The Test Method Of The Real-Time System Research And Application

With the rapid popularization of computer and Internet, real-time systems have been widely used in every field. Many actions’ implementation of the system are closely related to time, are required to satisfy certain time constraints. Therefore, the reliability and security issues of this kind of system has been widely attention of researchers. Model-based test method is a commonly method for real-time system testing and validation, the timed automata is one of the most widely used in many models of a modeling tool. It is an extension of automata theory, with simply descriptive method and strongly description ability, etc, and thus it acts as a real-time system simulation model has been widely research and application.This paper is based on timed automata model for modeling real-time systems, the main work includes the following aspects:(1) On the basis of the clock zoning method, we propose a new classification method, the infinite state space of the clock area is divided into various classes equivalently in the clock number corresponding coordinate diagram, and only divide them into inner regions and outer regions. It could made with the least amount of points to corresponding more equivalent state space, simplifies the selection of each clock space, thus reduce the number of generated test cases.(2) For the execution of state space explosion problem of timed automata, especially its simulated space exist infinite state, we reduct the state space based on the abstract reduction methods. The technique can keep simulation and bisimulation relations in accessibility and safety, and can be reduct the infinite state space to finite state space while maintaining the appropriate properties, further reduct the original number and the length of the state space, and finally achieved the test cases reduction.(3) Aiming at the problem of the time constraint expression in execution status of redundancy and unanswered, we reduct the constraint expression based on the bounded difference matrix(DBM) expression reduction technology, determine the expression whether has solution and whether has a redundant expression, and ultimately generate the most simple expression that has no redundant, then implements the expression time value reduction, further reduct the path node time dimension values and the combination explosion problem.Finally, by the division of time dimension rules, combined with the state space reduction technique, expression reduction technique, we can get the space more simple than the original reduction of state space. With the help of a specific example, we select the corresponding region in the middle of the point of meet the conditions as a regional sample point, and finally to meet the time dimension corresponds to generate test cases.