Analysis And Design Of Freshwater Fish Cutting And Processing Equipment

Cutting and removing viscera,head-cutting and tail-cutting is an important process of freshwater fish initial processing.The development of new and efficient head-cutting and tail-cutting methods and equipment determines the utilization rate of fish resources,thereby affecting the development of fishery and aquatic product processing industry in China.In this paper,Hypophthalmichthys molitrix,Ctenopharyngodon Idella and Aristichthys nobilis of freshwater fish were selected as the main research objects.Physical characteristics of fish and location of head-cutting and tail-cutting was researched.Studying contents include fish body geometry parameters,compression characteristics,head and tail shear characteristics test,and fish body binary image extraction.It provides a theoretical basis for the processing equipment of cutting off viscera,the location method of fish head and tail resection and the design of headcutting and tail-cutting device.1)Study on Physical Properties of Fish.The main conclusions are as follows : In the elastic deformation range,the average compressive stress on the midline of Ctenopharyngodon Idella abdomen is 0.12 MPa,and the average elastic modulus is1.83 MPa.Hypophthalmichthys molitrix were 0.25 MPa and 2.61 MPa,.Aristichthys nobilis were 0.17 MPa,2.08 MPa respectively.These provide the main basis for the clamping method and design of the clamping device.The average maximum shear stresses of head-cutting and tail-cutting of Hypophthalmichthys molitrix were 280.4 N and 154.7 N.Ctenopharyngodon Idella were 319.7 N and 176.3 N.Aristichthys nobilis were 297.2 N and 168.5 N.The average maximum shear force of cutting abdomen of Hypophthalmichthys molitrix,Ctenopharyngodon Idella and Aristichthys nobilis was98.3 N,69.8 N and 84.7 N.These provide the main basis for the shearing force required for the cutting device and the head and tail removal device.2)Evaluation Test of Freshwater Fish Cutting Equipment.The equipment has good applicability for different varieties and specifications of fish processing,and has different processing effects for different varieties of freshwater fish.The effect of processing Ctenopharyngodon Idella is better than that of processing Hypophthalmichthys molitrix.The success rate of cutting Ctenopharyngodon Idella is100 %,and that of cutting Hypophthalmichthys molitrix is 80 %,and the effect of cutting abdomen is better.The swim bladder yield of Hypophthalmichthys molitrix and Ctenopharyngodon Idella is 10 % and 40 % respectively,and the swimming bladder yield is low.It is necessary to further optimize the visceral removal device to obtain higher swimming bladder yield.3)Location of head and tail resection.The highlight is to use the threshold method and region growth method to binarize the fish image and generate the binarized figure of its body shape.An image processing flow based on the gray image of freshwater fish is proposed to extract the cutting position of fish head and tail.There are two novel processing steps : firstly,the specific gradient value of the obtained gradient map is zeroed;secondly,extraction rules are proposed to automatically extract the target edge region from the threshold binary image of the gradient map;One of these two rules is used to determine the cutting position of fish head or tail.4)Design of fish head-and-tail cutting device.Based on machine vision technology,combined with the above image recognition method,the head-and-tail cutting device was designed for fish body.The industrial camera is used to collect the image of the processed object.The image is calculated and processed to provide data for the processing and positioning,so as to control the feed parameters of the servo motor and realize the positioning and cutting of the fish head and tail.The highlight of the device is that the cutting system use the cylinder-driven cutting tool to cut the gill cover bone in the form of V shape,ensuring that the head of fish is cut off and a higher meat harvesting rate is obtained.