A wireless passive tension sensor

In this paper, a new type of tension sensor is designed according to the needs of measuring the tension of varieties of ropes such as ropes in parachute. The sensor is designed to have a T-shape structure, so that the rope can cross over the sensor without any damage during measurement. In the process of measuring parachute haulage cable, it requires strict requests on the shape and structure of the sensor. The shape and structure of the sensor may have impacts on the measurement or even disabled measurement. So a wireless passive operating mode of measurement is proposed. Surface acoustic wave which is a wireless passive object is used at sensor surface functioning as both sensor element and signal transmission medium. The change of tension in a rope is converted into the change of stress in such sensor, leading to the change of resonant frequency of the surface acoustic wave device, which can be detected by the reader. Simulation results show that the sensor has better sensitivity and linearity.