Position Sensors for Industrial Applications Based on Electromagnetic Encoders

Area of Science:

• Measurement Science
• Electromagnetism
• Materials Science

Background:

• Traditional optical and magnetic encoders are industry standards for displacement and velocity measurement.
• Existing encoder technologies have limitations that drive the need for alternative solutions.

Purpose of the Study:

• To propose and investigate a novel electromagnetic encoder system for linear and rotary measurements.
• To demonstrate the feasibility of implementing electromagnetic encoders using various materials and manufacturing processes.

Main Methods:

• Utilized a transmission line structure (stator) perturbed by a chain of inclusions (metallic, dielectric, or apertures) on a substrate.
• Analyzed amplitude modulation of a harmonic signal by the encoder chain to extract position and velocity information.
• Investigated linear encoders with metallic and dielectric inclusions, including additive manufacturing prototypes.

Main Results:

• Electromagnetic encoders successfully measure linear/angular displacements and velocities via pulse counting principles.
• The envelope function of the modulated harmonic signal accurately encodes position and velocity data.
• Demonstrated the potential for synchronous electromagnetic encoders to provide quasi-absolute position, velocity, and direction.

Conclusions:

• Electromagnetic encoders present a viable alternative to traditional optical and magnetic systems.
• Additive manufacturing techniques like 3D printing and screen printing are suitable for fabricating these novel encoders.
• The developed electromagnetic encoder technology offers accurate and potentially quasi-absolute position sensing capabilities.