Deriving Homing Sequences for Finite State Machines with Timed Guards

Abstract

State identi cation is the well-known problem in the theory of Finite State Machines (FSM) where homing sequences (HS) are used for the identi cation of a current FSM state, and this fact is widely used in the area of so ware and hardware testing and veri cation. For various kinds of FSMs, such as partial, complete, deterministic, non-deterministic, there exist su cient and necessary conditions for the existence of preset and adaptive HS and algorithms for their derivation. Nowadays timed aspects become very important for hardware and so ware systems and for this reason classical FSMs are extended by clock variables. In this work, we address the problem of checking the existence and derivation of homing sequences for FSMs with timed guards and show that the length estimation for timed homing sequence coincides with that for untimed FSM. e investigation is based on the FSM abstraction of a Timed FSM, i.e. on a classical FSM which describes behavior of corresponding TFSM and inherits some of its properties. When solving state identi cation problems for timed FSMs, the existing FSM abstraction is properly optimized.