Development Of The Bivalve Molluscan Shellfish Separator

Bivalve molluscan shellfish is the seafood which people prefer to eat in daily life. But theabnormal shellfish such as mud shellfish, dead shellfish and cracked shellfish are ofen producedbecause of water pollution as well as the links of harvest and transportation. If these abnormalshellfish are not eliminated, it will harm people’s health seriously once they eat them. Therefore,development of a device that can automatically recognize and eliminate the abnormal shellfishsuch as mud shellfish, dead shellfish and cracked shellfish has a very important practicalsignificance.Live shellfish close shells and form closed cavities when muscle contraction due to externalvibration stimulation. But the abnormal shellfish are not. Obvious differences between the voicesignals of live shellfish and the abnormal were found by collecting and analysing the knockingvoice signals of them. Clam is the research object of this topic. Based on differences amongvoice signals obtained by knocking various shellfish and computer technology, mechanical andelectrical integration technology, the subject was proceed to develop a equipment that canidentify and eliminate the abnormal shellfish.Knocking voice signals acquisition and processing of Clam, mechanical structure design ofprototype, control system design and prototype test are the four aspects which this topic researchon. Knocking voice signals acquisition and processing mainly involves collect percussion signalsof each type. The special signals of all types have been obtained after analysed and processedoriginal signals obtained in the time domain and the frequency domain. Both sorting process andthe component parts of separator have been preliminary made on the basis of the differencesamong voice signals as well as the Black-Box-Principle. Then, making the detailed design forvibrator feeding system，trapezoidal gears synchronous belt transmission system, lectromagneticknocking system, the microphone signal acquisition system, electromagnetic eliminating systemand clam collection system respectively. The control system of separator, which completed theoverall control by using single chip microcomputer AT89C2051, is mainly contain with UARTcommunication based on MATLAB environment and external circuits. The UARTcommunication between Single chip microcomputer and computer was established to achieve thereal-time signal collection and real-time processing. Next, power supply circuit, voltage drivingcircuit and LED circuit were designed. In order to judge the communication was normal or not,data have been tested by making use of UART debugging Software. Finally, a test was made to examine the performances of the Separator. Experimental results show that the bivalvemolluscan shellfish separator can separate shellfish accurately.The Clam separator developed has advantages with high choose efficiency, accurate select,low labor intensity and so on. Also, the equipment can be applied to separate other bivalvemolluscan shellfish. So, there will be broad prospects for application.