Research On Detection By Acoustic Impulse And Technology Of Its Classification Of Crack Duck Eggshell

Getting rid of cracked eggshells is an important procedure for guaranteeing quality of processing duck eggs and saving cost. Detecting duck eggs by hand not only is badness for it's working conditions and laboring intension, but also the efficiency is very low. So finding a scientific, applicable and fast detecting method for removing cracked eggshells is very urgent.In this paper, first, we should explore an acoustic impulse method to detect duck eggshells. The sound is different between normal duck eggshells and cracked duck eggshells when being knocked by stiffer materials; the sound of normal eggshells is very silvery and sonorous, while the sound of cracked eggshells is very toneless and tedious. In the established microphone-sound blast-computer detecting system, we carried out experiments, first collected the sound signals of duck eggshells by the microphone, then converted analog signals into digital signals, and then we could make frequency chart for the sound signal by the computer, after this we could find out remarkable factors that are affected to distinguish cracked eggshells and normal eggshells, then we made use of "Bays" discriminance according to these influence genes, we could establish the distinguishing functions of normal eggshells and cracked eggshells respectively. We can judge whether the eggshell is cracked according to the distinguish functions and send the signal to the grader so that we could get rid of cracked eggs.Second, in this paper, we should program. We programmed the testing procedure by using MATLAB, so we could acquire some testing data, and then we established distinguishing models. According to this research method and the model, we use Visual C++ programming the procedure of detecting crack eggshells basing on the Windows system. The procedure was programmed to collect sound signals and analyze signals and judge if the eggshell is cracked, to get rid of cracked eggshells from the grader and to log the production and display wave figure of sound, in addition to amend the parameters of model according to different conditions.At last, in this paper, we have done two jobs to deal with in hardware designing. One is the designing of automatically knocking equipment, it consists the circuit with the 555-chip> some electronic components and the corresponding mechanic equipment. It could knock at duck eggshells automatically and continuously and it can alter the frequency and force of knocking neatly when it worked. The other is the designing of the grader, PLC programming is the key during this. The PLC procedure programmed could realize classification of duck eggs on the grader and the communication between PC and PLC.The system has tested by experimentation, the results showed that the detecting system could detect normal eggshell at the accuracy of 93 percent and detect cracked eggshells at the accuracy of 91 percent.