With Acceleration Measuring Instruments Patents (Class 318/651)
  • Patent number: 11742738
    Abstract: An embodiment of a linear electric machine includes two or more phases that define a central bore, and alternating permanent magnets that are disposed within the central bore and are free to move relative the windings. An embodiment of a method for selectively powering the windings is disclosed that enables the machine to realize a commanded force, or to determine the force present by using the current within the windings and the alignment of the magnets relative to the windings.
    Type: Grant
    Filed: April 14, 2022
    Date of Patent: August 29, 2023
    Assignee: IRIS DYNAMICS LTD
    Inventors: Kyle A. Hagen, Patrick A. McFadden, Maximilien F. Bethune-Waddell, Jeffrey R. Rendell
  • Patent number: 11231441
    Abstract: Exemplary embodiment of a tilting z-axis, out-of-plane sensing MEMS accelerometers and associated structures and configurations are described. Disclosed embodiments facilitate improved offset stabilization. Non-limiting embodiments provide exemplary MEMS structures and apparatuses characterized by one or more of having a sensing MEMS structure that is symmetric about the axis orthogonal to the springs or flexible coupling axis, a spring or flexible coupling axis that is aligned to one of the symmetry axes of the electrodes pattern, a different number of reference electrodes and sense electrodes, a reference MEMS structure having at least two symmetry axes, one which is along the axis of the springs or flexible coupling, and/or a reference structure below the spring or flexible coupling axis.
    Type: Grant
    Filed: April 7, 2020
    Date of Patent: January 25, 2022
    Assignee: INVENSENSE, INC.
    Inventors: Giacomo Laghi, Matthew Julian Thompson, Luca Coronato, Roberto Martini
  • Patent number: 10566919
    Abstract: An electric motor control system includes an electric motor motion signal detection part, configured to provide an electric motor motion signal of the electric motor every other first interval time based on a received first encoder signal sent by the first encoder; a shaft motion signal detection part configured to provide a shaft motion signal of the shaft every other second interval time based on a received second encoder signal sent by the second encoder; and a main control apparatus configured to receive and calculate, according to the electric motor motion signal and the shaft motion signal, an electric motor motion parameter of the electric motor at a moment every other second interval time.
    Type: Grant
    Filed: September 24, 2015
    Date of Patent: February 18, 2020
    Assignee: SIEMENS AKTIENGESELLSCHAFT
    Inventor: Fu Chang Huang
  • Patent number: 10309855
    Abstract: A torque sensing system which includes a torque sensor capable of wirelessly communicating torque and misalignment data to a smartphone or a tablet using a protocol such as Wi-Fi or Bluetooth technology, and wirelessly communicating commands from the smartphone or table back to the torque sensor. The torque sensor electronics include an rf coil for taking power off of a stationary housing to a rotary shaft and one or more accelerometers for indicating misalignments.
    Type: Grant
    Filed: August 23, 2016
    Date of Patent: June 4, 2019
    Assignee: FUTEK Advanced Sensor Technology
    Inventors: Javad Mokhbery, Amirreza Mehran, Ehsan Niroomand
  • Patent number: 10063124
    Abstract: Disclosed herein is a shaft-mounted monitor for monitoring conditions of a rotating shaft using a calculated rotational component of the rotating shaft. The monitor may include a sensor such as an accelerometer, thermal sensor, strain gauge, or the like. In various embodiments, a variety of parameters relating to the rotating shaft may be monitored, such as a temperature, rotational speed, angular position, torque, power, frequency, or the like. The monitor may include a wireless transmitter to transmit the monitored condition of the rotating shaft to an intelligent electronic device or a monitoring system.
    Type: Grant
    Filed: December 7, 2016
    Date of Patent: August 28, 2018
    Assignee: Schweitzer Engineering Laboratories, Inc.
    Inventor: Marcos A. Donolo
  • Patent number: 9952252
    Abstract: A system and method for reducing offset in a MEMS sensor are disclosed. In a first aspect, the system is a MEMS sensor that comprises a sensing reference plane, at least one anchor coupled to the sensing reference plane, at least one proof mass coupled to the at least one anchor, wherein one of the at least one proof mass moves under an external excitation, a pattern of sensing elements coupled between the sensing reference plane and the at least one proof mass to detect motion normal to the sensing reference plane, wherein the pattern of sensing elements shares at least three axes of polarity anti-symmetry, and a signal processing circuit to combine the pattern of sensing elements thereby providing an output proportional to the external excitation. In a second aspect, the sensing reference plane is divided by two axes forming four quadrants on the sensing reference plane.
