Biblio

When building large concurrent systems, one of the key difficulties lies in coordinating component behavior and, in particular, managing the access to shared resources of the execution platform. Components may interact through buses, message buffers, etc. leading to resource contention and potential deadlocks compromising safety-critical operations. The concurrent nature of such interactions is the root cause of the complexity of the resulting software. Thus, the complexity of software systems is exponential in the number of their components, making a-posteriori verification of their correctness practically infeasible. An alternative approach, taken by the BIP framework, consists in ensuring correctness-by-construction by applying automatic transformations to obtain executable code from formally defined models. Following this latter approach, we have designed and implemented a BIP design studio. We have studied extensions of the BIP language for specifying parameterized models and integrated them in the design studio to enhance scalability, reusability, and reduce model size. Additionally, we have studied and implemented a set of necessary and sufficient conditions for validating the consistency and encodability of BIP models at design time. We have developed code generation plugins from graphical BIP models to equivalent Java and BIP code. The generated BIP code can be verified for deadlock-freedom or safety properties using compositional verifications tools offered by the BIP framework.

The Behavior-Interaction-Priority (BIP) framework, rooted in rigorous semantics, allows modeling heterogeneous component-based systems. BIP is supported by a textual modeling language, as well as a tool-set including run-time platforms and verification tools. We present a web-based design studio that allows specifying BIP behavior and interaction models in a purely graphical way and generating the equivalent textual specifications. To facilitate scaling and reusability of BIP models, we have extended architecture diagrams, a graphical language for modeling architecture styles, to define parameterized BIP models. We present the various services provided by the design studio, including model repositories, design guidance mechanisms, code generators, and integration with the BIP tool-set.

Small Unmanned Aircraft Systems (sUAS) are already revolutionizing agricultural and environmental monitoring through the acquisition of high-resolution multi-spectral imagery on-demand. However, in order to accurately understand various complex environmental and agricultural processes, it is often necessary to collect physical samples of pests, pathogens, and insects from the field for ex-situ analysis. In this paper, we describe a sUAS for autonomous deployment and recovery of a novel environmental sensor probe. We present the UAS software and hardware stack, and a probe design that can be adapted to collect a variety of environmental samples and can be transported autonomously for off-site analysis. Our team participated in an NSF-sponsored student unmanned aerial vehicle (UAV) challenge, where we used our sUAS to deploy and recover a scale-model mosquito trap outdoors. Results from indoor and field trials are presented, and the challenges experienced in detecting and docking with the probe in outdoor conditions are discussed.

This talk describes how the Cyber-Physical Systems Virtual Organization (CPS-VO) is hosting competitions for the purpose of improving CPS verication tools. We describe the 2016 Challenge, which focused on quadrotor control and codesign of payload, and the 2017 Challenge which focuses on populating a ground vehicle simulator with realistic obstacles. In addition, the interfaces by which participants compete are described, in order to articulate the means by which models can be decoupled from the system for the purposes of evaluation by external tools.