Researches On Municipal Solid Waste Classification Based On Microwave Nondestructive Testing Technology

Municipal Solid Waste(MSW) sorting collection and sorting treatment is an innovation of traditional methods and a scientific management method for effectively waste disposing, which can not only recycle and utilize waste resources, but also decrease the yield of MSW. However, existing design and invention by some special mechanical structures and physical methods can only classify part kinds of MSW and have strong pertinence. Moreover, traditional waste classification and procession mixes kitchen wet waste and dry waste together, which increases the difficulty of waste classification and cases poor result of classification and bad classification processing environment.This paper puts forward a research method of classification of MSW using microwave nondestructive testing technology based on the principle of superposition of reflection and transmission of space plane electromagnetic wave. Classify kitchen wet waste and mixed dry waste contains in garbage bag by whole bag, further classify mixed dry garbage in garbage bags. The whole process achieves classification of MSW according to the material points for of food, paper, metal, plastic, glass, fabric, wood, ceramic tile and so on.First of all, the overall research program is put forward: The experimental device in this research is same with space wave transmission measurement; signals of transmitting antenna and receiving antenna at the same time are detected. Microwave signals at the sender and receiver are transformed into voltages by microwave detector; the voltages are acquired by acquisition card and analyzed in upper computer, microwave signal at the sender need to be attenuated to satisfy the detection range of microwave detector by attenuators. Finally, research on classification using KNN algorithm for MSW according wet and dry waste contain in garbage bags, further according to materials of dry waste.Secondly, several main components of MSW and air(no detection sample)are simulated according to space wave transmission measurement in order to get the S parameters of them by CST electromagnetic simulation software, then diversity of simulation results is analyzed using double variables variation Gini coefficient method. The maximum difference point is the best detection point which is used to be working frequency and designed the rectangular microstrip patch antenna.Again, functions of the upper computer software developed using LabVIEW graphical programming language are as bellow: the software can acquit output voltage signals of microwave detectors and communicates with ACCESS database to save collected voltage signal. The software can also draw error bar graphs of detected voltages of at the sender and receiver using MATLAB node in and have function of KNN classification.Finally, set up the experimental platform, collect experimental samples and carry out experiments. Error bar graphs of detected voltages at the sender and receiver are in accordance with simulation results. MSW was classified using KNN classifier according to kitchen wet waste and mixed dry waste contains in garbage bags, and got a perfect result. Further, most samples were classified correctly according to materials of dry waste in garbage bags apart from several materials like rubber and plastic, glass and wood have similar transport characteristics. Comprehensive experimental results under laboratory condition show that it is feasible to use the microwave nondestructive testing technology for the classification of MSW,then shows that complex situation may be encountered when the method is applied in practice, and some puts forward some corresponding suggestions...