| The Balise is a piece of equipment for train-to-wayside information transmission based on the electromagnetic coupling mechanism. In recent years the high-speed railway and urban rail traffic system have developed rapidly in China, and the speed of the train have been increasing gradually, but there is a phenomenon that sometimes the Balise wasn’t detected in the process of practical operation, which affects the efficiency of train operation and also brings security risks to some extent. In order to promote the telegram receiving ability of on-board transmission equipment, the method for optimizing the size of Balise antenna was proposed and the influence of Balise angular deflection on the transmission performance was studied to optimize the electromagnetic transmission performance of the Balise system. The main work is as follows:The Balise system was modeled by electromagnetic simulation software, and the correctness of the model was verified combining with theoretical calculation. Based on the theoretical model of the Balise system, the tele-powering receiving model and the up-link transmitting model were established under Balise tilting, pitching and yawing. The transmission process of interface ’A’ was analyzed. The method for determining the effective Balise distances was obtained under the restriction of tele-powering radiation pattern, weakest possible Balise, strongest possible Balise and BTM receiving threshold.Using the electromagnetic model of Balise system for simulation analysis, and three indexes were determined to evaluate Balise antenna electromagnetic transmission performance comprehensively, which include the activation distance or the range of action, the total receiving power and the total receiving power in lateral deviation within the range of necessary reception. The BP neural network was established and the sample data was selected by uniform design to train neural network, then the nonlinear relationship between the size of the Balise antenna and the electromagnetic transmission performance was obtained. Finally, combining with the nonlinear optimization ability of particle swarm optimization algorithm, the optimal antenna length-width ratio of tele-powering receiving antenna and up-link transmitting antenna were found in different perimeters.The conformity assessment methods of tele-powering field and up-link field were determined. Using these theoretical models of Balise system angle deviation, the conformity of tele-powering field and up-link field were evaluated while Balise was tilting, pitching and yawing. The angular ranges meeting the conformity requirements for Balise installation were obtained. The interface ’A’ transmission process was established by theoretical calculation and the effective Balise distances were calculated, and then the influence of Balise angular deflection on the effective Balise distances was obtained. |
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