    Type: Grant
    Filed: May 15, 2015
    Date of Patent: April 24, 2018
    Assignee: InvenSense, Inc.
    Inventors: Matthew Julian Thompson, Kirt Reed Williams
  • Publication number: 20140191702
    Abstract: A motor controlling device is provided. The device includes a position controller for generating a speed reference based on a positional reference and a motor position, a speed controller for generating a torque reference based on the speed reference and a motor speed, a motor drive for driving a motor based on the torque reference, the motor driving machinery to which an acceleration sensor is attached, an acceleration feedback signal generator for generating a feedback signal to the speed reference based on an acceleration detection signal that is a detection signal of the acceleration sensor, and a positional reference filter inputted with the positional reference and suppressible of low frequency vibration of the machinery.
    Type: Application
    Filed: January 7, 2014
    Publication date: July 10, 2014
    Applicant: KABUSHIKI KAISHA YASKAWA DENKI
    Inventors: Yasufumi YOSHIURA, Yasuhiko KAKU
  • Patent number: 8456127
    Abstract: Provided is a method of obtaining an image of a disc, in which the method obtains an image of an analysis or test result object of a disc by minimizing a difference between the positionings of a magnet of the disc and a magnet of a feeding unit, and an apparatus for driving a disc, wherein the apparatus performs the method. The method includes: fixing a positioning of a disc by using magnetic attraction between a first magnet installed on the disc and a second magnet installed on a feeding unit; minimizing a difference between the positionings of the first and second magnets; and obtaining an image of an analysis or test result object of the disc.
    Type: Grant
    Filed: February 18, 2010
    Date of Patent: June 4, 2013
    Assignee: Samsung Electronics Co., Ltd.
    Inventors: Jong-cheol Kim, Chung-ung Kim, Ki-ju Lee, Jong-jin Park, Dong-hwi Cho, Su-bong Bae
  • Patent number: 7958620
    Abstract: A method of determining the eccentricity of an encoder scale member of a rotary encoder includes taking an encoder scale blank having a geometric center and mounting the encoder scale blank centered about a second center. A scale can then be produced on the encoder scale blank thereby forming an encoder scale member. The scale of the encoder scale member is centered about the second center. Any eccentricity between the geometric center and the second center is measured by, for example, measuring any change in the apparent radius of the encoder scale member. The encoder scale member may then be mounted in a working location wherein it is rotated about a third axis. The eccentricity when mounted in the working location may be matched to that measured during manufacture thereof and/or the eccentricity errors arising from both manufacture and mounting of the encoder scale member may be determined.
    Type: Grant
    Filed: April 25, 2006
    Date of Patent: June 14, 2011
    Assignee: Renishaw PLC
    Inventor: James Reynolds Henshaw
  • Patent number: 7633256
    Abstract: Correction of rotary encoder eccentricity in an image forming device having a motor controller using period and position pulse train feedback signals. A motor includes an encoder disc rotating with the motor and at least two encoder sensors disposed at different circumferential positions about the encoder disc. A controller may use a high speed clock to calculate a corrected speed count based on speed counts determined from the number of clock cycles that elapse per cycle of pulse trains from the encoders. The controller may also calculate a corrected position count based at least partly on one or more position counts determined from the number of clock cycles that elapse between periodic sampling points and transitions of encoder pulse trains. The corrected position count may also be calculated based on a position count and one or more speed counts.
    Type: Grant
    Filed: May 4, 2005
    Date of Patent: December 15, 2009
    Assignee: Lexmark International, Inc.
    Inventors: Brian Anthony Reichert, Steven Michael Turney, Danny Keith Chapman, Thomas Austin Fields
  • Patent number: 7602135
    Abstract: An arrangement having at least one movable furniture part, in particular having a drawer or the like, having at least one drive unit and at least one regulating device for regulating the at least one drive unit, wherein the arrangement (7) has at least one, preferably analog, acceleration measuring device (2), with the at least one acceleration measuring device (2) generating an acceleration signal that is characteristic of accelerations caused by forces applied to the at least one movable furniture part (3) from the outside and that may be supplied to the at least one regulating device (1).
    Type: Grant
    Filed: May 29, 2003
    Date of Patent: October 13, 2009
    Assignee: Julius Blum Gesellschaft m.b.H.
