As a case study of hybrid system, a redundancy management system in flight control system is formally investigated and its specification and verification are presented using an approach incorporating program logic into duration calculi.

This paper focuses on the modeling methods, including Equivalent Discrete Event (EDE) model, hybrid automata, petri nets, duration calculi and its extension.

A formal semantics of VHDL based on duration calculus;

switch platform with the aid of the duration calculus theory.

In order to formalize the parallel model of DDS, we firstly introduce duration calculus with which we can formalize DDS model.

The general expressions are obtained by using the conclusion from teaching material with the charged square coil considered as four sections charged rods,using partition computation and the principle of superposition of field.