# Optimized Design of an Ultrasonic-Based High-Efficiency Wireless Passive Monitoring System for Sealed Metal Compartments

## TL;DR

This paper presents a high-efficiency wireless system for monitoring sealed metal compartments using ultrasound, enabling battery-free and wire-free condition monitoring.

## Contribution

An optimized ultrasonic wireless system for sealed metal compartments with improved energy transfer and data communication.

## Key findings

- The system achieves 60% energy transfer efficiency at 1.045 MHz ultrasonic frequency.
- It supports 50 kbps communication rate and monitors temperature and humidity in a 13 mm thick SMC.
- The system is validated on a steel wall and simulates real-world engine compartment monitoring.

## Abstract

The condition monitoring (CM) of sealed metal compartments (SMCs) is an urgently required restructure. Ultrasound penetrates SMCs to power and communicate with built-in sensors, enabling the CM of SMCs. However, current ultrasonic wireless power transfer and data communication (UWPTADC) systems are large and complex, and limited by the efficiency of energy transfer and data reliability. In this paper, an optimized design of a high-efficiency wireless passive monitoring system using UWPTADC techniques is proposed for SMC. The circuit model of the system is developed and analyzed to achieve an optimal design for efficient wireless power transfer and effective data communication coupling. A test system was constructed using a steel wall of 11 mm thickness as a validation object. At the ultrasonic carrier frequency of 1.045 MHz, the system has an energy transfer efficiency of 60%, and a communication rate of 50 kbps. In addition, the system realizes temperature and humidity monitoring inside a 13 mm thick cylindrical SMC, simulating the process of ultrasonic CM of an actual engine compartment. The system provides a wiring-free and battery-free solution for CM in SMCs, advancing CM in aerospace, marine and other fields.