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Öğe A comparative study of energy management systems under connected driving: cooperative car-following case(OAE Publishing Inc., 2022) Yazar, Ozan; Coskun, Serdar; Zhang, Fengqi; Li, LinIn this work, we propose connected energy management systems for a cooperative hybrid electric vehicle (HEV) platoon. To this end, cooperative driving scenarios are established under different car-following behavior models using connected and automated vehicles technology, leading to a cooperative cruise control system (CACC) that explores the energy-saving potentials of HEVs. As a real-time energy management control, an equivalent consumption minimization strategy (ECMS) is utilized, wherein global energy-saving is achieved to promote environment-friendly mobility. The HEVs cooperatively communicate and exchange state information and control decisions with each other by sixth-generation vehicle-to-everything (6G-V2X) communications. In this study, three different car-following behavior models are used: intelligent driver model (IDM), Gazis–Herman–Rothery (GHR) model, and optimal velocity model (OVM). Adopting cooperative driving of six Toyota Prius HEV platoon scenarios, simulations under New European Driving Cycle (NEDC), Worldwide Harmonized Light Vehicle Test Procedure (WLTP), and Highway Fuel Economy Test (HWFET), as well as human-in-the-loop (HIL) experiments, are carried out via MATLAB/Simulink/dSPACE for cooperative HEV platooning control via different car-following-linked-vehicle scenarios. The CACC-ECMS scheme is assessed for HEV energy management via 6G-V2X broadcasting, and it is found that the proposed strategy exhibits improvements in vehicular driving performance. The IDM-based CACC-ECMS is an energy-efficient strategy for the platoon that saves: (i) 8.29% fuel compared to the GHR-based CACC-ECMS and 10.47% fuel compared to the OVMbased CACC-ECMS under NEDC; (ii) 7.47% fuel compared to the GHR-based CACC-ECMS and 11% fuel compared to the OVM-based CACC-ECMS under WLTP; (iii) 3.62% fuel compared to the GHR-based CACC-ECMS and 4.22% fuel compared to the OVM-based CACC-ECMS under HWFET; and (iv) 11.05% fuel compared to the GHR-based CACC-ECMS and 18.26% fuel compared to the OVM-based CACC-ECMS under HIL. © The Author(s) 2022.Öğe A data-driven energy management strategy for plug-in hybrid electric buses considering vehicle mass uncertainty(Elsevier, 2024) Ma, Zheng; Luan, Yixuan; Zhang, Fengqi; Xie, Shaobo; Coskun, SerdarConventional energy management strategies (EMSs) for hybrid electric vehicles are devised assuming the vehicle mass remains constant under dynamic driving conditions. However, the EMSs cannot adapt to different load conditions due to the dynamic change of vehicle mass. Investigating the characteristics of vehicle mass change plays significant roles in energy optimization, thereby improving overall efficiency and mobility. To this end, we propose an adaptive EMS for a plug-in hybrid electric bus (PHEB) based on artificial neutral network-Pontryagin minimum principle (ANN-PMP) by considering mass distribution characteristics. Firstly, the skew-normal distribution characteristics of PHEB mass are analyzed, and the distribution characteristic spectrum of vehicle mass is obtained based on the Monte Carlo method. Secondly, the influence of mass uncertainty on the PMP is analyzed, and then the ANN-PMP is devised by updating a dynamic co-state with ANN. Finally, an enhanced ANN-PMP (so-called ANN-PMP-CS) is proposed by combining the ANN-PMP strategy obtained by mass distri-bution training and CS (charge sustaining strategy) to include the no-load or full-load cases. The simulation results demonstrate that the ANN-PMP can adapt to mass change while ensuring that the final state-of-charge (SOC) convergence to the target value. We also observe that the fuel economy of ANN-PMP-CS is similar to that of the widely-used dynamic programming (DP) strategy. Compared with the charge depletion-charge sus-taining (CD-CS) strategy, the fuel economy can be improved by about 46.93 % on average.