TY - JOUR
T1 - Nonlinear Dynamic Inversion with Actuator Dynamics: An Incremental Control Perspective
AU - Steffensen, Rasmus
AU - Steinert, Agnes
AU - Smeur, E.J.J.
PY - 2023
Y1 - 2023
N2 - In this paper, we derive a sensor-based nonlinear dynamic inversion (NDI) control law for a nonlinear system with first-order linear actuators, and compare it to incremental nonlinear dynamic inversion (INDI), which has gained popularity in recent years. It is shown that, for first-order actuator dynamics, INDI approximates the corresponding NDI control law arbitrarily well under the condition of sufficiently fast actuators. If the actuator bandwidth is low compared to changes in the states, the derived NDI control law has the following advantages compared to INDI: 1) compensation of state derivative terms, 2) well-defined error dynamics, and 3) exact tracking of a reference model, independent of error controller gains in nominal conditions. The comparison of the INDI control law with the well-established control design method NDI adds to the understanding of incremental control. It is additionally shown how to quantify the deficiency of the INDI control law with respect to the exact NDI law for actuators with finite bandwidth. The results are confirmed through simulation results of the roll motion of a fixed-wing aircraft.
AB - In this paper, we derive a sensor-based nonlinear dynamic inversion (NDI) control law for a nonlinear system with first-order linear actuators, and compare it to incremental nonlinear dynamic inversion (INDI), which has gained popularity in recent years. It is shown that, for first-order actuator dynamics, INDI approximates the corresponding NDI control law arbitrarily well under the condition of sufficiently fast actuators. If the actuator bandwidth is low compared to changes in the states, the derived NDI control law has the following advantages compared to INDI: 1) compensation of state derivative terms, 2) well-defined error dynamics, and 3) exact tracking of a reference model, independent of error controller gains in nominal conditions. The comparison of the INDI control law with the well-established control design method NDI adds to the understanding of incremental control. It is additionally shown how to quantify the deficiency of the INDI control law with respect to the exact NDI law for actuators with finite bandwidth. The results are confirmed through simulation results of the roll motion of a fixed-wing aircraft.
UR - http://www.scopus.com/inward/record.url?scp=85146385407&partnerID=8YFLogxK
U2 - 10.2514/1.G007079
DO - 10.2514/1.G007079
M3 - Article
SN - 0731-5090
VL - 46
SP - 709
EP - 717
JO - Journal of Guidance, Control, and Dynamics: devoted to the technology of dynamics and control
JF - Journal of Guidance, Control, and Dynamics: devoted to the technology of dynamics and control
IS - 4
ER -