A Smoke Flow Control Method for Aircraft Cargo Cabins Considering Delay and Disturbance

In the airworthiness verification experiment of the aircraft cargo compartment fire smoke detection system, it is necessary to control the simulated smoke flow field generated by the smoke generator, in order to achieve equivalence with real fire smoke. The difficulty of simulated smoke control lies in the hysteresis effect during smoke diffusion and the nonlinearity caused by its own turbulent motion.Using the data generated by CFD (Computational Fluid Dynamics) numerical simulation for system identification, the simulated smoke flow field is approximated as a transfer function with a delay link, and the random pulsation during the smoke turbulent diffusion process is treated as a disturbance in the model. Analyzing the influence of delay and disturbance on closed loop control of systems, And then, design a control law based on this. For the delay link, a Smith compensator is used to compensate, A sliding mode control method is used to overcome the disturbance caused by turbulence in the system, compare the control performance with PID (Proportional-Integral-Differential) algorithm. The simulation results show that the Smith compensator can effectively reduce the impact of system delay, and the sliding mode controller exhibits a strong control effect on disturbances. The combination of Smith compensator and sliding mode control can better achieve closed-loop flow control of simulated smoke. At the same time, research ideas and control methods can provide meaningful theoretical guidance for the airworthiness verification experiments of aircraft cargo fire smoke detection systems