The Detection And Analysis Of The Stored Grain Insect Sound Characteristic And Its Database Instauration

The stored grains are usually subject to infraction from baleful biology such as insect, mildew and mouse, et al in the course of storing, but insects are the main jeopardy to provision-storage. According to FAO investigation, provision loss, due to insects, account to 4-8% in provision-storage gross, and even high up to 30% in some countries. Simultaneously, the bad storage method would make provision loss more seriously in some developing countries. China is one of the largest countries on provision produce, storage and consumption, and has done a number of works in protecting provisions, but provision loss is also huge due to insects. In provision-storage, prevention and cure of insect pests have become a austere problem to every country. Now, the most efficient method of preventing and curing insect pests is by chemical medicament, however, pesticide-leftover and anti-drug could not have been neglected. Before the more efficient method appears, forecasting or real-timely detecting insects is the best method to effectively prevent insects and decrease pesticide-leftover. At present, sound detection has been proven a potential method of insect storage detection. Foreign studies mainly place the number estimation of insect but seldom discriminate the insect species. The insect polyphagous character along with the development of insect classification technology makes it possible for different kinds of insects to live in the single grain. The elementary studies show that insect species can be accurately distinguished through the sound-frequency characteristics of insect activity in grain.In this paper, our main aim is to deeply study the mechanism of sound-frequency characteristics of insect and its application. The main studies are as follows:(1) The sound propagation characteristics in grain are theoretically studied by treating grain as quasi-.granule medium and using homogenization method. The sound wave equation and velocity in grain medium are presented and discussed, on the big and small granule, respectively. The study shows that the results tally with ones from phenomenology.(2) Insect activity sound in grain belongs to weak signal and ones from the barn are subjected to noise. The insulation chamber based on the stored grain insect sound detection is designed and the effect is evaluated experimentally by using a quasi-double...