Research On Ballistic Planning And Guidance Methods For Guided Projectiles

The number of precision-guided weapons used in warfare has gradually increased in recent years,reflecting the importance of accurately guiding weapons in modern warfare.This also indicates that the direction of future weapons development is the development of precision-guided weapons.Glider-advanced projectile-guided artillery projectiles have the characteristics of great power,long range,high precision,and low cost,and therefore have extremely high research value and operational application value.In this paper,based on the gliding extended range trajectory planning and implementation of guided projectiles,the Gauss pseudo-spectral method(GPM)is used to design the gliding extended range trajectory.The tracking control law with disturbance is used to track the trajectory of the project,and the study the guidance law with the dynamic characteristics of the autopilot.Complete the design and implementation of a gliding extended range trajectory for launching a guided projectile from the launch to a precision strike target.The main research contents of this article are as follows:First,explain the background of the project and the purpose and significance of the study.The domestic and international research overviews of guided projectiles,as well as domestic studies on ballistic planning,trajectory tracking control,and guidance laws with angle-constraint guidance,etc.,are briefly analyzed.In order to facilitate the design and numerical simulation of the following controllers,the definition of the guided projectile coordinate system and the transformation relationship between them are introduced first.To study the overall ballistic problem of guided projectiles,it is necessary to establish an accurate three-dimensional centroid mathematical model based on the characteristics of the guided projectile itself and the specific flight phases.Then introduced the guidance model and related calculations.According to the reference data,interpolation is performed to obtain specific aerodynamic parameters according to different inputs.Finally,the basic principles of the sliding mode control are briefly introduced.Second,based on the three-dimensional plane guided projectile ballistic trajectory model,combined with the objective function of the constraint condition and the maximization of the range,an extended range trajectory planning model was established.The basic principle and characteristics of the Gauss pseudo-spectral method are introduced.Then how GPM transforms the continuous dynamic optimization problem into a discrete optimization problem is described.An optimization algorithm combining the GPM and the sequential quadratic programming method is used to solve the trajectory of the guided range projectile.In the simulation,different launch speeds and different launch angles are used as the initial conditions,and the maximum range is used as the performance index function to give simulation results for different situations.Finally,a set of optimization trajectories with the longest range is selected as the trajectory for follow-up.Again,the Gaussian pseudo-spectral method is used to obtain the three-dimensional optimization trajectory with the largest longitudinal plane range.The corresponding robustness tracking guidance law will be designed to track the three-dimensional optimization trajectory obtained before.The centroid control system for guided projectiles with six states is simplified as two subsystems,longitudinal and lateral,using a feedback linearization control to simplify the control system to write the form of a general nonlinear second-order system.And give the conversion between direct control and virtual control.Then for the simplified system,the sliding surface is designed and a tracking controller is designed to track the trajectory for the situation where the disturbance upper bound is known.Due to the fact that the disturbance upper bound is difficult to obtain in the actual process,an adaptive tracking controller is designed for the case where the disturbance upper bound is unknown.Both of the above methods are required to give proof of stability,and the effectiveness of the controller is further proved by digital simulation.The performance of the designed controller is briefly analyzed based on the simulation results.Finally,a three-dimensional guidance model considering the dynamic delay of a first-order autopilot is first established for the terminal guidance phase.Aiming at the situation that the target is bounded and unknown,a three-dimensional integral sliding mode guidance law based on self-adaptive,with angle constraint and dynamic delay characteristics is designed.The stability of the system is proved by Lyapunov stability theory.In order to further verify the effectiveness of the designed controller,the digital simulation was given according to the actual initial conditions,and the simulation results were briefly analyzed.Finally,the previously designed methods were integrated together to perform an overall ballistic implementation of the artillery shell ascent section,the extended range gliding trajectory section and the terminal guidance section.