What is the role of the encoder?！

Encoder Encoder is a kind of sensor (Sensor). It is mainly used to detect the speed, position, angle, distance or counting of mechanical motion. In addition to industrial machinery, many motor control servo motors and BLDC servo motors are used. An encoder is required for the motor controller to detect the commutation, speed and position, so the application range is quite wide. According to the detection principle, the encoder can be divided into optical, magnetic, inductive and capacitive. According to its scale method and signal output form, it is divided into incremental encoder and absolute encoder. The photoelectric encoder realizes the displacement-digital conversion by the principle of grating diffraction. It has been applied to machine tools and computing instruments since the 1950s. Due to its simple structure, high measurement accuracy and long life, it has been valued and promoted at home and abroad. Positioning, speed, length, acceleration, vibration and other aspects have been widely used.
Contact encoder----With brush output, a brush contacts the conductive or insulating area to indicate whether the status of the code is "1" or "0".
Non-contact encoder----the receiving sensitive component is a photosensitive component or a magnetic sensing component. When the photosensitive component is used, the light-transmitting area and the opaque area are used to indicate whether the state of the code is "1" or "0".
Incremental encoder----converts the displacement into a periodic electrical signal, and then converts this electrical signal into a counting pulse, and uses the number of pulses to represent the magnitude of the displacement. When the rotating shaft rotates, there is a corresponding pulse output, and the counting starting point is arbitrarily set, so that multiple infinite accumulation and measurement can be realized.
Absolute encoders - directly output digital sensors, commonly used in motor positioning or speed measurement systems. Since each angular position corresponds to a unique digital code, its indication is only related to the start and end positions of the measurement, regardless of the intermediate process of the measurement.
Rotary incremental encoder----outputs the pulse when rotating, and knows its position by counting device. When the encoder is not moving or power-off, it depends on the internal memory of the counting device to remember the position.
Multi-turn absolute encoder----Using the principle of watch gear machinery, when the center code wheel rotates, another set of code wheels (or sets of gears, multiple sets of code disks) can be driven by gears, and the basis of single-turn coding The code of the number of turns is further increased to expand the measurement range of the encoder, and the code is determined by the mechanical position, and each position code is uniquely not repeated without memory.

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