Modeling Non-Functional Application Domain Constraints for Component-Based Robotics Software Systems

Service robots are complex, heterogeneous, software intensive systems built from components. Recent robotics research trends mainly address isolated capabilities on functional level. Non-functional properties, such as responsiveness or deterministic behavior, are addressed only in isolation (if at all). We argue that handling such non-functional properties on system level is a crucial next step. We claim that precise control over application-specific, dynamic execution and interaction behavior of functional components -- i.e. clear computation and communication semantics on model level without hidden code-defined parts -- is a key ingredient thereto. In this paper, we propose modeling concepts for these semantics, and present a meta-model which (i) enables component developers to implement component functionalities without presuming application-specific, system-level attributes, and (ii) enables system integrators to reason about causal dependencies between components as well as system-level data-flow characteristics. This allows to control data-propagation semantics and system properties such as end-to-end latencies during system integration without breaking component encapsulation.

Dealing with Run-Time Variability in Service Robotics: Towards a DSL for Non-Functional Properties

Service robots act in open-ended, natural environments. Therefore, due to combinatorial explosion of potential situations, it is not possible to foresee all eventualities in advance during robot design. In addition, due to limited resources on a mobile robot, it is not feasible to plan any action on demand. Hence, it is necessary to provide a mechanism to express variability at design-time that can be efficiently resolved on the robot at run-time based on the then available information. In this paper, we introduce a DSL to express run- time variability focused on the execution quality of the robot (in terms of non-functional properties like safety and task efficiency) under changing situations and limited resources. We underpin the applicability of our approach by an example integrated into an overall robotics architecture.