Computationally Efficient Control Allocation Using Active-Set Algorithms

Computationally Efficient Control Allocation Using Active-Set Algorithms

Blaha, Till (TU Delft Aerospace Engineering)

Smeur, E.J.J. (mentor)
Remes, B.D.W. (graduation committee)

Delft University of Technology

Aerospace Engineering | Control & Simulation

2023-02-10

An effective distribution of flight control commands over many aircraft actuators (engines, control surfaces, flaps, etc.) can be achieved with constrained optimisation. Active-Set methods solve these problems efficiently, but their computational time requirements are still prohibitive for aircraft with many actuators or slower digital flight control processors. This work shows how these methods can be improved in these regards, by updating the required matrix factorisations at lower computational costs, rather than solving a separate optimisation problem at every step of the iterative algorithm. Additionally, it is shown how the sparsity of the problem matrices can be exploited. Both open-loop simulations and flight tests have been performed, which show that worst-case timings for a 6-rotor multicopter UAV can be improved by 65% over a current Active-Set solver. Furthermore, methods are presented that remedy numerical stability issues occurring in micro-controller floating point arithmetic but introduce a small but measurable adverse effect on the flight behaviour.

Control Allocation
Quadratic Optimisation
Active-Set algorithm

http://resolver.tudelft.nl/uuid:bffb47bf-5864-4b18-921b-588b3a664866

51.99054537147252, 4.376866902085184

Student theses

master thesis

© 2023 Till Blaha