125 results about "Absolute rotation" patented technology

There is provided a rotation detection device 1 which includes a plurality of magnetic encoders (2A, 2B) of a ring shape arranged coaxially and having different numbers of magnetic poles, a plurality of magnetic sensors (3A, 3B) each operable to detect the magnetic field of the corresponding magnetic encoder and having a function of detecting positional information within a single magnetic pole of the corresponding magnetic encoder, a phase difference detector (6) for determining the phase difference of magnetic field signals detected respectively by the magnetic sensors (3A, 3B), and an angle calculator (7) for calculating an absolute rotation angle of the magnetic encoders based on the detected phase difference.

A method for detecting an absolute rotational position of an electromechanical device or the at least one component thereof comprising determining a first absolute position of the electromechanical device or the at least one component thereof based on a commutation index signal, obtaining a Z-index signal, and determining a second absolute position of the electromechanical device or the at least one component thereof based on the Z-index signal. The method initially determines a coarse rotational position of the electromechanical device such as a rotor or steering wheel based on the commutation index signal. When a device's position is first initialized by a commutation index signal before the Z-index pulse is detected, the device's position is re-initialized upon detection of the Z-Index pulse to provide a more accurate absolute device rotational position.

A rotation angle detector that is able to detect an absolute rotation angle of a detection body accurately and is able to reduce the installation space required. The rotation angle detector includes a first rotation angle detector connected to the detection body for generating a first detection signal having a cycle corresponding to the rotation of the detection body. The first rotation angle detector includes a first rotating body which is connected to the detection body and rotates together with the detection body. The detector includes a second rotation angle detector connected to the first rotation angle detector. The second rotation angle detector includes a second rotating body that rotates together with the first rotating body at a rate greater than that of the first rotating body, and generates a second detection signal having a cycle corresponding to the rotation of the second rotation body. The control device detects an absolute rotation angle of the detection body in accordance with the first detection signal and the second detection signal.

The present invention relates einen energy-self-sufficient multiturn rotary encoder for detecting a number of complete 360° revolutions of an encoder shaft, rotating about a rotational axis and to which an excitation magnet is mounted in a rotationally fixed manner for generating an external magnetic field, as well as for determining an absolute rotational angle indicating a fine-resolved position within one 360° revolution of the encoder shaft, wherein the multiturn rotary encoder for energy-self sufficiently detecting the number of the complete 360° revolutions of the encoder shaft several functional blocks comprises. Further, a corresponding method is taught.

The present invention provides an absolute encoder device, including: a permanent magnet including a first magnetic pattern (bipolar) and a second magnetic pattern (multipolar); a first magnetic sensor for detecting a magnetic field of the first magnetic pattern; a second magnetic sensor for detecting a magnetic field of the second magnetic pattern; and a signal processing circuit for calculating an absolute rotation angle of a rotation shaft based on output signals of the first and second magnetic sensors. The first and second magnetic sensors and the signal processing circuit are fixed to a single substrate. The first magnetic pattern is formed on a plane extending in a direction crossing an axial direction inside the permanent magnet, and the second magnetic pattern is formed on an outer peripheral surface of the permanent magnet.

In a power steering system, a torque sensor obtains first and second rotation angles, and a steering angle sensor obtains third and fourth rotation angles. A controller includes a first absolute rotation angle calculation section, a second absolute rotation angle calculation section, and an abnormality detection section. The first absolute rotation angle calculation section calculates a first absolute rotation angle as a first estimate of an absolute rotation angle of a steering wheel based on the first and third rotation angles. The second absolute rotation angle calculation section calculates a second absolute rotation angle as a second estimate of the absolute rotation angle of the steering wheel based on the third and fourth rotation angles. The abnormality detection section detects an abnormality by comparison between the first absolute rotation angle and the second absolute rotation angle.

