Research On Three-dimensional Integrated Guidance And Control Design

The traditional guidance law design separates the guidance loop and the attitude control loop separately,and also decomposes the guidance problem in three-dimensional space into two planes for individual design.Therefore,most guidance laws are de-signed based on guidance loop in the pitch plane.The separate design of the guid-ance loop and the attitude control loop is based on the assumption that the control loop has fast response speed.Actually,there is a dynamic delay characteristic.The three-dimensional guidance problem is decomposed into two planes,which also ignores the coupling between each channel.Therefore,advances in modern science and technol-ogy have made it possible for target aircraft to make large-scale escape movements and have a high requirement for the guidance accuracy of interceptor missiles.The method of separate and independent design is increasingly unable to meet actual operational requirements.In this paper,missiles are used to intercept maneuvering targets in the air.In the three-dimensional space,integrated guidance and control design is studied.Integrated guidance and control model in three-dimensional space is deduced,and the three-dimensional integrated guidance and control law is designed.The main research works include:First,the missile's integrated guidance and control model in three-dimensional space is deduced.The missile and the target are regarded as particles,and a three-dimensional guidance loop model is derived from their relative motion in the three-dimensional space.Then the attitude control loop of the missile is modeled,and a six-degree-of-freedom nonlinear model is deduced.By coordinate transformation of veloc-ity vector,viewing the acceleration elements calculated by velocity as a connection,the integrated guidance and control model in three-dimensional space is formulated.The model can reflect not only the changes of various attitude angles during the flight pro-cess,but also the relative motion relationship between the missile and the target.It is the basis for the integrated guidance and control law design in the three-dimensional space.Then,the incomplete integrated guidance and control law in the three-dimensional space is proposed.By combining the guidance loop and the attitude control loop(au-topilot),which is considered as the second-order dynamic model,and is more realistic than the first-order dynamics,the guidance law and the finite time guidance law are presented.The input-to-state stability(ISS)theory and backstepping design method are used to design the three-dimensional guidance law considering the second-order dynamic characteristics of the autopilot.The finite-time ISS theory and backstepping design method are used to design the three-dimensional finite-time guidance law con-sidering the second-order dynamics characteristics of the autopilot.The application of tracking differentiator technology solves the "calculation explosion" problem in the backstepping design method and simplifies the design of the guidance law,which is easy to implement in engineering.Finally,the design of complete integrated guidance and control law in three-dimensional space is studied.Based on the integrated guidance and control model in three-dimensional space,the guidance law is designed directly using the small gain theorem and ISS the-ory.For the STT missiles,which maintain the roll angle of zero and use the attack angle and sideslip angle to generate guidance instructions,the three-dimensional inte-grated guidance and control law is proposed.For the BTT missiles,which maintain the sideslip angle of zero and use the attack angle and roll angle to generate guidance in-structions,the three-dimensional integrated guidance and control law is proposed.The designed guidance laws can accurately intercept the maneuvering target with no infor-mation of the target.Theoretical analysis and numerical simulation verify the validity of the proposed guidance laws.