A measurement system includes a plurality of RFID tags, each RFID tag configured to output tag information, each RFID tag having a width and spaced from an adjacent RFID tag by a pitch, a single RFID reader configured to read the tag information from at least one RFID tag of the plurality of RFID tags and a plate having a window disposed between the RFID reader and the plurality of RFID tags, wherein the window is dimensioned to control a transmission range between the RFID tags and the RFID reader. The system further includes a carrier to which the plurality of RFID tags are mounted and a control system configured to determine a position of the at least one RFID tag based on the tag information.

Provided is an absolute position color scale disposed to represent a binary code using a first symbol, having a first width and representing a first state (HIGH), and a second symbol having the first width and representing a second state (LOW). Each of the first and second symbols is divided into two or more segments having the same structure, and the first symbol has the same shape as the second symbol, but has a color pattern different from a color pattern of the symbol.

An optical position-measuring device for determining the relative position of two objects includes two scanning units which are connected to one of the objects and each include a light source, one or more gratings and a detector assembly. A scale is connected to the other object and has two tracks each containing incremental graduations extending along a first one of the measurement directions. The incremental graduations each are composed of graduation regions which have different optical properties and are periodically arranged along an incremental graduation direction. The two incremental graduation directions form an angle of between 0 and 90 relative to each other. Each of the two incremental graduations has a reference mark integrated therein such that scanning of the reference mark allows a reference signal to be generated at a defined reference position along each of the measurement directions. The reference marks include both aperiodic and periodic portions.

A sensor system and a joystick including the sensor system. The sensor system comprises a magnetic field sensor, and first and second magnetic sources. The first magnetic source is rotatable relative to a sensitive surface of the sensor and generates a first magnetic field contribution of at least quadrupolar order. The second magnetic source is pivotable with respect to the sensitive surface and generates a second magnetic field contribution. The sensor is configured for detecting at least an in-plane component of a superimposition field of the first and second magnetic contributions at a plurality of lateral measurement locations on the sensitive surface, obtaining measurements, and determining a rotation angle for the first source from the field gradient measurements and two angular directions for the second source from the field mean measurements. Lateral measurement locations are arranged into two pairs of diametrically opposite measurement locations with respect to the sensitive surface.

Apparatus and method estimate a position of a movable stage. The apparatus comprises: a stator comprising 2D array of sensors arranged relative to one another to provide a plurality of stator-Y oriented sensor columns and a plurality of stator-X oriented sensor rows; a movable stage comprising a first Y-magnet array comprising a plurality of first magnetization segments generally linearly elongated in a stage-Y direction, each first magnetization segment having a stage-Y direction length, L.sub.yy, and a magnetization direction generally orthogonal to the stage-Y direction, the magnetization directions of the plurality of first magnetization segments exhibiting a first magnetic spatial period .sub.x over a stage-X direction width, W.sub.yx, of the first magnet array; and a controller connected to receive information based on an output from each of the sensors and configured to use the information to determine a stator-X direction position of the movable stage.

A monitoring system for monitoring the axial position of a rotating shaft is provided. The system includes first and second, axially adjacent phonic wheels which are mounted coaxially to the shaft for rotation therewith. The first and second phonic wheels respectively have first and second circumferential rows of detectable features. The system further includes a sensor configured to detect the passage of the first row of detectable features by generating a first alternating measurement signal component, and to detect the passage of the second row of detectable features by generating a second alternating measurement signal component. The first and second rows of detectable features are configured such that the first and second alternating measurement signal components have distinguishably different frequencies and/or such that the first alternating measurement signal component generated by the sensor when the sensor is axially aligned with the first row has a distinguishably different amplitude to the second alternating measurement signal component generated by the sensor when the sensor is axially aligned with the second row. The sensor is positioned relative to the first and second phonic wheels such that axial displacement of the shaft causes the signal generated by sensor to contain less of the first alternating measurement signal component and more of the second alternating measurement signal component whereby the axial position of the shaft can be monitored.

A torsion detecting device for a rotary shaft is provided. The position detecting device for a rotary shaft comprises a shaft and two encoding elements disposed at two portions of the shaft with a predetermined distance. Each encoding element comprises a first coding unit, a second coding unit and a detecting unit wherein the first coding unit and the second coding unit are coaxial to the shaft. Therefore, the detecting unit detects the signal of the first coding unit and the second coding unit to retrieve the angular position of the two portions and provide the torsion in accordance with the rotation angle difference and the predetermined distance.

An encoder includes a main body and a toothed encoding unit. The main body is made of material with magnetic permeability. The toothed encoding unit is made of material with magnetic permeability, and includes a toothed encoding set and a position toothed encoding set that are disposed on the main body. The toothed encoding set includes a plurality of recesses that are disposed in a first direction. Each of the recesses of the toothed encoding set extends in a second direction that is transverse to the first direction. The position toothed encoding set includes a plurality of recesses that are disposed in the second direction. Each of the recesses of the position toothed encoding set extends in the first direction.

A magnetic encoder has an annular main body, a magnetic encoding unit and a position encoding unit. The main body is made of material with magnetic permeability, surrounds a central axis, and includes a first surface and a second surface opposite to said first surface. The magnetic encoding unit is disposed on the first surface of the main body, and includes a plurality of first and second magnetic poles, each of which is annular and is centered at the central axis. The annular position encoding unit is centered at the central axis, that is adjacent to the magnetic encoding unit, and that is disposed on the one of the first surface on which the magnetic encoding unit is disposed. The first and second magnetic poles are arranged in an alternating sequence.

Disclosed embodiments include a two-dimensional scale with a simple arrangement capable of omitting setting of an origin mark in the Y-axis direction. In a linear scale, a reference origin mark array and a tilting origin mark array that is a tilting marker array are provided in an origin mark region. Since the reference origin mark array is parallel to X-coordinates, an X-direction origin signal is correctly generated. On the other hand, for the Y direction in which no origin mark is provided, the distance between a reference origin mark and a tilting origin mark is detected. A Y-direction absolute position is decided in accordance with the distance.