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Showing papers on "Angular displacement published in 2007"


Patent
Shigeru Omori1
07 Aug 2007
TL;DR: In this article, a gear body is disposed forwardly of a tubular member around which a wire is wound and having a rotational axis disposed substantially parallel to the tubular part, and a first gear and a second gear for transmitting rotation of a gearbody to another gear body.
Abstract: A working unit includes a gear body disposed forwardly of a tubular member around which a wire is wound and having a rotational axis disposed substantially parallel to the tubular member, and a first gear and a second gear for transmitting rotation of a gear body to another gear body. The numbers of turns of wires, the size of a main shaft, and the size of a gear body, which are positioned forwardly of the tubular member, have no adverse effect on the manner in which a wire is wound around the tubular member. The wire can be wound around the tubular member over a wide region thereof for increasing the angular displacement of the gear body. The increased angular displacement of the gear body makes it possible to increase the angular displacement and rotational torque of the gear body.

561 citations


Patent
13 Mar 2007
TL;DR: In this article, the angular position of a shaft of an electric motor relative to a nonrotating element is estimated by using a single-revolution angular position sensor and a reduction gear.
Abstract: Device 1 for detecting the angular position of a shaft of an electric motor relative to a nonrotating element, comprising a reduction gear 5 comprising an input connected in rotation to the shaft 2 , and an output such that the output of the reduction gear 5 moves over an angle of less than 2π, a single-revolution angular position sensor 26 being placed to measure the angle of the output of the reduction gear 5 and an angular position sensor 27 being placed on the input of the reduction gear 5.

444 citations


Journal ArticleDOI
TL;DR: In this article, a sensorless algorithm was proposed for angular resampling of the acceleration signal of a gearbox submitted to limited speed fluctuation. But it requires only the knowledge of an approximate value of the running speed and the number of teeth of the gears.

201 citations


Journal ArticleDOI
TL;DR: In this paper, a pseudo-dynamic method is used to compute the rotational displacements of rigid retaining wall supporting cohesionless backfill under seismic loading for the passive earth pressure condition.

82 citations


Journal ArticleDOI
27 Nov 2007
TL;DR: In this paper, a variety of interferometric techniques that may be used for measuring the angular location of a spacecraft with respect to natural celestial radio sources or another spacecraft are described.
Abstract: This paper describes a variety of interferometric techniques that may be used for measuring the angular location of a spacecraft with respect to natural celestial radio sources or another spacecraft. The differential propagation time-delay techniques largely cancel the common error sources and normally achieve low angular coordinate errors. Currently, the accuracy of the techniques are in the 1-2 nrad range for observations with a duration of one hour and 3-6deg of mean angular separation between the spacecraft and the reference sources at X-band frequencies. There are various possible ways to implement the differential angular measurements depending upon the determination of the phase cycle ambiguities associated with the differential propagation time delays of remote sources. There are methods that utilize a sufficiently large range of observing frequencies and others that rely upon the spatial arrangement of the receiving system and the rotation of the terrestrial platform. We summarize the methodologies and the advantages and disadvantages of the various techniques.

77 citations


Proceedings ArticleDOI
10 Jun 2007
TL;DR: In this article, the authors developed a new integrated magnetic sensor based on the Hall effect, suitable for contactless 360deg absolute angle encoding, which consists of a narrow n-well ring with a chain of 64 contacts equally distributed along the ring, connected to on-chip biasing and signal conditioning circuits that provides the magnitude and the phase of the magnetic field.
Abstract: We developed a new integrated magnetic sensor based on the Hall effect, suitable for contactless 360deg absolute angle encoding. The sensing device consists of a narrow n-well ring with a chain of 64 contacts equally distributed along the ring. It is connected to on-chip biasing and signal conditioning circuits that provides the magnitude and the phase of the in-plane component of the magnetic field. In a homogenous magnetic field, the transducer angular resolution is 0.01deg in the 1 kHz frequency bandwidth and the absolute accuracy is about 1deg and 0.1deg without and with output offset calibration, respectively.

