generator for generating a master clock signal of a predetermined frequency, a first frequency divider for frequency-dividing the master clock signal by 2.sup.1, 2.sup.2, . . . , 2.sup.N, a second frequency divider for frequency-dividing the signal frequency-divided by 2.sup.N to generate a master index signal upon each rotation of the spindle motor, a time interval detector for detecting a time interval between the master index signal and an index signal output from a magnetic disk unit and outputting a phase control signal and a select signal corresponding to the detected time interval, a data selector for selecting and outputting one of the signals frequency-divided by 2.sup.1, 2.sup.2, . . . , 2.sup.Type: GrantFiled: December 28, 1988Date of Patent: December 26, 1989Assignee: NEC CorporationInventor: Hiromi Ishizuka
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Patent number: 4888541Abstract: A method and apparatus for controlling stepmotors having a broad range of applications including fuel control for gas-turbine engines, and operating powered automatically controlled doors for mass transit vehicles is disclosed. Step motor control through analysis of the motor winding currents during application of controlled voltage pulse provides a basis for evaluating shaft torque conditions at the motor load without return or feedback signals from the driven load. This type of current analysis utilizing digital techniques provides a convenient, reliable, and economical means for detecting stepmotor output shaft position and loading. Detection and recognition of output shaft load or drive requirements is then utilized in a control system wherein functional requirements of the system including motion and/or torque requirements of the shaft output load can be controlled in accordance with desired system operation.Type: GrantFiled: October 23, 1987Date of Patent: December 19, 1989Inventor: Jack Russell
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Patent number: 4888534Abstract: A numerical control can be performed on one or more independently controllable objects on the basis of existence of such objects and the control itself is performed selectively on the axis and other objects which are not axes. Therefore, it is possible to control one to all of various objects which are to be operated simultaneously independently, by means of a single numerical control apparatus. Thus, a plurality of objects can be controlled independently from other objects, resulting in high producibility of products.Type: GrantFiled: February 2, 1989Date of Patent: December 19, 1989Assignee: Mitsubishi Denki Kabushiki KaishaInventor: Kiyoshi Kuchiki