A detection device which detects a state of a moving member such as an origin position of the moving member in a short time, is provided with a dog which includes the multiple slits, in which at least one of a separation distance between adjacent slits and a width of the slits themselves is formed in multiple kinds, a sensor which detects the presence or absence of the slits, a count position acquisition section which acquires a count start position and a count end position corresponding to the separation distance between the adjacent slits or the width of the slits themselves based on detection results of the sensor, and a state detection section which acquires a count value increase or decrease number from the count start position to the count end position and detects a state of the moving member based on the acquired count value increase or decrease number.

An optical position-measurement device includes a reflection measuring standard and a scanning unit, which is movable in relation thereto in at least one measurement direction. The reflection measuring standard has an incremental measuring graduation and a reference marking in at least one reference position. In addition to scanning device(s) for the incremental signal generation, the scanning unit includes for the reference signal generation at least one light source, imaging optics, a diaphragm structure arranged in a diaphragm plane, and a plurality of detector elements. Via the imaging optics, imaging of the reference marking onto the diaphragm structure is implemented. The reference marking is provided on the reflection measuring standard and is integrated into the incremental measuring graduation. In addition, the imaging optics has a variable, object-side focal length along a transversal direction oriented perpendicular to the measurement direction.

A rotation angle detector is smaller and less expensive and has higher detection accuracy. A rotation angle detector for detecting a rotation angle of a rotator including at least two pole pairs arranged in a ring includes an electrical angle calculator that calculates an electrical angle of the rotator, a pole pair number setter that sets a pole pair number for each of the at least two pole pairs in the rotator, an origin pole pair detector that detects, based on magnitudes of magnetic fluxes of the at least two pole pairs, an origin pole pair as an origin and sets an origin pole pair number to the origin pole pair, and an absolute mechanical-angle calculator that calculates an absolute mechanical angle of the rotator based on the electrical angle, the pole pair number, and the origin pole pair number.

Disclosed is a method for determining the angular position of a shaft by a sensor including a toothed wheel including p teeth distributed at equal angles and an additional tooth and a sensitive element that is able to detect a tooth, including the following steps: receiving a tooth signal and the date thereof; shifting the preceding time intervals: Tn-3←Tn-2, Tn-2←Tn-1, Tn-1←Tn; determining the current time interval according to the formula Tn=tn−tn-1; calculating a ratio according to the formula Rn=(Tn*Tn-3)/(Tn-1*Tn-2); and comparing the ratio with a threshold, if the ratio is greater than the threshold, the current tooth signal corresponds to the second tooth immediately following the first tooth, itself immediately following the additional tooth.

An encoder includes a code disc and a processor communicatively coupled with the code disc. The code disc is configured to rotate along with a rotating object and includes a plurality of fan teeth extending radially. One of the plurality of fan teeth is different from other ones of the plurality of fan teeth, and the other ones of the fan teeth are same to each other. A first portion of a detection signal that is generated in one rotation of the code disc, corresponding to the one of the plurality of fan teeth, is different from a second portion of the detection signal, corresponding to each of the other ones of the fan teeth. The processor is configured to detect the rotation of the code disc to obtain the detection signal and a rotation parameter of the rotating object based on the detection signal.

An incremental encoder apparatus including: a scale including a series of periodic features defining an optical incremental scale, and at least one magnetic reference mark; and a readhead. The readhead includes at least one incremental sensor configured to detect light from the optical incremental scale and to output at least one signal dependent thereon, and at least two analogue Hall sensors, each including at least two output terminal pairs, and each configured to switch repeatedly between each output terminal pair so as to reduce any inherent offset in the output of the analogue Hall sensor. The apparatus is configured to determine the presence of the reference mark from the outputs of the at least two analogue Hall sensors.

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.

Identifying position of a first rotating shaft may comprise a first position detection system and a second position detection system. A controller may be coupled to a first sensor and a second sensor and may identify the position of the first shaft using the identified shaft position from either the first detection system or the second detection system, whichever is identified faster. The first shaft may have a first wheel disposed thereon with targets and one or more gaps disposed about the first wheel. A second shaft may have a second wheel disposed thereon with targets and one or more gaps disposed thereon. The second wheel is in a fixed relationship relative to the first wheel. The first detection system may use data simultaneously from the first sensor and the second sensor to eliminate targets to determine position. The second detection system uses data only from the first sensor.

A sensor for a motor vehicle, the vehicle including a combustion engine and an engine control computer. The engine includes at least one drive shaft able to be driven in rotation, the at least one drive shaft having at least one magnetic element, the sensor being disposed facing the at least one magnetic element, the computer being configured to determine the angular position of the at least one drive shaft in relation to a predefined reference angular position on the basis of an output signal supplied by the sensor, the sensor being characterized in that it is able to generate a square wave output signal. Each square wave is characterized by an initial instant and a temporal width, by associating each initial instant with a predefined angular position of the drive shaft.

A method for determining an offset of an angular position encoder is associated with a rotor of an electric machine, wherein a reference offset of a reference angular position encoder of a reference electric machine is known at a reference rotational speed and a reference current with a reference phase angle and a reference absolute value. The method includes the steps of applying a current having the reference absolute value; setting a phase angle of the current to achieve the reference rotational speed; comparing the phase angle with the reference phase angle and the reference offset; and determining the offset on the basis of this comparison.