Öğe A multi-objective hierarchical deep reinforcement learning algorithm for connected and automated HEVs energy management(Pergamon-Elsevier Science Ltd, 2024) Coskun, Serdar; Yazar, Ozan; Zhang, Fengqi; Li, Lin; Huang, Cong; Karimi, Hamid RezaConnected and autonomous vehicles have offered unprecedented opportunities to improve fuel economy and reduce emissions of hybrid electric vehicle (HEV) in vehicular platoons. In this context, a hierarchical control strategy is put forward for connected HEVs. Firstly, we consider a deep deterministic policy gradient (DDPG) algorithm to compute the optimized vehicle speed using a trained optimal policy via vehicle-to-vehicle communication in the upper level. A multi-objective reward function is introduced, integrating vehicle fuel consumption, battery state-of-the-charge, emissions, and vehicle car-following objectives. Secondly, an adaptive equivalent consumption minimization strategy is devised to implement vehicle-level torque allocation in the platoon. Two drive cycles, HWFET and human-in-the-loop simulator driving cycles are utilized for realistic testing of the considered platoon energy management. It is shown that DDPG runs the engine more efficiently than the widely-implemented Q-learning and deep Q-network, thus showing enhanced fuel savings. Further, the contribution of this paper is to speed up the higher-level vehicular control application of deep learning algorithms in the connected and automated HEV platoon energy management applications.Öğe Actor-Critic TD3-based Deep Reinforcement Learning for Energy Management Strategy of HEV(Institute of Electrical and Electronics Engineers Inc., 2023) Yazar, Ozan; Coskun, Serdar; Li, Lin; Zhang, Fengqi; Huang, CongIn the last decade, deep reinforcement learning (DRL) algorithms have been employed in the design of energy management strategy (EMS) for hybrid electric vehicles (HEVs). Investigation of the real-time applicability of DRL algorithms as an EMS is critical in terms of training time, fuel savings, and state-of-charge (SOC) sustainability. To this end, we propose a twin delayed deep deterministic policy gradient (TD3) algorithm that is an improved version of the deep deterministic policy gradient (DDPG) algorithm for HEV fuel savings. Compared to the existing Q-learning-based reinforcement learning and the deep Q-network-based and DDPG-based deep reinforcement algorithms, the proposed TD3 provides stable training efficiency, promising fuel economy, and a lower variation range of SOC charge sustainability under various drive cycles. © 2023 IEEE.Öğe Co-optimization on ecological adaptive cruise control and energy management of automated hybrid electric vehicles(Pergamon-Elsevier Science Ltd, 2025) Zhang, Fengqi; Qi, Zhicheng; Xiao, Lehua; Coskun, Serdar; Xie, Shaobo; Liu, Yongtao; Li, JiachengElectrified drive systems and eco-driving technologies play a crucial role in promoting energy conservation. Ecodriving for hybrid electric vehicles(HEVs) is an intricate problem involving intertwined speed planning and energy management. In this context, an ecological adaptive cruise control (eco-ACC) and powertrain energy management strategy considering Signal Phase Timing Message (SPaT) can enhance both performance and realtime implementation. Specifically, this study develops a novel co-optimization method based on Pontryagin's minimum principle (PMP) that combines car-following control rules with the SPaT for a parallel HEV. The methodology involves the following steps: firstly, the parallel HEV model is established; secondly, the safe following distance model is constructed and the car-following control rules are devised to ensure safe driving. Subsequently, the co-optimization method based on PMP is then presented to simultaneously optimize the ecodriving problem of an ego-vehicle by converting the inter-vehicle distance constraint of the lead-vehicle into the limitation of the speed of the ego-vehicle. Finally, simulations are conducted under different scenarios for both fused SPaT and non-fused SPaT strategy. The simulation results demonstrate a reduction in fuel consumption by 6.27% and 5.69 % in two different scenarios, respectively, and a shorter driving time for the fused SPaT strategy compared to the non-fused SPaT strategy.Öğe Co-optimized Analytical Solution of Speed Planning and Energy Management for Automated Hybrid Electric Vehicles under Multi-Signal Intersections Scenario(Institute of Electrical and Electronics Engineers Inc., 2025) Zhang, Fengqi; Xiao, Lehua; Xie, Shaobo; Coskun, Serdar; Guo, Yingshi; Yang, Yalian; Hu, XiaosongEco-driving is a viable technology with higher energy-saving potential at signalized intersections. The rapid development of connected and automated technology provides more opportunities for the eco-driving of hybrid electric vehicles (HEVs). However, it is more challenging to co-optimize speed planning and energy management due to their coupling and complex features. To this end, a co-optimization method of speed planning and energy management under multi-signal intersections scenario is proposed for automated HEV by obtaining an explicit optimal analytical solution. Firstly, considering the shifting