Design Of Control System For Small Cable Underwater Vehicle

With the development of underwater vehicle technology,different types of underwater vehicles play an important role in the underwater field.For the small cable-controlled underwater vehicle,this paper takes the underwater vehicle developed by Oceanbotech Intelligent Technology(Shanghai)Co.Ltd.as the study object.It focuses on the motion control algorithm of the underwater vehicle,the sensor acquisition scheme,and the task scheduling and communication strategy based on real-time operating system.This paper narrates from the following four aspects:1.To improve the adaptability of the motion and attitude control algorithm of underwater vehicle,the fuzzy control algorithm which belongs to the intelligent control and the cascade PID control algorithm are combined to realize an underwater vehicle control algorithm.The combined control algorithm is independent of the precise mathematical model,which improves the applicability of the control algorithm and reduces the difficulty and workload of parameter adjustment.2.For better real-time performance and reliability of sensor data,the sensor subsystem modular is designed for sensor data acquisition and processing,which reduces the occupancy of master controller,improves the execution frequency of control algorithm and the update rate of sensor data.It ensures that the master controller can acquire the correct and reliable sensor data at the first time.The use of subsystem modular also simplifies the software design of the master controller and improves the modularization level of the underwater vehicle.3.In order to achieve better real-time performance and stability at the lowest cost,master controller ports an open source and free embedded real-time operating system,FreeRTOS,and achieves a task communication mechanism based on message subscription and distribution mode.By using this communication mechanism,different tasks don't operate and share data directly anymore,and the security of data transfer is ensured.At the same time,the communication between tasks is simplified,and the flow of data is clearer.4.To validate the feasibility and performance of the whole control system,experimental environment and experimental platform are built and then a series of experiments are carried out.The final results of experiments show that the system can effectively control the underwater vehicle,and the whole system does well in real-time and stability.