CPSWEEK

We consider a viability based approach to guarantee recursive feasibility of a finite horizon path planner. The path planner is formulated as a hybrid system for which a difference inclusion reformulation is derived by exploiting the special structure ...

We consider a reach-avoid differential game, in which one of the players aims to steer the system into a target set without violating a set of state constraints, while the other player tries to prevent the first from succeeding; the system dynamics, ...

A sampled data model falls somewhere between continuous and discrete time models: The plant evolves in continuous time, but the controller receives feedback and can modify its control input(s) only at periodic points in time. In previous work we have ...

Recursive hybrid automata generalize recursive state machines in a similar way as hybrid automata generalize state machines. Recursive hybrid automata can be considered as collection of classical hybrid automata with special states that correspond to ...

Bounded-rate multi-mode systems are hybrid systems that can switch among a finite set of modes. Its dynamics is specified by a finite number of real-valued variables with mode-dependent rates that can vary within given bounded sets. Given an arbitrary ...

We study the boundedness of products of matrices associated with words in a regular language. This question naturally arises in the stability analysis of switching systems with constrained switching sequences.

Our main contribution is a sufficient ...

We present an efficient computational procedure for finite abstraction of discrete-time mixed monotone systems by considering a rectangular partition of the state space. Mixed monotone systems are decomposable into increasing and decreasing components, ...

In this paper we propose a compositional construction of approximate abstractions of interconnected control systems. Our notion of approximate abstraction is based on so-called simulation functions. The abstraction acts as substitute in the controller ...

We present BFComp, an automated framework based on Sum-Of-Squares (SOS) optimization and δ-decidability over the reals, to compute Bisimulation Functions (BFs) that characterize Input-to-Output Stability (IOS) of dynamical systems. BFs are Lyapunov-like ...

The model-based fault diagnosability analysis is concerned with the timely detection and isolation of faults by using the system model and observations of the system output. In this paper, we propose the (δ_d, δ_m, α)-diagnosability notion for hybrid ...

An integrated approach, embracing both control and scheduling theories, is proposed to implement multiple control loops upon shared network and computational resources, where the network may additionally introduce packet losses. Each control system is ...

Recent work addressing the stability analysis of controllers at code level has been mainly focused on the controller alone. However, most of the properties of interest of control software lie in how they interact with their environment. We introduce an ...

This paper studies the impact of clock mismatches in spatially distributed real-time control systems. We consider a configuration in which sensor measurements are collected by one processor that transmits the measurements to another control/actuation ...

A number of powerful and scalable hybrid systems model checkers have recently emerged. Although all of them honor roughly the same hybrid systems semantics, they have drastically different model description languages. This situation (a) makes it ...

We present ProbReach, a tool for verifying probabilistic reachability for stochastic hybrid systems, i.e., computing the probability that the system reaches an unsafe region of the state space. In particular, ProbReach will compute an arbitrarily small ...

This paper considers the problem of safety verification for discrete-time, possibly discontinuous dynamical systems. Typical solutions rely on finding invariant sets or Lyapunov functions and require solving optimization problems, which suffer from ...

Computing an approximation of the reachable states of a hybrid system is a challenge, mainly because overapproximating the solutions of ODEs with a finite number of sets does not scale well. Using template polyhedra can greatly reduce the computational ...

We consider the problem of verification of safety specifications for stochastic hybrid systems with a controller that has access to partial observations of the state. We address this problem through a finite state approximation of the stochastic hybrid ...

Modeling, analyzing and verifying real physical systems has long been a challenging task since the state space of the systems is usually infinite and the dynamics of the systems is generally nonlinear and stochastic. In this work, we employ an extension ...

This paper defines a suite of requirements for future hybrid cosimulation standards, and specifically provides guidance for development of a hybrid cosimulation version of the Functional Mockup Interface (FMI). A cosimulation standard defines interfaces ...

Networked dynamical systems are increasingly used as models for a variety of processes ranging from robotic teams to collections of genetically engineered living cells. As the complexity of these systems increases, so does the range of emergent ...

