Research On Optimal Control Trajectory Technology Of Command Guided Rocket

With high precision,strong power,long range,low cost and many other advantages,the guided rocket has attracted more and more attention around the world.In this paper,the canard controlled stabilized rocket with a rotating tail is studied,and some theoretical and technical problems for measuring roll attitude angle and optimizing flight trajectory during flight are discussed.The main contents include:Considering the design requirements of high precision,anti-jamming and low cost of the guided rocket,the technology and scheme for command correction of missile attitude based on radio measurement combining with geomagnetic compass and canard wings is proposed.The attitude measurement and the trajectory optimization of the command-guided rocket are mainly discussed.According to the aerodynamic and trajectory characteristics of the canard configuration guided rocket,the flight dynamics model with six degrees of freedom,the attitude control system model of the spinning rocket,the controllable particle motion equation of the rocket are established.The corresponding numerical simulation analysis software are developed.To ensure the overall accuracy of geomagnetic compass in measuring the roll angle,the main error factors in the measurement are analyzed by detailed simulation.The roll angle measurement error caused by the scatter of firing data and the motor inconsistency under the uncontrolled trajectory,and the control force addition in the programmable trajectory under the independent magnetic compass,are separately considered and studied.In addition,the precision range of the geomagnetic compass for measuring the roll angle of the missile under the closed-loop control mode of radio + geomagnetic compass is analyzed,which proves the superiority and feasibility of the geomagnetic compass in measuring the roll angle of the command-guided rocket.A linear magnetic measurement model for measuring sensor error,PCB manufacturing deviation,structural installation deviation,and soft and hard magnetic interference of themissile body is established.A two-step fast reconfigurable unscented Kalman filter algorithm based on ellipse fitting and UKF is proposed for the correction of missile strapdown geomagnetic compass.By this algorithm,the real-time processing of geomagnetic digital signal can be realized,in which the roll attitude angle and angular velocity can be extracted for controlling the steering engine.The numerical simulation results show that the algorithm can accurately identify the correction parameters of the geomagnetic compass in 100 ms at sampling frequency of 0.5 ksps.Moreover,the hardware-in-the-loop simulation is performed,and the results indicate that the roll attitude angle of the missile can be stably output in 150 ms with the calculation accuracy of ?0.8?.Based on the controllable particle motion model of the guided rocket,a variational model for the midcourse trajectory optimization of the guided rockets with minimum energy consumption for objective function is established.This model is restricted by the starting trajectory data,terminal trajectory data,and the steering range of the midcourse guidance.Combining the direct parametric method and sequential quadratic programming algorithm,the optimal trajectory scheme of guided rocket in midcourse guidence is obtained.The simulation calculation and comparative analysis are presented to get the trajectory characteristics of the guided rocket under typical control.The flight mathematical model of rocket existing strong nonlinearity,coupling and multiple constraints,which makes it difficult to select the initial value of direct trajectory optimization algorithm and slow the solve process.The planning and design of the optimal flight control trajectory of midcourse guidance requires real-time completion in a measurement and control rhythm on the flight trajectory.To solve the optimal planning trajectory,the calculation method of finite trajectory arc for planning trajectory variation is proposed.In this method,the finite trajectory arc function is used to replace the integral formula in the variational method,which greatly reduces the time complexity of the algorithm.The simulation results show that the algorithm can realize real-time calculation of planning trajectory with typical trajectory computers.