Abstract:

The virtually composed train technique ensures that transport capacity aligns with passenger flow by employing a flexible formation operating strategy. Utilizing the concept of relative braking distance, it operates based on the principle of reducing the interval between trains within a formation. Calculating the safety intervals for protection is a complex process, which is exacerbated by the variable-deceleration braking process owing to line gradients. To address this complexity and overcome the impracticality of existing overly simplified methods, a novel safety protection approach based on equivalent trajectory time deviation is proposed. This approach translates the actual trajectories of trains within the formation into equivalent trajectories with a constant gradient acceleration, thus establishing the upper and lower limits of the time deviation between these trajectories before and after conversion. By analyzing the equivalent trajectory time deviation, the safety protection issue of virtually composed trains is converted into a task of determining whether the lead train's latest passing time at a given point precedes the earliest passing time of the following train at the same point. This conversion simplifies the calculations and effectively manages the variable deceleration movements of the preceding and following trains. Simulations are conducted using real-world line data to calculate the equivalent gradient deceleration and time deviation of trains at various positions and speeds. The results indicate that the method utilizing the equivalent trajectory time deviation can effectively monitor the safe running intervals of virtually composed trains and accommodate variations in deceleration owing to factors such as line gradients, train running resistance, braking force characteristics, and performance disparities between the leading and following trains. The proposed method is feasible for engineering applications.

Key words: flexible composed train, virtual composed train, equivalent trajectory, time deviation, safety braking model, automatic train control, automatic train protection

摘要：

列车虚拟编组技术通过灵活的编队运行方式实现运能与客流的匹配, 其原理是基于相对制动距离原则缩短编队内列车的运行间隔。线路坡度使得列车制动过程为变减速度运动, 导致安全间隔防护计算过程较为复杂, 而既有方法处理该过程存在过于简化、缺乏工程可实施性的问题, 针对此, 提出一种基于等效轨迹时间偏差的安全防护方法。该方法将编队内列车的实际运行轨迹转换为恒定坡度加速度运行的等效轨迹, 并推导出转换前后两种轨迹的时间偏差上下界。基于对等效轨迹时间偏差的分析, 将虚拟编组列车的安全防护转换为对领航列车通过某位置的最晚时间是否早于跟随列车通过该位置的最早时间的判断, 从而既简化了运算, 又能够处理前后列车的变减速度运动过程。选取某实际线路数据, 通过仿真计算不同位置、不同速度时列车的等效坡度减速度和时间偏差, 结果表明采用等效轨迹时间偏差的计算方法能够监控虚拟编组列车的安全运行间隔, 能够处理线路坡度、列车运行阻力、制动力特性, 以及前后车性能差异造成的减速度变化, 具备工程可行性。

关键词: 灵活编组, 虚拟编组, 等效轨迹, 时间偏差, 安全制动模型, 列车自动控制, 列车自动防护