70 citations


Proceedings ArticleDOI
01 Jan 2007
TL;DR: In this article, the authors proposed a new mechanical design of piezoelectric unimorph actuator that generates large static deflection angle by accumulating angular displacement in a cascaded PEC cantilever.
Abstract: In this paper, we propose a new mechanical design of piezoelectric unimorph actuator that generate large static deflection angle by accumulating angular displacement in a cascaded piezoelectric cantilever formed in a meandering shape. The new actuator design was adopted in a double-gimbal two-dimensional optical scanner of a 4 mm times 6 mm foot print. The scanner delivered a relatively large static angle of mechanical plusmn8.6deg at an applied voltage of 20 Vdc at a non-resonant operation.

66 citations


Patent
Shigeo Enomoto1
16 Feb 2007
TL;DR: An anti-shake apparatus of a photographing apparatus consisting of a hand-shake quantity detector and a controller is described in this article, where a first detector having angular velocity sensor and a second detector having an angular displacement sensor are used.
Abstract: An anti-shake apparatus of a photographing apparatus comprises a hand-shake quantity detector and a controller. The hand-shake quantity detector has a first detector having an angular velocity sensor and has a second detector having an angular displacement sensor. The controller performs an anti-shake operation based on a first angular signal from the first detector and a second angular signal from the second detector.

43 citations


Journal ArticleDOI
TL;DR: It is concluded that the CAREN system is an appropriate device for postural and balance research with some unique features and a specification of its technical performance should help researchers to identify the tasks for which it is most suitable.

41 citations


Patent
Janez Trontelj1
25 Oct 2007
TL;DR: In this paper, a method and a device using a special tracking technique is proposed to improve the accuracy and possible resolution of a magnetic positioning system, which is used to select or combine the sensing elements for a best approach to the actual orientation of the magnet.
Abstract: 1. Method and device for contactless sensing rotation and angular position using orientation tracking. 2.1 To improve the accuracy and possible resolution of a magnetic positioning system, a method and a device using a special tracking technique is proposed. 2.2. The method and the device are using multiple magnetic field sensing elements at different positions below a magnetic target. The sensed signals are used to select or combine the sensing elements for a best approach to the actual orientation of the magnet. This allows putting out the related orientation of the approach as a coarse value and the remaining displacement as a fine value. 2.3. A device using this method allows highly accurate measurement of angular positions controlling or tolerating the placement of a magnet as the input source.

40 citations


Journal ArticleDOI
TL;DR: In this paper, a new method based on the "Inform" principle is presented enabling control of permanent-magnet synchronous motors without speed-and position sensors, and a special measurement procedure detects the electrical rotor angular position by using test signals generated by the inverter.
Abstract: A new method based on the “Inform” principle is presented enabling control of permanent-magnet synchronous motors without speed- and position sensors. A special measurement procedure detects the electrical rotor angular position by using test signals generated by the inverter. The basic idea is to measure the different inductances in direct and quadrature axis due to saturation effects or construction. The sign of the magnetic flux is detected by shifting the magnetic set-point with a certain armature current. Some possibilities of how to calculate the rotor angular position from test signals are given. Measurements using a DSP-controlled drive verify the practical applicability of the new principle.

Patent
13 Jul 2007
TL;DR: In this article, a control scheme for a power tool having a rotary shaft is presented, where the torque is inversely related to an angular displacement of the tool about the longitudinal axis of the shaft.
Abstract: A control scheme is provided for a power tool having a rotary shaft The control scheme includes: monitoring rotational motion of the tool generally about a longitudinal axis of the shaft; detecting a condition of the tool based on the rotational motion of the tool; and controlling torque imparted to the shaft upon detecting the tool condition, where the torque is inversely related to an angular displacement of the tool about the longitudinal axis of the shaft

Patent
26 Oct 2007
TL;DR: In this paper, an electric impact tool in which a rotating mass rotates in a forward direction to impact upon and transfer torque to an anvil, and rotates opposite the forward direction in response to such impact is presented.
Abstract: An electric impact tool in which a rotating mass rotates in a forward direction to impact upon and transfer torque to an anvil, and rotates in a reverse direction opposite the forward direction in response to such impact. A direction sensor monitors the direction of rotation of the rotating mass, and a controller turns an electric motor on and off during respective forward and reverse rotation of the rotating mass. An energy storing mechanism may be used to absorb energy from reverse rotation of the rotating mass and release the absorbed energy to rotate the rotating mass in the forward direction. A controller may be used to store the angular position of the rotating mass upon each impact and turn off the motor prior to the following impact to avoid energizing the motor during stall.