    Inventors: Edgar Huber, Uwe Scheffknecht
  • Patent number: 7514893
    Abstract: The method is for interacting with a wearable interactive device. A pathway extends through an interactive device that is non-slidably attached to the pathway. The pathway has a first end and a second end. At least one end of the pathway is attached to a body of a user. The user accelerates the device in a first direction. A sensor senses the acceleration in the first direction. The sensor triggers a motor to move gears so that the device travels towards the first end of the pathway. The user accelerates the device in a second opposite direction. The sensor triggers the device to move towards the second end of the pathway.
    Type: Grant
    Filed: May 2, 2007
    Date of Patent: April 7, 2009
    Inventors: Jin Moen, Johan Sandsjo
  • Patent number: 7471056
    Abstract: A control device includes a first switch (400) by which an input signal to a motor speed control loop (910) is selected from a signal of a position control loop (300) and a signal of the speed control loop (200), and a switch controller (500) that controls switching of the first switch (400), so that the first switch (400) can switch between a quadruple loop (a current control loop, the motor speed control loop, the speed control loop (200) and the position control loop (300)) with the speed control loop (200) embedded therein, and a triple loop (the current control loop, the motor speed control loop and the position control loop (300)) without the speed control loop (200), corresponding to a transient state and a steady state.
    Type: Grant
    Filed: December 1, 2005
    Date of Patent: December 30, 2008
    Assignee: Mitutoyo Corporation
    Inventors: Shingo Kiyotani, Nobuhiro Ishikawa
  • Patent number: 7423393
    Abstract: A car control apparatus including a wheel sensor, wheel torque calculating means for calculating wheel torque from the wheel speed, drive force detecting means for detecting drive force generated by an electric motor, car body drive force calculating means for calculating car body drive force from the above drive force and wheel torque, car body drive force fluctuating component extracting means for extracting multiple frequency band fluctuating components of the car body drive force, and drive or braking force control unit for controlling the running state of a car.
    Type: Grant
    Filed: May 6, 2003
    Date of Patent: September 9, 2008
    Assignee: Kabushiki Kaisha Bridgestone
    Inventors: Yasumichi Wakao, Keizo Akutagawa
  • Publication number: 20080150468
    Abstract: The invention relates to a method and a circuit layout for the position and/or speed control of a linear drive, in particular a servo drive for a linear robot. An electric motor is supplied via a converter (3) with a control unit (4) and the motor position is determined, in particular in a sensor-free manner or via a position sensor (7). This motor position signal and an acceleration signal generated via an accelerometer (5) provided in the control unit (4) and arranged on the moving part of the linear drive are mathematically converted to a speed signal. This speed signal is used for controlling the drive. The accelerometer (5) is embodied as a microelectromechanical system (MEMS) and integrated into the entrained control unit (4).
    Type: Application
    Filed: May 24, 2006
    Publication date: June 26, 2008
    Inventor: Tomas Kalender
  • Patent number: 7245103
    Abstract: A method of controlling the speed and position of a motor includes receiving a pulse train indicative of the speed of the motor, and a periodic signal at a frequency greater than the pulse train. The number of cycles of the periodic signal per cycle of the pulse train is counted, and compared to a predetermined number. The speed of the motor is adjusted to match the count to the predetermined number, thus effecting speed control. A command position signal defining a plurality of sampling points is generated. The number of cycles of the periodic signal between a sampling point of the command position signal and an operative edge of the pulse train is counted and compared to a predetermined number. The speed of the motor is further adjusted to match the count to the predetermined number, thus effecting position control.
    Type: Grant
    Filed: March 3, 2003
    Date of Patent: July 17, 2007
    Assignee: Lexmark International, Inc.
    Inventors: Danny Keith Chapman, Steven Michael Turney
  • Patent number: 7196489
    Abstract: The invention aims to suppress or prevent the vibration that can occur due to the intervention of a low-rigidity part between detector and rotating body. An angular acceleration sensor for detecting the rotational angular acceleration of a rotating body is provided, and an angle/angular speed command value is compensated in accordance with the value of the angular acceleration.
