The Feedforward Fuzzy Control Research Of Road Tunnel Ventilation System

With the development of China's highway construction, road tunnel safety and energy-saving receive more and more attention. Because of the uncertainty of the concentration of CO and the value of VI, the system is big time-variant, non1inear and time delay.It's hard to control the fans according to the air condition, meantime as few as possible. At present, lots of domestic road tunnels still use manual or semiautomatic operation in the ventilation systems, the automaticity is poor on the whole.Therefore, establishing an energy-efficient ventilation control system in China under the situation of the energy shortage is very necessary, this article sets up an a feedforward ventilation control system based on fuzzy control.At first, the paper does research on every components of the ventilation system. In aerodynamics model, it considers the traffic flow capacity, mechanical wind pressure, natural ventilation wind etc. In the pollution model, it considers the pollutant convection and turbulent diffusion, and its mathematical model. In traffic flow prediction part, in order to overcome the problem of lacking prediction of fuzzy control, the BP neural network of short-term traffic prediction is used as the original system's forward-feed input signal to improve real-time and reliability, and tests it's simulation. The result shows that it's an effective way to predict the flow of communication. Then it is used to improve the effect of the Ventilation system together with fuzzy control.In fuzzy control part, because the tunnel CO concentration and VI concentration have no obvious dependence on each other, it designs the two aspects independently, and gives out the surface simulation.Besides, it also introduces the application design of wireless CO electrochemical sensor.Finally, it tests the effect of the control model on a simple platform, which are composed by simple channel, CO sensor, fan, IPC and PLC etc. The Configuration program on the IPC is the core of the feedforward fuzzy control method, PLC controls the ON or OFF of the fan according the IPC.Practice proves that the fuzzy control can overcome the weakness that ventilation system lacks exact ventilation control model. Using traffic flow prediction in feed-forward pre-control, it can achieve energy-saving and satisfy the need of ventilation control. It's an effective method to solve nonlinear and time lags.