Encoder

A encoder is a device that converts a linear or angular position into an electrical signal, used to determine the position, velocity or direction of an object.

This device is essential in automation and control systems, as it provides accurate, real-time information on the movement of different mechanical components.

What is an encoder?

Encoders, also known as encoders, can be classified as linear position meters (linear encoders) or angle encoders (rotary encoders).

The linear encoders measure position along a straight trajectory, whereas the rotary encoders measure the rotation of an axis.

How does an encoder work?

The basic function of an encoder is based on the detection of changes in a pattern or mark which the device converts into electrical signals.

These patterns can be Optical, magnetic, mechanical or capacitive. In optical encoders, for example, a beam of light passes through a disc with patterns of dark and transparent marks; as it passes through these marks, the sensor detects the variations and generates a corresponding digital signal.

Absolute encoder vs. incremental encoder

Encoders are mainly divided into two types: absolutes e incremental.

1. Absolute encoderThis type of encoder provides a unique and precise position for each shaft position. It uses a disc with multiple coded tracks that allow the exact position of the shaft to be known at any time, even after a power failure or reset. This is very important in applications where a high level of accuracy and safety is required, such as robotics or precision machinery.

2. Incremental encoderUnlike the absolute encoder, the incremental encoder generates pulse signals when the shaft moves, which are counted to determine the displacement. This type does not retain information about the absolute position, so it does not know what position it is in when it is turned on, and requires a homing process. It is simpler and cheaper than the absolute encoder, and is commonly used in systems that can tolerate interruptions and where position control is not critical.

Difference between encoder and resolver

The resolvers and encoders are position feedback devices, but they operate differently. A resolver is a type of rotary transformer that converts an angular position into analogue voltage signals, while an encoder provides a digital output.

Encoders generally offer higher accuracy and are easier to integrate with digital control systems. Resolvers, however, are more robust and can operate in more hostile environments, with high resistance to temperature, vibration and dirt.

Examples of encoder applications

Encoders are essential in many industrial and commercial applications, such as:

• Robotics: For precise control of the position and movement of robotic arms or Cartesian robots.

• CNC machinery: To measure and control the movement of parts and tools with high precision.

• Industrial automationIn assembly systems, production lines and material conveying, where accurate position control is required.

• Wind energyIn wind turbines, to measure blade orientation and optimise efficiency.

• MedicineIn medical equipment, such as surgical robots and imaging scanners, where accuracy is critical.

In short, encoders are key components in the measurement and control of motion in a wide range of applications, providing accuracy, reliability and versatility in industrial and technological processes.