طراحي و ساخت يك سامانه بر خط به منظور اندازه گيري سفتي خرما مبتني بر روش غير مخرب ضربه

چكيده انگليسي :

2 5 N Hamdami Assist Prof Examiner Department Graduate Coordinator M Majidi Design and Development of an Online Date Fruit Firmness Measuring System Based on Nondestructive Impact Force Alireza Heidari heidari alireza@ag iut ac ir April 20 2013 Department of Agricultural Machinery Engineering Isfahan University of Technology Isfahan 84156 83111 Iran Degree M sc Language Farsi Supervisors M Sadeghi Assoc Prof sadeghimor@cc iut ac ir S A Mireei Assist Prof samireei@cc iut ac ir Abstract Date Phoenix dactylifera is an ancient fruit containing great source of minerals and nutritive materials Date palm is also one of the most important trees in desert Iran has the largest fields of planting and ranks second grade in terms of producing date This product plays an important role in foreign exchange income Grading of date fruit is currently done manually which causes mechanical damage to the fruit during the operation Therefore developing an automatic grading system in order to increase the quality of the product and reduce the labor cost is of great importance In this research an electro mechanical system was developed for online measuring firmness of date fruit based on nondestructive impact force The samples of Mazzafati variety were prepared form Jiroft Kerman provience at four different maturity stages Kimri Khalal Rutab andTamr The nondestructive tests were performed on two sides of the samples at three different speeds and m s Since the firmness of date fruit is related to the maturity stage this property was considered as the grading index Each fruit was divided into two equal parts and the core was removed Destructive tests were also performed on both sides separately based on Magness Taylor MT test using a universal tension compression device with a probe of mm diameter The maximum force of penetration was considered as the firmness index Three different analysis methods were used to obtain a functional relationship between the firmness as the dependent variable and the recorded signal as the independent variable In the first method three characteristics of the signal s first half wave were defined including peak force Fp its duration Pd and the area under its diagram Ig The non linear multivariate regression approach was performed on MT firmness against these properties The results showed no accepatable results The partial least squares PLS regression was then applied to the total impact signal data which resulted in a better firmness prediction The calibration coefficients were also revealed that only up to a specific duration of the total signal data ms were effecitive on firmness prediction In other words the data after this period could be considered as noise Consequently a new linear multivariate regression approach considering the above mentioned characteristics Fp Pd and Ig for the first half waves of the signal was applied for predicting firmness The results showed an appropriate improvement in prediction confirming the applied assumption According to the similar results for both sides separately and considering all data together it can be concluded that firmness prediction was not dependent to the oreientation of fruit during the impact hence the developed approach can be used for practical grading purposes Overall regarding enginireeing considerations related to grading system andPDF created with pdfFactory trial version www pdffactory com

حيدري، عليرضا

طراحي و ساخت يك سامانه بر خط به منظور اندازه گيري سفتي خرما مبتني بر روش غير مخرب ضربه

آزمون غير مخرب , حداقل مربعات جزئي , خواص رئولوژي , سفتي