QoS-Oriented Adaptation Management in Networked Multi-vehicle Cruise Control Systems

Networked embedded software systems incorporate varying degrees of adaptation behavior to sustain their operations with acceptable quality of service (QoS), in the face of hostile external events — such as resource outages in a cloud service, road slipperiness in a car driving, etc. For instance, a highly agile cruise control system of a car may dynamically adjust its controller parameters to generate a higher-than-normal increase in torque when encountering a higher road elevation (relative to a normal controller). With the high complexity of such dynamic adaptive systems, their QoS capability depends on how well they respond to hostile external events. The paper formulates model-based assessment techniques to reason about how capable is a networked system S in meeting its QoS specs. We benchmark the QoS capability of S by a stress-testing of S with artificially injected failures. As a case study, we describe the QoS assessment of a multi-vehicle adaptive cruise control system.