Patent
26 Jun 2007
TL;DR: In this article, an apparatus for determining an angular position of a shaft, such as a steering column, comprises a coil assembly, a coil support, and a coupler element having a angular position correlated with the angular positions of the shaft.
Abstract: An apparatus for determining an angular position of a shaft, such as a steering column, comprises a coil assembly, a coil support, and a coupler element having a coupler angular position correlated with the angular position of the shaft. The coil assembly includes a transmitter coil and at least one receiver coil, the coupler element modifying an inductive coupling between the transmitter coil and at least one receiver coil. A signal processing circuit receives coil signals from the coil assembly and determines the angular position using a receiver signal, and a reference signal that is correlated with an axial displacement but otherwise substantially independent of angular position. The reference signal can be used for ratiometric sensing, to substantially eliminate common mode factors, and also to determine the number of revolutions of the shaft. A combined angle and torque sensor further determines a twist angle across a torsion bar.

Patent
13 Apr 2007
TL;DR: In this article, the steering control system is operatively connected to each ground engaging structure for pivoting the wheel of each of the ground-engaging structures about the steering axis, and the steering system may be operable to selectively configure the ground engaging structures into a plurality of different steering configurations, such as crab steering and side steering.
Abstract: A loader type construction vehicle includes a chassis having a longitudinal axis, a plurality of wheeled ground-engaging structures pivotally coupled to the chassis, and a steering control system. Each of the plurality of ground-engaging structures includes a wheel pivotable about a steering axis and drivable about a drive axis, wherein each of the wheeled ground-engaging structures is shaped and configured so that the wheel of each of the ground-engaging structures can be pivoted from a first angular position in which the drive axis is perpendicular to the longitudinal axis, to a second angular position that is at least 90° degrees from the first angular position. The steering control system is operatively connected to each of the ground engaging structures for pivoting the wheel of each of the ground-engaging structures about the steering axis. The steering system may be operable to selectively configure the ground engaging structures into a plurality of different steering configurations, such as crab steering and side steering. The loader vehicle may include a telescopic loader arm.

Journal ArticleDOI
TL;DR: In this paper, the authors considered the problem of determining the angular position of a rigid body in space from its known angular velocity and initial position (the Darboux problem) in quaternion setting and presented a solution based on Lappo-Danilevskii's recursion relations.
Abstract: We consider the problem of determining the angular position of a rigid body in space from its known angular velocity and initial position (the Darboux problem) in quaternion setting. For an arbitrary angular velocity vector of the body, we present a solution based on Lappo-Danilevskii’s recursion relations [1]. New special cases of solvability of the Darboux problem in closed form are obtained.

Journal ArticleDOI
TL;DR: In this article, equations of motion of a closed-type manipulator, whose mechanism can easily be made lighter, are derived in consideration of the characteristics of the driving source.
Abstract: In this article, equations of motion of a closed-type manipulator, whose mechanism can easily be made lighter, are derived in consideration of the characteristics of the driving source. Considering the final condition of angular displacement and angular velocity in throwing motion, trajectories of velocity for saving energy are calculated by iterative dynamic programming, and the dynamic characteristics of manipulator control based on the trajectory for saving energy are analyzed theoretically and investigated experimentally.

