There are two types of rotary encoders: absolute and incremental. Absolute encoders can read the angle of rotation directly without any calculations. They typically use optical or magnetic sensors to detect tick marks or magnetic markings on a rotating disk. Incremental encoders, on the other hand, require calculations, and they typically use two sensors to detect graduated lines or magnetic markings on the rotating disk to determine the direction and angle of rotation.
Rotary encoders are used in a wide range of applications such as robotics, industrial automation, medical devices, aerospace, automotive and game controllers. They can be used to measure the angle of rotation of a robot's joints, control the robot's position and speed, measure the robot's attitude and orientation, and control the robot's trajectory. In industrial automation, rotary encoders can be used to control the position and speed of a robot arm, control the robot's trajectory, measure the robot's attitude and orientation, and more. In medical equipment, rotary encoders can be used to control the position and speed of a surgical robot, measure the patient's posture and orientation, and more. In aerospace, rotary encoders can be used to control the position and speed of an airplane, measure its attitude and orientation, etc. In automobiles, rotary encoders can be used to control the position and speed of a vehicle, measure a vehicle's attitude and orientation, and more. In a game controller, a rotary encoder can be used to control the movement and direction of a game character, measure the attitude and direction of a game character, and so on.
In short, rotary encoder is a very important sensor, which can be used to measure the angle and direction of rotation, control the position and speed of the robot, measure the robot's attitude and direction, and control the robot's trajectory and so on. It has a wide range of applications in robotics, industrial automation, medical devices, aerospace, automotive and game controllers.