behavior of a parallel HEV, a single-parameter gear-shifting model is adopted. Then, the co-optimization method is proposed, which consists of two steps. In the first step, the vehicle arrival time at signalized intersections is determined by calculating a vehicle reference speed. In the second step, the speed and powertrain energy management are co-optimized using the Pontryagin minimum principle by deriving an optimal analytical solution under multi-signal intersections. Finally, an iterative loop algorithm is utilized to compute the initial co-states, and the sensitivity analysis is conducted in this sequel. Simulation results demonstrate that the proposed co-optimization approach can greatly reduce the computational cost while maintaining satisfactory energy efficiency as compared with the widely-used dynamic programming method. © 2015 IEEE.Öğe Comparative study of energy management in parallel hybrid electric vehicles considering battery ageing(Pergamon-Elsevier Science Ltd, 2023) Zhang, Fengqi; Xiao, Lehua; Coskun, Serdar; Pang, Hui; Xie, Shaobo; Liu, Kailong; Cui, YahuiThis article presents a thorough comparative study of energy management strategies (EMSs) for a par-allel hybrid electric vehicle (HEV), while the battery ageing is considered. The principle of dynamic programming (DP), Pontryagin's minimum principle (PMP), and equivalent consumption minimization strategy (ECMS) considering battery ageing is elaborated. The gearshift map is obtained from the opti-mization results in DP to prevent frequent shifts by taking into account drivability and fuel economy, which is then applied in the PMP and ECMS. Comparison of different EMSs is conducted by means of fuel economy, battery state-of-charge charge-sustainability, and computational efficiency. Moreover, battery ageing is included in the optimization solution by utilizing a control-oriented model, aiming to fulfill one of the main cost-related design concerns in the development of HEVs. Through a unified framework, the torque split and battery degradation are simultaneously optimized in this study. Simulations are carried out for DP, PMP, and ECMS to analyze their features, wherein results indicate that DP obtains the best fuel economy compared with other methods. Additionally, the difference between DP and PMP is about 2% in terms of fuel economy. The observations from analysis results provide a good insight into the merits and demerits of each approach. (c) 2022 Published by Elsevier Ltd.Öğe Computationally Efficient Energy Management in Hybrid Electric Vehicles Based on Approximate Pontryagin's Minimum Principle(Mdpi, 2020) Zhang, Fengqi; Wang, Lihua; Coskun, Serdar; Cui, Yahui; Pang, HuiThis article presents an energy management method for a parallel hybrid electric vehicle (HEV) based on approximate Pontryagin's Minimum Principle (A-PMP). The A-PMP optimizes gearshift commands and torque distribution for overall energy efficiency. As a practical numerical solution in PMP, the proposed methodology utilizes a piecewise linear approximation of the engine fuel rate and state of charge (SOC) derivative by considering drivability and fuel economy simultaneously. Moreover, battery aging is explicitly studied by introducing a control-oriented model, which aims to investigate the effect of battery aging on the optimization performance in the development of the HEVs. An approximate energy management strategy with piecewise linear models is then formulated by the A-PMP, which targets a better performance for the Hamiltonian optimization. The gearshift map is extracted from the optimal results in the standard PMP to hinder frequent gearshift by considering both drivability and fuel economy. Utilizing an approximated Hamilton function, the torque distribution, gearshift command, and the battery aging degradation are jointly optimized under a unified framework. Simulations are performed for dynamic programming (DP), PMP, and A-PMP to validate the effectiveness of the proposed approach. The results indicate that the proposed methodology achieves a close fuel economy compared with the DP-based optimal solution. Moreover, it improves the computation efficiency by 50% and energy saving by 3.5%, compared with the PMP, while ensuring good drivability and fuel efficiency.