Formal Verification for Task Description Languages. A Petri Net Approach

Abstract

One of the main challenges in verifying robotic systems is its asynchronous interaction with an unstructured environment, observed by imperfect sensors. Autonomous robot systems usually require some language to support task-level control. This paper presents an effective approach to apply formal verification methods for that kind of language. A main contribution of this method is to avoid modeling the robotic system with a specific formalism. The approach translates the task-level control models into a Petri net (PN) based representation. This is used to define new methods to analyze some task properties such as liveness, deadlock-freeness and terminability. The approach has been applied to the Task Description Language (TDL) and it is illustrated by experiments. The final goal is to create new tools within the application development environment to include formal verification as part of the normal software development cycle. The TDL to PN translator uses the Petri Net Markup Language (PNML) as its file format. This format permits interoperability with other Petri net tools that can also be used to analyze the PNs.

Implementing Autonomous Driving Behaviors Using a Message Driven Petri Net Framework

“…The problem of state-space explosion in PNs comes with the reachability analysis because somehow all the states need to be unfolded. To solve that problem, we use hierarchical PNs, as described in [11]. The hierarchical interpreted PNs are used to model the behaviors for each driving situation or scenario.…”

“…The hierarchy is used to break down the complexity of the model so that a PN can be started from another one. A full description of the reachability analysis of these hierarchical model is described in [11].…”

“…Formal verification: Using this PN model representation, the formal verification can be included as part of the normal software development cycle as described in [11].…”

Simplifying the Verification of Simulation Models through Petri Net to FlexSim Mapping

“…Petri Nets, like SDL does not need the addition of any extension, hence a model defined in a Petri Net is complete and can be fully codified. Petri Nets become an excellent alternative to represent simulation models and to analyze the correctness of executing a task or representing its behavior, in multiple areas, like in robotics and microcontrollers [20,21], to study biological and social systems [22][23][24] or infrastructures and logistics analysis [25][26][27] among other multiple scopes, hence several works exist to transform to Petri Nets models represented in other languages, like BPMN or Flowcharts, see [28][29][30] as an example.…”

Combining decision making and dynamical systems for monitoring and executing manipulation tasks

“…Robots operating in everyday environments need increased flexibility to cope with sudden and unexpected variations in their executive context. In dynamic environments, the robot needs to perform sensing and planning operations at low cost, as well as to monitor its own actions in a goal-oriented fashion [1,2]. High flexibility and adaptation capabilities are required at each level of the senseplan-act loop to deploy robust and effective robotic solutions [3].…”