Due to the remarkable technological progress of late years, software applications tend to have a considerable role in solving most problems of everyday life. The medical, financial or automotive fields are just three of the main areas in which software products are intensively used. Given the importance of these areas in every individual's life, ensuring product quality and functionality is an essential step in the development process. The safety of software systems for large-scale use is ensured by testing. Software testing aims to validate the fulfillment of the requirements defined for the developed product, as well as to identify possible unwanted behaviors triggered by simulating certain operational contexts.

Thorough testing of safety-critical autonomous systems, such as self-driving cars, autonomous robots, and drones, is essential for detecting potential failures before deployment. One crucial testing stage is model-in-the-loop testing, where the system model is evaluated by executing various scenarios in a simulator. However, the search space of possible parameters defining these test scenarios is vast, and simulating all combinations is computationally infeasible. To address this challenge, we introduce AmbieGen, a search-based test case generation framework for autonomous systems. AmbieGen uses evolutionary search to identify the most critical scenarios for a given system, and has a modular architecture that allows for the addition of new systems under test, algorithms, and search operators. Currently, AmbieGen supports test case generation for autonomous robots and autonomous car lane keeping assist systems. In this paper, we provide a high-level overview of the framework's architecture and demonstrate its practical use cases.