SPACECRAFT COLLISION AVOIDANCE USING COULOMB FORCES WITH SEPARATION DISTANCE FEEDBACK

摘要

A 2-spacecraft collision avoidance problem is discussed in this paper. The spacecraft are assumed to be floating freely in deep space. A control strategy using cluster internal Coulomb forces is developed to prevent a collision between two spacecraft. The control law is designed to keep the separation distance greater than a constraint value, and is also designed to keep the departure relative kinetic energy at the same level as the approach kinetic energy. Further, this strategy only requires measurements of the separation distances. If spacecraft charge saturation is also considered than it is not guaranteed that the collision can always be prevented. Conditions under which a collision can be avoided are discussed by formulating the charged spacecraft relative motion using concepts of orbital mechanics. Given an initial separation distance and distance rate, the minimum spacecraft charge limit required to guarantee collision avoidance is determined. Or, inversely, when the limitations of charges are given, the maximum approach speed at which a potential collision can be avoided is estimated. Numerical simulations illustrate the analytical results.