A method for determining the angular position of a shaft of a motor vehicle, including in particular the calculation of a first virtual angle on the basis of the values of the measured angle calculated since the zero crossing of the sine signal, plus 90, the calculation of an intermediate compensated angle by finding the mean of the measured angle value stored for the instant and of the first virtual angle value stored for the instant, the calculation of a second virtual angle on the basis of the values of the intermediate compensated angle calculated, plus 45, and the calculation of a final compensated angle by finding the mean of the intermediate compensated angle value stored for the instant and of the second virtual angle value stored for the instant.

Provided is an encoder device capable of reducing interference between a magnetic field generated in a reference mark and a magnetic field generated in a scale. An encoder device is provided with a reference mark and a head. The reference mark has: a first scale coil; and a second scale coil electrically connected to the first scale coil. The head has: a transmission coil that transmits an electromagnetic wave without any contact to the first scale coil; a reception coil that receives an electromagnetic wave without any contact from the second scale coil; and electric circuits that generate a pulse for generating an origin signal from the electromagnetic wave received by the reception coil, if the transmission coil faces the first scale coil and the reception coil faces the second scale coil.

There is provided an optical encoder with alignable relative positions between elements including an encoding medium, a sensor package and a memory. The sensor package includes a photodiode array and two alignment photodiodes opposite to the encoding medium. The memory records an alignment pattern associated with output signals of the two alignment photodiodes when the encoding medium and the sensor package are at nominal operating positions. When the encoding medium and the sensor package are not at the nominal operating positions, the relative position alignment is performed by adjusting current relative positions between the encoding medium and the sensor package to cause a current pattern associated with output signals of the two alignment photodiodes to be identical to the alignment pattern.

An encoder apparatus comprising a readhead moveable relative to a scale, configured to produce a position signal, as well as to produce a reference mark signal when the readhead passes over a reference mark on the scale, configured such that the process for producing the reference mark signal adapts automatically in response to a change in circumstance so as to at least pursue maintenance of a given relationship between the position and reference mark signals.

Provided is a crank angle detection device that includes an ACG rotor supported by an end of a crank shaft and configured to rotate integrally with the crank shaft, a metal-plate-made pulsar ring including a ring-shaped plate portion and a detected portion that includes a plurality of convex portions formed at an outer circumference of the ring-shaped plate portion, and being configured to rotate integrally with the ACG rotor with the ring-shaped plate portion fixed to the ACG rotor, and a magnetic sensor arranged at an outer circumference of the pulsar ring and configured to detect the detected portion. Such a crank angle detection device is capable of detecting a crank angle with high accuracy.

A method for determining the angular position of an engine by a crankshaft sensor, having the following steps: production by the crankshaft sensor of a signal exhibiting a revolution event, determination of the revolution out of two revolutions, since a crankshaft makes two revolutions per engine cycle for a four-stroke engine, for each no tooth event potentially produced, a change in the direction of rotation of the engine is suspected, and an analysis step is performed which comprises: if, during an inverse window, a further no tooth event is produced, the change in direction of rotation is confirmed.

A multi-pole annular encoder having 2N poles distributed irregularly is positioned facing a sensor that detects transitions between the poles. Times corresponding to the detected transitions are stored and the times that have elapsed between each transition and the previous transition of order 2N, which constitute durations for a complete revolution of a rotating member, are calculated. When the durations thus calculated are stable, a time that has elapsed between a tested transition and the previous transition is calculated, and a characteristic angle of the tested transition is deduced therefrom, this being proportional to a ratio between a time that has elapsed since the previous transition and a stabilized duration for a complete revolution. An index transition is identified and is used to ascertain absolute position of the encoder with respect to the sensor.

Optical encoders and methods of determining rotational movement are provided. The optical encoders include an encoder disk having a patterned signal track comprising a plurality of optically detectable elements disposed on a periphery of the encoder disk, wherein each optically detectable element is associated with a bit in a binary sequence, wherein each bit has a predefined bit depth, a boundary dividing the patterned signal track into at least two sub-regions, wherein each sub-region comprises a subset of the optically detectable elements, at least one sensor arranged to detect an optical signal associated with at least one optically detectable element, and a controller in communication with the at least one sensor, the controller configured to determine an angular position of the encoder disk, wherein the controller determines the angular position based on a detected binary sequence, a detected sub-region, and a look-up-table.

The present invention provides an apparatus for sensing rotor location, the apparatus comprising: a sensing magnet; and a substrate arranged above the sensing magnet, wherein the sensing magnet comprises a main magnet and sub-magnet, the substrate comprises a first sensor and second sensor arranged along the same circular path with respect to the center of the sensing magnet, the first sensor comprises a plurality of first hole sensors adjacent to each other on the circular path, the second sensor comprises a plurality of second hole sensors adjacent to each other on the circular path, the plurality of first hole sensors are arranged separated by a first angle along the circumference of the circular path, the plurality of second hole sensors are arranged separated by the first angle along the circumference of the circular path, and the adjacent first hole sensor and second hole sensor are arranged separated by a second angle different from the first angle along the circumference of the circular path.

The linear conveyor device includes a position detecting device including a scale attached to a slider, and a sensor structural body including a sensor and a driver. The driver is provided with a first and a second signal processing units, and a signal comparison processing unit. The first signal processing unit performs predetermined first interpolation processing on an output signal from a first sensor, generates and outputs first positional data. The second signal processing unit performs predetermined second interpolation processing on an output signal from a second sensor, generates second positional data, and outputs the second positional data. The signal comparison processing unit recognizes the first positional data as positional information of the slider, generates identification information unique to the slider, and outputs the identification information, where the identification information corresponds to a difference between the first positional data and the second positional data.