A drug delivery device comprising: a housing; a plurality of sensors; and a cylindrical member supported within the housing, an outer surface of said cylindrical member being provided with a helical track, the helical track comprising track segments of a first type and track segments of a second type, the first and second types of track segments being respectively capable of inducing first and second responses in the sensors; wherein: the helical track has a width; the helical track includes across the width of the helical track at least one track segment of the first type and at least one track segment of the second type at plural positions along a length of the helical track; the device is configured such that during a first phase of a drug delivery operation the helical track is moved axially, without rotation, relative to the plurality of sensors between a first position and a second position, and during a second phase of the drug delivery operation the track is moved helically relative to the plurality of sensors from the second position; and responses induced in the plurality of sensors by the track segments of the helical track are different in the first position compared to responses induced in the plurality of sensors by the helical track in the second position.

A vernier sensor including a coarse sensor and a fine sensor may require calibration to ensure accurate position measurements. Calibration may include determining coefficients for harmonics that can be added to the coarse sensor output and the fine sensor output to reduce harmonic distortion. The disclosure describes using the offset and variance of a difference signal as the basis for calibration. This approach is possible at least because the frequencies of the coarse sensor and fine sensor can be selected to reduce the complexity of these calculations.

A position-measuring device for determining an absolute position includes a measuring scale and a scanning unit that is movable relative to the measuring scale along at least one measuring direction. To generate a scannable signal pattern, the measuring scale has a measuring graduation which includes a raster of stripe elements arranged along the measuring direction at a measuring-scale longitudinal period. For the encoding of an absolute position, the stripe elements have a periodic structure having a measuring-scale transverse period along a transverse direction that is oriented perpendicular to the measuring direction. For scanning the signal pattern, the scanning unit has a two-dimensional detector system having a plurality of detector elements, which includes multiple detector columns having a plurality of detector elements in each case. The detector columns are periodically arranged along the measuring direction and the detector elements are periodically arranged along the transverse direction, so that by scanning the signal pattern, at least three periodic partial incremental signals are able to be generated with regard to relative movements along the measuring direction, as well as at least one absolute-position signal per detector column.

An encoder system includes a group of programmable detectors, a group of programmable channels, and a programmable connectivity network coupled between the programmable detectors and the programmable channels. Each of the programmable detectors is operable to produce an electric current in response to an optical or magnetic input. Each of the programmable channels is operable to produce an output in response to an electric current input. The outputs from the programmable channels form at least a part of a code word for determining an absolute position of a motion object. The programmable connectivity network is operable to route electric currents from at least a part of the programmable detectors to each of the programmable channels.

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.

In a length or position measuring system which has an at least locally substantially linear measuring gauge and at least one sensor able to be moved relative to the measuring gauge wherein the measuring gauge includes an incremental track and at least one absolute track and wherein the incremental track and the at least one absolute track have pole pairs arranged in the longitudinal direction of the measuring gauge, it is provided in particular that at least one pole pair of the absolute track is phase-shifted relative to a corresponding pole pair of the incremental track.

An absolute position measurement system includes a multipole magnet including alternating magnetic poles extending along a multipole extension direction, the multipole magnet has a linear changing configuration relative to a linear path and produces a magnetic field having a field strength that undergoes a sinusoidal change along the linear path due to the alternating magnetic poles and a linear change along the linear path according to the linear changing configuration relative to the linear path; and a magnetic sensor configured to move along the linear path. The magnetic sensor includes a first sensor element arrangement configured to generate a first sensor signal, a second sensor element arrangement configured to generate a second sensor signal that is phase shifted with respect to the first sensor signal, and a processing circuit configured to calculate an absolute position of the magnetic sensor based on the first sensor signal and the second sensor signal.

A multi-turn non-contact sensor includes a rotationally mounted driver magnet, and a rotationally mounted driven magnet. The driver magnet has a first number (P.sub.1) of magnetic poles and is configured to selectively receive a rotational drive torque and, upon receipt of the drive torque, to rotate about a first rotational axis. The driven magnet is spaced apart from, and is coupled to receive a magnetic force from, the driver magnet. The driven magnet has a second number (P.sub.2) of magnetic poles and is responsive to rotation of the driver magnet to rotate about a second rotational axis that is parallel to the first rotational axis. The driven magnet rotates one complete revolution each time the driver magnet rotates a predetermined number (N) of complete revolutions, P.sub.2>P.sub.1, and N=(P.sub.2/P.sub.1).

A rotary encoder comprises a sensor configured to measure an angle of a rotating shaft; and a controller configured to: determine a first angle of the rotating shaft at a first time; determine a second angle of the rotating shaft at a second time; calculate an angular velocity based on: 1) an angular difference between the first angle and the second angle; and 2) a time difference between the first time and the second time; and transmit an output packet comprising the angular velocity.

In order to transmit data from an absolute position measurement system to an incremental interface, the transmission of an absolute position is carried out in a virtual reference journey of a position counter (cnt) via several phase-shifted electrical signals. During the virtual reference journey, at least one further information is transmitted in addition to the absolute position. For this purpose, a correspondingly designed absolute measurement system and a computing device are used, the computing device being designed to receive and evaluate data via an incremental interface.