Rotational Speed Measurement Based on LC Wireless Sensors

Area of Science:

• Electrical Engineering
• Sensor Technology
• Wireless Communication

Background:

• Traditional rotational speed sensors can be complex or require physical connections.
• Wireless sensing offers advantages in environments where wiring is challenging.

Purpose of the Study:

• To develop and validate a wireless method for detecting rotational speed using inductor-capacitor (LC) resonant tanks.
• To demonstrate the feasibility of using mutual coupling between LC tanks for speed measurement.

Main Methods:

• The proposed system utilizes two identical LC resonant tanks, one on the rotating component and one in the readout circuit.
• Maximum mutual coupling, indicated by a peak amplitude in the readout LC tank, is achieved during coaxial alignment.
• Advanced Design System (ADS) software was employed for simulation and optimization, alongside a synchronous detection circuit.

Main Results:

• Experimental validation was performed on an electric motor's rotational speed.
• The method demonstrated accurate measurements within a range of 16 to 41 rotations per second (rps).
• The maximum error observed in the rotational speed measurements was 0.279 rps.

Conclusions:

• The developed wireless LC sensor system provides an effective and accurate means for rotational speed detection.
• The correlation between signal peak periods and rotational speed is confirmed.
• This wireless sensing approach offers a practical solution for monitoring rotational dynamics in various applications.