【作者】 梁卓；

【导师】 薛晓中；

【作者基本信息】 南京理工大学 ， 导航、制导与控制， 2009， 博士

【摘要】 SINS/GPS制导炸弹工程研制中制导控制系统设计将面临两大实际问题：其一,炸弹是无动力的,要达到“大射程、大落角、高精度”的战术技术指标要求,制导律应如何设计；其二,大空域的工作环境,导致制导炸弹在飞行中必然受到气动参数大范围摄动以及外界随机干扰的影响,如何解决飞行控制系统的鲁棒性问题。针对上述实际工程问题,本文基于变结构控制理论研究了SINS/GPS制导炸弹制导与控制系统设计的关键技术,并通过相关仿真与试验对方法的正确性与可行性进行了验证。所做的研究工作归纳如下：1、根据SINS/GPS制导炸弹无动力特点和末端弹道角约束要求,采用了“中制导+有落角约束的变结构末制导”的复合制导律,确保了“大射程、大落角、高精度”的战术技术指标得以有效实现。中制导基于升阻比最大对攻角进行优化,以增加制导炸弹的前飞距离。末制导采用两种变结构控制方法设计了有落角约束的末制导律,其一是模糊变结构末制导律,设计了时变滑模面与指数趋近律,可根据弹目相对距离来自适应地调整滑模趋近速度,同时引入模糊控制来自动调节变结构控制中的切换项大小以削弱系统抖振；其二是非奇异terminal滑模末制导律,采用非奇异terminal滑模控制方法设计了制导律,能够保证制导系统状态非奇异地于有限时间内到达滑模面,并且较模糊变结构末制导律具有较大的过载指令裕度,为大机动制导飞行创造了条件。2、针对SINS/GPS制导炸弹大空域飞行条件下的参数不确定性以及飞行过程中受到的外界各种随机干扰,采用模型参考变结构自适应控制方法来设计制导炸弹自动驾驶仪。该自动驾驶仪集自适应控制与变结构控制二者优点于一体：一方面确保系统状态按照规定的动态特性进入滑动模态,以利于改善控制系统的动态品质；另一方面变结构控制固有的鲁棒自适应性特点能抑制参数大范围摄动,有利于提高控制精度。通过几类典型的数字仿真说明了模型参考变结构自动驾驶仪的有效性。3、为使得制导与控制系统具有更好的综合性能,基于非奇异terminal滑模控制进行了制导与控制系统的一体化综合设计。首先建立了制导控制系统的一体化状态方程,在充分考虑制导回路与控制回路的不确定性基础上,利用非奇异terminal滑模控制方法,设计了制导控制一体化状态反馈控制律。然后通过数字仿真的方法,与将制导回路和控制回路分开独立设计的传统制导控制系统设计方法做比较。结果表明一体化变结构制导控制系统不仅能保证制导炸弹以期望的落角精确地命中目标,而且能更好地动态规划控制量大小,控制信号输出平稳,为更复杂情况下的飞行控制系统设计提供了理论参考。4、从制导炸弹投放域与命中精度两个方面研究了变结构制导控制系统的性能。建立了计算投放域的六自由度模型,提出了基于优化理论解算投放域的方法,仿真计算了不同投弹条件下的投放域,研究了影响投放域大小的因素。全面分析了SINS/GPS制导炸弹飞行过程中的各种制导误差和非制导误差,并建立了相应的误差模型。然后进行了存在各种误差源干扰下的蒙特卡洛打靶仿真,仿真结果表明了命中精度仍满足战术技术指标要求,从而说明变结构制导控制系统良好的鲁棒性。5、最后通过转台半实物仿真试验和模拟轰炸跑车试验的研究,进一步验证了所设计的变结构制导控制系统的有效性与可行性。研究成果对于SINS/GPS制导炸弹的总体设计、飞机挂飞试验以及投弹试验等有重要的参考价值。更多还原

