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Showing papers on "Angular displacement published in 1991"


Journal ArticleDOI
TL;DR: The Biodex dynamometer was found to be both a valid and an accurate research tool; however, caution must be expercised when interpreting and ascribing torques and angular velocities to the limb producing motion.
Abstract: The validity and accuracy of the Biodex dynamometer was investigated under static and dynamic conditions. Static torque and angular position output correlated well with externally derived data (r = 0.998 and r greater than 0.999, respectively). Three subjects performed maximal voluntary knee extensions and flexions at angular velocities from 60 to 450 degrees.s-1. Using linear accelerometry, high speed filming and Biodex software, data were collected for lever arm angular velocity and linear accelerations, and subject generated torque. Analysis of synchronized angular position and velocity changes revealed the dynamometer controlled angular velocity of the lever arm to within 3.5% of the preset value. Small transient velocity overshoots were apparent on reaching the set velocity. High frequency torque artefacts were observed at all test velocities, but most noticeably at the faster speeds, and were associated with lever arm accelerations accompanying directional changes, application of resistive torques by the dynamometer, and limb instability. Isokinematic torques collected from ten subjects (240, 300 and 400 degrees.s-1) identified possible errors associated with reporting knee extension torques at 30 degrees of flexion. As a result of tissue and padding compliance, leg extension angular velocity exceeded lever arm angular velocity over most of the range of motion, while during flexion this compliance meant that knee and lever arm angles were not always identical, particularly at the start of motion. Nevertheless, the Biodex dynamometer was found to be both a valid and an accurate research tool; however, caution must be exercised when interpreting and ascribing torques and angular velocities to the limb producing motion.

165 citations


Patent
21 Jun 1991
TL;DR: In this article, an apparatus is disclosed for monitoring the movement and force production of the lumbar spine during flexion and extension in each of several sagittal-frontal planes of the body, as well as during movement into he transverse (twisting) plane.
Abstract: An apparatus is disclosed for monitoring the movement and force production of the lumbar spine during flexion and extension in each of several sagittal-frontal planes of the body, as well as during movement into he transverse (twisting) plane. The apparatus includes a rotatable platform upon which the patient is adapted to stand, and the platform is pivotable about a vertical axis, so that the platform may be pivoted to a selected angle and locked in position. A pelvic stabilization belt is mounted to the platform, and an overhead frame member is provided for rotation about a horizontal axis which is adapted to pass through the lumbro-sacral junction of the patient. An upper body yoke is mounted to the overhead frame member for rotation about a generally vertical axis which is perpendicular to the horizontal axis. An upper body engaging member is mounted to the yoke, and a control system is provided whereby the apparatus may be operated in a flexion/extension mode, or in a twisting mode, and with the foot platform in a selected angular position.

55 citations


Patent
22 Oct 1991
TL;DR: In this paper, two reactive circuits, for example inductive circuits, extending in the direction of the displacement to be measured, and a slide integral with the object whose displacements are measured are measured.
Abstract: The sensor of the invention essentially comprises two reactive circuits, for example inductive circuits, extending in the direction of the displacement to be measured, and a slide (4) integral with the object whose displacements are measured. The first circuit (2) has a constant cross-section, whilst the second (3) has a progressively decreasing cross-section. The slide, made here of a ferromagnetic material, alters the coupling between these two circuits. It is sufficient to measure the voltage variations at the terminals of the second circuit, and to calibrate them in distance values.

32 citations


Journal ArticleDOI
TL;DR: In this article, a novel type of high-resolution absolute angular encoder is presented, which is based on the capacitive coupling between four driving electrodes on a stator and a rotor electrode.
Abstract: A novel type of high-resolution absolute angular encoder is presented. The operation is based on the capacitive coupling between four driving electrodes on a stator and a rotor electrode. The four driving electrodes are connected to four sinusoidal voltages with equal amplitudes and relative phase differences of 90 degrees. A sinusoidal voltage arises on the rotor electrode, which is due to the capacitive coupling of these voltages and results in a phase shift that depends on the angle of rotation. The voltage on the rotor is capacitively coupled back to the pick-up electrode on the stator to enable a contactless measurement to be made. In this way a dimensionless transduction of the angle of rotation of the rotor with respect to the stator into an electrical phase shift is possible. This transduction can be linearized by means of a special patterning of the driving electrodes. The resolution of the phase measurement is usually the limiting factor, so an improved sensor structure has been designed with a high-resolution incremental encoder part combined with a low-resolution absolute encoder structure. The combined operation results in a high-resolution absolute angular encoder. The rotor should be aligned with respect to the stator for proper operation of the sensor and an alignment technique is implemented, which is based on the same principle as that used in the sensor and gives information on both the magnitude and the direction of the misalignment, thus enabling automatic alignment to be carried out during assembly. The main source of error is buckling of the sensor parts.