Öğe Dynamic Traffic Prediction-Based Energy Management of Connected Plug-In Hybrid Electric Vehicles with Long Short-Term State of Charge Planning(Ieee-Inst Electrical Electronics Engineers Inc, 2023) Zhao, Nan; Zhang, Fengqi; Yang, Yalian; Coskun, Serdar; Lin, Xianke; Hu, XiaosongVehicle electrification, automation, and connectivity in today's transportation require significant efforts in control design to meet conflicting goals of energy efficiency, traffic safety, as well as comfort. The rapid development of intelligent transportation systems (ITS) and the rapid growth of connectivity technologies enable vehicles to receive more information about traffic conditions, which provides a reliable solution for the energy management of plug-in hybrid electric vehicles (PHEVs). This article proposes a predictive energy management strategy (EMS) for connected PHEV based on real-time dynamic traffic prediction. First, the future traffic information is predicted by establishing a wavelet neural network (WNN). Thus, the global driving condition can be predicted. Then, the particle swarm optimization (PSO) algorithm is used to optimize the parameters of WNN to plan a global battery state-of-charge (SOC) reference. Second, a long short-term memory-based velocity predictor is proposed for the predictive EMS, by planning SOC over a prediction horizon based on the global SOC reference. Finally, the performance of the proposed EMS with WNN and PSO-WNN is verified by the actual traffic data. The results show that it can improve the fuel economy by 17.57% and 28.19%, respectively.Öğe Economic-social-oriented energy management of plug-in hybrid electric vehicles including social cost of carbon(Elsevier, 2024) Zhang, Tao; Peng, Guozhi; Zhang, Yanwei; Xie, Shaobo; Zhang, Fengqi; Serdar, CoskunFor plug-in hybrid electric vehicles (PHEVs), conventional energy management strategies (EMSs) incorporate the output of the battery and power sources for energy-saving studies. The source of the battery charge and the social cost of carbon (SCC) associated with carbon emissions result in the economic-social cost of climate and environmental damage, particularly when the battery charge comes from thermal power. Consequently, conventional EMSs cannot improve the efficiency of PHEVs with respect to the SCC from an environment-friendly perspective. Also, overuse of battery charge can provide low-cost vehicular propulsion, but lead to battery aging, implying an associated cost. In this context, the battery discharge and aging are conflicted in the design of EMSs for PHEVs. This paper develops a novel EMS by explicitly considering the social cost of carbon emissions using model predictive control (MPC). The strategy devises the trade -off between the energy consumption cost, battery life loss cost, and social cost of carbon emissions by minimizing their total cost over a specific driving range. The driving cycle is developed based on real -world data in Xi ' an City, and the MPC is employed to assess the performance of EMS in a PHEV bus. Meanwhile, the widely used EMSs are compared in the simulation analysis, including the rule-based strategy, dynamic programming, and Pontryagin ' s minimum principle. Moreover, two sources of thermal power and wind power for the battery charge are conducted and compared. The results demonstrate that the proposed MPC-based EMS can generate the minimum total cost compared to the EMSs only considering the energy consumption and battery aging costs. Compared to thermal power as the source of battery charge, wind power can remarkably lower the total cost using the MPC, achieving a 19.2 % improvement. In addition, the results also demonstrate that the total cost in the case of wind power can be lowered by 24.6 %, 25.7 %, and 27.5 % compared to thermal power for battery charge under the methods of rule-based strategy, Pontryagin ' s minimum principle and dynamic programming, respectively.Öğe Energy Management Strategies for Hybrid Electric Vehicles: Review, Classification, Comparison, and Outlook(Mdpi, 2020) Zhang, Fengqi; Wang, Lihua; Coskun, Serdar; Pang, Hui; Cui, Yahui; Xi, JunqiangHybrid Electric Vehicles (HEVs) have been proven to be a promising solution to environmental pollution and fuel savings. The benefit of the solution is generally realized as the amount of fuel consumption saved, which by itself represents a challenge to develop the right energy management strategies (EMSs) for HEVs. Moreover, meeting the design requirements are essential for optimal power distribution at the price of conflicting objectives. To this end, a significant number of EMSs have been proposed in the literature, which require a categorization method to better classify the design and control contributions, with an emphasis on fuel economy, providing power demand, and real-time applicability. The presented review targets two main headlines: (a) offline EMSs wherein global optimization-based EMSs and rule-based EMSs are presented; and (b) online EMSs, under which instantaneous