Local controllability and attitude stabilization of multirotor UAVs: Validation on a coaxial octorotor

Abstract

Local controllability and attitude stabilization of multirotor UAVs: Validation on a coaxial octorotor. Robotics and Autonomous Systems, Elsevier, 2017, 91, pp. AbstractThis paper addresses the attitude controllability problem for a multirotor unmanned aerial vehicle (UAV) in case of one or several actuators failures. The small time local controllability (STLC) of the system attitude dynamics is analysed using the nonlinear controllability theory with unilateral control inputs. This analysis considers different actuators configurations and compares their fault tolerance capabilities regarding actuators failures. Analytical results are then validated experimentally on a coaxial octorotor. A stabilization control law is applied on the coaxial configuration under one, two, three and four motors failures, when the system is controllable. Real-time experimental results demonstrate the effectiveness of the applied strategy.

Stability and nonlinear controllability analysis of a quadrotor-like autonomous underwater vehicle considering variety of cases

“…with det ðCÞ ¼ ðb 2 ðm 1 À m 3 ÞÞ=ðm 2 1 m 2 m 2 3 m 4 m 5 m 2 6 Þ 6 ¼ 0 when m 1 6 ¼ m 3 . This system also satisfies the LARC with r ¼ 3, and the corresponding bad brackets are same as equation (21). In zero-velocity states, the first four of those brackets are equal to 0 6Â1 , and the last bad bracket is expressed as…”

“…the accessibility algebra spans the tangent space to M at x 0 ), then for any T > 0, the set R T ðx 0 Þ has a nonempty interior, that is, the system has the accessibility property from x 0 . 21 When the hypotheses of this theorem hold, one can say that the system satisfies Lie Algebra Rank Condition (LARC) at x 0 . 29 For a driftless system where the vector filed f equals a zero vector, the system is STLC if it verifies the LARC.…”

“…29 For a driftless system where the vector filed f equals a zero vector, the system is STLC if it verifies the LARC. 21 However, the condition is not sufficient with a drift system, as some of the Lie brackets involved the drift term may have directional constraints, which obstructs the controllability of the system. 30 For the systems with drift, Sussman 14 proposed a general theorem which states that some additional conditions about good and bad Lie brackets should hold besides the LARC in order to guarantee the STLC.…”

“…with det ðCÞ ¼ ðb 2 Þ=ðm 1 m 2 m 3 m 2 6 Þ 6 ¼ 0. It satisfies the LARC with r ¼ 3, and the corresponding bad brackets are same as equation (21). In zero-velocity states, they are equal to 0 4Â1 ; thus, considering u; v; w; r degrees, the system satisfies STLC from zero-velocity states.…”

“…The result is not applicable to judge the STLC of the QLAUV. Moreover, the work of Saied et al 21 explores only the attitude controllability issue but not expands the result to full-dimension states for a UAV.…”