Research On Test Case Generation Method Of Real-time System Based On Timed Automata

With the rapid development of computer related technology,the application field of real-time system has been greatly expanded.In real-time system,the occurrence of a lot of actions must meet the prescribed time constraints,otherwise it may lead to serious losses.Therefore,how to ensure the correctness and security of real-time system has been concerned by researchers.Software testing is a key method to verify the correctness and security of real-time system,and the model based test is a common method.According to the characteristics of real-time system,timed automata model is often used to model the real-time system.In this paper,the test case generation method for real-time system based on timed automata model is studied,the main work includes the following aspects:(1)On the basis of the test case generation method for timed automata based on domain decomposition,an improved test case generation method for time automata based on domain decomposition is proposed.This method preprocesses the generated test path and adds the new time variable relationship formed at the time of the conversion to the target symbol state to reduce the clock area of the symbol state,thus reducing the number of test case points,and then follows the law of all the clock variables grow synchronously when selecting the test case points,generates executable test cases dynamically,reduces the number of test cases.(2)Both the improved test case generation method for time automata based on domain decomposition and original method use regional equivalence method to divide the time state space.Aiming at the problem of large number of test cases caused by regional equivalence method,a timed automata test case generation method based on time-abstracting bisimulations is proposed.The method uses the symbol state splitting algorithm to acquire the state space of the simulation timed automata.The state space of the simulation timed automata and the original timed automata are simulation and bisimulation relation,but the state space of the timed automata is greatly reduced.The test path is generated according to the reduced timed automata,and the redundant delay transition is removed in the test path.Finally,the executable test cases are generated dynamically,which further reduces the number of test cases.(3)Aiming at the problem of low implementation efficiency of symbolic state splitting algorithm,an improved symbol state splitting algorithm is proposed.The algorithm performs the split operation and obtains the constraint between the clock variables according to the clock constraint and the clock variable reset information on the current transition,and adds it to the corresponding symbol state to reduce the state space and reduce the number of split operation,so as to improve the efficiency of execution.On the basis of the above methods,the paper analyzes the typical modules of UAV flight control,and validates the effectiveness of the proposed method.