29 citations


Journal ArticleDOI
TL;DR: The design of a two-dimensional magnetic field search coil system based on the extension of the phase detection principle for measuring the angular position and displacements of a search coil in three-dimensional space is described.
Abstract: The design of a two-dimensional magnetic field search coil system based on the extension of the phase detection principle for measuring the angular position and displacements of a search coil in three-dimensional space is described. The extended phase detection principle was implemented in a two-axis angular detector, which generates a spatially rotating magnetic field. The system was developed to record horizontal and vertical eye and head movements of small, unrestrained laboratory animals. It is also applicable for measuring 3-D eye and head movements in primates and man. The output is linear over 355 degrees in the horizontal plane and over +or-60 degrees in the vertical direction. The procedure of recording 3-D eye and head movements is discussed. >

28 citations


Patent
18 Dec 1991
TL;DR: In this paper, a tension control apparatus for a material winder of the type including a material supply package and a material take up package, an electric motor for driving the take-up package, and a tension responsive dancer arm positioned intermediate between the material supply and the material takeup package for angular movement about an axis proportional to tension variation in the moving material.
Abstract: A tension control apparatus for a material winder of the type including a material supply package and a material take-up package, an electric motor for driving the take-up package and a tension responsive dancer arm positioned intermediate the material supply package and the material take-up package for angular movement about an axis proportional to tension variation in the moving material. The tension control apparatus includes a polar magnet mounted for axial rotation about the axis of movement of the dancer arm in fixed relation to the movement of the dancer arm about the axis. A magnetic angular position sensor is positioned in magnetic field sensing relation to the polar magnet for sensing the change in the angular position of the polar magnet responsive to tension variation in the moving material and outputting an electrical signal proportional to the angular position of the polar magnet. A signal processing feedback circuit receives and processes the electrical signal and outputs a voltage and current as required to vary the speed of the motor to maintain constant tension.

27 citations


Patent
17 Jun 1991
TL;DR: In this article, a rotary object table with a stator (112), a rotor (114), and a positioning servo and measuring system (16) is calibrated using an angular interferometer and an intermediate table having stators (122) and rotor (124).
Abstract: A rotary object table which has a stator (112), a rotor (114), and positioning servo and measuring system (16). The system (16) is calibrated using an angular interferometer and an intermediate table having stator (122) and rotor (124). Values of angular displacement of stator (124) are determined by the interferometer by solving 3 orthogonal simultaneous equations derived from the equation R + Ro = K sin (Υ - Υo), and are compared with corresponding angular displacement as determined by the system (16).

