论文标题
自动移动性网络的时空定价和车队管理:一种分解和动态编程方法,具有有限的最佳差距
Spatiotemporal Pricing and Fleet Management of Autonomous Mobility-on-Demand Networks: A Decomposition and Dynamic Programming Approach with Bounded Optimality Gap
论文作者
论文摘要
本文研究了时空定价和车队管理,以实现弹性需求的同时,以实现需求的自动迁移率(AMOD)系统。我们考虑使用一个使用自动驾驶汽车的车队提供乘车服务的平台,并为需求波动做出定价,重新平衡和机队尺寸的决策。开发了网络流模型,以表征系统状态在时空上的演变,从而捕获了乘客匹配过程,并要求相对于价格和等待时间弹性。该平台最大化利润的目标是作为一个约束的最佳控制问题,由于非线性需求模型和复杂的供求需求相互依赖性,因此高度非概念。为了应对这一挑战,提出了一种集成的分解和动态编程方法,我们首先通过变化来放松问题,然后通过双重分解将放松的问题分离为一些小规模的子问题,最后使用动态编程解决每个子问题。尽管有非概念性,但我们的方法仍建立了一种理论上的上限来评估解决方案最优性。提出的模型和方法论在曼哈顿的数值研究中得到了验证。我们发现,与基准案例相比,所提出的上限明显更紧密。我们还发现,与仅定价相比,只有在准确预测需求时,共同的定价和舰队重新平衡才能提供较小的利润。但是,在意外的需求激增期间,联合定价和重新平衡可以大大提高利润,并且需求冲击的影响尽管更为广泛,但可以更快地消散。
This paper studies spatiotemporal pricing and fleet management for autonomous mobility-on-demand (AMoD) systems while taking elastic demand into account. We consider a platform that offers ride-hailing services using a fleet of autonomous vehicles and makes pricing, rebalancing, and fleet sizing decisions in response to demand fluctuations. A network flow model is developed to characterize the evolution of system states over space and time, which captures the vehicle-passenger matching process and demand elasticity with respect to price and waiting time. The platform's objective of maximizing profit is formulated as a constrained optimal control problem, which is highly nonconvex due to the nonlinear demand model and complex supply-demand interdependence. To address this challenge, an integrated decomposition and dynamic programming approach is proposed, where we first relax the problem through a change of variable, then separate the relaxed problem into a few small-scale subproblems via dual decomposition, and finally solve each subproblem using dynamic programming. Despite the nonconvexity, our approach establishes a theoretical upper bound to evaluate the solution optimality. The proposed model and methodology are validated in numerical studies for Manhattan. We find that compared to the benchmark case, the proposed upper bound is significantly tighter. We also find that compared to pricing alone, joint pricing and fleet rebalancing can only offer a minor profit improvement when demand can be accurately predicted. However, during unanticipated demand surges, joint pricing and rebalancing can lead to substantially improved profits, and the impacts of demand shocks, despite being more widespread, can dissipate faster.