Research on the robustness analysis of distributed engine control system was conducted to describe the robustness quantitatively. Stability criterion for control system model considering transmission delay/packet dropout was simultaneously presented in linear matrix inequality form. Gain matrix was designed utilizing regional poles assignment technology

and the delay/packet dropout margin of closed-loop systems with poles in various regions was solved and verified. Discussion was extended to the closed-loop poles region selection in terms of delay packet dropout robustness and dynamic performance. Simulation confirmed the validity of the stability criterion. Further analysis result showed that the strongest delay/packet dropout robustness was obtained when closed-loop poles were assigned near -4. Considering the control requirements of delay/packet dropout robustness and dynamic performance comprehensively

it was feasible to place closed-loop poles in disk area with center between -8 and -4 and radius of 1.