A magnetic encoder comprising an encoder element having at least two tracks of encoder regions, each region comprising a magnetic pole, the poles along each track being arranged as an alternating pattern of North and South poles, and one or more sensors, each sensor comprising one or more sensing elements associated with a respective track and generating an output that is indicative of the magnetic field associated with that track in the vicinity of the sensor, in which at least one track has a differing number of poles to at least one of the other tracks, and in which the properties of the poles of a first one of the tracks differ along the track such that there is a periodic variation along the first track of the magnetic field emitted by the first track that is detected by the sensing elements associated with the first track which at least partially cancels out a corresponding periodic variation in field from the other tracks that is also detected by the sensing elements associated with the first track.

An absolute encoder configured to, when a rotation range of a measurement target member is limited by a brake mechanism, generate an AB-phase signal and a Z-phase signal for calculating a rotation angle of the measurement target member. The absolute encoder includes a brake mechanism, a plurality of Z-phase-signal-detection-target portions each having a Z-phase-signal-rise-detection-target portion and a Z-phase-signal-fall-detection-target portion, a plurality of AB-phase-signal-detection-target portions each located between a Z-phase-signal-rise-detection-target portion and a Z-phase-signal-fall-detection-target portion that are adjacent to each other in a circumferential direction, to thereby form a plurality of restriction ranges each including at least one of the Z-phase-signal-rise-detection-target portions and at least one of the Z-phase-signal-fall-detection-target portions. An interval in the circumferential direction between a Z-phase-signal-rise-detection-target portion and a Z-phase-signal-fall-detection-target portion that are adjacent to each other in the circumferential direction is different among the plurality of restriction ranges.

Detection accuracy of a rotation angle of a sub-shaft is to be improved. In an absolute encoder according to an embodiment of the present invention, a second worm wheel part is a second driven gear, has a central axis orthogonal to a central axis of a first worm wheel part, and meshes with a second worm gear part. A support shaft rotatably supports the second worm wheel part. A magnet (Mq) rotates integrally with the support shaft. An angle sensor (Sq) is provided near the magnet (Mq) and detects a change in a magnetic flux generated from the magnet (Mq). A first bearing has an outer ring fixed at the second worm wheel part and an inner ring fixed at the support shaft. A second bearing has an inner ring fixed at the support shaft.

An inductive angle measuring device includes a scanning element and a scale element having scale tracks. First and third scale tracks have an equal first number of scale structures, and a second scale track has a different number of scale structures. The scale tracks are arranged circumferentially and concentrically about an axis, such that the first scale track is located radially inwardly, the second scale track is located radially between the first scale track and the third scale track, and the third scale track is located radially outwardly. The scanning element includes receiver conductors by which the signals having angle-related signal periods can be generated. The first signal period is equal to the third signal period. An overall signal can be generated from the first signal and the third signal and can be combined with the second signal for determining absolute angle position information.

This invention provides a linear encoder having an arbitrary size while maintaining high producibility. An absolute linear encoder includes a long scale formed by continuously connecting a first short scale and a second short scale in which a first cyclic bit string and a second cyclic bit siring generated using the same initial value for different generator polynomials are arranged, and at least two sensors arranged at positions facing the long scale side by side in a longitudinal direction of the long scale.

A rotary transducer is described. The rotary transducer includes a Hall effect sensor, a rotary dial comprising at least two recessed pockets, a first magnet that is positioned within one of the at least two recessed pockets, and a second magnet that is positioned within another one of the at least two recessed pockets. In an acceleration only mode, the rotary dial is rotatable from a center position in a first direction and is not rotatable from the center position in a second direction. This mode is selected when a mode selection screw is inserted into a mode selection orifice. In a bi-directional acceleration/deceleration mode, the rotary dial is rotatable from the center position in the first direction and is rotatable from the center position in the second direction. This mode is selected when the mode selection screw is not inserted into the mode selection orifice.

For determination of the position of a movable component with a plurality of position magnets relative to a stationary component with a plurality of position sensors, it is provided that the sensor responses are detected for a group of position sensors in the region of the movable component, sensor model responses of the group of position sensors are determined from a sensor model for a plurality of assumed different relative positions of the movable component relative to the stationary component, the sensor model responses are compared with the sensor responses and the assumed relative position with the smallest deviation between the sensor model responses and the sensor responses is used as the relative position of the movable component.

For determination of the position of a movable component with a plurality of position magnets relative to a stationary component with a plurality of position sensors, it is provided that the sensor responses are detected for a group of position sensors in the region of the movable component, sensor model responses of the group of position sensors are determined from a sensor model for a plurality of assumed different relative positions of the movable component relative to the stationary component, the sensor model responses are compared with the sensor responses and the assumed relative position with the smallest deviation between the sensor model responses and the sensor responses is used as the relative position of the movable component.

A method of correcting a position reading from a position sensing arrangement. The position sensing arrangement is suitable for sensing the position of a revolute joint of an articulated structure, and comprises a disc having a magnetic ring with magnetic pole pairs and a magnetic sensor assembly comprising a magnetic sensor array for detecting the magnetic pole pairs of the magnetic ring. The method comprises: for each pole pair of the magnetic ring, taking a calibration pole pair position reading with the magnetic sensor array, and generating a pole pair correcting function by comparing the calibration pole pair position reading with a model pole pair position reading; averaging the pole pair correcting functions of the pole pairs of the magnetic ring to generate an average pole pair correcting function for the magnetic ring; taking a position reading with the magnetic sensor array, the position reading comprising a plurality of pole pair position readings; and generating a corrected position reading by deducting the average pole pair correcting function from each pole pair position reading.

A magnetic encoder includes one or more sensors and an encoder element having at least two tracks of encoder regions. Each region comprises a magnetic pole. Each sensor has one or more sensing elements associated with a respective track and generates an output that is indicative of the magnetic field associated with that track. At least one track has a differing number of poles to at least one of the other tracks. The properties of the poles of a first one of the tracks differ along the track such that there is a periodic variation along the first track of the magnetic field emitted by the first track that is detected by the sensing elements associated with the first track which at least partially cancels out a corresponding periodic variation in field from the other tracks that is also detected by the sensing elements associated with the first track.