Research On Space Three-body Confrontation Guidance And Game Problem

Three-body confrontation is a new problem in the traditional pursuit-evasion game,which has been paid more and more attention in the military and civil fields.Nowadays,the high velocity of homing missiles(Attacker)poses a great threat to safety of critical targets,which cannot be guaranteed by traditional methods.In this case,the active defense measures of launching Defender(missiles or other inducible targets)can be used to intercept and counter.Therefore,effective defense guidance strategy and pursuit strategy become the concern.When designing the defense guidance strategy,to intercept the Attacker as much as possible,it is necessary to consider the disadvantageous situation of the Target-Defender team,that is,the performance of the Attacker is better than that of the Target and the Defender and the guidance information of the Attacker is unavailable.For the convenience of analysis,the existing related works usually assume that the performance of the Defender is comparable to that of the Attacker,or assume that the state information of the three-body confrontation is completely known.The performance of the individual and the availability of the guidance information will affect the result of the three-body confrontation.To solve the problem that the Attacker’s performance is better than that of the Target and the Defender and the Attacker’s guidance information is unknown,the active defense guidance design in two-dimensional plane and three-dimensional space are respectively considered in this dissertation,and related works are carried out.The main results are summarized as follows:First,consider the three-body confrontation scenario where the Target-Defender confronts a more maneuverable Attacker in a plane.Based on the concept of threepoint guidance,the model of line-of-sight(LOS)angle error and LOS angular velocity error is established by taking the lateral acceleration of the Target and the Defender as the control input.The assumption that the Attacker’s guidance information(lateral acceleration)is known is relaxed,and the Attacker’s lateral acceleration is only required to be upper bounded.The Attacker’s lateral acceleration is treated as the unknown disturbance of the system.Combined with the input-to-state(ISS)stability,a two-degreeof-freedom cooperative LOS guidance law is proposed for the Target and Defender,so that the instantaneous lateral acceleration can be minimized by static optimization.In addition,the optimal evasion strategy of the Target is designed based on the optimal control method.To avoid solving the nonlinear two-point boundary value problem,the case that the Attacker adopts pure pursuit guidance is analyzed and designed.Second,the three-body confrontation problem is considered in three dimensional space.To eliminate the system deviation that arises from the linearization of the model,the Attacker unavailable lateral acceleration as the disturbance of the system,and establishes the Target and the Defender of lateral acceleration for the input of the second order nonlinear system model to describe the Target-Defender-Attacker relative motion in three dimensions.Combined with the ISS stability,a three-body confrontation 3-D cooperative LOS guidance law is designed,which makes the LOS angle error and angular velocity error stable for the Attacker’s maneuvering.Furthermore,a high-gain observer is designed to estimate the LOS angular velocity,and the stability of the closed-loop system,namely the effectiveness of the designed guidance law,is proved by theoretical analysis combined with the above 3-D cooperative LOS guidance law.Then,the three-body confrontation problem is described as a multi-agent differential game.Aiming at the coplanar situation,a simplified three-body confrontation model is established by taking the LOS distance the angle between the LOS of the Attacker-Target and the LOS of the Attacker-Defender as the system state.On the basis of transforming the three-body game into the LOS included angle game,considering the special case,combined with the terminal surface obtained by the existing work,the dissertation analyzes the distance ratio between the LOS of the Attacker-Target and the LOS of the Attacker-Defender,and obtains a LOS distance ratio game.Combined with Apollonius circles,the terminal surfaces are constructed in two subgames,and the optimal strategies of three players on terminal surfaces are derived.Compared with the existing works,the results obtained are analyzed from the aspect of LOS distance ratio,which fills the deficiency of the results obtained from the LOS included angle game.Finally,the quadrotor UAV is taken as the control object and the participant in the three-body confrontation,and the speed and attitude tracking controller is designed for it.Then,a three-body confrontation experiment platform with three UAVs as the main body is built.After the reliability is verified by simulation,outdoor experiments are conducted to verify the designed optimal guidance strategy of three-body confrontation game and the performance of the designed controller in the actual flight.The experimental results show that the optimal guidance strategy of the three-body confrontation game is feasible in the quadrotor UAV platform.