Patent ID: 7706979

Claim:
A computer-based method for estimating and displaying time and distance of closest approach of first and second aerial vehicles (“AVs”), numbered AVu (u=1, 2), with at least the first AV being an unmanned aerial vehicle (“UAV”) controlled from a Ground Control Station (“GCS”), the method comprising: for a selected time t=t0, providing an estimate of a position vector a0(u), a velocity vector a1(u) and an acceleration vector 2a2(u) of AV no. u; for a time interval t≧t0, estimating a future position vector of AV no. u (u=1, 2) as r ( t;u )= a 0( u )+ a 1( u )( t−t 0)+ a 2( u )( t−t 0) 2 ; estimating a time of closest approach, t=t e , greater than t0 for which a difference |Δ r ( t )| 2 =|r ( t;u= 1)− r ( t;u= 2)| 2 has a locally minimum value, and estimating a distance squared of closest approach |Δ r ( t=t e )| 2 ; and when |Δr(t=t e )| 2 is less than a selected safe separation distance squared threshold value |Δr(min)| 2 , modifying the acceleration vector a2 for the UAV to a modified acceleration vector a2′ so that, with the modified acceleration vector a2′ used to compute a modified time value t=t′ e and to compute and display a modified distance squared of closest approach value, |Δr′(t=t′ e )| 2 , the modified distance squared of closest approach value is greater than the safe separation distance squared threshold value |Δr(min)| 2 .