  This paper presents iterative Sequential Action Control (iSAC), a receding
horizon approach for control of nonlinear systems. The iSAC method has a
closed-form open-loop solution, which is iteratively updated between time steps
by introducing constant control values applied for short duration. Application
of a contractive constraint on the cost is shown to lead to closed-loop
asymptotic stability under mild assumptions. The effect of asymptotically
decaying disturbances on system trajectories is also examined. To demonstrate
the applicability of iSAC to a variety of systems and conditions, we employ
five different systems, including a 13-dimensional quaternion-based quadrotor.
Each system is tested in different scenarios, ranging from feasible and
infeasible trajectory tracking, to setpoint stabilization, with or without the
presence of external disturbances. Finally, limitations of this work are
discussed.
