Pakhomov Y. Models and methods for the testable design of critical systems of logic control based on finite-state machines

The PhD thesis is devoted to the development of models and methods of computer-aided design and diagnosis of automaton logic control systems on FPGA using hardware description languages. The extension of the input alphabet of the finite state machine is proposed by introducing an additional column in the table of transitions-outputs of the automaton and an additional input to the circuit implementation of the control automaton. The procedures for performing a diagnostic experiment are improved through the use of synchronization sequences. The methods for developing hardware diagnostics devices have been improved; they implement a strategy for bypassing all the states or arcs of the transition graph of a control automaton by simulating the algorithm of an operational automaton in a logical control system. The methods for calculating the testability of finite state machine, controllability, observability and the reachability of nodes (states) of a transition graph of control automata have been improved. A new approach to computer-aided design of testable finite state machines has been proposed, based on the use of hardware description languages for describing models (HDL models), in which additional transitions are implemented by adding conditional statements to the VHDL description of transition functions and automaton pattern. The developed HDL descriptions are simulated and synthesized by computer-aided design tools based on the FPGA technology platform. The developed procedures for calculating the testability of the control automaton made it possible to optimize of entering additional transitions in automaton models through calculating the Quine estimate of the synthesized automaton models. A software module has been developed; it has visual interface for creating the transition graph of the control automaton and automating the construction of testable HDL models of automata in the form of automaton pattern in a synthesized subset of the VHDL language. The results obtained in the course of the research are reliable, which is confirmed by the experiments carried out to verify the proposed models and methods for monitoring and controlling gas supply systems.