Introduction

The invented system, placed in rigid contact with an object, makes it possible to detect its vibrations and transfer their evolution in real time to a radio receiver, from which this information can be sent to any management center in the most congenial form. The system uses a directional coupler used as a transducer to transform the vibration into AM modulation of a radio signal exchanged between the reader and the sensor. TRL 3-4.

Technical features

The heart of the system is represented by the three-dimensional directional coupler shown in the adjacent figure. This component is able to change the coupling between two adjacent transmission lines according to the mechanical stress to which it is subjected. By circulating a radiofrequency signal in the system, an “amplitude modulation” of the circulating signal is easily obtained, directly proportional to the amplitude of the vibration detected, thus obtaining an AM signal at the output of the transducer (therefore capable of traveling in space) containing the desired information. This transducer can be interrogated both via cable, and wirelessly through suitable pairs of antennas.

Possible Applications

• Massive industrial monitoring;
• Preventive maintenance;
• Structural health monitoring;
• Accident prevention.

Advantages

• Fully passive;
• Unlimited autonomy;
• Real-time response;
• Low cost;
• Absence of electronic device;
• Realized with materials 100% recyclable;
• Adaptability and scalability