Advanced maintenance cycle optimization of urban rail transit vehicles

With the development of the economy and the increase in passenger flow, the contradiction between urban rail transit demand and capacity is becoming more and more prominent. Increasing the number of on-line vehicles can ease this situation. Because of no increase in investment, the total number of subway vehicles is fixed. And the total vehicles include the maintenance vehicles and the on-line vehicles. Therefore, this article aims to optimize advanced maintenance cycle, so that the maintenance vehicles reduce and the on-line vehicles increase. First, the minimum value of the key components safe and reliable operating mileage is determined. Then, the Queuing Theory is used to obtain the optimized advanced maintenance cycle. Finally, reasonable maintenance plans are arranged based on the optimized maintenance cycle. The on-line vehicles increase by the optimized advanced maintenance cycle, which can relieve passenger flow pressure and meet urban rail transit demand. In addition, the reasonable maintenance plans can ensure that vehicles at the same level of reliability and within the specified mileage to complete the advanced maintenance and ensure the safe and reliable operation of vehicles