An electronic absolute position encoder is provided having a scale, a detector, and a signal processor configured to determine an absolute position of the detector along the scale. The scale includes a signal modulating scale pattern comprising a periodic pattern component and a gradual pattern variation component. The detector includes N spatial phase sensing elements (e.g., conductive windings) and at least one reference sensing element, which is spaced apart along the measuring axis direction by a distance corresponding to an integer multiple of 360 degrees of spatial phase shift relative to a first one of the N spatial phase sensing elements. A first reference signal from the first reference sensing element and a first signal from the first one of the N spatial phase sensing elements include nominally similar signal contributions from the periodic pattern component, and a difference between the two signals is due to a difference in their signal contributions from the gradual pattern variation component. The difference may be used to determine a scale factor M1 for a gradual signal variation exhibited by the detector signals output from the detector.

An electronic absolute position encoder is provided having a scale, a detector, and a signal processor configured to determine an absolute position of the detector along the scale. The scale includes a signal modulating scale pattern comprising a periodic pattern component and a gradual pattern variation component. The detector includes N spatial phase sensing elements (e.g., conductive windings) and at least one reference sensing element, which is spaced apart along the measuring axis direction by a distance corresponding to an integer multiple of 360 degrees of spatial phase shift relative to a first one of the N spatial phase sensing elements. A first reference signal from the first reference sensing element and a first signal from the first one of the N spatial phase sensing elements include nominally similar signal contributions from the periodic pattern component, and a difference between the two signals is due to a difference in their signal contributions from the gradual pattern variation component. The difference may be used to determine a scale factor M1 for a gradual signal variation exhibited by the detector signals output from the detector.

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).

The present disclosure relates to a method and an apparatus for the contactless measurement of the steering angle of an aircraft landing gear, in particular of a nose landing gear. Furthermore, this present disclosure relates to an aircraft landing gear, in particular a nose landing gear, which allows a contactless measurement of the steering angle.

Methods and systems for encoding position markings are provided. A plurality of markings are identified, and are encoded by a processor. Each of the plurality of markings corresponds to one of a sequence of positions. The plurality of markings are encoded via the processor using a first digit representing a current position of the sequence of positions, and a plurality of additional digits, each of the plurality of additional digits representing a previous one of the positions of the sequence, such that the current position can be determined based on the first digit in combination with the additional digits.

An encoding sequence is configured to detect the position and direction of motion of an actuator. The actuator includes at least two members where one of the members moves with respect to the other. Two sets of binary indicators are either affixed to or integrally assembled along one of the members. Each pair of indicators defines a position of the actuator and each binary indicator is configured to identify one of two states, such as a magnetic pole or a graphical mark where each state corresponds to a logical zero or a logical one. The indicators are arranged on the actuator such that at least one of the indicators transitions between one of the two states at each position along the actuator. At least one sensor is provided to detect the state of the binary indicators as the two members of the actuator move with respect to each other.

An encoding sequence is configured to detect the position and direction of motion of an actuator. The actuator includes at least two members where one of the members moves with respect to the other. Two sets of binary indicators are either affixed to or integrally assembled along one of the members. Each pair of indicators defines a position of the actuator and each binary indicator is configured to identify one of two states, such as a magnetic pole or a graphical mark where each state corresponds to a logical zero or a logical one. The indicators are arranged on the actuator such that at least one of the indicators transitions between one of the two states at each position along the actuator. At least one sensor is provided to detect the state of the binary indicators as the two members of the actuator move with respect to each other.

An absolute position measurement system includes a multipole magnet comprising alternating magnetic poles extending along a multipole extension direction, the alternating magnetic poles generating a magnetic field. A magnetic sensor includes a first sensor element arrangement configured to generate a first signal in response to a first magnetic field component and a second sensor element arrangement configured to generate a second signal in response to a second magnetic field component. The absolute position measurement system is configured, as a position of the magnetic sensor relative to the multipole magnet changes, to generate a first oscillating sensor signal with decreasing first signal amplitude and to generate a second oscillating sensor signal with decreasing second signal amplitude based on the first and second signals. A processing circuit is configured to calculate an absolute position of the magnetic sensor based on the first oscillating sensor signal and the second oscillating sensor signal.

A method includes receiving a sine feedback signal and a cosine feedback signal from a resolver coupled to an output shaft of an electric motor. Rectified sine and cosine signals are generated by sampling the feedback signals. A direction of rotation of the output shaft is determined using the feedback signals and the rectified signals. The rectified sine signal and the rectified cosine signal are converted into a signed sine signal and a signed cosine signal, respectively, using information associated with the direction of rotation. A speed of rotation of the output shaft is determined using the signed sine signal and the signed cosine signal. The direction and the speed of rotation are compared to a respective direction and a respective speed determined by a resolver-to-digital converter. The electric motor is operated based on the comparison.

A position detection device includes: a first support; a second support that is movable relative to the first support; a power generation sensor disposed on the first support; and a magnetic field generation source fixed to the second support. The relative movement of the second support causes a plurality of magnetic poles having the same polarity to sequentially enter the detection region of the power generation sensor. The power generation sensor includes: a magnetic wire configured to exhibit a large Barkhausen effect; a coil wound around the magnetic wire; and a first magnetic flux conducting piece and a second magnetic flux conducting piece respectively magnetically coupled to the opposite end portions of the magnetic wire and each having a magnetic flux conducting end opposed to the detection region.