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Study Of Tomato Basic Physical Properties And Mechanical Properties And Its Application Research

Posted on:2006-11-28Degree:MasterType:Thesis
Country:ChinaCandidate:C LiFull Text:PDF
GTID:2133360155973062Subject:Agricultural mechanization project
Abstract/Summary:PDF Full Text Request
Many quality and variety properties can be indicated by their basic physical properties and mechanical --rheological properties。 Eight varieties tomatoes was choosed in this paper, acquired images from machine vision system,studied basic physical properties.Mechanical properties data acquired from mechanical testing machine and self-maded creep testing system,studied mechanical rheological properties of tomato and researched application of classification of variety and mature degree.At first ,studied pre-processing method of tomato images eliminated tomato mirror reflection effectively; solved difficulty of separation of support and tomato.Drawing width , height, area of tomato through image processing, picked up width and height ratio, sphere degree ,circle degree and shape parameters of tomato, which can be used in variety classification, used Fourier description method described of each variety effectively ,fast, multi-information ,high accuracy, Used the first 6 heft of compose frequency of image edge curve and dimension shape parameters totally ten shape parameters as variety recognition characteristic parameters, variety recognition by using human mental network, the accuracy of which is more than 85%.Choosed HSI color model studied color properties of tomato .color parameter was average value of tone, made an objectively quantity description of every kind tomato's color property..Results shown that :tone angle can express tomato mature degree's change ideally,which can be testified by relationship between tone and acid content of the same kind tomato under different mature degree. Choosing the same kind different mature degrees tomato's average value of tone hist figure and average tone ,totally eight parameters as input ,choosing 8-13-4 structure of BP neutral network as mature degree's classification , training and classification .accuracy of which is up to 95%.Researched mechanical rheological properties of tomato,, researched creep testing equipment, arranging creep property testing system, analyzed stress distribution on the contact area and tomato crush equation by using Hertz theory;set up three uints Maxwell stress-relaxation model, using Z transformation recognized relaxation property parameters;set up four uints Burgerscreep model applied theory basis of fit testing data arithmetic.Studied tomato compression mechanical property stress relaxation property and creep property by experiments, acquring tomato compression prop-erty parameters, such as: elastic modulus, compression failure energy, compression failure stress , amount of Maxwell cell, relaxation modulus, relaxation time and creep property parameters : the amount of Kelvin cell ,delay modulus ,delay time ,and so on.Studied the compression property.stress relaxation and creep propertiesof different mature de-grees,acquired part rule of change of mechanical parameters according to mature degree. Results is the effect of mature degree on mechanical reeological property parameters is obvious, where elastic modulus ,failure force, the first relaxation quantum, the first delay modulus are more sensitive on mature degree;First studied relationship of mature degree and elastic modulus expressed by tone angle.Due to tomato will bear force during harvest ,transports, processing. So ,the conclusion of this paper can be used in reducing mechanical injure, the design of new processing machine, definition of art processing ,variety recognition classification of mature degree ,etc ,which has much importance in improving products quality and economical value.
Keywords/Search Tags:Tomato, Machine vision, Fourier descriptor, Mature degree, Netural network, Mechanical rheological property
PDF Full Text Request
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