Abstract: A radial movement capacitive torque sensor includes a pair of concentric capacitor plate rings lying in a common plane, a capacitor plate ring facing the pair of concentric capacitor plate rings, and a paddle assembly disposed between the pair of concentric capacitor plate rings and the capacitor plate ring. The paddle assembly includes a first rotor having a circular opening and having at least one pair of spaced apart bearings mounted thereon, a second rotor having a circular opening and having at least one pivot point located thereon, and at least one paddle having a dielectric head, a curved neck and a body. The curved neck is disposed between a corresponding one of said at least one pair of spaced bearings, and the body is pivotally coupled to a corresponding one of said at least one pivot point.
Type:
Grant
Filed:
May 11, 2004
Date of Patent:
October 18, 2005
Assignee:
BEI Sensors & Systems Company, Inc.
Inventors:
Asad M. Madni, Jim B. Vuong, Robert K. Hansen
Abstract: A method and system for sensing angular displacement is provided. More specifically, the system includes a brushless DC motor, three Hall effect sensors, an angular displacement signal processor, and an output state observer. The Hall effect sensors provide three electrical angles of the motor rotor which are used in an angular displacement signal processor that is implemented in hardware and software. The angular displacement signal processor provides an improved resolution angular displacement output. Based on the angular displacement output from angular displacement signal processor and the motor control command signal from the motor drive, an output state observer is applied to generate a high resolution angular displacement signal.
Abstract: An optical torque sensor comprises a radiation source emitting radiation of at least one wavelength. At least one sensor senses the emitted radiation and generates at least one intensity signal indicative of the intensity of the emitted radiation. At least one signal conditioner is receptive of the emitted radiation and is positioned on a shaft between the radiation source and the at least one sensor thereby conditioning the emitted radiation. A circuit is receptive of the at least one intensity signal and determines the torque acting upon the shaft and compensates for the attenuation of the emitted radiation.
Abstract: A torque measuring device for a rotating body comprises: a rotary section composed of first and second flanges to be joined respectively to a driving shaft and a driven shaft, and a hollow cylinder having the first and second flanges formed respectively on both edges thereof; light emitting elements provided at an outer circumference of the rotary section and adapted to emit light according to an output from torque detectors provided at an inner circumference of the cylinder thereby generating an optical signal; a light receiving fiber to receive the optical signal from the light emitting elements; optical-electrical signal converters provided so as to face both end surfaces of the light receiving fiber, and adapted to convert the optical signal into an electrical signal; and a malfunction detector to detect malfunction of the light receiving fiber according to the electrical signal from the optical-electrical signal converter.
Abstract: An encoder includes an encoder body adapted to detect the rotation of an object to be measured, a cover that covers a rear part of the encoder body, and a connector that connects an inner circuit of the encoder body to an outer circuit. The connector is mounted on the cover by a change direction adaptor, which makes it possible to change the connection direction of the connector with a single cover.
Abstract: A neutral point voltage regulator of a torque sensor which has a pair of coils having inductances changing in opposite directions based on torques, and torque detecting means for outputting a torque detecting voltage Vt based on a voltage difference between a first voltage and a second voltage based on respective inductance changes of the pair of coils.
Abstract: A wave gear device torque detection method in which the gain of the output of each of a plurality of strain gauge sets affixed to the diaphragm of a flexible external gear is amplified and the outputs are then combined to form a detection signal. Adjusting the gain of each of the strain gauge outputs makes it possible to compensate for rotational ripple included in the output. Compensation of up to n order ripple components is possible by using at least (2n+1) strain gauges.
Type:
Grant
Filed:
April 22, 2003
Date of Patent:
January 11, 2005
Assignee:
Harmonic Drive Systems Inc.
Inventors:
Ivan Godler, Masashi Horiuchi, Minoru Hashimoto
Abstract: A method and system for sensing angular displacement is provided. More specifically, the system includes a brushless DC motor, three Hall effect sensors, an angular displacement signal processor, and an output state observer. The Hall effect sensors provide three electrical angles of the motor rotor which are used in an angular displacement signal processor that is implemented in hardware and software. The angular displacement signal processor provides an improved resolution angular displacement output. Based on the angular displacement output from angular displacement signal processor and the motor control command signal from the motor drive, an output state observer is applied to generate a high resolution angular displacement signal.
