According to an embodiment, an encoder system includes an encoder and an interface. The encoder detects the position and speed of a motor, and generates A-, B- and Z-phase signals. The interface includes an AB waveform recognition circuitry to recognize a waveform of an AB phase, a Z waveform recognition circuitry to recognize a period of an enable state of a Z phase, a starting point storage device to store a value of the AB phase when the Z phase changes and stores an AB-phase change pattern, a starting point recognition circuitry to generate an interrupt signal, and a rotation angle counter to start a new count of the rotation angle of the motor.

A system for determining an absolute position of a device includes a high resolution track (14), a sensor and processing unit (22) associated with the high resolution track (14), a reference track (18) having a plurality of pole pairs arranged to define a single-track Gray code segment, and an array of Hall effect sensors (26) associated with the reference track to output a reference signal to the sensor and processing unit indicative of the coarse absolute position of the device over the single-track Gray code segment. The sensor and processing unit (22) combines the reference signal with the position of the device over the high resolution track to determine an initial, fine absolute position of the device. An up/down hardware counter (34) increments the initial fine absolute position using a signal generated from the high resolution track, and without any further software-based processing, to maintain and continuously update the fine absolute position of the device.

A sensor system for determining at least one rotation characteristic of an element rotating around at least one rotation axis. The sensor system includes at least one sensor wheel, which is connectable to the rotating element, the sensor wheel having a sensor wheel profile. The sensor system also includes at least one position sensor and at least one phase sensor. The sensor system further includes at least one digital interface and at least one incremental interface, the sensor system being configured to output at least one absolute position signal generated with the aid of the position sensor via the digital interface and to output at least one incremental signal generated with the aid of the phase sensor via the incremental interface.

A system is provided with a magnetic field sensor being positioned in a magnetic field of a magnet that is coupled to a rotatable driving shaft. The magnetic field sensor is configured to sense a rotation of the magnetic field in response to a rotation of the rotatable driving shaft, and generate an angle sensor signal based on an orientation angle of the magnetic field. The angle sensor signal includes angular values that represent an absolute orientation angle of the rotatable driving shaft. The system includes a memory storing a mapping of values of a patterned signal to the angular values, electronic circuitry configured to generate, based on the angular values and the stored mapping, the patterned signal, and a signal generator circuit configured to generate a signal representing the absolute orientation angle of the rotatable driving shaft based on the angle sensor signal.

An encoder (10) for determining an angular position, the encoder (10) comprising a shaft (14, 16), a housing (18) and a transition region (32), the shaft (14, 16) projecting outwards from the housing (18) into the transition region (32), a measuring element (20) connected to the shaft (14), a sensor (22) for detecting the measuring element (20), and a control and evaluation unit (28) for generating, from the signals of the sensor (22), an angle signal in dependence on the angular position of the measuring element (20), wherein a protective cap (34) is arranged in the transition region (32) for protection against fluids (12) directed with pressure onto the transition region (32).

A rotary encoder may include a first sensor unit including a first magnet, and a first magnetosensitive unit facing the first magnet; a second sensor unit including a second magnet with a plurality of pairs of N poles and S poles alternately magnetized, and a second magnetosensitive unit facing the second magnet; a circuit to generate pulses for counting from an output of the second sensor unit; and a counter to count the pulses. During activation, an angle position of the rotating body is calculated based on outputs of a first and second sensor unit, and after activation, pulse counting is counted by a counter.

A rotary encoder may include a first sensor unit comprising a first magnet, and a first magnetosensitive unit facing the first magnet; a second sensor unit comprising a second magnet, and a second magnetosensitive unit facing the second magnet; a circuit to generate pulses; a counter to count the pulses; a first arithmetic unit to calculate a first angle value based on an output of the first magnetosensitive unit; and a second arithmetic unit to calculate a second angle value based on an output of the second magnetosensitive unit. One of the first magnet and the first magnetosensitive unit is provided in the fixed body and the other is provided in the rotating body. One of the second magnet and the second magnetosensitive unit is provided in the fixed body and the other is provided in the rotating body.

An absolute encoder is driven by backup power from an external battery for backup. The absolute encoder includes: a clock generator configured to generate backup clock pulses at intervals of a predetermined period when the backup power is supplied; an analog signal generation circuit configured to operate according to the clock pulse so as to detect a displacement position of a motor and generate an analog signal corresponding to the detected displacement position; a comparator configured to operate according to the clock pulse so as to compare the analog signal with a predetermined voltage; and a clock control circuit configured to control the clock generator to change the pulse width of the clock pulse.

A device for sensing the relative rotary position of first and second parts about a rotation axis, the device comprising a follower constrained to move on a first track fast with the first part and on a second track fast with the second part, the first track being linear and the second track comprising a plurality of circular arcs and at least one transition section connecting one of the circular arcs to another, the tracks being arranged so as to convert relative rotation of the parts into linear motion of the follower, wherein the second track is generally spiral, each circular arc is of constant radius about the rotation axis and the first track is perpendicular to the rotation axis.

A system is provided with a magnetic field sensor being positioned in a magnetic field of a magnet that is coupled to a rotatable driving shaft. The magnetic field sensor is configured to sense a rotation of the magnetic field in response to a rotation of the rotatable driving shaft, and generate an angle sensor signal based on an orientation angle of the magnetic field. The angle sensor signal includes angular values that represent an absolute orientation angle of the rotatable driving shaft. The system includes a memory storing a mapping of values of a patterned signal to the angular values, electronic circuitry configured to generate, based on the angular values and the stored mapping, the patterned signal, and a signal generator circuit configured to generate a signal representing the absolute orientation angle of the rotatable driving shaft based on the angle sensor signal.