With the rapid development of China's economy and the acceleration of urbanization, urban rail transit is flourishing. The increase in operational mileage and the complexity of routes have imposed higher demands on train operation in terms of energy consumption, punctuality, and passenger comfort. Generally, trains operate within sections according to several pre-planned target speed profiles. However, unexpected incidents, such as equipment failures or emergency operational commands, can cause trains to make unplanned stops within sections. Such unexpected stops disrupt normal operations and pose challenges to maintaining efficiency, punctuality, and passenger comfort. This study addresses this scenario by considering the current position and the expected arrival time, employing an improved rapid dynamic programming method to solve the train operation profile, thereby enabling the efficient resumption of operations. Validation with actual line data demonstrates that, compared to methods based on fixed operating conditions that satisfy time constraints, the proposed method exhibits stronger real-time performance while maintaining minimal performance differences.