Abstract: A torque detector that suppresses fluctuation of an output value relative to fluctuation of an input value and that also has the output value accurately follow the input value even when the input value changes suddenly. The torque detector includes a detection element, a converter, and a hysteresis processor. The detection element detects the steering torque applied to a steering shaft when the steering shaft is rotated to generate an analog torque signal corresponding to the steering torque. The converter converts the analog torque signal to a digital torque signal. The hysteresis processor performs hysteresis processing on the digital torque signal to include the value of the digital torque signal in a predetermined range.
Abstract: A rotation sensor functioning as both a rotation-angle sensor and a torque sensor is provided which, when applied to a steering sensor for an automobile, for example, permits reduction in the number of components and thus in the weight of the automobile and contributes to conservation of global environment. The rotation sensor has slip rings covered with conductive synthetic resin having small coefficient of friction, allowing the contact pressure of brushes disposed in sliding contact with the slip rings to be kept low and the life duration of the slip rings to be prolonged. Further, no metal powder is produced when the brushes slide on the respective slip rings, and it is therefore possible to prevent the formation of unwanted insulating film.
Abstract: A physical amount estimating apparatus including first outputting means for outputting a first physical amount that does not include a hysteresis characteristic, second outputting means for outputting a second physical amount that has a predetermined physical relationship to the first physical amount and includes a hysteresis characteristic, hysteresis removing means for calculating a corrected value with the hysteresis characteristic removed therefrom based on the second physical amount, and estimating means for estimating a third physical amount based on a physical relationship between the first physical amount and the corrected value.
Abstract: A method for detecting the angular position of a rotor in a brushless electric motor, of the type in which the emission of a polarity signal of the back electromotive force by a detection circuitry associated with the motor, includes the using a bi-directional counter for counting the residence time difference of the logic states ‘0’ and ‘1’ at the output of the detection circuitry. The method is aimed at improving the detection of the instantaneous position of the rotor in a brushless motor through the detection of the zero-crossing signal.
Abstract: A magnetoelastic torque sensor assembly is provided for sensing torsion load of a shaft, such as an automotive steering column. The assembly includes a molded plastic body that defines an axial channel and includes an axial opening. The assembly also includes a U-shaped lead frame that is embedded within the molded plastic body and includes side portions that extend within side sections of the molded plastic body about the channel. Magnetic flux sensors are embedded in the side sections of the molded plastic body and connected to the lead frame. For use, the shaft is radially received through the axial opening in the molded plastic body and coaxially positioned within the channel. The magnetic flux sensors are positioned about the shaft in a predetermined and fixed arrangement. The sensor array preferably includes sensors that are disposed in a plane through the axis, either diametrically opposed or axially spaced.
Type:
Grant
Filed:
November 22, 2002
Date of Patent:
July 6, 2004
Assignee:
Visteon Global Technologies, Inc.
Inventors:
Jeffrey Louis Viola, John Francis Laidlaw
Abstract: Micro electromechanical components in a novel configuration to allow wireless normal direction pressure transducers to be used for oblique or shear forces. The invention includes a novel cantilever beam configuration and algorithm, the readings of the MEMS sensors are averaged to reduce the experimental variability, to estimate the shear stress that may occur between a human and external equipment or possibly between materials. The shear force component is calculated via the formula:
Shear Force=Vt={square root over ({overscore (V)})}23+4+ . . . +n1−{overscore (V)}21+2+ . . . +n2.
Type:
Grant
Filed:
November 4, 2002
Date of Patent:
May 18, 2004
Assignee:
The United States of America as represented by the Secretary
of the Air Force
Inventors:
Daniel W. Repperger, David B. Reynolds, James Berlin
Abstract: A pressure monitoring system has a first chamber (11) and a second chamber (12) separated by a diaphragm. The diaphragm carries respective SAW devices on the respective sides thereof, the SAW devices having different resonant frequencies. Variations in pressure within the second chamber (12) relative to the pressure within the first chamber (11) will cause deflection of the diaphragm and the resulting changes in resonant frequency of the SAW devices can be analyzed to indicate the pressure differential between the chambers. The pressure-measuring device is incorporated within a valve assembly for a vehicle tire. When the vehicle tire is inflated, the inflation pressure is trapped within the first chamber (11) as a reference. Any subsequent loss of pressure from the second chamber (12), e.g. as a result of a puncture, will cause deflection of the diaphragm and a corresponding output from the SAW devices.
