Design Of General Scheme And Attitude Control System For Spinning Guided Rockets

Conventional rockets have the characteristics of low speed, poor maneuverability, low hit precision, which is difficult to meet the needs of modern warfare. With development of the precision guidance technology, this technology can be used to improve the precision strike capability of rockets. In this paper, the rockets can have ability of guidance based on some modified rockets by introducing the flight control systems and actuator, with the condition of no change of the diameter of the original rockets. Overall design scheme of new type of rockets is given. The analysis of coupling problem between pitch and yaw channel is made, and the design of its decoupling and attitude control system for modified rockets are studied deeply.The overall design of spinning rockets is given based on tactical and technical requirements. Only a pair of rudder actuator is allowed to use because of the limitations of the size of body. In order to achieve the function of a canard controlling two channels, the modified rockets flight by spinning, that is, the control of pitch and yaw channel can be realized with the spin of body. As for the overall design scheme, the designs of flight trajectory, configuration and structure are made, and the key technical parameters are determined.Due to the spin of rockets, its dynamic characteristics are significantly different from other aircraft. For this purpose, the generation mechanism of the periodic operating force and the steering torque is analyzed, and the concept of equivalent rudder angle is adopted to establish the homogeneous state kinetic model for spinning rockets. The spinning of rockets can effectively reduce the influence of the disturbance factors such as the aerodynamic asymmetry, the thrust eccentricity, and so on, and the dispersion of no flight controlling section, and keep the stability of the rockets body, improve the hit precision. At the same time, the spin will also lead to the problems, such as aerodynamic coupling, inertial coupling and control coupling. The coupling mechanism of dynamic system and steering system is discussed, and multivariate frequency domain theory is used to analyze the relationship between coupling and the spin speed. In order to design the attitude control system for the spinning rockets, the dynamic system and the steering system are decoupled by the feed forward compensation method.In the first place, the PID control method is used to design the attitude control system. Then, the model reference adaptive control (MRAC) method is adopted to design adaptive control system with taking into consideration the influence of parameter perturbation and external disturbance and taking into account the calculation of the control algorithm and the efficiency of the implementation. The simulation results show that MRAC can effectively suppress the influence of parameter perturbation and external disturbance on the system, and satisfy requirements of flight control design for spinning rockets.