【Abstract】 The design of guidance and control system for the project of Strapdown Inertial Navigation System/Global Positioning System(SINS/GPS) guided bomb is confronted with two main practical problems. First, how to present a guidance law for the guided bomb with no thruster to satisfy tactical guideline of’large range, big hitting angle, high hitting accuracy’. Second,how to solve the problem of robust flight control with uncertain pneumatic parameters and various random outside disturbances due to the guided bomb maneuvering in huge airspace.In this dissertation, acording to the above practical engineering problems, key technolog--ies of guidance and control system are deeply studied based on variable structure control theory for the guided bomb. Simulations and tests are carried out to validate the validity and feasibility of above methods. The main research points done of the dissertation are listed as follows:1. According to the constraint of terminal trajectory angle of the guided bomb with no thruster, a compound guidance law is developed, consisting of midcourse guidance and terminal guidance with hitting angle constraint, which makes the tactical guideline of’large range, big hitting angle, high hitting accuracy’achieved effectively.In the midcourse guidance phase, optimal attack angle with maximal lift-drag ratio is obtained to add the guided bomb’s flight range. In the terminal guidance phase, two guidance laws with hitting angle constraint are designed. One is named as fuzzy variable structure guidance law. The time-varied sliding mode surface and exponential apporach law are designed, adjusting the speed of approaching sliding mode surface automaticly on the basis of the distance between the guided bomb and target. In order to reduce system’s chattering, fuzzy control is used to select the gain of the switching term adaptively. The other is non-singular terminal sliding mode(NTSM) guidance law.It is designed via the method of NTSM control, and the time of the guidance system state reaching the sliding mode surface is guaranteed to be finite without singularity. And more overload can be afforded by the NTSM guidance law compareing with the fuzzy variable structure guidance law, which provides opportunities for guided flying with quick maneuver.2. When the SINS/GPS guided bomb maneuvers in huge airspace, parameters uncertain and various random outside disturbances are existent. Taking these into account, autopilots are designed using model reference adaptive variable structure control method. Thus, both model reference adaptive control and variable structure control’s advantages are hold by the autopilots. On the one side, system state is pledged to approach sliding mode surface in conformity to the stated dynamic, which redounds to improve the system’s dynamic trait. On the other side, the variable structure control’s excellent robust is useful to resist system parameters disturbation and enhance control precision. In succession, the adaptive model reference variable structure autopilots are proved to be effectual by several classes of representative simulations.3. In order to obtain better integrative performance, integrated guidance and control system is designed using NTSM control. Firstly, integrated guidance and control state equations are established. Then uncertainties of guidance loop and control loop are taken into consideration adequately, the integrated guidance and control feedback law is designed based on NTSM method. By means of numerical simulations, it is compared with the conventional method of which guidance loop and control loop are designed separately. Simulation results indicate that integrated guidance and control system can not only keep hitting accuracy and terminal angular constraint well, but also can rectify control output dynamicly and make control signal smooth, which provides academic reference for even more complicated flight control conditions.4. The capability of variable structure guidance and control system is studied by the guided bomb’s release regions and hitting accuracy. Six degrees of freedom model to compute release regions is established, and the technique for calculating release regions is proposed based on optimized theory. By calculation and simulation, guided bomb’s release regions under various bombing conditions are obtained and factors affecting the boundary of release regions are also analyzed. And then, all kinds of guidance errors and none-guidance errors are analyzed roundly and relevant error models are established for the guided bomb maneuvering in huge airspace. Simulations of target practice with various errors are carried out using Monte Carlo method. Simulation results show that the tactical guideline demand of hitting accuracy is still satisfied primely, which proves favorable robustness of variable structure guidance and control system.5. Finally, validity and feasibility of variable structure guidance and control system of the guided bomb are testified in virtue of researching on hardware-in-loop simulations with three-axis turntable and vehicle tests of simulating bombing.All the research results are very valuable and important to the guided bomb’s overall design, aeroplane’taking test and bombing test etc.更多还原