23 citations


Book
01 Jan 1991
TL;DR: In this article, the authors present a model of the plane physics of rigid bodies in 3D space and describe the forces and acceleration of the planes of a rigid body in three dimensions.
Abstract: 1. Fundamentals 2. Forces 3. Equilibrium of Particles 4. Moments of Forces 5. Equilibrium of Rigid Bodies 6. First Moments: Centroids and Centers of Gravity 7. Second Moments: Moments of Inertia 8. Structures 9. Friction 10. Virtual Work 11. Kinematics of Particles 12. Kinetics of Particles: Force and Acceleration 13. Kinetics of Particles: Work and Energy 14. Kinetics of Particles: Impulse and Monetum 15. Plane Kinematics of Rigid Bodies 16. Plane Kinetics of Rigid Bodies: Force and Acceleration 17. Plane Kinetics of Rigid Bodies: Work and Energy 18. Plane Kinetics of Rigid Bodies: Impulse and Momentum 19. Motion of Rigid Bodies in Three Dimensions 20. Vibrations Appendices A. Prior Basic Mathematics B. Review of Basic Mathematics C. Infinitesimal Angular Displacement D. Simultaneous Equations Solver E. Digital Root Finder F. Supplementary Software Answers to Selected Developmental Exercises and Problems Index 1. Fundamentals 2. Forces 3. Equilibrium of Particles 4. Moments of Forces 5. Equilibrium of Rigid Bodies 6. First Moments: Centroids and Centers of Gravity 7. Second Moments: Moments of Inertia 8. Structures 9. Friction 10. Virtual Work 11. Kinematics of Particles 12. Kinetics of Particles: Force and Acclleration 13. Kinetics of Particles: Work and Energy 14. Kinetics of Particles: Impulse and Momentum 15. Plane Kinematics of Rigid Bodies 16. Plane Kinetics: Force and Acceleration 17. Plane Kinetics: Work and Energy 18. Plane Kinetics: Impulse and Momentum 19. Motion of Rigid Bodies in Three Dimensions 20. Vibrations Appendices Prior Basic Mathematics Review of Basic Mathematics Infinitesimal Angular Displacement Simultaneous Equations Solver Digital Root Finder Supplementary Software Answers to Selected Developmental Exercises and Problems Index

23 citations


Patent
16 Sep 1991
TL;DR: In this paper, a rotatable unit with paired electrical signal paths on closely adjacent portions to establish capacitive coupling there between is coupled to an electrical power unit to provide power assisted steering of a vehicle.
Abstract: A device utilizing capacitive coupling to provide an output indicative of angular relationship. Relatively rotatable units have paired electrical signal paths on closely adjacent portions to establish capacitive coupling therebetween. A high frequency AC signal is conducted through the electrical signal paths, which paths are preferbaly shielded, with the capacitance of one of the paired electrical signal paths being dependent upon the angular relationship between the closely adjacent portions of the units and with the capacitance of others of the paired electrical signal paths being substantially independent of the angular relationship between the closely adjacent portions of the units. A three unit configuration is utilized for determining angular displacement or torque and torque direction with respect to the two rotatable elements rotatable relative to a stator element, and a two unit configuration, which may be combined with the three unit configuration, is utilized for determining angular position between a rotatable element and a stationary element. The output is coupled, for example, to an electrical power unit to provide power assisted steering of a vehicle.

22 citations


Patent
27 Sep 1991
TL;DR: In this article, an ion beam processing method of processing a rotating workpiece for a very small-size rotary member, using an ionbeam or a focused ion beam, was disclosed.
Abstract: There is disclosed an ion beam processing method of processing a rotating workpiece for a very small-size rotary member, using an ion beam or a focused ion beam. Apparatus for performing this method is also disclosed. In the formation of a product having a non-circular cross-section, when the amount of application of the ion beam is kept constant, the rotational angular velocity of the workpiece is varied in accordance with the rotational angular position of the workpiece. On the other hand, when the rotational angular velocity of the workpiece is kept constant, the amount of application of the ion beam is varied. When it is difficult to align the axis of the workpiece with the axis of rotation of a workpiece holder, the focused ion beam is applied in accordance with the oscillation of the workpiece.

21 citations


Patent
30 Aug 1991
TL;DR: In this article, a brushless DC motor-driven spindle assembly for a textile ring spinning frame is presented, where a shaft for rotatably supporting a bobbin for yarn collection is mounted for rotation about a central axis of rotation in a bolster section and under certain conditions of operation, including rotor/stator position detecting elements comprising sensed elements comprising mounted on the motor rotor for rotation therewith and sensing elements mounted in fixed position relative to the rotor and adjacent the path of movement of the sensed elements so as to maintain the same radial distance between the sensing elements and the sensed
Abstract: A brushless DC motor-driven spindle assembly for a textile ring spinning frame wherein a shaft for rotatably supporting a bobbin for yarn collection is mounted for rotation about a central axis of rotation in a bolster section and, under certain conditions of operation, for rotation about axes which are incrementally angularly displaced from the central axis of rotation, and including rotor/stator position detecting elements comprising sensed elements mounted on the motor rotor for rotation therewith and sensing elements mounted in fixed position relative to the rotor and adjacent the path of movement of the sensed elements so as to maintain the same radial distance between the sensing elements and the sensed elements during incremental angular displacement of the axis of rotation of the shaft and motor rotor. In a preferred embodiment, the sensed elements may be a magnetic ring mounted on the rotor and having alternating North and South pole sections, and the sensing elements may be Hall effect sensors mounted in fixed position on a portion of the bolster section to correspondingly move with the incremental angular displacement of the rotational axis of the bobbin support shaft of the spindle assembly.

