Research On Decoupling And Control Stability Of Two-Channels Spinning Missiles

With its rotating coupling characteristics as the breakthrough point,this paper mainly analyzes its influence on the dynamic stability of the two-channels control spinning missiles,draw the corresponding conclusion,and put forward the control strategy.Generally speaking,this paper has certain guiding significance to the control system design and increase the stability of spinning missiles.Firstly,the development situation of a class of spinning projectiles,such as guided rockets and antiaircraft missiles,is investigated by this paper.Based on this,the design methods of control system for spinning projectiles are summarized,and theoretical results of decoupling and stability analysis are also concluded.The mathematical model of the integration of pitch and yaw channels of spinning missiles is established in the second chapter of this paper,and based on the assumption of small disturbance and the coefficient freezing theory,the mathematical model of spinning missiles was linearized.Besides,a linear state space mathematical model expression is obtained,and the transfer function matrix of rudder outputs to the projectile outputs is also deduced.Secondly,the control block diagram of the control system is established,and the coupling effect caused by the spinning motion of projectile is discussed in detail.In the third paper,the control principle block diagram of two-channels autopilot of spinning missiles in the non-spinning coordinate is deduced,and the transfer function matrix of spinning missiles actuator output to the output of projectile is also obtained.According to the mathematical expression,the Inertial coupling effect and Magnus effect in the non-spinning coordinate are analyzed.What’s else,the coupling effect of rudder control of spinning missiles is decoupling analyzed,and the rudder control decoupling strategy is proposed,which adopts the phase advance compensation and the gain compensation of the rudder.Then in view of the coupling effects between two channels of spinning projectile,a decoupling control strategy based on feedforward compensation is proposed.The feedforward decoupling matrix of autopilot is derived,and the effectiveness of the strategy is verified by mathematical simulations.In the fourth chapter,the pole placement algorithm of the two-loop and three-loop acceleration autopilot is mainly given.The autopilot design of spinning projectile is completed under the neglect of channels coupling.On this basis,considering the coupling between channels,the relationship between the design parameters of the autopilot and the stability of the autopilot under the initial disturbance is analyzed.The results show that ensuring the forward channel gain of autopilot is less than the critical value,and improving damping gain coefficient appropriately,it can ensure the stability of rotating motion of projectile under the initial disturbance.The fifth chapter takes the strapdown homing spinning missile as the research object,and considering the influence of parasitical loop of seeker,the guidance loop model consists of seeker isolation parasitic loop is built.The state space equation of two-channels spinning projectiles was built by using the method of complex coefficient,and the necessary and sufficient condition for the system to maintain the stability is maintained by the Routh-Hurwitz criteria.A large number of mathematical simulations show that the lower the spinning rate of body,the more conducive to maintaining the system stability.Besides,the application of decoupling control strategy and ensuring that the autopilot design indexes is located in the stable domain is beneficial to weaken the influence of the seeker isolation degree on the dynamic stability of spinning projectile,so as to enhance the terminal guidance accuracy of missile body.