Dynamics Modeling And Control Research Of Missiles With Deflectable Nose

With the growing complexity of modern war environment,missile control technology and tactical guide line commands a higher level. Missile with deflectable nose is a kind of new missile with fast response control technology,distinguished from rudder control,which has the advantages of high maneuverability, short response time and good performance of aerodynamic characteristic. In this paper, a model of missile with deflectable nose is established and the control methods of it are investigated as follow.The influence of nose to body of missile is not constrained in aerodynamic aspect; the dynamic model of missile is changed afterwards. So we set the dynamic model of missile nose firstly in order to investigate control technology of missile with deflectable nose.According to the delectable character of the nose,a moment of momentum theorem method is used to formulate the model of the missile with deflectable nose. In this method,we remain the coupling components and linearize the model. After linearization, the equation of motion is obtained with easy access of control system design and system analysis.For missile with deflectable nose, deflectable mechanism is the core of control system.In this paper,two kinds of mechanisms and control strategies missile with deflectable nose are compared and researched. The control schemes of two kinds are then formulated respectively and the simple rational control methods are established. Simulation results show that both of proposed two kinds of mechanism can satisfy the command of system and rolling-sloping plat scheme can response the desired target more precisely and faster.In order to design control system of missile with deflectable nose, the influence of nose deflecting to body’s motion is analyzed. Based on the control scheme, the standalone design method is adopted, which is regarding coupling as the disturbance of each single channel.Based on classical control theory, the double-loop structure is used to design the controller and the inner loop is determined before the outer loop. In the processes of design, frequency domain methods are used to assure the stability of system. And then the simulation results of characteristic point show that the designed controller is rational. Based on Finite time stability theory (FTST) and high order sliding mode control theory, the overload tracking error equation is induced and the control law is designed to make sure finite time stable of the overload system. Stimulation results shows that the designed control law can decline the coupling between pitch channel, yaw channel and roll channel effectively, and inhibiting the missile aerodynamic parameter perturbation preferably, and have higher steady state precision and better dynamic performance.In the end,the guidance system of missile with deflectable nose and guidance law is investigated. A stable platform controller for guidance system of missile with deflectable nose is designed and the proposed controller is validated then. The relative motion model of missile and target is formulated and the optimal control law is designed based upon this. Then the stimulation results are compared with classical control theory to validate that the designed optimal control law has superior performance.