Design and Simulation of TF and TA Controller for Missile

A nonlinear terrain following(TF) and terrain avoidance(TA) controller is proposed for missile control systems. Based on classical TF algorithm (adaptive angle method), a new method for TF controller is proposed by using angle of attack. A method of obtaining terrain outline data from digital elevation map (DEM) for TF control is discussed in order to save store space. A TA algorithm is proposed by using bank-to-turn technique. The block control model, which is suitable for backstepping design, is given for nonlinear model of missile. Making full use of the characteristics of the system and combining block control principle and backstepping technique, a robust controller design method is proposed. Uncertainties in every sub-block are allowed, and can be canceled by using the idea of nonlinear damping. It is proved that the state tracking errors are converged to a neighborhood of the origin exponentially. Finally, nonlinear six-degree-of-freedom simulation results for the missile model are presented to demonstrate the effectiveness of the proposed control law.     

Guidance Law Design Under Impact Angle Constraint Based on Nussbaum-type Gain Technique

Aiming at the guidance problem under impact angle constraint for homing missile against ground targets,a new adaptive robust nonlinear terminal guidance law was proposed in this paper.According to nonlinear kinetic relationship between the missile and target in vertical plane,a mathematic model was formulated while the motion of target and the system structure perturbation were regarded as limited disturbances.Based on the ideas of zeroing the rate of line-of-sight(LOS)angle and the impact angular tracking error,a nonlinear control strategy was contrived to obtain adaptive robust guidance law by adopting Nussbaum-type gain technique under a desired impact angle.The stability of guidance system in finite time is strictly proven by using Lyapunov stability theory.Finally,the numerical simulation verifies the effectiveness of the proposed scheme.     

Indirect robust control of agile missile via Theta-D technique

An agile missile with tail fins and pulse thrusters has continuous and discontinuous control inputs. This brings certain difficulty to the autopilot design and stability analysis. Indirect robust control via Theta-D technique is employed to handle this problem. An acceleration tracking system is formulated based on the nonlinear dynamics of agile missile. Considering the dynamics of actuators, there is an error between actual input and computed input. A robust control problem is formed by treating the error as input uncertainty. The robust control is equivalent to a nonlinear quadratic optimal control of the nominal system with a modified performance index including uncertainty bound. Theta-D technique is applied to solve the nonlinear optimal control problem to obtain the final control law. Numerical results show the effectiveness and robustness of the proposed strategy. Copyright . 2014, China Ordnance Society. Production and hosting by Elsevier B.V. All rights reserved.     

Research on Airborne Electro-Optical Tracking and Sighting System Based on Fuzzy PID and H∞ Control

Airborne electro-optical tracking and sighting system is a three-degree-of-freedom angular position servo system which is influenced by multi-disturbance, and its control system consists of stabilizing and tracking components. Stabilizing control is applied to track angular velocity order and control multi-disturbance under airborne condition, and its robustness should be very good; tracking control is applied to compensate tracking error of angular position. A mathematical model is established by taking the control of yaw loop as example. H∞ stabilizing controller is designed by taking the advantage of H∞ control robustness and combining with Kalman filter. A fuzzy control is introduced in general PID control to design a decoupled fuzzy Smith estimating PID controller for tracking control. Simulation research shows that the control effect of airborne electro-optical tracking and sighting system based on fuzzy PID and H∞ control is good, especially when the model parameters change and the multi-disturbance exists, the system capability has little fall, but this system still can effectively track a target.     

Robust Graded Sliding Mode Tracking Control for Low Speed Spinning Ballistic Missiles

The nonlinear dynamic model of spinning ballistic missiles is established during the first boosting phase of the missile. Based on the conventional backstepping sliding mode control and the assumption of a two time-scale separation of missile dynamics, a graded sliding mode controller is designed with two sub-sliding surfaces which have invariability to external disturbances and parameter perturbations, and a matrix which comprises three first order low pass filters is introduced to prevent ＂explosion of terms＂. Owing to the upper bounds of the uncertainties are difficult to obtain in advance, adaptive laws are introduced to estimate the values of the uncertainties in real-time. Eventually, the numerical simulation results given to show the proposed controller can ensure the steady flight of missiles.     

Application of Adaptive Backstepping Sliding Mode Control in Alternative Current Servo System of Rocket Launcher

An adaptive backstepping sliding mode control approach is introduced to control the pitch motion of a rocket launcher. Its control law is proposed to guarantee that the control system is ultimately bounded in a Lyapunov sense and make the servo system track the instruction of reference position globally and asymptotically. In addition, the sliding mode control can restrain the effects of parameter uncertainties and external disturbance. The functions of adaptive mechanism and sliding mode control are analyzed through the simulation in the different conditions.The simulation results illustrate that the method is applicable and robust.     