Abstract: A contact type rotation sensor includes a contact brush having a contact and an electrical resistor disposed for sliding motion relative to the contact. The contact brush provided at a side face of an arm portion with a projecting piece has asymmetric shape and asymmetric weight distribution about its longitudinal axis, and is large in moment of inertia in a direction of torsion. During relative sliding motion, suppressed torsional vibration of the contact occurs not only at natural frequencies but also at dispersed frequencies other than natural frequencies, reducing the sound pressure of sliding sound. A stable contact state is ensured between the contact and the electrical resistor, resulting in improved durability.
Type:
Grant
Filed:
January 6, 2003
Date of Patent:
April 6, 2004
Assignees:
The Furukawa Electric Co., Ltd., Tokyo Cosmos Electric Co., Ltd.
Abstract: The invention relates to a method for ascertaining the pole wheel position in electrical machines (1), for example rotary current generators with pulse inverters. These electrical machines have a rotor excitation device (2) and a stator (4) provided with inductances (4.1, 4.2, 4.3 or 20, 21, 22). An alternating voltage source (7) is provided on the stator output side, between two stationary terminals (5). By means of first and second switch elements (15, 16), a split into two branches (13 and 14) can be produced, in which the respective branch voltage curves (17, 18) are measured, the superposition of which permits the rotor or pole wheel position (11) to be definitely ascertained.
Abstract: A method of analyzing the condition of a motor driven rotating system using a current waveform produced by the motor. The motor position is initially identified from the current waveform produced by the motor and more particularly, a step of identifying the segment switching of the motor is performed to identify the system position with reference to individual rotations of the motor. The current waveform is then normalized to a preselected number of data points, each rotation being described by the preselected number of data points, such that the current waveform is converted from the time domain to a spatial domain corresponding to positions of the system. Subsequently, a frequency analysis is performed to identify frequencies corresponding to characteristics of the system, including calculating a frequency dependent distribution of the normalized current waveform to determine the energy content of the waveform at particular frequencies.
Abstract: A rotation sensor functioning as both a rotation-angle sensor and a torque sensor is provided which, when applied to a steering sensor for an automobile, for example, permits reduction in the number of components and thus in the weight of the automobile and contributes to conservation of global environment. The rotation sensor has slip rings covered with conductive synthetic resin having small coefficient of friction, allowing the contact pressure of brushes disposed in sliding contact with the slip rings to be kept low and the life duration of the slip rings to be prolonged. Further, no metal powder is produced when the brushes slide on the respective slip rings, and it is therefore possible to prevent the formation of unwanted insulating film.
Abstract: A potentiometer to be utilized in an electric power steering system of a vehicle for generation of assist torque. The power steering system includes a torsion bar spring which receives steering torque and is twisted by the torque. The potentiometer comprises a magnet device having two magnetic polar faces, which create a magnetic field and a magneto-sensitive device placed in the magnetic field. The magnet device is rotatable relative to the magneto-sensitive device in proportion to the twist of the torsion bar spring and changes the relative angle between the magneto-sensitive device and the magnetic field causing the potentiometer to generate voltage for use in generating assist torque.
Abstract: There are provided a stable and highly sensitive nanometric mechanical oscillator having a considerably high detection resolution that enables detection of variation in force or mass on the nanometer order, as well as a method of fabricating the same, and a measurement apparatus using the same.
A nanometric mechanical oscillator (10) includes a base (11), a tetrahedral oscillator mass (13); and an elastic neck portion (12) for connecting the base (11) and the tetrahedral oscillator mass (13). The oscillator (10) assumes a mushroom-like shape and has a nanometric size. The oscillator mass (13) assumes a tetrahedral shape and is suitable to be used as a probe of a scanning forth microscope in which the oscillator mass (13) serving as a probe is caused to approach to an arbitrary sample surface in order to observe the surface state.
Type:
Grant
Filed:
December 14, 2001
Date of Patent:
August 26, 2003
Assignee:
Japan Science and Technology Corporation
Abstract: Torque in a torsion member, such as a rotating shaft, is sensed by a piezoelectric element that is attached to the torsion member. The piezoelectric element has a resonant frequency that varies with changes in the torque and is part of a transducer oscillator that produces a first signal. A reference oscillator has a similar piezoelectric element and produces a second signal having a frequency that varies in response to environmental parameters. The first and second signals are heterodyned, thereby cancelling the effects due to environmental parameters acting on both piezoelectric elements and producing a resultant signal that has a frequency which corresponds to the torque applied to the torsion member.
