Coupling displacement sensors with energy harvesting: A study of wireless self-powered displacement detection methods

Highlights

• Proposes a wireless self-powered displacement measurement method.

• Innovative coupling of displacement sensors and energy harvesting.

• Self-energy supply to the sensor is achieved through the sensor's operating principle.

• Accurate mathematical models of induced voltage and displacement are obtained.

• The proposed theoretical model is more accurate and environmentally friendly in terms of displacement detection.

Abstract

With the rise of miniature energy harvesting, energy harvesting from the surrounding environment provides a new solution for the sensor’s power supply. Combining energy harvesting with the energy required by sensors has become a new research idea. Firstly, an accurate theoretical model of the voltage and displacement parameters is constructed based on the law of electromagnetic induction and the Lenz’s law. Then, the theoretical model is validated in COMSOL simulation software. The factors affecting the voltage and displacement parameters in the theoretical model are analyzed to verify the rationality of the theoretical model. Finally, the constructed electromagnetic displacement sensor prototype verifies the rationality and accuracy of the theoretical model of the sensor proposed in this paper. When the frequency is higher than 1Hz, the displacement measurement accuracy of the mathematical model proposed in this paper can best reach 98%. This shows that the proposed mathematical model for measuring displacement is suitable for scenarios with a frequency higher than 1 Hz. The induced voltage of the coil involved in this article is the open circuit voltage. Because there is no need to connect to an external circuit, the influence of the external circuit on the measurement accuracy can be effectively avoided. The theoretical model studied in this paper can directly use the relative motion of the magnet and the coil to directly replace the displacement parameters of the motion with the induced voltage generated. The research in this article can greatly reduce the cost of displacement sensors. It has a good energy-saving effect, which provides a new design idea for the design and construction of the sensor.