Customization Product Design Based on User‘s Emotion and Needs

The paper presents a design method that ensures the ingenuity of the product form as well as the whole and exact expression of user‘s needs. The key idea is to establish an automatic design system which can transform the users language needs into the product features in real-time. A rifle was taken as a research instance and soldiers were chosen as evaluation customers. The theory of fuzzy set and semantic difference are adopted to evaluate the relationship between user‘s needs and product features as well as their alternatives. FAHP (fuzzy analytic hierarchy process) is utilized to judge the users satisfactory forms. This method can also be applied to other product form designs.     

Using Fractional-order PI^λD^μ Controller for Control of Aerodynamic Missile

A new type of PID controller is introduced and .some properties are given. The novelty of the proposed controller consists in the extension of derivation and integration order from integer to non-integer order. The PI^λD^μ controller generally has three advantages when compared to the integerl-order controller： the first is that it has more degrees of freedom in the model; the second is that it has a memory in model, the memory insure the history and its impact to present and future, the third is it ensures the stability of missile. This approach provides a more flexible tuning strategy and therefore an easier achieving of control requirements. Flight dynamic model of an aerodynamic missile is taken into account in implementing the PI^λD^μ controller. Simulation results show that the PI^λD^μ controller is not sensitive to the changes of control parameters and the system parameters. Also, the controller has more flexible structure and stronger robustness.     

Using Fractional-order Piλ Dμ Controller for Control of Aerodynamic Missile

A new type of PID controller is introduced and some properties are given. The novelty of the proposed controller consists in the extension of derivation and integration order from integer to non-integer order. The PIλDμ controller generally has three advantages when compared to the integerl-order controller: the first is that it has more degrees of freedom in the model; the second is that it has a memory in model, the memory insure the history and its impact to present and future, the third is it ensures the stability of missile. This approach provides a more flexible tuning strategy and therefore an easier achieving of control requirements. Flight dynamic model of an aerodynamic missile is taken into account in implementing the PIλDμ controller. Simulation results show that the PIλDμ controller is not sensitive to the changes of control parameters and the system parameters. Also, the controller has more flexible structure and stronger robustness.     

Vibration Control of High-speed Cannonball Transport Mechanism Driven by Impact

A method is presented to control the vibration of high-speed cannonball transport mechanism due to the reduction of its weight, which adhere a nonlinear Zn-27Al-1Cu damping alloy layer and a constraint layer partly to the part of mechanism driven by impact. Based on the equivalent viscous damping theory and using curve fitting to describe the rule of the dissipation factor of damping alloy changing with stress, the nonlinear constitutive relation of Zn-27Al-1Cu damping alloy is given. The nonlinear spring damping contact model is adopted to describe the contact force of the clearance joint.Based on the nonlinear finite element contact theory, the outer impact contact force between the mechanism and its working environment is analyzed, and a coupled dynamic model of structural impact and mechanism motion with clearance joint is put forward. A dynamic model is established for the cannonball transport mechanism partly adhering Zn-27Al-lCu damping alloy layer and constraint layer under complex impact conditions. At last, the feasibility of the method presented is proved by numerical simulation.     

一种基于自适应模糊系统的导弹自动驾驶仪设计方法

针对导弹非线性不确定系统,提出了基于动态逆方法及模糊自适应理论的导弹自动驾驶仪设计方法.基于导弹的非线性模型设计了快、较慢回路的动态逆控制器以实现其非线性解耦,将系统不确定性和外界干扰引入到较慢回路中.根据系统跟踪误差在线调整模糊系统权值,使其一致逼近导弹较慢回路的非线性函数.设计了在模糊系统的最小逼近误差上界未知情况...     

基于神经网络动态逆的巡逻导弹自动驾驶仪设计

针对巡逻导弹,讨论一种将神经网络与非线性动态逆相结合的自动驾驶仪设计方法。基于双时标假设,将弹体动力学分为慢变子系统和快变子系统,并分别进行动态逆设计。为克服模型不精确和参数摄动引起的逆误差对动态逆控制的不利影响,引入神经网络对逆误差进行在线补偿。推导了神经网络权值调整规律,并证明系统的闭环稳定性。通过仿真验证,采用神经网络能弥补动态逆控制的不足,提高控制系统的鲁棒性,是一种有效的非线性设计方法。     

基于动态逆理论的自旋弹控制方法

针对自旋弹存在的非线性耦合特性,研究了以时标分离方法进行分段设计的动态逆理论解决途径.根据系统的变量快慢区分子系统,采取层叠结构设计控制器对分系统进行单独设计,并考虑实际应用中存在的具体实现问题,得到了过载驾驶仪控制器的基本结构.引入实际系统延迟及噪声等因素由dSpace与三轴转台进行了验证性试验,得出了具有工程应用价值的控制器设计方法.     

基于L1动态逆的自主空中加油对接控制

为实现无人受油机与加油机的自主安全对接,提出基于L1自适应动态逆的无人机自主空中加油对接跟踪控制方法.根据时标分离的原则,将无人受油机的姿态控制分为快、慢回路,采用动态逆方法设计姿态回路控制器,设计L1自适应系统补偿外界气流干扰和系统模型误差,并采用自主空中加油对接段仿真系统对所设计控制系统进行验证.仿真结果表明:该对接跟踪控制系统具有很高的抗干扰能力和鲁棒性,能满足自主空中加油的控制精度要求.     

