Study And Design Of Self-cruising Mowing Boat System For Shrimp And Crab Culture Based On IMU/DGPS

With the progress of the Internet of Everything era and the increasing cost of labor,the aquaculture industry produces new changes inevitably.In the traditional shrimp and crab culture model,the regular cleaning of aquatic plants mainly relies on manual salvage,which is easy to cause secondary pollution,which affects the breeding efficiency seriously.In order to improve the level of mechanization and intelligence,navigation and positioning technology,full coverage path planning and path tracking control technology,embedded and Internet of Things technology are applied comprehensively,a mowing boat system with self-cruising function suitable for shrimp and crab culture waters is designed.The main work includes the following four aspects:(1)In order to meet the demand of grass cleaning in shrimp and crab culture,and then a paddle-wheel-driven mowing boat is designed.The overall design of the mowing boat is carried out,including the mechanical structure,integrated navigation system,full coverage self-cruising control system,and host computer/APP monitoring system.Mainly completed the waterproof grass winding wheel drive device,reciprocating water grass cutting device,and water grass conveying and paving device mechanical design.(2)For the heading angle and longitude and latitude detection of the mowing boat are easily disturbed by factors such as the environment,an IMU/DGPS integrated navigation system is designed.By analyzing the attitude measurement methods of IMU inertial measurement elements,the Extended Kalman Filter(EKF)algorithm based on quaternion attitude calculation is used to improve the measurement accuracy of attitude angle,and the superiority of the algorithm is verified through simulation;At the same time,GPS base station receiver is added and carrier phase differential navigation mode are applied,therefore the coordinate positioning accuracy of the mowing boat is improved.(3)A full coverage self-cruising control system is designed for the problems of low coverage rate,high repetition rate and missing harvesting.In order to solve the problem that the mower missed harvesting when turning,the internal spiral combined with the cross path planning method is used to realize the full coverage operation of the mower,and the effectiveness of the method is verified by simulation.Meanwhile,a fuzzy PID heading/speed controller combined with the insertion point algorithm and speed switching control strategy is designed to achieve efficient operation and safe turning of the mowing boat.(4)The control system software and hardware test platform based on the STM32 series chips are designed,and the remote monitoring software is also developed.The hardware design includes data acquisition module,wheel drive module,power detection module,wireless transmission module and data storage module.The software of integrated navigation system,shipboard control system,and remote monitoring system based on the hardware design that is designed and tested.The field test of the pond is carried out by building the paddle-driven test sample ship.The results show that the mowing boat is able to generate a full coverage operation path under the remote monitoring platform;Combined with IMU/DGPS navigation and control algorithm,the fast response of heading and speed can be realized.The linear error of the full coverage of the self-cruising mowing boat is kept within 0.08 m,and the maximum error of turning is not more than 0.35 m,which can meet the actual operation requirements.