TY - GEN
T1 - Online inner approximation of reachable sets of nonlinear systems with diminished control authority
AU - El-Kebir, Hamza
AU - Ornik, Melkior
N1 - Publisher Copyright:
Copyright © 2021 by SIAM.
PY - 2021
Y1 - 2021
N2 - This work presents a method of efficiently computing inner approximations of forward reachable sets for nonlinear control systems with diminished control authority, given an a priori computed reachable set for the nominal system. The method functions by shrinking a precomputed convex reachable set based on a priori knowledge of the system’s trajectory deviation growth dynamics. The trajectory deviation growth dynamics determine an upper bound on the minimal deviation between two trajectories emanating from the same point that are generated by control inputs from the nominal and diminished set of control inputs, respectively. These growth dynamics are a function of a given Hausdorff distance bound between the nominal convex space of admissible controls and the possibly unknown impaired space of admissible controls. Because of its relative computational efficiency compared to direct computation of the off-nominal reachable set, this procedure can be applied to on-board fault-tolerant path planning and failure recovery. We consider the implementation of the approximation procedure by way of numerical integration and a root finding scheme, and we present two illustrative examples, namely an application to a control system with quadratic nonlinearities and aircraft wing rock dynamics.
AB - This work presents a method of efficiently computing inner approximations of forward reachable sets for nonlinear control systems with diminished control authority, given an a priori computed reachable set for the nominal system. The method functions by shrinking a precomputed convex reachable set based on a priori knowledge of the system’s trajectory deviation growth dynamics. The trajectory deviation growth dynamics determine an upper bound on the minimal deviation between two trajectories emanating from the same point that are generated by control inputs from the nominal and diminished set of control inputs, respectively. These growth dynamics are a function of a given Hausdorff distance bound between the nominal convex space of admissible controls and the possibly unknown impaired space of admissible controls. Because of its relative computational efficiency compared to direct computation of the off-nominal reachable set, this procedure can be applied to on-board fault-tolerant path planning and failure recovery. We consider the implementation of the approximation procedure by way of numerical integration and a root finding scheme, and we present two illustrative examples, namely an application to a control system with quadratic nonlinearities and aircraft wing rock dynamics.
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U2 - 10.1137/1.9781611976847.2
DO - 10.1137/1.9781611976847.2
M3 - Conference contribution
AN - SCOPUS:85121463781
T3 - SIAM Conference on Control and Its Applications, CT 2021
SP - 9
EP - 16
BT - SIAM Conference on Control and Its Applications, CT 2021
PB - Siam Society
T2 - 2021 SIAM Conference on Control and Its Applications, CT 2021
Y2 - 19 July 2021 through 21 July 2021
ER -