A method and apparatus for determining the position of a motor-driven actuating part, in particular a window, a sliding roof, a boot lid, a sliding door or a seat, wherein a current position is determined and, in order to determine the current position, a position newly determined for this purpose is taken into account in conjunction with a last valid position, wherein the current position is selected to be between these two positions and closer to that position which has a comparatively lower uncertainty.

An apparatus is provided and includes a rotary encoder that comprises a stator, a rotor, and a controller. The stator has an opening adapted to surround a first portion of a rotatable shaft, a transmit region, and a receive region. The rotor has an opening adapted to surround a second portion of the rotatable shaft, an annular conductive region, and at least one conductor electrically coupled with the annular conductive region. The controller has an input coupled to the receive region and has an output coupled to the transmit region. The controller is configured to transmit a first signal on the output of the controller and to the transmit region of the stator, receive a second signal on the input of the controller and from the receive region of the stator, and determine, based on the second signal, a proximity of the at least one conductor to the receive region.

In some embodiments, a method can include receiving, by an angle sensor, a first periodic angle signal indicative of an angle of a first magnetic field associated with a first track of a target; receiving, by the angle sensor, a second periodic angle signal indicative of an angle of a second magnetic field associated with a second track of the target; generating an uncorrected absolute angle signal indicative of an absolute angle of the target based on the first and second periodic angle signals; determining an estimated error associated with the uncorrected absolute angle signal based on the first periodic angle signal and the second periodic signal; subtracting the estimated error from the uncorrected absolute angle to generate a corrected absolute angle signal; and providing the corrected absolute angle signal as output of the angle sensor.

A signal processing circuit includes a correction function determination section for performing correction function determination processing, and a correction processing section for performing correction processing. The correction processing is to correct first and second detection signals by using a correction function to thereby generate first and second corrected signals. The correction function is expressed as a coefficient matrix for converting a first column vector containing the first and second detection signals as elements into a second column vector containing the first and second corrected signals as elements. The correction function determination processing includes performing arithmetic processing using a plurality of pairs of values of the first and second detection signals to determine one or two provisional correction coefficients as the correction coefficients of the correction function.

A sensing system and a method for sensing position include a first magnetic track comprising a first number of multipoles for generating a magnetic field solidarily fixed to a second magnetic track for generating a magnetic field and a second sensor for sensing magnetic field, forming a magnetic structure. At least two sensors are included. The first sensor is positioned proximal to the first magnetic track, closer to the first magnetic track than to the second magnetic track. The second sensor is positioned between the first sensor and the second magnetic track. The distance between the first sensor and the second magnetic track is larger than the distance between the second sensor and the second magnetic track. The magnetic flux density generated by the first and second magnetic tracks follow a ratio of two or more.

An interpolated position of an incremental encoder is provided. A first signal and a second signal having a quadrature relationship are received from the incremental encoder. A coarse position of the incremental encoder at a first time is produced using the quadrature relationship between the first signal and the second signal. An arcsine or arccosine value based on the first signal at the first time is determined using a lookup table and a fine position of the incremental encoder is calculated using the determined value. The interpolated position of the incremental encoder, based on both the coarse position and the fine position, is then provided.

An apparatus is provided and includes a rotary encoder that comprises a stator, a rotor, and a controller. The stator has an opening adapted to surround a first portion of a rotatable shaft, a transmit region, and a receive region. The rotor has an opening adapted to surround a second portion of the rotatable shaft, an annular conductive region, and at least one conductor electrically coupled with the annular conductive region. The controller has an input coupled to the receive region and has an output coupled to the transmit region. The controller is configured to transmit a first signal on the output of the controller and to the transmit region of the stator, receive a second signal on the input of the controller and from the receive region of the stator, and determine, based on the second signal, a proximity of the at least one conductor to the receive region.

An electric power steering apparatus has a rotation detection device that includes a sensor section that detects a rotation of a motor and outputs a mechanical angle and a count value, and a signal obtainer that obtains the mechanical angle and the count value from the sensor section. The rotation detection device also includes an absolute angle calculator that calculates an absolute angle based on the mechanical angle and the count value and a storage area for storing a reference value that is used for correcting calculation errors in the absolute angle.

A landing gear system includes a landing gear collar and a strut assembly supported by the landing gear collar. The strut assembly includes a piston that is adjustable between a fully extended position and a fully compress position. The landing gear system further includes a rotary encoder and a controller. The rotary encoder rotates in response adjusting the piston and to outputs a data value in response to its rotation. The controller is in signal communication with the rotary encoder and determines a stroke of the piston based on the data value output from the rotary encoder.

A rotary encoder includes: a rotary disk with an angle code; a light source; a detector reading the angle code; and a processing unit acquiring a reading value. The light source includes at least two light-emitting elements spaced from each other. Every time the rotary disk is rotated by a predetermined angle, where an arbitrary angle from a rotation angle θ within a reading range on the detector is provided as φ, the processing unit acquires reading values f.sub.I(θ+φ) and f.sub.I(θ) with a first light-emitting element and a reading value f.sub.II(θ+φ) with a second light-emitting element, to calculate a reading value error due to deflection at an angle θ+φ based on the difference between the reading values f.sub.II(θ+φ) and f.sub.I(θ+φ), to obtain a difference g.sub.I(θ,φ) between the reading values f.sub.I(θ+φ) and f.sub.I(θ) such that the error is reflected, and to self-calibrate based on a change in the difference g.sub.I(θ,φ).