Control Strategies for Flight Stability of Trajectory Correction Projectile with Air-Ducts Structure

Aiming at the controllability of spin-stabilized projectile trajectory correction, a new two-dimensional trajectory correction projectile model with a controllable air-ducts structure suitable for the spin-stabilized projectile is proposed in this paper. Furthermore, control strategies of the projectile in the corrected configuration are studied to ensure a stable flight. The correction scheme of the projectile is innovated on the basis of the ram air control mechanism. The air-ducts structure is designed inside the projectile body, and the internal air valve is used to control the lateral air-jet to achieve trajectory correction of the projectile. This is a new two-dimensional trajectory correction scheme with a relatively simple control method. Firstly, the correction mechanism of the new air-ducts structure projectile is analyzed. Secondly, based on the dynamic equation of the projectile, the key parameters of the impulse air valve control, including the safe range of the working pulse width and frequency, are calculated, and the corresponding control strategies are proposed. Finally, the flow field of the projectile in the corrected configuration of the terminal trajectory is numerically simulated, and aerodynamic parameters of the projectile are obtained. Through stability conditions established in this paper and combined with aerodynamic parameters, the validity of the proposed projectile stable flight control strategies is confirmed. The innovations of this paper include: (1) a proposed new aerodynamic configuration model with the air-ducts structure for the spin-stabilized projectile and (2) proposed innovative stable flight control strategies of the corrected configuration projectile. The numerical simulation results show that, compared with the reference projectile without air-ducts structure, the lateral force of the air-ducts structure projectile can produce a radial correction effect on the moving projectile. The simulation results of control strategies indicate that the control strategies can ensure stable flight of the corrected configuration projectile under different conditions.