    Type: Grant
    Filed: November 29, 2005
    Date of Patent: March 27, 2007
    Assignee: Fanuc Ltd
    Inventors: Mitsuyuki Taniguchi, Keisuke Imai
  • Patent number: 7187148
    Abstract: Disclosed is a controller for restraining vibration of a driven element driven by a servomotor. The driven element driven by the servomotor is provided with acceleration detecting means. A correction value is obtained by multiplying a detected acceleration value detected by the acceleration detecting means by a coefficient. Correction is made by subtracting the correction value from a velocity command, and velocity feedback control is executed in a velocity control processing section to obtain a current command. Further, the servomotor is driven by current control processing, whereupon the driven element is moved. If the detected acceleration value is increased by vibration of the driven element, the velocity command is corrected to restrain the vibration, so that the vibration of the driven element can be restrained.
    Type: Grant
    Filed: November 28, 2005
    Date of Patent: March 6, 2007
    Assignee: Fanuc Ltd
    Inventors: Tadashi Okita, Yukio Toyozawa, Hiroyuki Kawamura, Satoshi Ikai
  • Patent number: 6940248
    Abstract: Motion controlling includes a combining network having an acceleration input for receiving an acceleration signal representative of acceleration of a movable element and a position input for receiving a position signal representative of position of the movable element and an output for providing an inferred position signal representative of an inferred position of the movable element. The network includes a first signal processor for processing the acceleration signal to provide modified acceleration signal, a second signal processor for processing the position signal to provide a modified position signal and a combiner for combining the modified acceleration signal with the modified position signal to provide the inferred position signal.
    Type: Grant
    Filed: July 21, 2003
    Date of Patent: September 6, 2005
    Assignee: Bose Corporation
    Inventors: Robert Maresca, Thomas Aho
  • Patent number: 6876167
    Abstract: A non-invasive apparatus and method for measuring the speed of a rotating device that includes a sensor that measures a dynamic characteristic of the rotating device. A sample of the signal is transformed from the time domain into a frequency spectrum. The frequency spectrum is then analyzed to determine the motor speed. The resulting motor speed can be combined with other motor data by an order analysis to identify malfunctioning or improperly installed components.
    Type: Grant
    Filed: January 24, 2003
    Date of Patent: April 5, 2005
    Assignee: TRW Automotive U.S. LLC
    Inventor: Michael A. Jones
  • Patent number: 6876168
    Abstract: In servomechanisms, like for example used in disk drives, disturbances, for example, friction, shock and vibration, prevent the system positioning accuracy from further improvement. These disturbances occur in a relatively low-frequency range compared to the electrical dynamics. In the present invention, an acceleration feedback control loop using a frequency-separated acceleration soft sensor (350) replaces the conventionally used current control loop in the low frequency range, where the disturbances occur, so as to attenuate the influence of the disturbances enclosed in the loop. The current feedback continues to manage the electrical dynamics in the high-frequency range. Estimating the required acceleration signal by a soft sensor (350) eliminates the need for physical accelerometers, which reduce system reliability and increase system cost.
    Type: Grant
    Filed: May 17, 2000
    Date of Patent: April 5, 2005
    Assignee: National University of Singapore
    Inventors: Yaolong Luo, Tong Heng Lee, Shuzhi Ge
  • Patent number: 6684132
    Abstract: This invention relates to an active anti-vibration apparatus having an anti-vibration table on which a stage is mounted. This anti-vibration apparatus includes a pneumatic spring actuator for supporting and driving the anti-vibration table, a PI compensator for PI-compensating a target velocity signal determined by a velocity profile concerning the stage and necessary for driving the stage, and a motion mode distributing operation unit for controlling the pneumatic spring actuator in accordance with an output signal from the PI compensator.
    Type: Grant
    Filed: February 7, 2001
    Date of Patent: January 27, 2004
    Assignee: Canon Kabushiki Kaisha
    Inventors: Shinji Wakui, Isao Iwai, Takashi Maeda
  • Patent number: 6597145
    Abstract: Motion controlling includes a combining network having an acceleration input for receiving an acceleration signal representative of acceleration of a movable element and a position input for receiving a position signal representative of position of the movable element and an output for providing an inferred position signal representative of an inferred position of the movable element. The network includes a first signal processor for processing the acceleration signal to provide modified acceleration signal, a second signal processor for processing the position signal to provide a modified position signal and a combiner for combining the modified acceleration signal with the modified position signal to provide the inferred position signal.
