Research On Floating Side Swept Draft Detection System Based On Ultrasonic Synchronization

Along with the development of shipping industry in our country,the value of inland waters gradually.The transportation of the goods also gradually to the water transportation.And then,the problem with that is how to ensure the security of the ship and the navigation safety.In order to solve this problem,around the maritime sector and navigation management invested a lot of human power and material resources to test the water depth of the ship.They have achieved some success,but the technology is still immature.In this paper,the draft detection technology will be studied in detail to improve the detection efficiency.Throughout for the ship's draft detection technology at home and abroad,all have their own defects.They can not be real-time,accuracy,and reliability.Beyond that,the installation and maintenance of these systems are complex.And also,they are heavily influenced by the testing environment.So in this paper,I propose a floating side swept draft detection system which based on ultrasonic synchronization.Firstly,this system uses the ultrasonic ability to carry information.So it can abandon the traditional method of using underwater cable to enhance the system work synchronously,which is convenient for installation and maintenance.At the same time,it also avoids the adverse impact on the detection system,which caused by the change of hydrological environment.Secondly,the floating compensation of the detection system is quantitatively analyzed by means of underwater acoustic field model and three-dimensional modeling,which makes the detection results more reasonable and accurate.In addition,the variable intercept processing of ultrasonic sensor is completed by using the distribution of underwater sound field and nonlinear least square method.In this paper,designs in detail the components of the floating side swept draft detection system based on ultrasonic synchronization.The real-time draft detection of navigable ships is completed through the hardware system of lower computer composed of FPGA and ARM dual-core architecture and the software system of upper computer.The data acquisition module based on FPGA,together with the conditioning circuit and the demodulation and amplification circuit,has completed the enablement and acquisition of ultrasonic detection information and ultrasonic synchronization information.The data fusion module based on ARM completes the integration of the collected ultrasonic detection information,water level information and inclination information,and then completes the communication with the upper computer software system by cooperating with the wireless transmission module.The upper computer software system optimizes the detection data by means of median filtering,nonlinear least square method,amplitude subdivision,and so on.Finally,obtains the real-time draft depth of navigable ships.In this paper,the system has been tested in Dalian Maritime University Rescue and Salvage Laboratory.And then,in Xiangjiaba downstream of ship lift approaches,has tested field experiments.According to the real-time detection data analysis,the draft detection system is stable and reliable.The detection rate reaches five frames per second.On the premise of 28m spacing between the two ends of the detection system,error standard deviation is about 0.04m,comply with the requirements for field application.