Testing the Input Timing Robustness of Real-Time Control Software for Autonomous Systems

The functional layer of an autonomous system such as a robot is required to carry out multiple real-time control activities in parallel. These activities are launched by asynchronous calls from clients situated at higher layers, so there is a need for the functional layer to provide built-in protection to ensure that it is robust with respect to requests that are issued at instants that are incompatible with its current state and could therefore cause catastrophic system failure. This paper addresses the testing of the robustness provided by such protection mechanisms. A hybrid black-box robustness testing approach is considered by which test cases are generated by random mutation of a valid sequence of requests and test verdicts are obtained by a set of property-based robustness oracles applied to a logged trace of requests and responses. An application of the proposed framework to an experimental planetary explorer robot is described.