一种水下航行体纵向运动控制方法研究

Study on Control Method of Underwater Vehicle’s Longitudinal Motion

针对水下航行体纵向运动受干扰因素多,航行深度以及俯仰角易产生较大幅度震荡的问题,运用滑模变结构控制理论设计水下航行体纵向运动控制律,利用系统的滑动模态设计模糊控制器,系统控制量由模糊控制器的输出确定。根据舵机响应曲线,建立模糊规则,确定控制器的输入、输出和其他参数,并进行仿真计算验证。结果表明:与传统比例微分控制相比,当无干扰时,两种控制方法都能使航行体按预定航路完成纵向运动;当存在较大流体干扰时,比例微分控制下航行体定角爬潜以及定深航行误差明细增大,而滑模变结构控制下航行体仍能按设定俯仰角和航行深度航行,误差很小,证明该控制方法对干扰具有良好的鲁棒性。

The underwater vehicle’s pitch angle and sailing depth oscillate obviously due to the disturbances that taken on the longitudinal motion.Therefore,the sliding mode variable structure theory was used to design underwater vehicle’s longitudinal motion control law.The system’s sliding mode was used to design fuzzy controller,and the system control parameter was confirmed by the output of the fuzzy controller.The rules table of fuzzy controller was determined by open loop of steering engine,then the controller’s input,output and other parameters were determined.Then the control effect was tested by computer imitation.It is proved that when without disturbances,the underwater vehicle can keep sailing as prediction.However,when the liquid disturbances existing,the underwater vehicle’s overshoot will become bigger obviously under proportional-derivative control.But under sliding mode fuzzy control,the underwater vehicle will keep steady state.The system’s chattering was alleviated and robustness was improved.