    Type: Grant
    Filed: July 5, 1996
    Date of Patent: July 22, 2003
    Assignee: Bose Corporation
    Inventors: Robert L. Maresca, Thomas L. Aho
  • Patent number: 6513958
    Abstract: A vehicle lamp system 1 having a leveling mechanism 2 for controlling the posture of a reflector RF and a stepping motor 3 as a driving source of the leveling mechanism. The lamp system has a detector 5 which may determine whether an external force, such as a vibration or a shock is given to the reflector RF or if there is a possibility that the vibration or shock may be given to the reflector. A rotor is prevented from being deviated from the original position by exciting each phase coil of the stepping motor with the same excitation phase as the last excitation phase at the time when the stepping motor 3 was last driven or otherwise a coil in only one of the last excitation phases at the time when the stepping motor 3 was last driven, and before vibration or a shock is given to the reflector RF after the coils in the respective phases are totally set to a non-excited condition in the stepping motor 3.
    Type: Grant
    Filed: October 29, 2001
    Date of Patent: February 4, 2003
    Assignee: Koito Manufacturing Co., Ltd.
    Inventor: Masaaki Ishikawa
  • Patent number: 6462501
    Abstract: When a movement destination P is designated, a switching time t1 when the movement is switched from acceleration to constant-speed-movement and a switching time t2 when the movement is switched from the constant-speed-movement to deceleration are determined with respect to a designated time T0. Then, a constant-speed-movement start position A and a deceleration start position B are set. Next, the constant speed (inclination of a straight line AB) during the constant-speed-movement period is found. An operation equation of the acceleration period is determined with an exponential function so that the panhead is smoothly shifted from the acceleration to the constant-speed-movement. In like manner, an operation equation of the deceleration period is determined with an exponential function so that the panhead is smoothly shifted from the constant-speed-movement to the deceleration.
    Type: Grant
    Filed: September 15, 2000
    Date of Patent: October 8, 2002
    Assignee: Fuji Photo Optical Co., Ltd.
    Inventor: Akira Higo
  • Patent number: 6128552
    Abstract: An anti-vibration apparatus has a feedback loop based on vibration information from an anti-vibration table, and a feedforward loop based on vibration information from a setting foundation. A compensation mechanism in the feedforward loop uses an adaptive filter. The adaptive filter sequentially sets parameters in the compensation mechanism on the basis of the vibration information form the anti-vibration table and setting foundation. The vibration information consists of vibration component information indicating vibrations in units of motion directions, and a determination mechanism and an operation switching mechanism arranged at the input side of the adaptive filter select the vibration component information and supply the selected information to the adaptive filter.
    Type: Grant
    Filed: November 4, 1997
    Date of Patent: October 3, 2000
    Assignee: Canon Kabushiki Kaisha
    Inventors: Isao Iwai, Shinji Wakui, Takehiko Mayama
  • Patent number: 5801507
    Abstract: An acceleration sensor includes a first acceleration sensor and a second acceleration sensor both disposed neither parallel to the plumb plane nor perpendicularly to the plumb plane, wherein the first acceleration sensor and the second acceleration sensor are disposed such that they are symmetrical to each other with reference to the plumb plane. A summing circuit is provided for obtaining the sum of an output signal of the first acceleration sensor and an output signal of the second acceleration sensor, and a differential circuit for obtaining the difference between the respective output signals of the first acceleration sensor and the second acceleration sensor, so that acceleration in the horizontal direction is obtained from one of the output signals of the summing circuit and the differential circuit, and the gravitational acceleration is obtained from the other of the output signals of the summing circuit and the differential circuit.
    Type: Grant
    Filed: May 24, 1996
    Date of Patent: September 1, 1998
    Assignee: Murata Manufacturing Co., Ltd.
    Inventor: Takeshi Nakamura
  • Patent number: 5545962
    Abstract: A positioning system includes a plurality of actuators for driving an object to be positioned, a plurality of current output type amplifiers for amplifying drive signals from the actuators and for producing drive currents corresponding to the drive signals, and a plurality of acceleration sensors for detecting acceleration of the object in the neighborhood of the actuators. A feedback circuit negatively feeds back the outputs of the acceleration sensors to input sides of the amplifiers such that the actuators are driven in response to the drive currents.
    Type: Grant
    Filed: September 30, 1994
    Date of Patent: August 13, 1996
    Assignee: Canon Kabushiki Kaisha
    Inventor: Shinji Wakui
  • Patent number: 5418442
    Abstract: The present invention is directed to a method of and an apparatus for detecting an angular velocity and a rotation angle of a rotary member and for controlling a motor disposed to drive the rotary member. In the present invention, first and second accelerations at first and second points of the rotary member are detected, respectively. The first and second accelerations are added. From the added value an angular velocity of the rotary member is calculated. A signal is generated representing the angular velocity and compared with predetermined control instructions. A control input is generated based upon this comparison, and the motor is controlled based upon the control input.
