Max-pressure signal control with cyclical phase structure
Max-pressure signal control with cyclical phase structure
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DOI：
10.1016/j.trc.2020.102828
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发表时间：
2020-11
影响因子：
8.3
通讯作者：
M. Levin;Jeffrey Hu;M. Odell
中科院分区：
文献类型：
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作者：
M. Levin;Jeffrey Hu;M. Odell
最大压力交通信号控制具有许多理想的特性。分析证明，如果任何信号控制都可以满足需求，则可以最大限度地提高网络吞吐量。尽管其网络级的稳定性，控制本身是分散的，因此很容易计算的个别路口控制器。与城市工程师的讨论表明，在实践中实施的主要障碍是最大压力控制的非周期性相位致动，其可以以任意顺序致动任何相位，以服务于具有最高压力的队列。这种任意的相位选择可能会使期望信号周期的旅行者感到困惑，因此对于一些城市交通工程师来说是不可接受的。本文修改了原来的最大压力控制，包括信号周期约束。最大压力控制必须按顺序致动一组外源相，每个相在每个周期至少致动一个时间步长。每个循环都有最大长度，但如果需要，长度可以减少。在这些约束条件下，我们定义了一个修改的最大压力控制，并证明其最大稳定性。修正后的最大压力控制采用一个周期前瞻的模型预测控制的形式，但我们证明，最优解可以很容易地通过枚举阶段。政策仍然是分散的。数值结果表明，正如预期的那样，周期性最大压力控制性能略差于原来的最大压力控制，由于额外的约束，但具有更大的适口性在实践中实施的优势。
Max-pressure traffic signal control has many desirable properties. It is analytically proven to maximize network throughput if demand could be served by any signal control. Despite its network-level stability properties, the control itself is decentralized and therefore easily computed by individual intersection controllers. Discussions with city engineers have suggested that a major barrier to implementation in practice is the non-cyclical phase actuation of max-pressure control, which can actuate any phase, in arbitrary order, to serve the queue(s) with highest pressure. This arbitrary phase selection may be confusing to travelers expecting a signal cycle, and is therefore unacceptable to some city traffic engineers. This paper revises the original max-pressure control to include a signal cycle constraint. The max-pressure control must actuate an exogenous set of phases in order, with each phase actuated at least one time step per cycle. Each cycle has a maximum length, but the length can be reduced if desired. Within those constraints, we define a modified max-pressure control and prove its maximum stability property. The revised max-pressure control takes the form of a model predictive control with a one cycle lookahead, but we prove that the optimal solution can be easily found by enumerating over phases. The policy is still decentralized. Numerical results show that as expected, the cyclical max-pressure control performs slightly worse than the original max-pressure control due to the additional constraints, but with the advantage of greater palatability for implementation in practice.