QoS metrics-in-the-loop for endowing runtime self-adaptation to robotic software architectures

Abstract

The design of a robot that is capable of operating autonomously in a changing and unstructured scenario is based on complex software architec- tures, in which perceptual and actuation components, as well as deliberative ones, are considered. The inherent dynamism of this kind of scenarios forces the software architecture to be able to adapt the robot’s behaviour to de- tected changes at runtime. This adaptation is often hard-coded by the robotic engineer within software components, thus considering the specific situations that s/he believes to be appropriate at design-time. Subsequently, when any of these situations occur, software components can react by updating parame- ters, planning decisions, etc., then ensuring that the robot provides the desired response. On the contrary, adding and managing situations that were not ini- tially considered is a cumbersome and expensive task. This paper describes a complete model-based framework for endowing a robot control architecture with the ability of self-adapting the robot’s behaviour at runtime. On the one hand, this framework provides robotic designers with a textual model editor allowing them to specify variation points in the robot behaviour and define how these variation points should be configured at runtime according to the perceived situation. On the other hand, the framework also includes a code generator that, taking the previous models as an input, generates and ap- propriately configures the runtime infrastructure needed to monitor relevant non-functional properties and, according to their evolution, perform the ap- propriate behaviour adaptations to meet the required robot quality-of-service (QoS). The proposed framework is discussed and validated in two case studies using different and well-known robotics software architectures. The first use case runs over a simulation environment generated using Webots. In a second use case a real robot is moved in an intralogistic scenario