A rotary coding disc and a method for designing the same is applied to an optical encoder. N-bit De Bruijn sequences include 1 and 0. The N-bit De Bruijn sequence has the maximum binary code and the minimum binary code. When a binary code having M bits is located between the maximum binary code and the minimum binary code, the corresponding N-bit De Bruijn sequences are selected as diagonal De Bruijn sequences, wherein $\frac{2^N-2N}{2}-\frac{N}{2}<M<\frac{2^N-2N}{2}+\frac{N}{2}.$
The De Bruijn sequence may be converted into a De Bruijn energy level. The total number of 1 consecutively neighboring 0 and (N−1) consecutively neighboring N of the De Bruijn energy level is calculated. The transparent areas and the opaque areas are located based on the De Bruijn sequence or the De Bruijn energy level that corresponds to the total number less than or equal to N.

An exemplary encoder assembly includes a substrate, a first encoder, and a second encoder. The substrate has two or more position sensors, each position sensor being configured for detecting a rotary position of a shaft or other rotating element of a machine. The first encoder includes at least one first position sensor of the two or more position sensors. The at least one first position sensor is disposed on the substrate for off-axis alignment with the shaft or other rotating element of the machine. The second encoder includes a second position sensor of the two or more position sensors, the second position sensor being disposed on the substrate for on-axis or off-axis alignment with the shaft or other rotating element of the machine. Each position sensor is configured to detect different or common signal types, and a signal type of the second position sensor excludes optical signals.

A controlling method of an encoder includes: detecting a rotation angle of a rotor of a motor coupled to the encoder to generate a first counting trigger signal and a second counting trigger signal so as to perform a turn number counting procedure; determining whether a period that an operating voltage of a driving circuit of the motor is smaller than a threshold voltage exceeds a preset time; and when the period exceeds the preset time, controlling a switching unit of the encoder to allow a battery of the encoder to provide a backup voltage to the encoder such that the encoder enters a low power processing procedure.

In one aspect, an angle sensor includes magnetic-field sensing elements that include a first pair, a second pair, a third pair and a fourth pair of magnetic-field sensing elements; and processing circuitry configured to determine an angle of a rotating ring magnetic having a plurality of North-South pole pairs each having a unique period length. The processing circuitry includes a first bridge formed from the first and second pairs of magnetic-field sensing elements and a second bridge formed from the third and fourth pairs of magnetic-field sensing elements. The angle includes a value from 0° to 360°. The first, second, third and fourth pairs of magnetic-field sensing elements are each disposed on a first axis. The first, second, third and fourth pairs of magnetic-field sensing elements each have a sensitivity in a first direction along the first axis. The angle sensor is formed on a single die.

A temporal multiplexing circuit can include a set of waveguides having different delay lengths, with the waveguides arranged according to a de Bruijn sequence. The set of waveguides can be coupled to a cyclic switch that selectably delivers a group of unsynchronized photons (or other signal pulses) from a contiguous group of input paths into a contiguous group of the delay waveguides. Similarly, a spatial multiplexing circuit can include a set of pairs of waveguides that each implement mode swapping of photons, with different swap distances, with the pairs of waveguides arranged according to a de Bruijn sequence. The set of waveguides can be coupled to a cyclic switch that selectably delivers a group of photons from a set of input paths into a contiguous group of the mode-swap waveguides. Temporal and spatial multiplexing can be combined in a switching network.

Encoder system (1) for a drive, including a revolution counter having a Wiegand sensor (23) which is disposed on a stationary part (13) of the encoder system (1), and at least two pairs of magnets which in the revolving direction (5) are disposed at different positions on a rotatable part (15) of the encoder system (1), wherein the pairs of magnets comprise in each case a first magnet (35) and a second magnet (37); and a position encoder having a magnetic field sensor (43) which is disposed on the stationary part (13), and a magnetic strip (47) which is disposed on the rotatable part (15); wherein, in each pair of magnets, the first magnet (35), the magnetic strip (47) of the position encoder, and the second magnet (37) in terms of a first direction are disposed in this sequence on the rotatable part (15).

A method and system to measure a parameter associated with a component, device, or system with a specified accuracy, including: providing one or more sensors operably disposed to detect the parameter; obtaining a coarse measurement of the parameter within a first range using the one or more sensors, wherein the first range includes minimum and maximum values for the parameter; obtaining a fine measurement of the parameter within a second range using the one or more sensors, wherein the second range is smaller than the first range and has a specified ratio to the first range that provides the specified accuracy; determining a current value of the parameter by combining the coarse and fine measurements; and providing the current value of the parameter to a communications interface, a storage device, a display, a control panel, a processor, a programmable logic controller, or an external device.

A rotary coding disc and a method for designing the same is applied to an optical encoder. N-bit De Bruijn sequences include 1 and 0. The N-bit De Bruijn sequence has the maximum binary code and the minimum binary code. When a binary code having M bits is located between the maximum binary code and the minimum binary code, the corresponding N-bit De Bruijn sequences are selected as diagonal De Bruijn sequences, wherein

[00001]$\frac{2^N-2N}{2}-\frac{N}{2}<M<\frac{2^N-2N}{2}+\frac{N}{2}.$

The De Bruijn sequence may be converted into a De Bruijn energy level. The total number of 1 consecutively neighboring 0 and (N−1) consecutively neighboring N of the De Bruijn energy level is calculated. The transparent areas and the opaque areas are located based on the De Bruijn sequence or the De Bruijn energy level that corresponds to the total number less than or equal to N.

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.

In one aspect, an angle sensor includes magnetic-field sensing elements that include a first pair, a second pair, a third pair and a fourth pair of magnetic-field sensing elements; and processing circuitry configured to determine an angle of a rotating ring magnetic having a plurality of North-South pole pairs each having a unique period length. The processing circuitry includes a first bridge formed from the first and second pairs of magnetic-field sensing elements and a second bridge formed from the third and fourth pairs of magnetic-field sensing elements. The angle includes a value from 0° to 360°. The first, second, third and fourth pairs of magnetic-field sensing elements are each disposed on a first axis. The first, second, third and fourth pairs of magnetic-field sensing elements each have a sensitivity in a first direction along the first axis. The angle sensor is formed on a single die.