The Design Of Surface Acoustic Wave Parafoil Riser Tension Sensor

Parafoil has been a new type of aircraft, it is a kind of ram-air parachute, its speed and direction of flight can be easily controlled. With the increasing requirements of military, civilian and defense, the research and development of the parafoil is becoming more and more urgent. One of the critical problems is monitoring and measuring the tension of the parafoil.In this paper, the SAW(surface acoustic wave) sensor has been used to accomplish the wireless passive measurement of the tension, aiming at the problem of the tension sensor can not be directly connected with the receiving device while the parafoil is opening, flying or landing. Tension is changed into strain, which is related to the SAW resonance frequency by the mechanical structure of sensor. Then we can finally get the tension value through the frequency.This paper is aiming at the parafoil riser. The structure of the sensor is designed, simulated and optimized by SolidWorks and ANSYS and then been made. The SAW resonator is pasted on the area which maximum strain performs. According to the experiment, the frequency and the tension has linear correlation, and after the repeated tests, it comes out the various performance indexes of our strain sensor.We also create the containment vessel which can protect the sensor out of the outer environment. Conformal antenna is pasted on the containment vessel in order not to interrupt the measurement of the sensor. In this paper, we firstly study the dipole antenna, then use the concept of conformal antenna and simulated by HFSS. At last, we test the entire system with both sensor and antenna by use of the reader. It shows the sensor and the antenna can be connected wirelessly and passively. A theory of improving the capacity of the reader has been mentioned in chapter 5.Finally, this paper gives the summary and prospect of the research, points out the innovative parts and provides reference value of other passive wireless tension sensor.