Ramp metering (RM) has been widely used for controlling RM flow to prevent capacity drop at merge bottlenecks. In many situations, bottlenecks such as lane reduction, curvature section and traffic incident, bottlenecks with smaller capacity than the merging area, may locate further downstream. They require faster responding speed and more accurate action of RM. This study aims at proposing a fuzzy self-adaptive proportional–integral–derivative (FSAPID) control strategy for RM control at distance downstream bottlenecks, this FSAPID control is composed of proportional–integral–derivative control and fuzzy control. For the simulation of control effects, three downstream bottlenecks with different distances to the merge area are developed in the cell transmission model. The results show that the proposed algorithm reduces the total travel time by 41–43% in the stable demand scenes, and 38–42% in the fluctuating demand scenes. The results also suggest that the FSAPID control strategy has the merits of fast convergence, strong predictive ability and high action precision, and achieves preferable performance especially when the bottleneck is located far downstream.

中文翻译：

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距离瓶颈处斜道计量的模糊自适应比例-积分-微分控制策略

斜坡计量（RM）已被广泛用于控制RM流量，以防止合并瓶颈时容量下降。在许多情况下，瓶颈（例如车道缩小，弯道截面和交通事故），容量小于合并区域的瓶颈可能位于更下游。他们需要更快的响应速度和更准确的RM操作。本研究旨在为下游瓶颈处的RM控制提出模糊自适应比例-积分-微分（FSAPID）控制策略，该FSAPID控制由比例-积分-微分控制和模糊控制组成。为了模拟控制效果，在单元传输模型中开发了三个到合并区域的距离不同的下游瓶颈。结果表明，所提出的算法在稳定的需求场景中减少了41-43％的总旅行时间，在波动的需求场景中减少了38-42％的旅行时间。结果还表明，FSAPID控制策略具有收敛速度快，预测能力强，动作精度高的优点，尤其在瓶颈位于下游时，具有较好的性能。