The Skorokhod distance is a natural metric on traces of continuous and hybrid systems. It measures the best match between two traces, each mapping a time interval [0, T] to a metric space O, when continuous bijective timing distortions are allowed. ...

Bipedal robots are prime examples of complex cyber-physical systems (CPS). They exhibit many of the features that make the design and verification of CPS so difficult: hybrid dynamics, large continuous dynamics in each mode (e.g., 10 or more state ...

In this paper, we present results for the vulnerability analysis of a power network to stochastic link failure attacks. We assume a network links are subjected to attacks where the link-based attack is modeled as stochastic perturbation to link weight. ...

Recent clinical studies suggest that the efficacy of hormone therapy for prostate cancer depends on the characteristics of individual patients. In this paper, we develop a computational framework for identifying patient-specific androgen ablation ...

We consider a case study of the problem of deploying an autonomous air vehicle in a partially observable, dynamic, indoor environment from a specification given as a linear temporal logic (LTL) formula over regions of interest. We model the motion and ...

We present a counterexample-guided inductive synthesis approach to controller synthesis for cyber-physical systems subject to signal temporal logic (STL) specifications, operating in potentially adversarial nondeterministic environments. We encode STL ...

Lack of complete run-time information about the environment behavior significantly increases the computational complexity and limits the applicability of practical reactive synthesis methods, e.g., synthesis from generalized reactivity( 1) ...

We consider the problem of computing the set of initial states of a dynamical system such that there exists a control strategy to ensure that the trajectories satisfy a temporal logic specification with probability 1 (almost-surely). We focus on ...

This paper presents a method for optimal trajectory generation for discrete-time nonlinear systems with linear temporal logic (LTL) task specifications. Our approach is based on recent advances in stochastic optimization algorithms for optimal ...

We consider the problem of controlling a system with unknown, stochastic dynamics to achieve a complex, time-sensitive task. An example of this problem is controlling a noisy aerial vehicle with partially known dynamics to visit a pre-specified set of ...

We describe an application of symbolic control to ventilation regulation in buildings. The monotonicity property of a nonlinear control system subject to disturbances, modeling the process, is exploited to obtain symbolic abstractions, in the sense of ...

This abstract presents an unified framework for aggregated modeling of various responsive loads. The general model consists of coupled partial differential equations derived by drawing the connection with stochastic hybrid systems.

We present on-going work on XSpeed, a tool for parallel state space exploration of continuous systems with linear dynamics and non-deterministic inputs. XSpeed exploits the computational power of multi-core architectures to speed up reachability ...

This paper presents a method to dynamically transform a one-input, one-output fuzzy inference system into a hybrid system. Hybrid systems are used to model and evaluate the discrete and continuous behavior of a physical systems. The method can easily be ...

In this poster, we present methods for randomly generating hybrid automata with affine differential equations, invariants, guards, and assignments. Selecting an arbitrary affine function from the set of all affine functions results in a low likelihood ...

In this work, we examine relaxations for the stability analysis and synthesis of stabilizing controllers for polynomial dynamical systems. It is well-known that such problems can be naturally solved using a reduction to polynomial optimization problems. ...

Legged robots naturally exhibit continuous and discrete dynamics when maneuvering over level-ground and uneven terrains. In recent years, numerous studies have focused on locomotion hybrid dynamics. However, locomotion on more challenging terrains such ...

This work presents a novel Model-Based Design (MBD) approach and associated tool-chain for the IEC 61131-3 specific Programmable Logical Controllers (PLC) [2]. Our tool-chain automatically synthesizes software for manufacturing Time-Triggered Real-time ...

In this project, we address the problem of synthesizing region-stabilizing controllers for switched systems. The plant model consists of a continuous-time switched system with finitely many switching modes. Our approach searches for a state-feedback ...

We present a search technique to falsify safety properties of hybrid systems that model a software system controlling a physical plant. Our approach takes as input (a) the controller code and (b) a plant model given as a black-box system that can be ...