The active collision avoidance maneuver of fractionated satellite cluster is studied. Especially, two clusters with different structure configuration in ellipse orbit and the collision description method between them are discussed. Due to the limitation of the collision probability based on the minimum distance, a new method is developed which including the effect of relative velocity on collision. Only J2 perturbation is considered in the relative dynamics and a PD controller based on BP neural network using automatic differentiation method is adopted when a collision is imminent. The simulation results validate that the presented active collision avoidance control law is effective.
