ST-Lib: A Library for Specifying and Classifying Model Behaviors

Abstract

Test and verification procedures are a vital aspect of the development process for embedded control systems in the automotive domain. Formal requirements can be used in automated procedures to check whether simulation or experimental results adhere to design specifications and even to perform automatic test and formal verification of design models; however, developing formal requirements typically requires significant investment of time and effort for control software designers. We propose Signal Template Library (ST-Lib), a uniform modeling language to encapsulate a number of useful signal patterns in a formal requirement language with the goal of facilitating requirement formulation for automotive control applications. ST-Lib consists of basic modules known as signal templates. Informally, these specify a characteristic signal shape and provide numerical parameters to tune the shape. We propose two use-cases for ST-Lib: (1) allowing designers to classify design behaviors based on user-defined numerical parameters for signal templates, and (2) automatic identification of worst-case values for the signal template parameters for a given closed-loop model of an embedded control system. We show how ST-Lib can be used to improve user productivity by demonstrating its effectiveness on two case studies.

Enhancing Temporal Logic Falsification With Specification Transformation and Valued Booleans

“…As has been noted before [34], writing specifications in temporal logic is not trivial. Approaches that have been used to solve this problem are creating tools that make it easier to write specifications [35], automatically detecting faulty specifications [36], and defining template specifications to make it easier for testers to formulate their requirements formally [37]. In this paper, we instead allow test engineers to write specifications in a formalism they already know, namely a causal signal-based framework (in our case using Simulink [13]).…”

“…If it is a goal to keep the automatically transformed STL formulas as short as possible, we use templates of combinations of different temporal operators that are implemented as their own subsystems in the model. This is in a way very similar to ST-Lib [37], but instead of defining templates that can be used to build specifications from the ground up directly in STL, we define templates in Simulink that are associated to predefined STL formulas.…”

Specification and Efficient Monitoring Beyond STL

“…Example 9 (Spike). The ST-Lib library [14] uses the following formula to define a start point of a spike:…”

Logical Clustering and Learning for Time-Series Data

“…We formalize this intuition in terms of relaxing the set of corners that can appear in E B . For instance, suppose that we replace E B in Eq (13)…”