Flight testing a real-time direct collocation path planner

A path-planning algorithm using direct collocation with nonlinear programming is demonstrated in both simulation and flight tests. Direct collocation, which approximates the states and controls with piecewise polynomials, has been widely applied in space vehicles and manned aircraft, but has only seen limited use in unmanned aerial vehicle applications. The algorithm is successfully used to generate a path that produces maximal surveillance time of a moving or stationary ground target by a sensor mounted on an unmanned aerial vehicle while compensating for aircraft performance or mission constraints. Flight tests of the path-planning algorithm operating in real tune onboard an unmanned aerial vehicle are also presented. These tests include surveilling a stationary and moving target with a video camera while compensating for any wind effects. Additionally, the effect of the use of road data in planning the path is simulated by tracking a second unmanned aerial vehicle flying a predefined pattern.