Saturated adaptive sliding mode control for autonomous vessel landing of a quadrotor

Robust Backstepping Trajectory Tracking Control of a Quadrotor with Input Saturation via Extended State Observer

“…To achieve theV 3 negative definite, the control vector U 2 and the dynamics of ξ 2 are designed as (46) where k 5 , k 6 ∈ R + and ∆U 2 = sat(U 2 ) − U 2 . Assume that ∆U 2 satisfies ∆U 2 ≤ υ 2 with υ 2 ∈ R + .…”

“…Consider the quadrotor dynamics as described in Equation 2, for the given sufficiently smooth trajectory command P d and heading angle ψ d , if the controller gains k i (i = 1, ..., 6) and the observer bandwidth parameters ω 1 , ω 2 are chosen such that the matrix Π defined in the following is positive definite, then the ESO-based saturated trajectory tracking controller, including the virtual controllers (25), (33), (38), and (46) and the applied controllers (35) and (46), can guarantee the ultimate boundedness of all signals in the closed-loop and make the tracking errors arbitrarily small.…”

“…For example, in [43], the authors proposed an adaptive and robust saturated control to achieve the TTC of quadrotors under the presence of disturbances. Robust saturated tracking controllers were also presented in [44][45][46], with [44,45] using a backstepping-based controller, whereas the work in [46] is based on the SMC technique.…”

“…However, these studies [43][44][45][46] require the full-state information from the sensor systems, which is not always possible to achieve.…”

“…(i) Unlike previous saturated control studies in [43,44,46], our method does not require full-state information of the system: partial state knowledge is sufficient. In addition, our approach can account for the presence of lumped disturbances (consisting of parameterized uncertainties and external disturbances) in both the translational and rotational dynamics of the quadrotor.…”