Research On Dynamical Stress Measurement System Based On Wireless Sensor Networks

With the development of the aviation industry, the airdrop or airborne systems have been appliedbroadly in various domains, such as airdropping relief supplies and ambulance personnel, recyclingparachute of aerospace and aviation aircraft. Since the opening process of parachutes changes rapidlyand dynamically, the canopy fabric material changes intensely under stress. The stress states, strengthand elongations of fabric differ significantly from that of static scenarios. There is no complete theoryor appropriate approaches, either domestic or foreign, for measuring the force at places on canopyduring the working process of the airdrop or airborne systems. Therefore, there is essential practicalsignificance and application value of the study on the dynamical stress measurement system forairdrop or airborne systems.This thesis studies on the dynamical stress measurement system for airdrop or airborne systemsbased on wireless sensor networks. The primary works are as follows:(1) The overall design of thestress measurement system, as well as the study of the essential technical problems involved in thesystem;(2) The transmission protocols used in the WSN are compared and analyzed. Thetransmission protocol of stress measurement TPSMS is designed. The TPSMS designs each level ofthe stress measurement sensor networks, as well as the structure of data frames. The protocol supportsthe transmission of the stress measurement data.(3) The energy-balancing routing algorithm,RA-ABC, for WSN based on an improved artificial bee colony algorithm, is presented to overcomethe short lifetime of WSN due to the small energy capacity of sensor nodes. The algorithm firstlygenerates clusters from the sensor networks. The nodes within the each cluster form a chain structure.The shortest data transmission path is dynamically formed in the each cluster by introducing theoperations of crossover and mutation into the artificial bee colony algorithm. Thus, the energyconsumption of each node is distributed more evenly in the networks and the lifetime of the sensornetworks is extended as well.(4) The compensated stress measurement algorithm, SMCABP, basedon the BP neural network, is proposed to reduce the deviation of the stress data collected by sensors.The SMCABP compensates and rectifies the stress values converted from the voltage collected bysensors. The empirical results indicate that the algorithm can solve the problem of compensating thedeviation of stress data.In summary, the preliminary prototype of the system of dynamical stress measurement based onwireless sensor networks is implemented. Preliminary experiments applying the system areundertaken to measure the stress during the working process of parachutes. It provides solutions forthe measurement and transmission of the stress data, as well as the problem of compensating thedeviation of stress data.