Patent
10 Jul 1991
TL;DR: In this article, a balance machine for motor vehicle wheels clamped to the main shaft of the machine contains a sensing device for distance measurement of the balance plane or planes and for detecting the balance radius.
Abstract: The balancing machine for motor vehicle wheels clamped to the main shaft of the machine contains a sensing device for distance measurement of the balance plane or planes and for detecting the balance radius. The sensing element has a retractable organ (10, 11, 17) in a common plane with the main shafts axis. The sensor provides electrical signals corresp. to the measured values to a device which evaluates the imbalance values measured during one or more measurement processes. The sensor has an angle measurement device (24) which measures the angular position of the sensing organ or its parts to determine the balance radius. ADVANTAGE - Ensures accurate position determination for each balance wt. on wheel rim.

Patent
17 Dec 1991
TL;DR: In this paper, a rotational force is applied to the shaft at an angular acceleration such that the two axes of the block successively intersect the axis of the waveguide within the decay period of the plasma species.
Abstract: A block of dielectric material having a long axis and a short axis and having low losses at a selected microwave frequency and a dielectric constant selected to produce a desired degree of phase modulation is mounted on a rotatable shaft in an orientation perpendicular to the long and short axes and arranged inside a waveguide feeding a CVD reactor containing a plasma species The block is spun by a rotational force applied to the shaft at an angular acceleration such that the two axes of the block successively intersect the axis of the waveguide within the decay period of the plasma species. The frequency of phase modulation can be varied by changing the angular acceleration of the shaft, and the amplitude of the phase modulation can be varied by changing the ratio of block length to thickness and/or by selecting a material with higher dielectric constant. The incident microwave power may be modulated as a function of angular position of the spin shaft. By moving the apparent plasma and modulating the applied microwave power, a customized temperature profile may be achieved over a desired substrate area.

Patent
29 Jul 1991
TL;DR: An optical interferometer used for measuring the rotational angle or the anglular position of a rotating object, in which a path deflection is caused by means of the rotation of a reflector, is described in this article.
Abstract: An optical interferometer used for measuring the rotational angle or the anglular position of a rotating object, in which a path deflection is caused by means of the rotation of a reflector, the rotational movement of which is coupled with that of the object to be measured and thus is synchronous with its rotation. Furthermore, a laser beam is introduced into the interferometer. The path deflection caused by the rotation of the retro-reflector creates in the introduced laser beam varying interferences of defined wave length, which are proportional to the rotational angle of the reflector and of the object to be measured which drives it. Furthermore, the angular resolution is inversely proportional to the wave length of the laser beam.

Patent
Kurt Hurst1, Klaus Dr Brill1, Hans Braun1
10 Sep 1991
TL;DR: In this paper, a no-contact angle sensor is proposed for use in motor vehicles, with the angle sensor including a component (10) that is carried along by the arrangement whose angular displacement is to be monitored, and a measuring device (12) for determining the rotational displacement angle.
Abstract: An angle sensor is proposed, preferably a no-contact angle sensor, particularly for use in motor vehicles, with the angle sensor including a component (10) that is carried along by the arrangement whose angular displacement is to be monitored, and a measuring device (12) for determining the rotational displacement angle (13, Ψ). The measuring device (12, 14, 16) is hermetically encapsulated and includes a magnetic coupling (22, 24) between the carried-along component (10) and the measuring device (12, 14, 16).

Patent
John D. Larson1
14 Jan 1991
TL;DR: In this paper, a method of manufacturing the transducer array is presented, which involves segmenting the transducers after assembling transducers components, based on preselected delay patterns.
Abstract: In ultrasonic apparatus has a large aperture annular transducer array which is mechanically rotated in a scanning motion. The ultrasound beam is electronically steered to compensate for angular position error caused by the scanning motion by means of preselected delay patterns to thereby produce an ultrasound beam which undergoes a discrete step scan pattern of an object of interest. Also disclosed is a method of manufacturing the transducer array which involves segmenting the transducer after assembling the transducer components.