An optical absolute rotary encoder can have a simple and small structure, for determining the absolute values of rotational positions with high accuracy. The encoder can include an optical scale having an absolute pattern representing a code corresponding to a single absolute value using a transmitting area and/or an intercepting area. A light emitting unit can be arranged at one side with respect to the optical scale, and configured to project light on the optical scale. A light receiving unit can be arranged at the same side as the light emitting unit, can configured to receive light passing through the transmitting area of the optical scale. A light guide unit can be provided and configured to guide the light from the light emitting unit to the light receiving unit. The optical scale and the light emitting unit can rotate relative to each other about an axis of rotation, and the light receiving unit can be disposed on the axis of rotation.

A multiple-rotation absolute-value encoder of a geared motor, wherein the geared motor (10) reduces the rotational speed of a motor shaft (12) and takes it out from a gear shaft (14) to drive a machine device (15) in an operating range corresponding to the two rotations of the gear shaft (14). The multiple-rotation absolute-value encoder (20) fitted to the geared motor (10) comprises a gear shaft absolute value encoder (30) detecting the absolute position of the gear shaft (14) and a load side absolute value encoder (50) having a two-pole magnet (51) and a magnetic sensor (52) rotating at a rotational speed reduced to half the rotational speed of the gear shaft (14) through the magnetic gear (40). Since the operating range of the machine device (15) corresponds to one rotation of the two-pole magnet (51), the absolute position of the machine device (15) is determined based on an output from the magnetic sensor (52). As a result, the original position of the machine device (15) can be established without requiring an additional rotating operation when the operation of the machine device is started.

In an electric power steering apparatus, at least one of a speed reduction gear ratio of the speed reduction gear mechanism and the number of pole pairs of a motor resolver is set in such a manner that a calculated value, which is obtained by multiplying the speed reduction gear ratio of the speed reduction gear mechanism with the number of pole pairs of the motor resolver, represents a non-integer having a numerical value of the decimal place. This electric power steering apparatus includes an absolute rotational position specifying device configured to specify an absolute rotational position of the steering wheel from among plural possible absolute rotational positions that are obtained based on the steering angle and the motor electrical angle. This electric power steering apparatus is hence capable of controlling an electric motor based on the absolute rotational position of the steering wheel.

A variable rotor blade mechanism for use in a gas turbine engine comprises a blade rotor, a blade, a harmonic drive system, a stepper motor and a bracket. The blade rotor rotates absolutely about an axial engine centerline during operation of the gas turbine engine. The blade extends radially from the blade rotor and is configured to be adjustable by rotation about a radial axis. The harmonic drive system is mounted to the blade rotor and connected to the blade to rotate the blade about the radial axis. The stepper motor drives the harmonic drive with relative rotational input with respect to the absolute rotation of the blade rotor. The bracket is disposed about the engine centerline and supports the stepper motor stationary with respect to the rotation of blade rotor such that the relative rotational input to the stepper motor is generated.

A device for detecting an absolute rotation angle of multiple rotation with a high accuracy and high resolution by using a target connected to the rotation axis and having an outer circumferential surface to which magnetic poles of alternate polarities are magnetized. The device includes: a first rotor holding a target connected to an input axis and having an outer circumferential surface to which magnetic poles of alternate polarities are magnetized at an identical interval and having a multi-rotatable gear; a second rotor connected to the gear of the first rotor, rotated at a low speed by the first rotor, and having a magnet at the center portion; a first detection unit and a second detection unit for detecting the rotation angles of them. With a simple configuration, it is possible to detect an absolution rotation angle with a high accuracy and a high resolution.

The present invention provides an optical encoder. The optical encoder includes a rotation disc arranged on a rotary shaft; a first annular slit arranged on the rotation disc and eccentric relative to a rotation center of the rotation shaft; a second annular slit arranged on the rotation disc and being eccentric in a different direction relative the first annular slit; a first detection part used to detect the displacement of the first annular slit; a second detection part used to detect the displacement of the second annular slit; and a signal processing device used to detect an absolute rotational angle of the rotation disc based on the detected signal output from the first and second detection parts.

