What is Absolute Encoder?

The absolute value rotary encoder is a detector that can output the angle data within one revolution of the motor to an external target. Absolute encoders are generally capable of outputting 360° with 8 to 12 bits. There are many optical channel engraving lines on the absolute encoder optical disc, and each engraving line is arranged with 2 lines, 4 lines, 8 lines and 16 lines in turn, the shaft encoder obtain a set of unique binary codes (Gray codes) from the zeroth power of 2 to the n-1th power of 2.

What is an absolute rotary encoder?

The high resolution absolute encoder is coded by the mechanical position determination, it does not need to memorize, does not need to find a reference point, and does not need to count all the time. When you need to know the position, you can read its position. In this way, the anti-interference characteristic of the encoder and the reliability of the data are greatly improved. From a single-turn absolute encoder to a multi-turn absolute encoder, the absolute value rotates the single-turn absolute encoder to measure the lines of the photoelectric encoder during rotation to obtain a unique code. When the rotation exceeds 360 degrees, The encoding returns to the origin, which does not conform to the principle of the only absolute encoding. Such encoding can only be used for measurement within a rotation range of 360 degrees, which is called a single-turn absolute encoder. Absolute encoders are feedback devices that provide velocity, position information by outputting digital words or bits related to motion. Unlike incremental encoders, which output a continuous, ubiquitous stream of pulses, absolute encoders output a unique word or bit for each position.

Principle of absolute encoder

Maintaining accuracy even in complex systems, absolute encoder discs Absolute rotary encoders use a static reference point to determine their position. The method differs slightly depending on whether the absolute rotary encoder is optical or magnetic, but the principle is the same for both.
Absolute encoders work by outputting a digital word of bits as the shaft rotates. There are two discs, both with concentric rings with offset markers. One disc is fixed on the central axis; the other is free to move. As the disc rotates, the marks on the absolute encoder track change position on the stationary disc. Each configuration on an absolute rotary encoder disc represents a unique binary code. The absolute position of an object can be determined by looking at the binary code inside an absolute rotary encoder. For optical absolute encoders, the mark is an opening through which light passes. For magnetic absolute encoders, the mark is an array of magnetic sensors that pass through a magnet and detect the position of the magnetic poles. The absolute encoder is coded by the mechanical position. It does not need to memorize, do not need to find a reference point, and does not need to count all the time. When you need to know the position, you can read its position. It is not affected by power failure and interference, so the anti-interference characteristics of the encoder and the reliability of data are greatly improved.

Advantages of absolute encoder

By outputting digital words or bits instead of a stream of pulses, absolute value rotary encoders offer the following advantages:

1. Higher overall resolution.
2. Better start-up performance due to shorter homing (or initial position) time.
3. Accurate motion detection along multiple axes.
4. Multiple output protocols for better electronic integration.
5. Better recovery from system or power failures.

Absolute encoder application

The absolute is used for special equipment such as textile machinery, irrigation machinery, papermaking and printing, water conservancy gates, robots and mechanical arms, port lifting machinery, iron and steel metallurgy equipment, heavy machinery equipment, precision measuring equipment, machine tools, food machinery, elevators and so on.

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