    Type: Grant
    Filed: April 1, 1994
    Date of Patent: May 23, 1995
    Assignee: Mitsubishi Denki Kabushiki Kaisha
    Inventor: Toru Araki
  • Patent number: 5385217
    Abstract: A vibration eliminating apparatus for eliminating vibration suspends a floor board from an installation floor. A supporting electromagnet is provided on the installation floor in order to suspend a magnetic member fixed to the floor board by a magnetic force. The magnetic member is provided with a thin magnetic pole through a non-magnetic member, and a control electromagnet having a yoke located in proximity to the thin magnetic pole is provided to control a horizontal position of the floor board. A vibration detector is provided to detect vibration of the floor board, and a vibration monitor is used to decide whether or not vibration detected by the vibration detector is within an allowable range of a machine mounted on the floor board and output an operation enable signal only when vibration is within the allowable range.
    Type: Grant
    Filed: May 19, 1992
    Date of Patent: January 31, 1995
    Assignee: Ebara Corporation
    Inventors: Katsuhide Watanabe, Yoichi Kanemitu, Yukio Ikeda
  • Patent number: 5336983
    Abstract: An accelerometer includes a main body, a displacing member, a scale, and a detecting unit. The displacing member is attached to the main body and has a displacing portion displaced relative to the main body at least in a direction of acceleration measurement in accordance with a force applied. The scale is provided to one of the main body and the displacing portion to detect displacement in the direction of acceleration measurement. The detecting unit is provided to the other one of the main body and the displacing portion to optically read the relative displacement of the scale. The acceleration applied to the main body is detected by the reading of the relative displacement of the scale performed by the detecting unit during relative displacing of the displacing portion.
    Type: Grant
    Filed: January 28, 1993
    Date of Patent: August 9, 1994
    Assignee: Canon Kabushiki Kaisha
    Inventor: Norito Watanabe
  • Patent number: 5272424
    Abstract: A generating device of a phase current instruction value for an A.C. servomotor and the generating method thereof, drives a synchronous A.C. servomotor. A sine wave, namely, a phase current instruction value for commutation of the A.C. servomotor driver can be generated by receiving as an interrupt the detection signal of a commutation sensor which detects the reverse electromotive force of the a motor at the microprocessor. The pulse position of the present since wave is.The pulse position of present sine wave is determined by the interrupt signal of the microprocessor. The motor is driven and controlled by converting by way of a D-A converter to an analog signal the data for generating a sine wave according to the increase or decrease of an encoder pulse.
    Type: Grant
    Filed: September 25, 1992
    Date of Patent: December 21, 1993
    Assignee: Samsung Electronics Co., Ltd.
    Inventor: Jin-Won Lee
  • Patent number: 5261026
    Abstract: A controlling apparatus for use in a balanced work or cargo handling system which aims at detecting the weight of the work or cargo suspended accurately even if a drift occurs in an acceleration detector due to changes in ambient temperature to thereby enable a stable work or cargo raising and lowering operation to be achieved. The controlling apparatus comprises an acceleration correcting arithmetic unit (23) adapted to output the difference between an averaged acceleration signal (Va.phi.) obtained by averaging the drifted acceleration signals (Va) transmitted by an acceleration; detector (8) during a predetermined period of time and the drifted acceleration signal (Va), as a corrected acceleration signal (Va') to a command arithmetic unit (17) and a load storage and arithmetic unit (22) when the absolute value (.vertline.Va.vertline.) of the drifted speed signal (Va) is less than a preset value (.epsilon.a) and the absolute value (.vertline.V.vertline.
    Type: Grant
    Filed: February 6, 1992
    Date of Patent: November 9, 1993
    Assignee: Kabushiki Kaisha Komatsu Seisakusho
    Inventors: Hitoshi Tomaru, Shuu Takeda, Seiji Kamata
  • Patent number: 5055759
    Abstract: A servo accelerometer includes a pendulum, a coil, a detection unit, and a servo unit. The detection unit has a photopotentiometer for receiving light passing through a slit of the pendulum and outputting a detection output on the basis of a change in resistance corresponding to a change in irradiation point. The servo unit has a displacement detection circuit for outputting a difference between a detection output from the photopotentiometer and a set value as a detection displacement amount.