A motor encoder is mounted on a motor shaft of a geared motor 1, and the origin position is detected by using a Z-phase signal. An absolute value encoder with a precision that allows the number of motor rotations to be determined is mounted on an output shaft 4 of a reduction gear, and the absolute rotational position thereof is detected. When the first Z-phase signal generated in conjunction with the rotation of the motor shaft 2a is obtained at startup and at other times, the mechanical starting point at which the motor shaft and output shaft are both positioned at the origin can be calculated based on the absolute rotational position of the reduction-gear output shaft obtained from the output-side absolute value encoder. Since the mechanical starting point is obtained by rotating the motor shaft a single rotation at most, the time required to calculate the mechanical starting point is short in comparison with conventional examples, and extraneous rotational movements can be avoided.

A rotating imaging system has a rotating portion, an idler, at least one sensor, a tilt sensor and a processor. The rotating portion has a diameter and rotates about a central axis. The idler rotates about an axis parallel to the central axis, and has a second diameter that is smaller than the diameter of the rotating portion. The rotating portion and the idler engage with each other such that both rotate simultaneously. The at least one sensor detects flags on the idler as the idler rotates. The tilt sensor is mounted to the rotating portion and determines a rotation angle of the rotating portion within a range of one revolution, and the processor determines an absolute rotation of the rotating portion based on at least a signal from the at least one sensor and the rotation angle determined by the tilt sensor.

An absolute rotary encoder comprises a rotor having a bore passing through the center thereof to receive a shaft therein and arranged rotatably about the shaft and opposite a stator. Tracks are arranged concentrically on the rotor to form a track group. A transmitting winding group is arranged on the stator as capable of flux coupling with the track group. A receiving winding group is arranged on the stator as capable of flux coupling with the track group. Each track in the track group comprises a flux coupling winding that includes linear arc portions having first and second radii and arranged alternately on the rotor and has the shape of a ring continuous about the shaft. At least two tracks in the track group have the linear arc portions different in number from each other.

A magnetic encoder includes a multi-pole magnetic detecting unit having a multi-pole magnet. In the multi-pole magnetic detecting unit, first and second magnetic detecting elements that output sinusoidal signals having a 90° phase difference are arranged apart from third and fourth magnetic detecting elements at a mechanical angle of 180°. The first and third magnetic detecting elements are disposed at the same position represented by an electrical angle and output sinusoidal signals of a same phase. The second and fourth magnetic detecting elements are arranged at the same position represented by an electrical angle and output sinusoidal signals of a same phase. A sum signal of the output signals of the first and third magnetic detecting elements and that of the output signals of the second and fourth magnetic detecting elements are obtained, thereby eliminating or remarkably reducing error components of detection signals of the first to fourth magnetic detecting elements caused by the magnetic flux of a two-pole magnet and those of the detection signals caused by rotational run out of the multi-pole magnet. A rotational angle can be detected with high accuracy.

A device for determining an absolute angle of rotation of a rotation axis (12) includes a first measurement arrangement for measuring an angle of rotation in a limited first measurement range and a second measurement arrangement for determining an absolute angle range. The second measurement arrangement comprises a deflection element (20) and a rotation element. The deflection element undergoes a deflection dependent on the rotation of the rotation axis (12). The deflection, in turn, is converted into a rotation of the rotation element (22).

The invention discloses an instant positioning and map construction method and system based on a structured environment. The method comprises the following steps: S1, shooting a plurality of positionsin the structured environment by using a camera so as to obtain a plurality of images, wherein each position corresponds to an image; S2, extracting the linear features of each of the plurality of images, and performing vanishing-point extraction on lines extracted from each of the plurality of images; S3, optimizing the absolute rotation matrix R of an image P to obtain an optimized absolute rotation matrix R<^>; S4 correcting the absolute rotation matrix R<^> according to a relative rotation matrix R<ij> between the image P and an image P<j>; S5, calculating relative translation t<ij><-> between the image P and the image P<j>; S6, optimizing the absolute translation t of the image P according to the relative translation t<ij><->; and S7, constructing a structuredmap according to the absolute rotation matrix R obtained after re-mapping and the optimized absolute translation t. The invention has the beneficial effects that information provided by the structured environment is made full use of, and high accuracy is guaranteed.