Patent
11 Jun 2007
TL;DR: In this paper, a three-dimensional non-contacting angular motion sensor, based on magnetometry, has been developed for velocity feedback in the ball wheel mechanism, which serves as the drivetrain for a class of omnidirectional mobile platforms.
Abstract: A three-dimensional non-contacting angular motion sensor, based on magnetometry, has been developed for velocity feedback in the ball wheel mechanism, which serves as the drivetrain for a class of omnidirectional mobile platforms. More generally, this scheme tracks rigid-body rotation about a fixed point with an undefined axis of rotation. The approach involves tracking the time-varying magnetic field of a permanent disc magnet, embedded at the center of the sphere. This data is then used to determine the absolute orientation of the magnet axis. Finally, an approach based on the natural invariants of rigid-body motion is used to determine the instantaneous axis of rotation and the angular speed of the sphere about this axis.

Patent
17 Jul 2007
TL;DR: In this paper, the authors proposed a control signal for the detection of the occurrence of operating malfunctions or failures when these signals are no longer correlated with one another in a predetermined relationship.
Abstract: The device (1) comprises: a stator portion (2) which is stationary in operation, a rotor portion (3) which may be gripped and which is mounted such that it can be manually rotated about an axis (A-A) with respect to the stator portion (2), against the action of an opposing spring (13), a first and a second permanent magnet (11a, 11b) connected to the rotor portion (3) in respective separate angular fields about said axis (A-A) and adapted to generate respective predetermined angular distributions of magnetic field intensity about said axis (A-A), first and second magnetic field sensors (14a, 14b) connected to the stator portion (2) in respective separate angular positions about said axis (A-A), and associated with the first and second permanent magnets (11a, 11b) respectively in order to provide, when the rotor portion (3) is rotated by a certain angle with respect to the stator portion (2), respective first and second electrical signals indicative of the relative angular position of the rotor portion (3). These signals are correlated with one another in a predetermined relationship such that one of the signals may be used as a control signal indicative of the extent of an associated controlled physical magnitude desired by the user, and the other signal may be used as a control signal adapted to enable the detection of the occurrence of operating malfunctions or failures when these signals are no longer correlated with one another in the predetermined relationship.

Journal ArticleDOI
TL;DR: In this paper, a three-dimensional noncontacting angular motion sensor based on magnetometry was developed for velocity feedback in the ball wheel mechanism, which serves as the drivetrain for a class of omnidirectional mobile platforms.
Abstract: A three-dimensional noncontacting angular motion sensor, based on magnetometry, has been developed for velocity feedback in the ball wheel mechanism, which serves as the drivetrain for a class of omnidirectional mobile platforms. More generally, this scheme tracks rigid-body rotation about a fixed point with an undefined axis of rotation. The approach involves tracking the time-varying magnetic field of a permanent disc magnet embedded at the center of the sphere. This data is then used to determine the absolute orientation of the magnet axis. Finally, an approach based on the natural invariants of rigid-body motion is used to determine the instantaneous axis of rotation and the angular speed of the sphere about this axis. In this paper, the sensing scheme is formulated, effects of geometric offsets within the tri-axial fluxgate magnetometer are addressed, and results from experimental verification are presented.

Patent
28 Mar 2007
TL;DR: In this paper, a control map is derived during production, comprising a predetermined advance angle profile representing energisation of the phase winding with respect to angular position of the rotor over a range of rotor speeds.
Abstract: An electrical machine, such as a switched reluctance motor (7), has a rotor and at least one electrically energisable phase winding. A control map is derived during production, comprising a predetermined advance angle profile representing energisation of the phase winding with respect to angular position of the rotor over a range of rotor speeds. This is stored in memory in a controller (9), together with an angle correction factor to be applied to a predetermined portion of the advance angle profile. The angle correction factor compensates for the difference between a desired input power and the measured input power. The correction factor may be transmitted to the controller by means of radio frequency signals.

Proceedings ArticleDOI
09 Jul 2007
TL;DR: The overall adaptive repetitive control system is thus robust to structured parameter uncertainty and spatially periodic disturbances under variable process speed.
Abstract: This paper extends the author's previous work on spatial-based repetitive control. We propose another repetitive control design for rotational motion systems required to operate at various speeds, and subject to structured parameter uncertainty and spatially periodic disturbances. To synthesize a repetitive controller in spatial domain, a linear time-invariant system is reformulated with respect to a spatial coordinate (e.g., angular displacement), which results in a nonlinear system. Adaptive feedback linearization is applied to linearize the system while seeking the correct system parameters online. Then, a spatial-based reduced-order repetitive controller along with a stabilizing controller is designed and operates in parallel with the adaptively feedback linearized system. The overall adaptive repetitive control system is thus robust to structured parameter uncertainty and spatially periodic disturbances under variable process speed. Feasibility and effectiveness of the proposed scheme is verified by simulation.

