Research On Active Control Of Cable-stayed Bridge Incorporated With EMD System Using Intelligent Theory

Benchmark bridge of Emerson Memorial was taken as the research object in the thesis. The electromagnet-drived active mass dampers (EMD) were selected as the active control devices. Intelligent theories such as fuzzy logic theory, artificial neural network, fuzzy neural network, genetic algorithm and so on, were applied to model the behavior of EMD system, find the optimal controller parameters, and identify the bridge structural dynamical characteristics. A set of evaluation criteria was designed to study the control effectiveness based on different intelligent theory. And online control method of EMD's input voltage was studied. Main contents of the thesis are as follows.1. Using non-linearity handling ability of the fuzzy neural network, take the test data as the training and checking data of FNN, establishes the relations between the input variable and the output variable under the generalized condition, builds an intelligent model of EMD vibration control system, thus computation effect of the existing force electricity relations for electromagnet-drived AMD vibration control system can be improved effectively.2. A control parameter optimization method based on genetic algorithm was presented. To the electromagnet-drived active mass damper's parameter design in bridge structural control, the optimal controller parameter under seismic excitation was found by the strong nonlinear optimization ability of genetic algorithm.3. A bridge structural system identification method based on artificial neural network was presented. Utilizing the strong learning and nonlinear approaches ability of the artificial neural network, the weakness of the traditional system identification such as bad weak tolerant ability and nonlinear identification was overcame. The method can identify the dynamic characteristics of the bridge under uncontrolled and controlled effectively. Through the numerical simulation example, validity and usability of the method was confirmed.4. The force electricity relation of electromagnet-drived active mass damper working for long span bridge was established based on the electromagnetic theory. According to the earthquake resistance design characteristic of long span bridge, online control method of EMD's input voltage based on GA-BP network was presented. The input voltage can be instantly chosen as soon as the dynamic response and earthquake acceleration are gathered by the sensors. The big slow computation and time delay problem are both resolved. Thus, the online vibration control of the long span bridge can be realized precisely.5. Intelligent active vibration control online of the bridge structure based on fuzzy logic theory was presented. Utilizing the characteristics of fuzzy logic theory such as the easiness forming the expert knowledge and experience, strong robustness, simple but practical. The active force can be instantly chosen as soon as the dynamic response and earthquake acceleration are gathered by the sensors. The force can be exerted in the bridge structure by the EMD, and then, the dynamic response of the bridge can be reduced effectively.6. Intelligent active vibration control online of the bridge structure based on fuzzy neural network was presented. Utilizing the strong learning and clustering ability of the fuzzy neural network, the active force can be instantly chosen as soon as the dynamic response and earthquake acceleration are gathered by the sensors. The force can be exerted in the bridge structure by the EMD, and then, the dynamic response of the bridge can be reduced greatly.