optimization-based EMSs, predictive EMSs, and learning-based EMSs are put forward. Numerous methods are introduced, given the main focus on the presented scheme, and the basic principle of each approach is elaborated and compared along with its advantages and disadvantages in all aspects. In this sequel, a comprehensive literature review is provided. Finally, research gaps requiring more attention are identified and future important trends are discussed from different perspectives. The main contributions of this work are twofold. Firstly, state-of-the-art methods are introduced under a unified framework for the first time, with an extensive overview of existing EMSs for HEVs. Secondly, this paper aims to guide researchers and scholars to better choose the right EMS method to fill in the gaps for the development of future-generation HEVs.Öğe Hierarchical Optimization of Speed Planning and Energy Management for Connected Hybrid Electric Vehicles Under Multi-Lane and Signal Lights Aware Scenarios(Ieee-Inst Electrical Electronics Engineers Inc, 2023) Peng, Jinghui; Zhang, Fengqi; Coskun, Serdar; Hu, Xiaosong; Yang, Yalian; Langari, Reza; He, JinsongConnected and automated vehicle technology via vehicle-to-everything communication, can assist in improving energy efficiency for hybrid electric vehicles (HEVs). In particular, information about the timing of traffic lights and surrounding vehicles can be exchanged between traffic vehicles and in conjunction with vehicle state information, to improve the fuel economy of HEVs significantly. To this end, we propose a multi-lane hierarchical optimization (MLHO) algorithm based on a predictive control framework. The dynamic behaviors of the surrounding vehicles are first predicted, and then the traffic light information (e.g., signal phasing and timing) and vehicles' state information are utilized in the design. MLHO is a two-level strategy wherein a multi-lane speed planning method for a host vehicle is formulated to plan the optimal speed and lane-change behaviors by considering vehicle power demand, driving comfort, and safety in the upper level. In the lower level, dynamic programming is adopted to devise energy management by tracking the optimal speed. Simulation results under real routes using the traffic simulation software Simulation of Urban Mobility show that the fuel economy of MLHO is improved by 32% on average compared to speed profile driven by a human driver model. In addition, traffic efficiency is enhanced significantly, i.e., different traffic occupancy results on the road indicate that the proposed MLHO is less affected by the traffic flow density. With different traffic densities, the maximum fuel consumption difference under the three considered scenarios is only 0.645L/100km.Öğe Predictive equivalent consumption minimization strategy for power-split hybrid electric vehicles using Monte Carlo algorithm(Gazi Univ, Fac Engineering Architecture, 2023) Gul, Merve Nur; Yazar, Ozan; Coskun, Serdar; Zhang, Fengqi; Li, Lin; Kaya, Irem ErsozPurpose: The underlying research goal of this article is to put forward a reliable fuel saving performance based on the forecasted velocities of drive cycles for a power-split hybrid electric vehicle. Theory and Methods: The power distribution between energy sources is devised by utilizing the P-ECMS for the power-split hybrid electric vehicle using the uncertain drive cycle velocity estimation based on MC algorithm. Results: The effectiveness and accuracy of the method are evaluated under seven drive cycles. The MC provides good prediction results of the velocities. On the basis of it, the P-ECMS method decreases fuel consumption up to 6.01% under NEDC, up to 9.09% under WLTP, up to 6.33% under UDDS, up to 5.14% under HWFET, up to 1.96% under NYCC, up to 11.47% under LA-92, and up to 7.92% under ALL-CYC compared to a standard ECMS method. Conclusion: It is seen from the analysis results that battery SOC decreases slightly using the P-ECMS since the electric motor is actively used to meet power demand instead of the engine over the predicted speed profiles. In the end, the MC algorithm-based P-ECMS strategy can verify the optimal power distribution based on fuel-saving potentials as compared to the baseline ECMS strategy while keeping the battery SOC at a reasonable interval.