49 research outputs found
Combined Global and Local Search for the Falsification of Hybrid Systems
In this paper we solve the problem of finding a trajectory that shows that a
given hybrid dynamical system with deterministic evolution leaves a given set
of states considered to be safe. The algorithm combines local with global
search for achieving both efficiency and global convergence. In local search,
it exploits derivatives for efficient computation. Unlike other methods for
falsification of hybrid systems with deterministic evolution, we do not
restrict our search to trajectories of a certain bounded length but search for
error trajectories of arbitrary length
The general purpose analog computer and computable analysis are two equivalent paradigms of analog computation
In this paper we revisit one of the rst models of analog
computation, Shannon's General Purpose Analog Computer (GPAC).
The GPAC has often been argued to be weaker than computable analysis.
As main contribution, we show that if we change the notion of GPACcomputability
in a natural way, we compute exactly all real computable
functions (in the sense of computable analysis). Moreover, since GPACs
are equivalent to systems of polynomial di erential equations then we
show that all real computable functions can be de ned by such models
Investigation of the near-grazing behavior in hard-impact oscillators using model-based TS fuzzy approach
Optimal Control of Nonlinear Switched Systems: Computational Methods and Applications
A switched system is a dynamic system that operates by switching between different subsystems or modes. Such systems exhibit both continuous and discrete characteristics—a dual nature that makes designing effective control policies a challenging task. The purpose of this paper is to review some of the latest computational techniques for generating optimal control laws for switched systems with nonlinear dynamics and continuous inequality constraints. We discuss computational strategiesfor optimizing both the times at which a switched system switches from one mode to another (the so-called switching times) and the sequence in which a switched system operates its various possible modes (the so-called switching sequence). These strategies involve novel combinations of the control parameterization method, the timescaling transformation, and bilevel programming and binary relaxation techniques. We conclude the paper by discussing a number of switched system optimal control models arising in practical applications