Real Time Trajectory Generation for Differentially Flat Systems
Michiel J. van Nieuwstadt and Richard M. Murray
Int'l. J. Robust & Nonlinear Control 8:(11) 995-1020, 1998
This paper considers the problem of real time trajectory generation and tracking for
nonlinear control systems. We employ a two degree of freedom approach that separates the
nonlinear tracking problem into real time trajectory generation followed by local
(gain-scheduled) stabilization. The central problem which we consider is how to generate,
possibly with some delay, a feasible state space and input trajectory in real time from an
output trajectory that is given online. We propose two algorithms that solve the real time
trajectory generation problem for differentially flat systems with (possibly non-minimum
phase) zero dynamics. One is based on receding horizon point to point steering, the other
allows additional minimization of a cost function. Both algorithms explicitly address the
tradeoff between stability and performance and we prove convergence of the algorithms for
a reasonable class of output trajectories. To illustrate the application of these
techniques to physical systems, we present experimental results using a vectored thrust
flight control experiment built at Caltech. A brief introduction to differentially flat
systems and its relationship with feedback linearization is also included.
CDS Technical
report (preprint) (PDF, 737K, 27 pages)
Downloading and printing FAQ
Richard Murray (murray@cds.caltech.edu)
Last modified: Tue Aug 30 07:42:19 2005