Compact Multifunctional Wireless Capacitive Sensor System and Its Application in Icing Detection.

Wolfgang Stocksreiter,Hubert Zangl

doi:10.3390/s19245562

Wolfgang Stocksreiter, Hubert Zangl

Open Access

https://doi.org/10.3390/s19245562

Copy DOI

Abstract

When sensors are used for the monitoring of surfaces, for example, with respect to ice aggregation, it is of interest to have a full coverage of the surface without sensor-inherent detection gaps, so-called “blind spots”. Since the components of such a sensor, like antennas and energy harvesting, also require space on the surface, the actual, effective sensing area is usually much smaller than the total surface of the device. Consequently, with an array of such sensors, it is not possible to monitor the entire surface of an object without gaps, even if the sensors are mounted directly adjacent to each other. Furthermore, the excessive size may also prevent the application of a single sensor in space constraint situations as they occur, e.g., on aircrafts. This article investigates a sensor concept in which the electrodes of the sensors are used for both radio data transmission and energy harvesting at the same time. Thus, the wireless data transmission in the 2.45 GHz Industrial, Scientific and Medical (ISM) band is combined with the sensor electrodes and also with a photovoltaic cell for energy harvesting. The combination of sensor technology, communication, and harvesting enables a compact system and thus reduces blind spots to a minimum. In the following article, the structure and functionality of a system is described and verified by laboratory experiments.

Highlights

The task of a sensor in condition monitoring is to provide a medium from which electrical information can be measured as reliably and accurately as possible, in order to reconstruct the condition from the measurement results
If the data conditioning is shifted to the sensor, more interference-resistant digital values can be transmitted instead of the more sensitive analog values
In the converter capacitive–digital converter (CDC), is based on a sigma–delta conversion principle, digital (CDC), which is based onwhich a sigma–delta conversion principle, the capacitance the capacitance between the electrode and one of the four electrodes is determined sequentially between the TX electrode and one of the four RX electrodes is determined sequentially by differential by differential[18,19,20]

Summary

Introduction

The task of a sensor in condition monitoring is to provide a medium from which electrical information can be measured as reliably and accurately as possible, in order to reconstruct the condition from the measurement results. If the data conditioning is shifted to the sensor, more interference-resistant digital values can be transmitted instead of the more sensitive analog values. This results in an increased functionality of the sensor and requires additional energy. For the communication of the sensor with the base unit there are basically two possibilities available: wired and wireless data transmission. The wireless in connection with an energy harvesting system has the appeal that the sensor can be operated completely without cable connections. The disadvantages are the environmental influences on the radio communication and the range of data transmission, especially in outdoor applications, where there are weather-related influences on the antenna and on the radio range. The sensor on which this investigation is based is an energy self-sufficient

Methods

Results

Conclusion