UAV guidance laws to arrival at desired position and time from desired direction

Many guidance laws for UAVs focus on path following. And trajectory tracking problem is enough when it satisfies path and time constrains. One more constraint will be considered in this research, that is, approaching direction to a terminal position. Two methods will be introduced; they are based on Pythagorean-Hodograph curve, and the Lyapunov vector field, respectively. The first algorithm consists of two steps. The first step is trajectory-planning using PH curve, and the second step is tracking algorithm for that curve. The second algorithm is based on vector field including a variable parameter. Using this parameter, contraction vectors toward the origin are tuned, and a desired terminal approaching condition is achieved.