Control And Communication System Of Underwater Vehicle

As the space for human activities expanding, study about underwater vehicle has become a hotspot. In this paper, a control system of tracked underwater vehicle is developed, and the underwater communication is studied in the lab.The control system consists of two parts: the video part and the electrical part. The former one includes camera, video server and PC terminal. The latter one is a two-level control system. The upper system consists of PC and the control box, the lower system is a vehicle-carried system.The vehicle -carried system is placed inside the vehicle, and it receives the command from the control box through UART, and controls the vehicle's actions. Besides, it executes PID algorithm to control vehicle's locomotion. Furthermore, the current of motors is sampled in order to avoid overloading.The control box is comprised of main-controller and video server. Besides receiving command from PC, the main-controller also can get the command according to keys and handles. Signal of the camera that fixed on the vehicle is transmitted by the cable to video server, and after digitized, it is transmitted to PC.PC controls the video server, processes and records the video data, offers interface to users, and communicates with the main controller.In this paper, the characters of underwater acoustic channel and several modulation in underwater acoustic communication are analysed. Based on that, a differential pulse position modulation (DPPM) using variable interval is brought forward. Comparing to DPPM, it improves transmission speed. Finally, experiments, which use circuit to simulate the underwater acoustic channel, are carried out, and the experiments prove its feasibility.At the end of the paper, the characters of the vehicle are analyzed and concluded and the further improvement of underwater pulse acoustic communication is also discussed.