Patent
06 Nov 1991
TL;DR: In this paper, an unbalance point positioning method and an apparatus that carries out a positioning operation with high precision and within a short time by using, as a trigger, a unbalance phase signal due to the revolution of a measured object, and effecting deceleration control through feedback control with a voltage corresponding to a rotational frequency of the measured object.
Abstract: The present invention relates to an unbalance point positioning method and an apparatus therefor, which carry out a positioning operation with high precision and within a short time by using, as a trigger, an unbalance phase signal due to revolution of an unbalance point of a measured object, and effecting deceleration control through feedback control with a voltage corresponding to a rotational frequency of the measured object. The apparatus includes means for rotating the object at a high speed and for determining the amount as well as the angular position of the unbalance of the object. Once the angular position is determined, this information is used to trigger a predetermined deceleration signal, which smoothly and continuously decelerates the measured object until the object is stopped with the unbalance point at a preselected position. A gradual deceleration curve, generated using a resistor and capacitor circuit, is used to minimize slippage between the rotating object and the drive mechanism. In order to further reduce the slippage between the rotating object and the drive mechanism while smoothly stopping the object, a feedback signal based on the actual rotation speed of the object is subtracted from the predetermined deceleration signal so that a negligible amount of slippage is achieved.

Patent
04 May 1991
TL;DR: In this article, a double integrator is used in a flywheel for satellite stabilization where it facilitates adjustment of the angular position while at the same time providing insulation against vibration, and the position of the body is caused to follow slow movements of the stator.
Abstract: A device for insulating a body on magnetic bearings from vibration of its stator and hence the environment and vice versa. The body may include a rotor which can produce undesirable vibrations during rotation. The position of the body is caused to follow slow movements of the stator, but does not follow higher frequency interference. However, intentional fast position regulating procedures are possible. The device includes a double integrator which generates a largely interference-free position sensor signal for low vibration bearing adjustment which is followed slowly by a true position sensor signal. The device can be used in a flywheel for satellite stabilization where it facilitates adjustment of the angular position while at the same time providing insulation against vibration.

Patent
06 Dec 1991
TL;DR: In this article, a "perfect word" bit sequence is applied to a binary code track 16 of an encoding disk 13, and a precision temporal pulse is generated when the logic circuitry has identified that the stored value is equal to the reference value.
Abstract: A precision temporal pulse 10 indicating accurate rotational velocity and precise angular position of a object rotating about an axis is generated. A "perfect word" 12 binary code sequence is applied to a binary code track 16 of an encoding disk 13. Binary code bits are synchronously detected as they pass through a code reader 22, that synchronously generates a bit by bit replica of the sequence of bits detected by the reader 22. The bits are stored in a shift register 28, and are synchronously compared to a stored reference value by logic circuitry. A temporal pulse is generated when the logic circuitry has identified that the stored value is equal to the reference value.

Book ChapterDOI
01 Jan 1991
TL;DR: In this paper, the ability of humans to use the vestibular system in "path integration" and to memorize the displacement of the head was investigated, where subjects were submitted, in complete darkness, to passive angular whole-body displacements about a vertical axis.
Abstract: This study investigates the ability of humans to use the vestibular system in “path integration” and to memorize the displacement of the head. Human subjects were submitted, in complete darkness, to passive angular whole-body displacements about a vertical axis, inducing a vestibular stimulation. They were presented, before the rotation, a stationary visual target. During the rotation, they had to fixate a target which moved with the head. After a memorization delay of either less than 20 sec, about 1 min, or 5 min, after the end of the rotation, they were required to make an eye saccade toward the “memorized” stationary target. The results show that the amplitude of an angular displacement detected by the vestibular system can be estimated and correctly memorized during 1 min. At 5 min, however, rotation angles below 25 deg are overestimated.

