Data-Driven Distributionally Robust Electric Vehicle Balancing for
Mobility-on-Demand Systems under Demand and Supply Uncertainties
Sihong He Lynn Pepin Guang Wang Desheng Zhang Fei Miao
Abstract— As electric vehicle (EV) technologies become
mature, EV has been rapidly adopted in modern trans-
portation systems, and is expected to provide future au-
tonomous mobility-on-demand (AMoD) service with eco-
nomic and societal benefits. However, EVs require frequent
recharges due to their limited and unpredictable cruising
ranges, and they have to be managed efficiently given the
dynamic charging process. It is urgent and challenging
to investigate a computationally efficient algorithm that
provide EV AMoD system performance guarantees under
model uncertainties, instead of using heuristic demand
or charging models. To accomplish this goal, this work
designs a data-driven distributionally robust optimization
approach for vehicle supply-demand ratio and charging
station utilization balancing, while minimizing the worst-
case expected cost considering both passenger mobility
demand uncertainties and EV supply uncertainties. We
then derive an equivalent computationally tractable form
for solving the distributionally robust problem in a com-
putationally efficient way under ellipsoid uncertainty sets
constructed from data. Based on E-taxi system data of
Shenzhen city, we show that the average total balancing
cost is reduced by 14.49%, the average unfairness of
supply-demand ratio and utilization is reduced by 15.78%
and 34.51% respectively with the distributionally robust
vehicle balancing method, compared with solutions which
do not consider model uncertainties.
I. INTRODUCTION
There are over 5 million EVs by December 2018
globally, and this figure is predicted to increase to 100-
125 million by 2030 [3]. Compared to conventional gas
vehicles, EV fleets have prolonged charging time and
concentrated mobility patterns due to current charging
technologies and limited charging infrastructures, espe-
cially for commercial EV fleets, e.g., e-taxi, future au-
tonomous mobility-on-demand (AMoD) systems, given
their long daily travel distances [14].
Researchers have been focusing on models and algo-
rithms to study EVs [16], [14]. There have also been
This work has been published in International Conference on
Intelligent Robots and Systems (IROS 2020). Sihong He, Lynn Pepin,
and Fei Miao are with the Department of Computer Science and
Engineering, University of Connecticut, Storrs Mansfield, CT, USA
06268. Email: {sihong.he, lynn.pepin, fei.miao}@uconn.edu. This
work is also partially supported by NSF SAS-1849238 and CPS-
1932223. Guang Wang and Desheng Zhang are with the Department
of Computer Science, Rutgers University, Piscataway, NJ, USA 08901.
Email: {gw255, desheng.zhang}@cs.rutgers.edu.
focusing on how to choose the optimal locations for
charging stations and how to assign charging points
to EVs in each station to minimize the charging time
of EVs considering various constraints, e.g., demand,
costs, and charging compatibility [6], [15]. However,
high costs of charging infrastructures and land resources
make it impractical to deploy abundant charging stations
and points at the early promotion stage [15]. Even when
there is enough charging infrastructure for all EVs in
theory, the uncontrolled and decentralized charging and
mobility behaviors of some EV fleets, e.g., e-taxi, cause
long waiting times when the demand for charging points
greatly exceeds the availability [12].
The above mentioned EV management issues have
posed key optimization and scheduling algorithm chal-
lenges for world-wide EV adoption of AMoD. The
interaction between AMoD systems and power networks
through EVs based on the vehicles’ charging require-
ments, battery depreciation, and power transmission
constraints have been investigated, and the economic
and societal value of EV AMoD has been analyzed [11].
To improve the performance of general AMoD systems,
mobility demand based vehicle balancing methods have
been proposed with various system design objectives,
such as reducing the number of vehicles needed to serve
all passengers [19], [4], reducing customers’ waiting
time [13], or taxis’ total idle distance [8]. However, the
limited knowledge we have about charging patterns [14]
affect the performance of vehicle balancing strategies,
and make real-time decisions under demand model un-
certainties still a challenging and unsolved task.
The contributions of this work are as follows:
•We are the first to consider both future demand
uncertainties and EV supply uncertainties predicted
based on charging activity data in designing a
system-level vehicle balancing algorithm. While
model predictive control algorithms [19], [4] have
been designed considering AMoD system demand
uncertainties in the literature, the supply side un-
certainties for EV AMoD is not well studied yet.
•We design a distributionally robust optimization
approach to balance EVs across a city for min-
imum total idle distance and balanced charging
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arXiv:2210.10887v1 [math.OC] 19 Oct 2022