Research On The Guidance System Of The Strap-down Laser Guided Bomb

The strap-down seeker removes the servo control system of the traditional seeker. With the advantages of low cost and high precision, the strap-down seeker is gradually used in various tactical weapons. The strap-down seeker can't directly give the guidance signal, which brings some problems for the design of the guidance system. In this paper, a certain type of strap-down laser guided bomb is studied. The decoupling, the influence of the seeker disturbance rejection rate and the application to the guidance law of the strap-down guidance law of the guidance system are studied. The main works are as follow:First of all, the dynamics equations and kinematics equations are established. Then the mathematical model of guided bomb was established by using small perturbation linearization method combined with missile aerodynamic data. The longitudinal plane guidance model is established, and the stability of the guidance system is analyzed.As the output signal of the strap-down laser seeker is coupled with the attitude angle information of the missile, the UKF filter is used to decouple the system. The results of the simulation show that the decoupling method can get the guidance signal and can be considered in most of the noise. At the same time, the relative distance and velocity information can be estimated.The seeker disturbance rejection rate which is generated by the input signal amplitude error or phase mismatch is analyzed, and the stability of the system is improved by the method of compensation.Finally, the stability and bandwidth of the guidance system with the proportional guidance law or strap-down guidance law are compared, the improvement of the strap-down guidance law is bright up to make the guidance bomb hit the target accurately. In this paper, we use the existing model to simulate the trajectory of the guided bomb, compare the guidance of the three guidance laws, and verify the stability requirements of the guidance system and the precision requirement of the guided bomb.