| China is a country of mountainous and tunnels. In recent years, with the rapid development of highway, the highway is constantly extended to mountain, the proportion of tunnel gradually increased. Tunnel is a relatively closed special section, pollutants will affect traffic safety when the vehicle is traveling in the tunnel and also cause harm to humans. In order to ensure that the vehicles in the tunnel with a good driving environment, shall be use mechanical ventilation, through cooperate of axial fan and jet fan to control the concentration of pollutants in a safe range.In our country, tunnel ventilation often use the method of classification control, it establish a direct linear relationship between the detected concentration of tunnel pollutant and output wind, start output of classification. However, the tunnel ventilation system has discrete, changeable, delay characteristics. Classification control method cannot meet with the tunnel environmental requirements of safety and energy saving. Therefore, this paper presents a practical method of intelligent control.First of all, in order to realize the intelligent control, must be based on real-time traffic data. Through the forecast of tunnel traffic, realize the pre-start of fan, in order to ensure the consistent with the change of fan start and stop as well as the change of pollutants concentration in the tunnel. This paper forecast tunnel traffic based on the PSO-LS-SVM, through the comparison of the simulation test results to verify the feasibility and accuracy of this method.Secondly, combination with the characteristics of long tunnel and the change of pollutants in tunnel, establish the feed-forward fuzzy control system. Based on the independence between the CO concentration and â…¥ concentration, independent fuzzy controllers have been establishment:CO concentration fuzzy controller and VI concentration fuzzy controller. According to the design concentration of pollutants and the predicted feed-forward value and the feedback value from the sensors inside the tunnel, calculate the error values and the error variation, then the CO/VI concentration fuzzy controller use fuzzy speculative respectively corresponding operation to get their outputs, according to outputs to decision the number of fans increased or decreased to start or stop. According to fuzzy control lack of precision and systematic design method of parameters, this paper use some characteristic of particle swarm optimization(PSO), such as easy to program, hard to return a local optimal solution and faster optimization speed, to optimize the key parameters of the fuzzy controller. It can improve control precision of fuzzy controller and the availability of control rules table. By establishing the system simulation diagram and to comparative analysis of the simulation results, concluded that the control method of this paper has significant energy saving effect.Finally, introduction of frequency control technology based on the fuzzy control theory, Governor to axial fan of vertical/inclined shaft which play a role of supply and exhaust in tunnel, to meet with the ventilation requirements of system and the purposes of extend the life of equipment as well as energy-efficient. |
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