Impact Point Prediction and Lateral Correction Analysis of Two-dimensional Trajectory Correction Projectiles

Compared with the one-dimensional trajectory correction technology which adjusts longitudinal range, not only does the two-dimensional trajectory correction technology adjust the force in velocity direction, but also need to modulate the lateral force or trajectory (perpendicular to the vertical plane of fire direction). Therefore, the structure of control cabin of two-dimensional trajectory correction projectile (TDTCP) is more complicated than that of one-dimensional trajectory correction projectile (ODTCP). To simplify the structure of control cabin of TDTCP and reduce the cost, a scheme of adding a damping disk to the control cabin of ODTCP has been developed recently. The damping disk is unfolded at the right moment during its flight to change the ballistic drift of spin stabilized projectile. For this technical scheme of TDTCP, a fast and accurate impact point prediction method based on extended Kalman filter is presented. An approximate formula for predicting the ballistic drift and trajectory correction quantity is deduced. And the lateral correction capability for different fire angles and its influencing factors are analyzed. All the work is valuable for further research.

Research on SINS Error Recursive Model of Ballistic Missile

The strap-down inertial navigation system (SINS) error of ballistic missile is generated by the mutual influence of gyroscope and accelerometer, and the recursive model is completely different from that of gimbaled INS. In the paper, a discrete error recursive model was obtained by studying the applied SINS error model of ballistic missile, and the discrete Kalman filtering simulation based on the model was carried out. The simulated results show that the model can depict the SINS error exactly and provide the advantages for research on integrated guidance and improved hit accuracy.

H_∞-Mixed Sensitivity Design of Roll Channel of Bank-to-Turn Autopilot for Small Diameter Bomb

According to requirements of the bank-to-turn (BTT) control for a small diameter bomb (SDB), the robust design problem for the roll autopilot was studied by H∞-mixed sensitivity control method. A roll channel dynamics model was established. Considering the couple between the yaw and roll channel as uncertain disturbance, the roll autopilot was designed using dual-loop scheme which takes a linear quadratic regulator (LQR) as inner-loop, to ensure the control effect of the certain part in model, and an H∞-mixed sensitivity control as outer-loop, to restrain coupling disturbance and strengthen the system's robust performance. The dynamic tracking performance and the robustness for the parameter disturbance of the roll controller were analyzed. The simulated results show that the roll control system functions better and robustly.

Guidance Law Design Under Impact Angle Constraint Based on Nussbaum-type Gain Technique

Aiming at the guidance problem under impact angle constraint for homing missile against ground targets,a new adaptive robust nonlinear terminal guidance law was proposed in this paper.According to nonlinear kinetic relationship between the missile and target in vertical plane,a mathematic model was formulated while the motion of target and the system structure perturbation were regarded as limited disturbances.Based on the ideas of zeroing the rate of line-of-sight(LOS)angle and the impact angular tracking error,a nonlinear control strategy was contrived to obtain adaptive robust guidance law by adopting Nussbaum-type gain technique under a desired impact angle.The stability of guidance system in finite time is strictly proven by using Lyapunov stability theory.Finally,the numerical simulation verifies the effectiveness of the proposed scheme.