    Type: Grant
    Filed: August 9, 1990
    Date of Patent: October 8, 1991
    Assignee: Jeco Co., Ltd.
    Inventor: Norio Miyahara
  • Patent number: 4910446
    Abstract: A three-coordinate measuring machine has a probe (22) connected to an output member (11). A driving system (10) is made up of three carriages (15, 17, 19) on guide rails (14, 16, 18). In parallel with this, there is provided a driven system (20) made up of three carriages (25, 27, 29) on guide rails (24, 26, 28). The carriages 19, 29) are connected together via the output member (11). The other pairs of carriages (15, 25 and (17, 27) are linked via respective devices (55). The devices (55) each apply a force between the respective carriages in dependence on acceleration or deceleration of the carriages of the driving system (10). This compensates for dynamic deflections of the guide rails of the driven system (20) which would otherwise be caused by the accelerations. Measuring devices such as scales and readheads are provided on the driven system (20) to determine the position of the probe (22).
    Type: Grant
    Filed: February 2, 1988
    Date of Patent: March 20, 1990
    Assignee: Renishaw plc
    Inventors: David R. McMurtry, Nicholas A. James
  • Patent number: 4806835
    Abstract: The electromagnetic device comprises at least one compensation ring placed in the vicinity of the fluid bearing and mounted relative to the rotor by means of an active radial magnetic bearing whose electromagnet windings are powered as a function firstly of the signals delivered by a position detector for detecting the position of the compensation ring relative to the rotor, and secondly of the signals delivered by at least two vibration detectors disposed on the casing of the machine and having nonparallel sensitivity axes which are perpendicular to the axis of the rotor. The signals delivered by the vibration detectors are applied to a high-gain narrow-band selective feedback circuit whose central frequency is synchronized with a reference frequency fo. The compensation ring is of relatively small mass and serves to exert a rotary compensation force on the rotor via the radial magnetic bearing, which force is equal to the centrifugal force due to the out-of-balance mass of the rotor but which is 180.degree.
    Type: Grant
    Filed: December 21, 1987
    Date of Patent: February 21, 1989
    Assignee: Societe Anonyme: Societe De Mecanique Magnetique
    Inventor: Helmut Habermann
  • Patent number: 4716347
    Abstract: In a rotary compressor provided with a motor to be controlled by an inverter, the power-supply frequency or impressed voltage during one rotation of the induction motor is varied in accordance with the changes in the load torque to make the production torque of the induction motor correspond to the changes in the load torque so as to fundamentally and effectively reduce the oscillations which are caused by the load torque changes.
    Type: Grant
    Filed: March 14, 1986
    Date of Patent: December 29, 1987
    Assignee: Daikin Industries, Ltd.
    Inventor: Satoru Fujimoto
  • Patent number: 4651075
    Abstract: Servoed accelerometer with isolated voltage torquing having first and second grounds, a servoed accelerometer having a torque coil, and an amplifier for driving said torque coil. The amplifier has inverting and non-inverting junctions. The second ground is coupled to the non-inverting junction of the amplifier. A torque signal supply is coupled to the first ground. A transformer is provided for coupling the torque signal supply to the non-inverting junction of the amplifier and serves to isolate the torque signal supply from the non-inverting input of the amplifier so that the amplifier and polarity of the torque signal are preserved.
    Type: Grant
    Filed: July 9, 1984
    Date of Patent: March 17, 1987
    Assignee: Systron Donner Corporation
    Inventors: Larry P. Hobbs, Harold D. Morris
  • Patent number: 4481588
    Abstract: A method and apparatus for adjusting the positions of switch members such as a deceleration limit switch installed on a machine tool in a numerical control system for controlling the machine tool on the basis of numerical control data and for executing predetermined numerical control processing on the basis of signals produced by the switch members. When the switch member such as a limit switch is actuated, a display device displays the current position of a movable member on the machine tool, or a numerical value corresponding to the current position of the movable member. Whether the switch member is installed on the machine tool at the correct position is determined on the basis of the displayed current position or numerical value corresponding thereto. When it is determined that the switch member is installed at an incorrect position, the switch member is positionally adjusted on the basis of the indication given by the display device.
    Type: Grant
    Filed: October 23, 1981
    Date of Patent: November 6, 1984
    Assignee: Fanuc Ltd.