Öğe Quadratic programming-based cooperative adaptive cruise control under uncertainty via receding horizon strategy(Sage Publications Ltd, 2021) Coskun, Serdar; Huang, Cong; Zhang, FengqiCooperative longitudinal motion control can greatly contribute to safety, mobility, and sustainability issues in today's transportation systems. This article deals with the development of cooperative adaptive cruise control (CACC) under uncertainty using a model predictive control strategy. Specifically, uncertainties arising in the system are presented as disturbances acting in the system and measurement equations in a state-space formulation. We aim to design a predictive controller under a common goal (cooperative control) such that the equilibrium from initial condition of vehicles will remain stable under disturbances. The state estimation problem is handled by a Kalman filter and the optimal control problem is formulated by the quadratic programming method under both state and input constraints considering traffic safety, efficiency, as well as driving comfort. In the sequel, adopting the CACC system in four-vehicle platoon scenarios are tested via MATLAB/Simulink for cooperative vehicle platooning control under different disturbance realizations. Moreover, the computational effectiveness of the proposed control strategy is verified with respect to different platoon sizes for possible real-time deployment in next-generation cooperative vehicles.Öğe Stochastic Velocity Prediction for Connected Vehicles Considering V2V Communication Interruption(Ieee-Inst Electrical Electronics Engineers Inc, 2023) Wang, Lihua; Zhang, Fengqi; Cui, Yahui; Coskun, Serdar; Tang, Xiaolin; Yang, Yalian; Hu, XiaosongReliable and accurate velocity prediction can significantly contribute to the quality of connected vehicle control applications. Existing efforts focus on the velocity prediction without considering vehicle-to-vehicle (V2V) communication interruption. Hence, a stochastic velocity prediction method for connected vehicles considering V2V communication interruption is put forward for the first time. The missing V2V communication data are addressed by the piecewise cubic Hermite spline interpolation. Then, the processed data are used as the input variables of the best conditional linear Gaussian (CLG) prediction model. Specifically, the best CLG model is obtained by analyzing the influence of different input variables on the velocity prediction without V2V communication interruption. The results demonstrate that the prediction accuracy of CLG-based model is acceptable if the communication interruption time is less than 5 s compared to the non-interrupted V2V communication case. The sensitivity study of the best CLG model under multiple vehicles scenario indicates that choosing appropriate historical data substantially improve the prediction accuracy. Furthermore, the CLG-based predictor is proved to be an effective method to achieve higher prediction accuracy in two test road networks when compared with the Back-propagation and Long Short-Term Memory network.Öğe Velocity Prediction Based on Vehicle Lateral Risk Assessment and Traffic Flow: A Brief Review and Application Examples(Mdpi, 2021) Li, Lin; Coskun, Serdar; Wang, Jiaze; Fan, Youming; Zhang, Fengqi; Langari, RezaForecasting future driving conditions such as acceleration, velocity, and driver behaviors can greatly contribute to safety, mobility, and sustainability issues in the development of new energy vehicles (NEVs). In this brief, a review of existing velocity prediction techniques is studied from the perspective of traffic flow and vehicle lateral dynamics for the first time. A classification framework for velocity prediction in NEVs is presented where various state-of-the-art approaches are put forward. Firstly, we investigate road traffic flow models, under which a driving-scenario-based assessment is introduced. Secondly, vehicle speed prediction methods for NEVs are given where an extensive discussion on traffic flow model classification based on traffic big data and artificial intelligence is carried out. Thirdly, the influence of vehicle lateral dynamics and correlation control methods for vehicle speed prediction are reviewed. Suitable applications of each approach are presented according to their characteristics. Future trends and questions in the development of NEVs from different angles are discussed. Finally, different from existing review papers, we introduce application examples, demonstrating the potential applications of the highlighted concepts in next-generation intelligent transportation systems. To sum up, this review not only gives the first comprehensive analysis and review of road traffic network, vehicle handling stability, and velocity prediction strategies, but also indicates possible applications of each method to prospective designers, where researchers and scholars can better choose the right method on velocity prediction in the development of NEVs.
