What are the tasks of encoder systems?
The basic function of encoders is to provide one of the following pieces of information:
- Absolute encoder: Motor shaft position of a rotary drive or linear motor
- Incremental encoder: Change in motor shaft position of a rotary drive or linear motor
- Absolute or incremental encoder: Rotational speed/speed of the motor shaft of a rotary drive or linear motor
The aforementioned information is used, for example, to enable one of the following functions:
- Position control in a closed loop system
- Speed control in a closed loop system
- Torque control in a closed loop system
- Realization of safety-related applications
- Monitoring of the position or speed
If the encoder system is operated in a closed loop system, the speed quality and control behavior can be significantly improved, even with major changes in load.
For dynamic control of synchronous motors under a wide range of load conditions, feedback of the rotor position is required to set the rotating field. By selecting the correct encoder and the optimum combination of signals for control processes and positioning, you can create an optimum drive system.
Due to control technology requirements, tacho-generators that determine direct information about a speed are rarely used today, as they do not enable positioning.
