3 research outputs found
Integrated Optimization of Power Split, Engine Thermal Management, and Cabin Heating for Hybrid Electric Vehicles
Cabin heating demand and engine efficiency degradation in cold weather lead
to considerable increase in fuel consumption of hybrid electric vehicles
(HEVs), especially in congested traffic conditions. This paper presents an
integrated power and thermal management (i-PTM) scheme for the optimization of
power split, engine thermal management, and cabin heating of HEVs. A
control-oriented model of a power split HEV, including power and thermal loops,
is developed and experimentally validated against data collected from a 2017
Toyota Prius HEV. Based on this model, the dynamic programming (DP) technique
is adopted to derive a bench-mark for minimal fuel consumption, using
2-dimensional (power split and engine thermal management) and 3-dimensional
(power split, engine thermal management, and cabin heating) formulations.
Simulation results for a real-world congested driving cycle show that the
engine thermal effect and the cabin heating requirement can significantly
influence the optimal behavior for the power management, and substantial
potential on fuel saving can be achieved by the i-PTM optimization as compared
to conventional power and thermal management strategies.Comment: 6 pages, 10 figures, 2 tables, The 3rd IEEE Conference on Control
Technology and Applications (CCTA, August 19--21, 2019, Hong Kong, Chin
Thermal Responses of Connected HEVs Engine and Aftertreatment Systems to Eco-Driving
Connected and automated vehicles (CAVs) have been recognized as providing
unprecedented opportunities for substantial fuel economy improvement through
CAV-based vehicle speed trajectory optimization (eco-driving). At the same
time, the implications of the CAV operation on thermal responses, including
those of engine and exhaust aftertreatment system, have not been fully
investigated. To this end, firstly, a sequential optimization framework for
vehicle speed trajectory planning and powertrain control in hybrid electric
CAVs is proposed in this paper. Next, the impact of eco-driving and power split
optimization on the engine and catalytic converter thermal responses, as well
as on the tailpipe emissions is characterized. Despite an average 16%
improvement in fuel economy through sequential optimization, this study shows
that eco-driving slows down the thermal responses, which could unfavorably
affect the tailpipe emissions.Comment: 6 pages, 7 figures, The 3rd IEEE Conference on Control Technology and
Applications (CCTA), August 19--21, 2019, Hong Kong, Chin
Integrated Power and Thermal Management of Connected HEVs via Multi-Horizon MPC
In this paper, a multi-horizon model predictive controller (MH-MPC) is
developed for integrated power and thermal management (iPTM) of a power-split
hybrid electric vehicle (HEV). The proposed MH-MPC leverages an accurate
short-horizon vehicle speed preview and an approximate forecast over a longer
shrinking horizon till the end of the driving cycle. This multiple-horizon
scheme is developed to cope with fast and slow dynamics associated with power
and thermal responses. The main objective of the proposed MH-MPC is to minimize
fuel consumption and enforce the power and thermal constraints on the battery
state-of-charge and engine coolant temperature, while meeting the driving
(traction) and cabin air conditioning (heating) demands. The proposed MH-MPC
allows for exploiting the engine coolant as thermal energy storage, providing
more flexibility for the HEV energy flow optimization. The simulation results
show that the proposed MH-MPC provides near-optimal results in reference to the
Dynamic Programming (DP) solution with an affordable computational cost.
Moreover, compared with a more conventional MPC strategy, the MH-MPC can
leverage the speed previews with different resolutions effectively to achieve
the desired performance with satisfactory robustness.Comment: 8 Figures, Accepted in 2020 American Control Conference (ACC), July 1
to 3, 2020, Denver, CO, US