Design And Experiment Of Unmanned Ship Integrating Water Quality Monitoring And Sampling

Favourable water quality is the basis of healthy pond breeding.Water quality monitoring and water sample collection are the key technologies of mobile water quality monitoring method and an important part of water quality monitoring research.In order to improve the efficiency and precision of water quality management in aquaculture ponds,reduce the labor of water quality monitoring and sampling,and improve the automation degree of water quality monitoring in aquaculture waters,an unmanned ship integrating water quality monitoring and sampling was designed.Equipped with cabin via catamaran bottom ship,the cabin is equipped with autonomous cruise control box,power supply,attitude sensor,GPS,water quality sampling bottles group,water quality monitoring sensor,etc.The ship adopts autonomous cruise to traverse the preset water quality monitoring points,and stops at the monitoring points to monitor water quality parameters and collect water samples.This design takes into account the needs of water quality monitoring and sampling,and designs the hull structure.The hull and cabin are made by rolling plastic process.The hull state is sensed by GPS and attitude sensor,and the autonomous cruise algorithm is used to control the hull running state.Uses the Internet of Things cloud platform to realize the real-time water quality data of return,reduce the water quality monitoring and sampling time and labor costs,improve the degree of automation,good adaptability,through real-time monitoring of water quality and water samples of complex work,makes up for the traditional way fixed-point water quality monitoring stations monitoring equipment to build cycle length,covering the area is small and the problem of high labor costs.The main research contents and achievements of this paper are as follows:(1)According to the design needs of mobile water quality monitoring and sampling,design and optimization of the structure based on the ship’s load,reliability and other issues.The catamaran is proposed as the bottom vessel,and the upper hull structure matching the double hull platform is designed for the installation and fixing of controller,power supply,water quality sensor,sampling water pipe and pump,sampling bottle and so on.The design and layout of the equipment are optimized according to the navigation attitude of the ship in the water.The design parameters of the integrated unmanned ship for water quality monitoring and sampling are as follows: 1.8m long,1.1m wide,0.76 m high and 0.28 m draft depth.(2)Integrated scheme design of water quality monitoring and water sample collection.Based on the sampling accuracy,sensitivity and reliability of water quality monitoring,the selection and applicability test of water quality parameter sensors were carried out.Design water sample collection scheme,according to scientific water sample collection requirements,ensure water sample quality,analysis of water sample collection velocity and collection volume requirements,design water sample collection system,including sampling bottle size,sample bottle layout in the sampling bottle fixed frame,water pump efficiency and water pipe size selection and design.Combined with the above parts of the realization of water quality monitoring and sampling integration scheme.(3)Hull control system design.Based on the accuracy of ship positioning,the reliability of path control and the performance of correcting deviation in small water area,an autonomous cruise control algorithm based on the differential twin-propellers driven model was designed,and an autonomous cruise control system was developed.The hardware and software of ship control were developed.GPS and attitude sensor are used to sense the positioning and deflection angle,and the algorithm is analyzed and processed to control the navigation status of the ship in the water area.The maximum deviation,minimum deviation and average deviation of monitoring points were 1.49 m,0.39 m and 1.003 m respectively.(4)Design and development of water quality monitoring system and water sample collection system.The selection of water quality sensor,sampling pump and related parts can realize the collection and transmission of water quality parameters collected by water quality sensor and the collection of fixed water samples.A real-time monitoring platform for water quality parameters is built based on the Cloud platform of the Internet of Things,and a physical model of water quality data is established to realize the online collection,control and uploading of water quality parameters,and the variation trend of water quality parameters can be recorded,analyzed and displayed on the platform.The monitoring and sampling function is stable,and the p H value,temperature and dissolved oxygen data of water can be returned in real time.Six 500 m L water sampling bottles can achieve accurate underwater sampling of 50 cm in accordance with the national water quality sampling standard.After the sub-unit test of each system and the on-site whole machine test,the research results show that the prototype structure design is reasonable,the system running state is stable,and the water sample collection and water quality monitoring function is reliable,which provides a low-cost and high reliable implementation scheme for the whole water quality monitoring of aquaculture.