【作者】 宋建国；

【导师】 王聪；

【作者基本信息】 哈尔滨工业大学 ， 一般力学与力学基础， 2011， 硕士

【摘要】 水下超空泡航行体在空泡的包裹下,其所受阻力大幅度减小,航行速度实现质的飞跃,超空泡技术可使鱼雷像导弹一样在水中“飞行”。然而,超空泡技术在水下航行体减阻方面取得巨大成果的同时,也给超空泡航行体的稳定与控制带来严峻的挑战。因航行体被空泡包裹,其流体动力特性发生了深刻的变化,对控制策略提出了更为严格的要求。本论文就是在对超空泡航行体进行受力分析的基础上,根据动量定理与动量矩定理完成运动方程组的建立,并据此完成对超空泡航行体的机动控制,主要研究内容如下:完成超空泡航行体的动力学建模。为描述超空泡航行体的运动规律定义了相关坐标系,选取运动参数,并推导坐标系之间的转换关系;对超空泡航行体在水中的稳定航行方案进行比对分析,并确定航行体尾部在空泡内壁稳定滑行方案;选取空泡模型方程,并对空泡形态的影响因素进行研究;确定航行体的几何模型,对航行体各部分的流体动力及力矩进行分析计算;最终建立了超空泡航行体六自由度的动力学与运动学方程。建立超空泡航行体纵向运动模型与侧向无横滚运动模型,并对模型的开环特性、动态耦合特性、操纵耦合特性进行分析。在模型的建立过程中,依据相关化简准则,对运动模型进行简化处理。在侧向运动模型的建立过程中,考虑到横滚角对纵向运动与侧向运动的交连,选择在横滚得到有效控制的情况下,建立侧向无横滚运动模型。完成超空泡航行体的非线性控制。在超空泡航行体动力学建模与动态特性分析的基础上,分别采用滑模变结构控制理论与LQR最优控制理论实现对超空泡航行体的定深控制、俯仰控制、侧移控制与偏航控制。基于模型本身的非线性与动态耦合、操纵耦合严重的特点,采取反馈线性化方法分别对纵向模型与侧向无横滚模型进行线性化与解耦处理。最后对滑模控制与LQR最优控制的控制效果进行比对分析。更多还原

【Abstract】 The supercavitating vehicle surrounded by gas surface can attain very high speed while it is traveling underwater, because the vehicle has very small skin friction drag. Supercavitation technology can make the torpedo actually fly in the water like a missile. Supercavitation technology makes great achievements in drag reduction but also poses technical challenges in system stability and control. Because the vehicle is surrounded by cavity, its fluid dynamic characteristics have a great changes, the control strategy was also proposed more stringent requirements. The article completes equations of motion according to theorem of momentum and theorem of angular momentum based on the force analysis of the supercavitating vehicle, and makes motor control and attitude control for supercavitating vehicle. The main works are:Complete supercavitating vehicle dynamics modeling. In order to describe the movement of vehicle, the coordinate systems are defined, parameters of the motion are selected, and the transform relationships between the coordinate systems are reckoned. By contrasting the stable navigation programs of underwater supercavitating vehicle, we select the appropriate program. We select the equation of cavity model and research the morphology factors of the cavity. We determine the geometrical model of vehicle, analyse the fluid force and moment. Finally, according to theorem of momentum and theorem of angular momentum, we establish six degree of freedom supercavitating nonlinear dynamic and kinematic equations.Establish vertical motion model and lateral movement without roll motion model of supercavitating vehicle and analyse the open-loop characteristics, dynamic coupling characteristics, manipulation of coupling characteristics of the two models. In the process of establishing models, we simplify motion models according to the relevant guidelines. In the process of establishing lateral movement model, taking into account the influence of the roll angle on the cross-connect between the vertical movement and lateral movement, establishe the lateral motion model without roll when the roll has been effectively controlled.Complete nonlinear control of supercavitating vehicle. Based on dynamic modeling and dynamic analysis of supercavitating vehicle, sliding mode variable structure control and LQR control are used on depth control, pitch control, lateral control and yaw control. Because of the nonlinear, dynamic coupling and control coupling characteristics of the models are serious, the feedback linearization is respectively used on vertical model and lateral motion model without roll. Finally, sliding mode variable structure control and LQR control are compared to analyse.更多还原