超空泡航行器极点配置变结构控制方法研究

Study on Pole Assignment Variable Structure Control Method for Supercavitation Vehicle

超空泡航行器在航行过程中,尾部会周期性拍打空泡壁而表现出强烈的“尾拍”现象,尾部空泡是由空化器经历的历史位置形成,呈现强烈的时滞特性,动力学建模和稳定控制是制约其发展的核心难题;针对泡体耦合问题,建立了空泡/刚体相对几何关系一体化实时解算的动力学模型;针对后体非线性特性,采用分段线性化方法,在保留后体尾拍非线性特性的基础上,建立了面向控制的简化模型;为了解决超空泡航行器非线性时滞控制问题,针对弹体运动极其敏感、操纵效率高等特点,采用极点配置的方式将控制模型配置到理想状态;针对尾拍过程非线性和不确定极大的特点,建立了面向扰动的变结构控制器,实现超空泡航行器扰动运动控制;采用极点配置变结构控制方法,分别设计了滚转通道和俯仰通道控制律;利用泡体耦合动力学模型进行6 DOF控制闭环轨迹仿真,稳定巡航过程中深度控制误差小于0.1 m,滚转角控制误差小于4°,表明该控制方法能够对航行器滚转角和深度实现稳定控制,控制效果较好,能够满足超空泡航行器航行要求。

During the sailing of a supercavitation vehicle,the tail will periodically beat the cavitation wall and show a strong“tail-beating”phenomenon.The cavitation in the tail is formed by the historical position experienced by the supercavitation vehicle and presents a strong time-delay characteristic.Dynamic modeling and stability control are the core problems restricting its development.Aiming at the cavitation-body coupling problem,the dynamic model of the integrated real time solution to the relative geometry relationship between the cavitation and rigid body is established.Aiming at the nonlinear characteristics,the sectional linearization method is used to establish a simplified control oriented model while preserving the nonlinear characteristics of the rear body tail beat.In order to solve the nonlinear time-delay control problem of the supercavitation vehicle,the control model is configured to the ideal state by the pole assignment in view of the characteristics of extremely sensitive movement and high control efficiency.A perturbation-oriented variable structure controller(VSC)is established to control the disturbance motion of the supercavitation vehicle due to the nonlinear and uncertain process.The control law of roll channel and pitch channel is designed by the pole assignment variable structure control method.The cavitation-body coupled dynamics model is used to simulate the closed-loop trajectory with 6 degrees of freedom(DOF)control,the simulation results show during the stable cruise,the depth control error is less than 0.1 m,and the roll Angle control error is less than 4°.The proposed control method can achieve the stable control of the roll Angle and depth of the vehicle.It has a good control effect,and can meet the navigation requirements of the supercavitation vehicle.