带矢量推力无人机动态逆控制律设计

介绍了带矢量推力无人机的相关知识，并将非线性动态逆理论应用到带矢量推力无人机的飞行控制中，通过对带矢量推力无人机数学模型的分析简化，进行了无人机角速度、姿态角、线速度三个回路的控制律设计，并进行了仿真试验，通过对试验结果的分析，验证了非线性动态逆控制法的正确性和有效性。     

一种改进的微型飞行器非线性动态逆解耦控制研究

针对微型飞行器在低雷诺数条件下具有明显的非线性、非定常及强耦合的特性,研究了一种改进的非线性动态逆与比例积分相结合的MAV非线性解耦控制方法。首先,应用奇异摄动理论对MAV进行时标分离,研究快、慢状态子系统的控制器设计;其次,将比例积分环节引入控制器中,以消除非线性对消误差带来的影响;最后,对系统进行了仿真验证,仿真结果表明非线性动态逆与比例积分结合的方法能够有效实现MAV的解耦控制,具有实用价值。     

基于预测控制和动态逆算法的翼伞飞行控制

针对传统无人机动态逆控制算法并不能完全适用于翼伞飞行控制的问题,提出了结合预测控制与动态逆的组合飞行控制算法,该算法选取偏航角及其变化速率作为控制回路,使其满足非线性动态逆的设计条件,根据内环线性反馈得到的线性模型作为预测控制模型,设计了组合飞行控制策略。仿真结果表明:组合控制算法相比非线性动态逆算法,对给定航向的跟踪具有较好的效果,验证了算法的有效性。     

基于动态逆的复合控制导弹H∞最优输出跟踪控制

针对姿控式直接力/气动力复合控制导弹,提出一种基于动态逆的H_∞最优输出跟踪控制方法。该方法考虑了复合控制导弹的非线性因素,将动态逆回路作为控制系统的内环以抵消系统的非线性因素,同时考虑系统实际存在的参数不确定性以及外部干扰,将鲁棒控制器作为外环以提高整个系统的鲁棒性。其中鲁棒控制器将传统的H_∞控制与最优输出跟踪控制相结合,既能有效地抑制干扰,降低系统对参数摄动的敏感程度,又能提高系统的跟踪性能。仿真结果表明,复合控制系统具有较强的抗干扰能力,在保证系统稳定的同时,也达到满意的控制效果。针对姿控式直接力/气动力复合控制导弹,提出一种基于动态逆的H_∞最优输出跟踪控制方法。该方法考虑了复合控制导弹的非线性因素,将动态逆回路作为控制系统的内环以抵消系统的非线性因素,同时考虑系统实际存在的参数不确定性以及外部干扰,将鲁棒控制器作为外环以提高整个系统的鲁棒性。其中鲁棒控制器将传统的H_∞控制与最优输出跟踪控制相结合,既能有效地抑制干扰,降低系统对参数摄动的敏感程度,又能提高系统的跟踪性能。仿真结果表明,复合控制系统具有较强的抗干扰能力,在保证系统稳定的同时,也达到满意的控制效果。     

基于加速度测量的高超声速飞行器抗干扰控制

针对吸气式高超声速飞行器气动特性复杂且不确定性强的特点,提出了一种基于加速度测量信号,包括内、外双回路设计的反步抗干扰控制方案。外回路在反步法中引入传感器所测加速度信号,并设计非线性干扰观测器对复合干扰进行观测与补偿;内回路设计采用基于奇异摄动理论的动态逆方法,利用Lyapunov理论证明了系统的一致最终有界。该控制方案均基于传感器可以直接测得的信号构成控制,对气动参数不确定鲁棒性强,且通过干扰观测进一步提高系统抗干扰能力。仿真结果表明,反步抗干扰控制方案在强不确定性与外部干扰条件下,可获得理想的控制效果。     

基于反步法和非线性动态逆的无人机三维航路跟踪制导控制

为实现无人机在大范围内稳定、精确地跟踪三维参考航路,基于制导与控制回路独立设计的思路,提出了一种无人机三维航路跟踪制导控制方法。在制导外环,引入沿参考航路飞行的虚拟无人机作为向导并利用反步法设计三维航路跟踪的非线性制导律;在控制内环,以非线性动态逆理论和奇异摄动理论为基础,设计由机动指令生成器、角度转换器、慢回路姿态控制器和快回路角速度控制器所组成的飞行控制模块,对制导外环给出的制导指令进行快速精确地跟踪。基于Lyapunov稳定性理论证明了无人机航路跟踪制导控制方法的稳定性。通过对比分析无人机6自由度模型下的三维航路跟踪仿真,说明所提出的制导控制方法能够使得无人机精确地跟踪参考航路,从而验证了该方法的有效性、合理性。