Position sensors are very diverse, but in the world of high performance automation, the encoder is a critical element. Position sensor encoders provide feedback for both rotary and linear servo motor control, as well as position information for metrology applications.
Rotary Position Sensors
Rotary position sensors monitor movement along an axis and generate an output signal that varies depending on underlying technology and principal of operation. It is based on the same basic principle as a linear position sensor, except the device translates angular positions into useful output signals. Rotary encoders may be absolute or incremental. Read the article linked below to learn more about the working principles of rotary position sensors:
Position Sensor Technologies
Rotary position sensors can be further defined based on the underlying technologies. Several sensor types can be used for both absolute and incremental position monitoring. The following is a brief selection of some of the primary types of sensor technologies:
- Capacitive position sensors
- Inductive sensors
- Magnetic position sensors
- Optical sensors
- Potentiometric position sensors
- Ultrasonic sensors
Although different sensing paradigms are preferred for different applications, optical position sensors typically offer the greatest accuracy and the highest resolution.
Optical Rotary Encoders
Optical encoders use photosensitive detectors and optical gratings to precisely indicate absolute or incremental position for rotary sensors. Interferential systems eclipse both transmissive and reflective encoders in terms of accuracy, compactness, repeatability, and resolution. They generate precise position data by impinging a laser beam on a diffraction grating printed on the rotary scale. This diffracts the incoming beam, generating a high contrast interference pattern on the detection array. Optical encoders require a readhead, which is used regardless of the scale being used.
Mercury I Interferential Optical Rotary Encoders
At Celera Motion, we offer compact interferential optical encoders with the MercuryTM Series encoders. The Mercury™ Series optical encoders are position sensors that can be used for rotary position sensing. The miniature rotary sensor fits into tight spaces and has wide alignment tolerances for easy installation. Mercury Series M1000 has analog outputs that can be interpolated by the customer’s electronics for resolution up to 5 nm.