Types of industrial encoders
Arta Tejarat Ayandeh (Universa ANEST IWATA Agency in Iran)
You can use different methods to control motion using encoder. Different approaches have been considered for this purpose, the most common approach is to choose the method according to the type of movement or the position of the device.
In this regard, the encoder can be divided into 5 main categories, which are:
- Linear Encoder
- rotary encoder
- Angle Encoder
- Absolute Encoder
- Incremental Encoder
Classification of encoders based on the type of movement
1. Linear Encoder
This type of encoder deals with the movement of objects along a linear path. The linear encoder measures the distance between 2 specified points by using a transducer that can be a cable or a small rod, thus converting the existing analog output into digital and determining the movement or position of the object. This method is used in various devices, including the cutting-to-length device.
2. Rotary Encoder
The second type of encoder that can be introduced is the rotary encoder. A rotary encoder is used to monitor the movement of a rotating object or device. In this encoder method, the position of the rotating object is converted into a digital signal, and it is possible for the control system to determine the position or speed of the object. This sensor can be installed directly on a rotating axis such as a motor.
3. Angle Encoder
Angular encoders have the same function as rotary encoders. Because in this type of encoder, rotational or oscillating movement is also monitored and information is obtained. But the issue that made us put these encoders in a separate category is that this type of encoder is much more accurate. Usually, this type of encoder is used in a situation where the accuracy of the information obtained from the source is of great importance.
Classification of encoders based on position
Previously, we introduced the classification of encoders based on their type of movement. But the remarkable thing is that you can also use the classification of encoders based on position. All linear, rotary and angular encoders can be classified into one of two categories: absolute or incremental.
1. Absolute Encoder
There is zero point in absolute encoder. For example, the power may be cut and the position of the encoder remains unchanged for a certain period of time. But even if the power is cut off, the absolute encoder can determine the position of the object. These encoders are used where the process is followed slowly or an interruption occurs during the process. Also, if knowing the momentary position of an object is important, the absolute encoder should be used.
2. Incremental Encoder
At the opposite point of the absolute encoder, there is another type of encoder classification based on position, where there is no zero point, and when the position of the encoder changes, its output also changes. In this case, in case of power failure, the incremental encoder can no longer determine the position of the object and must be referenced to a home position or reference point so that the counter can be reset and then used to calculate the relative motion.
An encoder is a type of sensor that is used to check the position, speed, number or direction of equipment. This sensor plays an important role in the operation of control systems, that's why it is necessary to get to know them and their features well. In this article, we tried to define encoder and then introduce different types of encoder. We hope this article was useful for you.