Patent
Yasuhiko Shiomi1
30 Jul 1991
TL;DR: In this paper, an electromagnetic means for controlling the relative angular displacement between the movable member and the outer cylinder, and a control means for nonlinearly changing the electromagnetic force of the electromagnetic means in accordance with the angular displacement was proposed.
Abstract: A vibration detection apparatus having an outer cylinder having a chamber in which a liquid is sealed, a movable member rotatably held about a predetermined rotating shaft, and detecting means for detecting a relative angular displacement of the movable member and the outer cylinder about the rotating shaft as a vibration signal, includes an electromagnetic means for controlling the relative angular displacement between the movable member and the outer cylinder, and a control means for nonlinearly changing the electromagnetic force of the electromagnetic means in accordance with the relative angular displacement between the movable member and the outer cylinder.

Patent
10 Oct 1991
TL;DR: In this paper, the angular position of the indentation or groove is determined by an analogue sensor (28), giving a voltage corresp. to the circumference of the piece, which is scanned and digitised into discrete voltage values as measuring signals.
Abstract: The system positions a tooth-cutting or groove-making tool (21) automatically relative to a workpiece (10) with a previously made indentation or groove (12). The tool is mounted on a spindle (14) running across, or oblique to, the workpiece spindle (3). The tool spindle can be adjusted in the direction of its axis (15) or across it by positioning motors. The angular position of the indentation or groove is determined by an analogue sensor (28), giving a voltage corresp. to the circumference of the piece. The voltage is scanned and digitised into discrete voltage values as measuring signals, while the angular position of the tool spindle is determined by a second analogue sensor (35) in a similar way, giving reference signals. The phase difference between the two sets of signals is found, providing a control signal for the positioning motors. ADVANTAGE - Improvement in accuracy and speed.

Patent
24 May 1991
TL;DR: In this article, a lower arm 17 with one end pivotally supported on a vehicle body 20 at a position nearly equal to the height of an axle section, and the other end fixed to the axle section was provided to enable the damping force of a shock absorber to be constantly controlled with the position of piston stroke regardless of displacement in the gradient angle of the force.
Abstract: PURPOSE:To enable the damping force of a shock absorber to be constantly controlled apparently with the position of piston stroke, regardless of displacement in the gradient angle of the force. CONSTITUTION:There are provided a lower arm 17 with one end pivotally supported on a vehicle body 20 at a position nearly equal to the height of an axle section, and the other end fixed to the axle section, a shock absorber S with the end of a cylinder 2 pivotally supported on a part of the lower arm 17, and the end of a piston rod 3 pivotally supported on a part of the body 20 at a position higher than the axle section and slantingly laid, and a angle displacement sensor 31 at the side of the end of the cylinder 2 for detecting the angular displacement of the shock absorber S. A controller 32 is caused to output a throttle control signal for keeping constant the damping force of the shock absorber S against vertical body vibration velocity on the basis of angle displacement data from the sensor 31. Furthermore, a throttle control device 30 is caused to throttle and control a passage continuous to the first and second oil chambers 4 and 5 cellularized with a piston 1 in the cylinder 2, on the basis of a throttle control signal outputted from an external controller 32.

Patent
14 Jan 1991
TL;DR: In this paper, a support shaft having a longitudinal axis with a locus that does not change, including when the shaft is positionally rotated about such axis, is mounted on the shaft for supporting an idler pulley.
Abstract: The inventive device includes a support shaft having a longitudinal axis with a locus that does not change, including when the shaft is positionally rotated about such axis. A collar is mounted on the shaft for supporting an idler pulley having an axis of rotation. An indexing plate is also mounted on the shaft for maintaining a selected position of the collar, the angular position of which is adjustable. An indexing surface is in position-affecting relationship to the collar and defines a plane oriented at an angle with respect to the shaft axis. This angle is adjustable for selecting the position of the collar. The device permits the locus of the axis of rotation of the idler pulley to be selected to maintain alignment of a belt with a driving pulley, thereby preventing such belt from becoming disengaged from the driving pulley.

Journal ArticleDOI
TL;DR: In this article, an optoelectronic setup was developed for in-situ measurements of thin glass cylinder diameters, based on the in-line far field diffraction pattern analysis.
Abstract: An optoelectronic setup has been developed for in-situ measurements of thin glass cylinder diameters. The principle of the method is based on the in-line far field diffraction pattern analysis. The photometric signal is recorded with a 2-D CCD array sensor. The running time is reduced (0.25 s) using the Newton method to solve the inverse problem of the diffraction. It is worth noting that the 2-D analysis of an 1-D diffraction pattern provides several spatial sampling lines at a given time. Thus, the signal to noise ratio (SNR) is improved with an average along the cylinder axis. Other filtering techniques and interpolation algorithms can be applied. After this signal processing, a moire pattern is observed. This pattern is strongly dependent on the object angular position and the distance between the object and the detector. Then, it provides additional information which can be used to validate the recording cycle.