    Inventor: Hidetsugu Komiya
  • Patent number: 4398418
    Abstract: A proof mass for an accelerometer is electromagnetically constrained in three orthogonal directions. An array of filaments forms an elastic suspension for the proof mass to constrain it in the remaining degrees of freedom. The resulting instrument has the potential for low cost and high-accuracy operation over a wide temperature range without the use of temperature controls. In a preferred embodiment, forcing along the longitudinal axis of the proof mass is provided by a single helical coil disposed in a magnetic field directed radially relative the proof mass longitudinal axis. The polarity of the magnetic field is fixed around the periphery of the helical coil.
    Type: Grant
    Filed: August 13, 1981
    Date of Patent: August 16, 1983
    Assignee: Rockwell International Corporation
    Inventors: Sidney G. Shutt, Adrian K. Dorsman, Doyle E. Wilcox
  • Patent number: 4372162
    Abstract: A proof mass for an accelerometer is electromagnetically constrained in three orthogonal directions. An array of filaments forms an elastic suspension for the proof mass to constrain it in the remaining degrees of freedom. The resulting instrument has the potential for low cost and high-accuracy operation over a wide temperature range without the use of temperature controls. Means are provided in the accelerometer for dynamically nulling the bias.
    Type: Grant
    Filed: August 13, 1981
    Date of Patent: February 8, 1983
    Assignee: Rockwell International Corporation
    Inventor: Sidney G. Shutt
  • Patent number: 4353254
    Abstract: An electro-static capacitive accelerometer is a square law device and includes two fixed plates and an intermediary movable plate. A control circuit detects unbalances in the accelerometer, due to acceleration, and generates a signal which induces a corresponding electro-static corrective torque on the accelerometer thus forcing it toward a null condition. The signal is proportional to the acceleration. The invention eliminates prior art summing amplifiers in the control circuit for linearizing the torque of the accelerometer.
    Type: Grant
    Filed: December 18, 1980
    Date of Patent: October 12, 1982
    Assignee: The Singer Company
    Inventors: George F. Schroeder, Edward A. Demers
  • Patent number: 4305028
    Abstract: A system for evaluating whether a work-performing robot can perform a series of programmed motions is disclosed which includes means for continuously comparing the velocity of the various links of a robot simulator, which is manually moved through the sequence of motions to be programmed, against predetermined velocity limits associated with the corresponding links of the work-performing robot which will reproduce the programmed steps, and providing humanly perceptible alarm indications uniquely identifiable with the various robot links when the motions manually programmed on the robot simulator exceed the velocity limits of the work-performing robot. Additionally, the individual velocities of the various robot simulator links are summed, and the sum continuously compared against the power limit of the hydraulic pump driving the link actuators of the work-performing robot.
    Type: Grant
    Filed: April 4, 1980
    Date of Patent: December 8, 1981
    Assignee: Nordson Corporation
    Inventors: Evans Kostas, Gerald W. Crum, Jerome F. Walker
  • Patent number: 4221995
    Abstract: A precision numerical controlled servo-positioning system is provided for continuous closed-loop position control of a machine slide or platform driven by a linear-induction motor. The system utilizes filtered velocity feedback to provide system stability required to operate with a system gain of 100 inches/minute/0.001 inch of following error. The filtered velocity feedback signal is derived from the position output signals of a laser interferometer utilized to monitor the movement of the slide. Air-bearing slides mounted to a stable support are utilized to minimize friction and small irregularities in the slideway which would tend to introduce positioning errors. A microprocessor is programmed to read command and feedback information and converts this information into the system following error signal. This error signal is summed with the negative filtered velocity feedback signal at the input of a servo amplifier whose output serves as the drive power signal to the linear motor position control coil.
    Type: Grant
    Filed: July 24, 1978
    Date of Patent: September 9, 1980
    Assignee: The United States of America as represented by the United States Department of Energy
    Inventor: William E. Barkman
  • Patent number: 4144764
    Abstract: A servo amplifier system for an accelerometer includes a torque coil. A torque coil is included in the output circuit of a first amplifier. A position sensor circuit develops a signal corresponding to the position of the coil which is applied to the input circuit of the first amplifier. An element, which may be a resistor, senses the current through to the coil and produces a voltage which is applied to a second amplifier having a low impedance output circuit. The output signal from the second amplifier is fed back to the input circuit of the first amplifier. Means are associated with the second amplifier to comply with the scaling and bandwidth requirements of the system.
    Type: Grant
    Filed: May 11, 1978
    Date of Patent: March 20, 1979
    Assignee: Schaevitz Engineering
    Inventor: Robert E. Hartzell, Jr.