Patent
09 Feb 2007
TL;DR: In this article, two code wheels are driven at a different gear ratio such that the code wheels in successive beat angle periods are offset by the nth part of the measuring range of a sensor element.
Abstract: A sensor determines the absolute angular position of a body that can rotate through rotations. The sensor includes two code wheels which rotate as the body rotates. The code wheels are driven at a different gear ratio such that the code wheels rotate faster than the body and the code wheels rotate at different rates. Two sensor elements respectively determine the rotational angle positions of the code wheels. The difference between the rotational angle positions is a beat angle. The different gear ratio is selected such that beat angle periods are in an angular measuring range of the sensor and the absolute angular positions of the code wheels in the beat angle periods is different. The absolute angular positions of the code wheels in successive beat angle periods is offset by the nth part of the measuring range of a sensor element, where n is number of beat angle periods.

Journal ArticleDOI
TL;DR: In this paper, a nonlinear feedback control system of the single-axis gyroscope governed by a servo motor is studied, where the closed-loop feedback is designed to account for the gimbal nutation as the gyroometer undergoing an angular velocity in the perpendicular directions.
Abstract: A nonlinear feedback control system of the single-axis gyroscope governed by a servo motor is studied in this paper. The closed-loop feedback is designed to account for the gimbal nutation as the gyroscope undergoing an angular velocity in the perpendicular directions. This paper integrates the singular perturbation modeling technology and sliding mode control strategy, while the stability of the closed-loop system is ensured by proof via Lyapunov direct method. Finally, comparisons among pole placement, sliding mode control and angular displacement feedback with respect to regulation capability and transient performance are reported. The simulation results demonstrate the superiority of singular perturbation sliding mode control and its potential to be facilitated in the aircraft safety module on detection and prevention from rollover during flight.

Patent
05 Apr 2007
TL;DR: In this paper, the angular position of the angular dependent filter with respect to the optical axis is adjusted to select a desired color of light, which can be used to adjust the wavelengths of light produced by the light emitting device.
Abstract: A light emitting device includes a light source (103) that produces light having a range of wavelengths and an angular dependent element (108) that filters the light. The angular dependent element, may be, e.g., a dichroic filter, dichroic mirror, a cholesteric film, a diffractive filter, and a holographic filter. The angular dependent element having one or more ranges in which wavelengths of light are more efficiently propagated than wavelengths of light that are not within the one or more ranges. The angular dependent element is positioned at an angle with respect to the optical axis. By adjusting the angular position of the angular dependent filter with respect to the optical axis, the wavelengths of light produced by the light emitting device can be controlled to select a desired color of light.

Patent
17 Jan 2007
TL;DR: In this paper, the authors proposed a method for determining position and angular orientation of a rotating shaft using Hall Effect Device (HED) signals, which are converted into sinusoidal reference signals having offset scale (415/435) and amplitude scale (420/440) factors.
Abstract: Methods and devices for determining position and/or angular orientation of a rotating shaft (112). Exemplary features include sensor module (120/340) and position determination module (335). Sensor module (120/340) may include Hall Effect Devices (222/224) arranged at a specified angular separation (230) to produce a signal in response to rotation of shaft (112). Position module (335) may be responsive to sensor module (120/340) to produce a converted signal, determine an error term, and produce a position estimate. Converted signal may be produced by processing Hall Effect Device signals into sinusoidal reference signals having offset scale (415/435) and amplitude scale (420/440) factors. Error term may be determined by processing the converted signals to produce an estimated position signal. Position estimate may be produced by processing the error term. Refined position measurement may be achieved by iterative elimination of regressive differences between position estimates with minimization of absolute magnitude of error term.