Journal ArticleDOI
TL;DR: In this paper, it was shown that the motion of the horizontal free, rigid slider-crank could be reduced to a quadrature for the angular displacement θ of the crankshaft, and the form of the solution for θ(t) was given explicitly.

Patent
23 Sep 1991
TL;DR: An inductance machine having a rotor assembly electromagnetically coupled to first and second synchronous magnetic fields was described in this article, where a relative angular displacement about the rotor axis was adjusted.
Abstract: An inductance machine having a rotor assembly electromagnetically coupled to first and second synchronous magnetic fields. The first and second synchronous magnetic fields have a relative angular displacement about the rotor axis which may be adjusted.

Proceedings ArticleDOI
01 Aug 1991
TL;DR: The Wideband Angular Vibration Experiment (WAVE) as discussed by the authors measured six degrees of freedom of optical bench base motion over a frequency band of 1-1,000 Hz.
Abstract: An objective of the Wideband Angular Vibration Experiment (WAVE) is to measure optical bench vibrations of the Relay Mirror Experiment (RME) laser beacon tracker. The WAVE sensor package measures six degrees of freedom of optical bench base motion over a frequency band of 1-1,000 Hz. The WAVE package is comprised of 16 sensors: three angular displacement sensors, six magnetohydrodynamic (MHD) angular rate sensors, and seven linear accelerometers. Redundant angular measurements allow the qualifying of the MHD sensor for space operation. The noise floor of the angular measurements, integrated over the full frequency band, is less than 0.1 (mu) rad in each axis. Measurements taken while tracking an internal self-check laser diode indicate that vibrations from attitude control system horizon scanners, reaction wheel, and excited structural modes in the beacon tracker optical assembly dominate the base motion environment. Most of the vibrations are narrow band with amplitudes on the order of 10.0 nanoradians. Coherence analysis between WAVE sensors and unrejected quad cell errors indicates that track performance during self-check is limited by base motion.© (1991) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Patent
07 May 1991
TL;DR: In this paper, a pick-off element is mounted on a steering column in order to determine the rotational movement of the steering column, and a fine signal is generated with the aid of an inductive sensor.
Abstract: Mounted in a rotationally secure fashion on a steering column in order to determine the rotational movement thereof is a pick-off element (12) which is constructed in the shape of a pot and has radially offset projections (17, 18). The contours of these projections (17, 18) extend in opposite senses. A fine signal is generated with the aid of an inductive sensor (13) by the pick-off element (12) by varying the inductance of the measuring coils (34, 35). This fine signal is repeated several times when the steering column is rotated. In order to assign this fine signal unambiguously, a second sensor (44) and a short circuiting ring (40) moving axially relative to the steering column are used to generate a coarse signal. The exact angular position of the steering column can be determined by computationally relating the coarse and the fine signals. The angle sensor (13) is of very compact design and supplies relatively accurate measuring signals.

Patent
01 May 1991
TL;DR: In this article, a rear view mirror for a motor vehicle, provided with an outer body housing a reflecting sheet and carrying a support casing for a transmission device driven by an electric motor, is presented.
Abstract: A rear view mirror for a motor vehicle, provided with an outer body housing a reflecting sheet and carrying a support casing (10) for a transmission device (13) driven by an electric motor (15) and adapted to cause turning motion of the outer body about a fixed shaft (26), and including positioning means (66, 72) adapted to define a predetermined stable angular position of the outer body with respect to the motor vehicle body, which acts in a substantially radial direction with respect to the said axis of rotation (26) and includes a cylindrical body (66) guided in a frame (67) fixed to this casing (10) and thrust by a spring (65) against the lateral surface of an annular body (35) fixed for rotation with the said shaft (26), on which there is formed a seat (72) adapted partially to house the cylindrical body (66) to define this stable angular position.