On Verification Method For Software Reliability Of FPGA Based Instrument Control System Of Nuclear Power Plants

Reliability is one of the important properties of instrument control system of nuclear power plants and it is the guarantee for safe and stable operation of nuclear power station.In the paper,we study the verification method for software reliability of FPGA based instrument control system of nuclear power plants which has practical significance for improving the verification technical level of domestic FPGA based software.The core of verification method for software reliability includes the completeness,efficiency of test and the ability to resist environmental impact.In the paper,we did the following work and made some innovative achievements by studying the key problems of FPGA based software reliability verification.Firstly,by describing the uncovered path with Boolean satisfiability problem,this method can improve the completeness of test.Secondly,for large-scale input problems,the method is insufficient to solve large-scale problems in single module with the shortage of decisionmaking strategy of traditional DPLL algorithm.Based on this,this paper optimized the decision-making strategy of DPLL algorithm and proposed an automatic generation method of test cases.The method is the combination of random method and the proposed DPLL algorithm which can effectively solve large-scale problem.Thirdly,for the problem of limited application scope in existing fault injectors and its bad portability,we explored a fault injection method which is suitable for FPGA based instrument control system of nuclear power plants and developed a fault injector based on the proposed fault injection method.We can assess fault tolerance of instrument control system software of nuclear power plants with this tool which can improve the performance of the software and further improve the software reliability.