Type:
Grant
Filed:
July 5, 2001
Date of Patent:
June 24, 2003
Assignee:
Eaton Corporation
Inventors:
Birger Pahl, James E. Hansen, Matthew F. Planning, Robert H. Mathews
Abstract: A vertical movement capacitive torque sensor for a rotating shaft such as the steering column of an automobile includes dielectric vanes interposed between capacitor plates which are moveable proportional to the angular displacement of two shaft portions which are linked by a torsion bar or concentric inner and outer shaft portions, the vanes move in a radial direction perpendicular to the shaft axis. Concentric capacitor rings are provided so that a bridge circuit can easily indicate differential capacitance which is proportional to clockwise or counter-clockwise torque.
Type:
Grant
Filed:
October 2, 2001
Date of Patent:
May 20, 2003
Assignee:
BEI Sensors & Systems Company, Inc.
Inventors:
Asad M. Madni, Jim B. Vuong, Mitchell London
Abstract: The invention concerns a vehicle steering column (2) comprising a manual control member (3) for applying a torque on the column (2) drive shaft (8), the column being equipped with a device for measuring the torque applied to the drive shaft (8), characterised in that the torque measuring device includes a sensing element without requiring a torsion bar to be located along the drive shaft (8) axis and thus producing a break therein.
Abstract: A sensor for measuring torque and position of a shaft having an internal torsion bar. The sensor has a torque sensor, located in the housing and connected to the shaft. The torque sensor has a rotor in electrical contact with a first and second resistive track disposed on an opposed disc. A position sensor is located in the housing and is connected to the shaft. The position sensor has a third contactor mounted to the housing in electrical contact with a third resistive track located on the disc. Several electrical terminals are located in the housing and are electrically communicated with the contactors to provide an electrical signal indicative of the torque and position of the shaft to an external electrical circuit. A slip ring is attached between the rotor and the housing. The slip ring has a fourth and fifth contactor in contact with the torque sensor. The slip ring is adapted to electrically connect the torque sensor to the electrical terminals.
Type:
Grant
Filed:
April 18, 2001
Date of Patent:
January 28, 2003
Assignee:
CTS Corporation
Inventors:
Roderic A. Schlabach, Jeffery Hershberger, John T. Lewis, Steven R. Mitchell, James E. White
Abstract: A method of manufacturing a piezoelectric torque transducer is provided, comprising the steps of (a) forming a prepared area on a surface of a torsion member adapted to be strained by an applied torque; (b) providing a piezoelectric element having an axis of maximum strain sensitivity and disposing first and second electrodes on opposite faces of the element, respectively, and attaching an electrical lead to each electrode; (c) connecting electrical leads to the electrodes; and (d) disposing the element on the prepared area and orienting the axis of maximum strain sensitivity on the member and securing the element to the prepared area with a material selected from a group consisting of (i) adhesive material and (ii) potting material.
Type:
Grant
Filed:
March 2, 2000
Date of Patent:
September 3, 2002
Assignee:
Eaton Corporation
Inventors:
John A. Kovacich, Wayne S. Kaboord, Fred J. Begale, Robert R. Brzycki, Birger Pahl, James E. Hansen
Abstract: The invention concerns an instrumented steering wheel comprising a torque sensor integrated or directly mounted in its armature. The torque measurement enables power steering control. The rigid monobloc torquemeter is unaffected by electromagnetic interference and is inexpensive.
Abstract: A rotary position transducer and method of mounting the same. The transducer includes a housing having a disc-shaped end plate, a guide in a main aperture in the end plate, a plurality of frangible coupling elements rigidly supporting the guide on the end plate, a stator rigidly supported on the transducer housing behind the end plate, and a rotor rigidly attached to the guide and supported inside of the stator with an annular gap therebetween. The transducer is mounted on a structural member around a shaft rotatably supported on the structural member by first mounting the guide on the shaft, then rigidly clamping the transducer housing to the structural member, and then applying torque to the shaft to fracture the frangible coupling elements and release the rotor for rotation with the shaft relative to the transducer housing and the stator.
Abstract: A process for removing a modulation sinusoidal error from signals of a rotating load cell measuring forces and/or moments with respect to a non-rotating orthogonal coordinate system includes mounting the load cell to the rotating object and obtaining a first set of signals from the load cell, wherein at least one signal of the first set of signals is indicative of a load as the object rotates. A characterization of a modulation error is obtained from the first set of signals. The modulation error is a periodic signal having a frequency greater than and proportional to a frequency of revolution of the load cell. A second set of signals is obtained from the load cell pursuant to object loading. A modulation error in the second set of signals is calculated as a function of the characterization of the modulation error from the first set. The calculated modulation error in the second set of signals is subtracted from the second set of signals.