Research On Cooperative Guidance And Control Of MIKV For Active Defense Against Near-earth Asteroid

Near-Earth asteroids may hit the Earth,causing loss of human life and property,which is threatening.Near Earth Asteroid defense has always been a hot topic.In this paper,Multi Kinetic-energy Impactor Vehicle(MIKV)are used to impact several characteristic points on the surface of near-Earth asteroids.Considering the problem of impact and interference,the cooperative guidance control strategy of MIKV should be come up with.The main contents are as follows:An anti-collision cooperative guidance control strategy for MIKV in long distance flight phase is proposed.In the process of intercepting characteristic points on the asteroid,MIKVs may have interference with each other even make collision due to the relative distance among the MIKVs.According to the interception scenario of MIKVs,the flight phase is divided into long-range guidance phase and short-range guidance phase based on whether the seeker can clearly distinguish the characteristic points.Considering the need of anti-collision and anti-interference in the long-range guidance phase,a MIKV cooperative guidance control strategy is designed.At the end of long distance flight phase,MIKVs are evenly distributed on the outer circle of the asteroid perpendicular to the initial line of sight(LOS)to avoid the collision and interference among MIKVs during the longdistance guidance phase and reduce the probability of collision or interference among the MIKVs in the short distance guidance phase.The target assignment strategy based on Hungarian algorithm for MIKV at the hand-over time is proposed.At hand-over time,the seeker of MIKV can measure the relative position from characteristic points in the initial LOS normal plane,and then assign the targets to the MIKVs.In this paper,a target assignment based on Hungarian algorithm is proposed,which can make the flight trajectories of MIKVs not cross in the initial LOS normal plane while intercepting multi-characteristic points on the surface of the asteroid.Thus the flight trajectories in the three dimensional space will not cross.And the probability of collision and mutual interference among the MIKVs can be reduced.A cooperative guidance and control strategy based on true proportional navigation law(TPN)and collision probability is proposed for MIKV in short distance flight phase.The MIKVs mainly rely on the seeker to observe the target points in the short distance flight phase,and directly impact the target points under the guidance of the TPN.Firstly,the characteristics of intercepting non-maneuvering targets by TPN are studied in this paper.Then the definition and formula of collision probability for MIKVs are presented.A cooperative guidance and control strategy based on TPN and collision probability for MIKV in the terminal guidance phase is designed,which can effectively reduce the collision probability of MIKVs while intercepting the characteristic points on the asteroid.Finally,a MIKV cooperative guidance and control simulation system is designed to verify the effectiveness of the method proposed in this paper based on the background of intercepting Comet Temple I("Deep Impact" program).