Vacuity Aware Falsification for MTL Request-Response Specifications

We propose a method to improve the automated test case generation for Metric Temporal Logic (MTL) falsification for Cyber-Physical Systems (CPS). In this work, we focus on request-response MTL specifications. That is, specifications that consist of at least one antecedent and a corresponding consequent. Test case generation is particularly difficult for these specifications since the consequent is only considered if the antecedent is satisfied. Therefore, we propose a method that first targets the antecedent in the specification. We show that our framework can improve upon existing falsification methods on a number of benchmark problems.