Journal ArticleDOI
TL;DR: In this paper, the motion of a rigid body with a single fixed point in a homogeneous gravity field was considered, and the initial conditions for its motion correspond to the case of Goryachev integrability.
Abstract: We consider the motion of a rigid body with a single fixed point in a homogeneous gravity field. The body mass geometry and the initial conditions for its motion correspond to the case of Goryachev—Chaplygin integrability. We study the orbital stability problem for periodic motions corresponding to vibrations and rotations of the rigid body rotating about the equatorial axis of the inertia ellipsoid.

Patent
12 Nov 2007
TL;DR: In this article, a method for synchronizing multiple generators is proposed, which involves locking the shaft of the first generator at the first angular position, aligning a pilot feature of a first shaft of a second generator with a second angular position that is substantially aligned with a first predetermined reference point located at a predetermined angular position relative to an axis, calculating an angular difference between the two angular positions, and rotating a second shaft splined with the first shaft about the axis in another direction, based on the calculated angular difference.
Abstract: A method for synchronizing multiple generators includes positioning a pilot feature of a shaft of a first generator positioned at a first angular position that is substantially aligned with a first predetermined reference point located at a predetermined angular position relative to an axis, locking the shaft of the first generator at the first angular position, aligning a pilot feature of a first shaft of a second generator with a second angular position that is substantially aligned with a second predetermined reference point located at a position relative to the axis that is substantially equal to the predetermined angular position, calculating an angular difference between the two angular positions, and rotating a second shaft splined with the first shaft of the second generator about the axis in another direction, based on the calculated angular difference.

Patent
16 Mar 2007
TL;DR: A knee-ankle foot orthosis capable of securely locking a patient's knee in a desired angular position thereof with a load of his body weight, and immediately shifting his knee to the unlocked state without requiring any extra motion when the load disappears is provided as mentioned in this paper.
Abstract: A knee-ankle-foot orthosis in accordance with the present invention can smoothly shift from the stance phase to the swing phase thereof. Namely, the knee-ankle-foot orthosis capable of securely locking a patient's knee in a desired angular position thereof with a load of his body weight, and immediately shifting his knee to the unlocked state without requiring any extra motion when the load disappears is provided. As shown in FIG. 1, the speed of the rotation of a knee axis gear 23 adapted to transmit the rotation of a knee axis 21 is increased by eight times with a speed increasing gear train 25, and is transmitted to a brake drum 41. A wire 31 wound around the brake drum 41 is connected to first and second levers 27 and 28 as load detecting members. When a foot holding portion 18 contacts the ground and the first lever 27 is stepped down, the wire 31 is pulled downwardly with a load of his body weight, whereby brakes are applied. The brake torque is increased by eight times, and is transmitted to the knee axis 21. Consequently, even with a small force due to the load of his body weight, the knee-ankle-foot orthosis can be securely locked with a braking method to prevent giving way thereof. In addition, since the braking method is used, shifting to the unlocked state can be smoothly achieved.

Patent
03 Jul 2007
TL;DR: In this paper, a motion restoring intervertebral prosthesis for replacing a failed or partially failed natural disc comprises two components (10,12) defining an imaginary longitudinal axis generally aligned with the spinal axis when installed, the components having vertebral body engaging surfaces on one side and mating articulating surfaces (10c,12c) on the other side, with peripheral rims (10d,12d) encircling the articulating surface.
Abstract: A motion restoring intervertebral prosthesis for replacing a failed or partially failed natural disc comprises two components (10,12) defining an imaginary longitudinal axis generally aligned with the spinal axis when installed, the components having vertebral body engaging surfaces on one side and mating articulating surfaces (10c,12c) on the other side, with peripheral rims (10d,12d) encircling the articulating surfaces. The articulating surfaces accommodate rotational motion about the longitudinal axis and limited pivotal motion about the A/P and M/L planes. The rims are arranged to contact and limit the pivotal motion between the components to about +/-6° and preferably +/-4° in both directions in the M/L plane and in the A/P plane in the forward direction. Optionally, the encircling rims allow pivotal action of about 20° to 30° in the A/P plane in the rearward direction.