| In response to the requirements of marine development strategy,China’s marine fishery has gradually focused on raising.Sepia pharaonis is a popular artificial mariculture object in southeast coastal area in recent years with high meat yield and high economic benefit.while it has a low breeding density,and its feed is fresh fish.When feeding,they will chase and attack each other due to insufficient feed or concentrated dropping point of feed,which leads to ink-jet and even the phenomenon of mutual hurt,causing economic losses.The existing automatic feeding systems are unqualified because the dropping points of feed are concentrated or some feeding systems realize uniform feeding by means of pipes and tracks with huge volume.Based on the above background,the design of uniform feeding system for Sepia pharaonis breed,was carried out to realize the uniform feeding of fresh feed in cement pond with small volume structure.The main research contents are as follows(1)The feeding system is divided into several subsystems to make speed,direction and elevation angle of feed adjustable in real time.The mechanical structure of the feeding system is designed,analyzed,calculated and modeled to make the dropping point of fresh feed discrete and not concentrated.The stepper motor in the horizontal casting system is selected and calculated.The minimum torque of the motor must be0.64N·m,56BYG250 C stepper motor can meet the demand.The load force and running track of the electric push rod in the elevation casting system are analyzed and calculated.The electric push rod with load force of 300 N,stroke of 300 mm and speed of 30 mm/s is selected.(2)Siemens 1200 PLC is selected as the control core to complete the control design of the automatic feeding system so that the devices controlling the feeding speed,horizontal direction and casting elevation angle can be operated according to the requirements of multi-stage feeding mode.(3)Based on LoRa module and MCGS configuration software of PC,a remote monitoring system with PROFINET protocol is built to realize remote wireless data communication,and remotely monitor the running status of each feeder terminal,view the running records,and realize the start-up,stop and quantitative casting of the feeder(4)The multi-stage feeding mode is designed and the running parameters in the mode are optimized by genetic algorithm for the sake of uniform casting.Professional analysis of the operating parameters,calculation of feed dropping point coordinate,edit of genetic algorithm fitness function are done for optimizing running parameters of multi-stage feeding mode.The simulation results show that the optimized multi-stage feeding mode can make dropping points uniform.On this basis,an interval contraction strategy is proposed to further improve the genetic algorithm,so that it can converge quickly under the background of feeding mode optimization.(5)The experimental prototype of automatic feeding system was designed and manufactured for the experiments.In the feeding experiment,the relative error between the set feeding amount and the actual feeding amount was basically less than 45.5g,which was acceptable in the Sepia pharaonis feeding environment with low feeding accuracy requirements.In feed casting experiment,the equivalent damping coefficient is checked at 0.002 in a calm environment,which can be used to optimize the running parameters of feeding mode.In feeding uniformity experiment,the results show that the maximum error is 7.76,and the minimum error is 2.20 compared with simulation result.The falling point of feed is not obviously concentrated. |
