Study For Trajectory Optimization And Terminal Guidance Law Of Laser Guided Bomb

With the increasing high-tech of modern warfare and the further enhancement of modern military means,the attacking ability of offensive weapons has been continuously improved.In order to improve the defense capabilities of important military targets,various countries in the world have adopted a number of defensive measures such as deep burial reinforcement.The ability of damage resistance is significantly enhanced.In order to maximize the effectiveness of the penetrating warhead and achieve the best damage effect,the warhead not only hopes to get the minimum off-target when hitting the target,but also hopes to have the best posture when hitting the target.Therefore,the design of the guidance program for aviation-guided bombs must comprehensively consider the constraints of the end of the attack on the attitude and end velocity of the end-off body such as miss distance and angle of fall.In response to the above problems,this paper has carried on the thorough research in the following several aspects:Firstly,in the guided gliding section,the optimization method is reduced to a nonlinear optimal control problem with state constraints and control constraints.The gliding segment trajectory optimization problem is solved by combining the direct shooting method and the sequence quadratic programming algorithm.Moreover,considering that the optimization result is sensitive to the initial guess value,the genetic algorithm is used to iteratively solve the feasible solution,and the initial value of the optimal guess is obtained.Then,in order to meet the end angle constraint,the bias proportional guidance law is designed to improve the striking effect.In order to improve the tracking accuracy of the attack accuracy and the drop angle constraint,the particle swarm optimization algorithm is applied to optimize the additional guidance coefficients of the bias proportional guidance law.In order to avoid the increase of algorithm complexity caused by the introduction of intelligent optimization algorithm,a terminal guidance law based on finite-time high-order sliding mode algorithm is designed.The guidance law consists of two parts: a non-singular terminal sliding surface and a generalized super-twisting reaching law.The non-singular terminal sliding surface can drive states to converge to zero in a finite time when the sliding mode variable is equal to zero,while avoiding singular problems.The generalized super-helical approach law can achieve the finite-time convergence of sliding mode variables under the influence of matched disturbances.At the same time,due to the continuous control signal,it can effectively suppress the chattering problem in traditional sliding mode control.The parameter design of the finite-time high-order sliding mode terminal guidance law obtained is intuitive and simply,and is easy to debug and implement.Compared with traditional guidance law,the combat miss distance is smaller,and the accuracy of the drop angle error is higher.