Online optimization of Pontryagin’s minimum principle for a series hydraulic hybrid wheel loader

2021 ◽  
pp. 095440702110398
Author(s):  
Qi Zhang ◽  
Feng Wang ◽  
Bing Xu ◽  
Zongxuan Sun
Keyword(s):  
Dynamic Programming ◽  
Fuel Consumption ◽  
Minimum Principle ◽  
Pontryagin’S Minimum Principle ◽  
Energy Management Strategy ◽  
Hybrid Powertrain ◽  
Rule Based ◽  
Wheel Loader ◽  
Hydraulic Hybrid ◽  
Pontryagin's Minimum Principle

The hydraulic hybrid powertrain has great potential for reducing fuel consumption and emission of off-road vehicles. The energy management strategy is the key to hybrid powertrain and currently there are many well-developed strategies. Of which the Pontryagin’s minimum principle is of research interest since it is a global optimization method while less computational burden than dynamic programming. However, it requires full cycle information to calculate co-state value in the principle, making it not implementable. Therefore in this study an implementable Pontryagin’s minimum principle is proposed for a series hybrid wheel loader, where the optimal co-state value in the principle is trained through repetitive wheel loader duty cycle. The Pontryagin’s minimum principle formulations of hybrid wheel loader are developed. The online co-state training algorithm is presented. A dynamic simulation model of hybrid wheel loader is developed. The fuel consumption of hybrid wheel loader with proposed strategy is compared with dynamic programming strategy and rule-based strategy in wheel loader long and short loading cycles. Results show the fuel consumption with proposed strategy is close to dynamic programming result and is lower than rule-based strategy. Finally, the influence of pressure level of hybrid powertrain on vehicle fuel consumption is studied.

Power Optimization of Series Hydraulic Hybrid Powertrain for Compact Wheel Loader

2019 ◽  
Author(s):  
Qunya Wen ◽  
Feng Wang ◽  
Bing Xu ◽  
Zongxuan Sun
Keyword(s):  
Energy Management ◽  
Fuel Economy ◽  
Management Strategy ◽  
Power Optimization ◽  
Parameter Study ◽  
Energy Management Strategy ◽  
Hybrid Powertrain ◽  
Wheel Loader ◽  
Hydraulic Hybrid ◽  
Equivalent Consumption Minimization Strategy

Abstract As an effective approach to improving the fuel economy of heavy duty vehicles, hydraulic hybrid has shown great potentials in off-road applications. Although the fuel economy improvement is achieved through different hybrid architectures (parallel, series and power split), the energy management strategy is still the key to hydraulic hybrid powertrain. Different optimization methods provide powerful tools for energy management strategy of hybrid powertrain. In this paper a power optimization method based on equivalent consumption minimization strategy has been proposed for a series hydraulic hybrid wheel loader. To show the fuel saving potential of the proposed strategy, the fuel consumption of the hydraulic hybrid wheel loader with equivalent consumption minimization strategy was investigated and compared with the system with a rule-based strategy. The parameter study of the equivalent consumption minimization strategy has also been conducted.

scholarly journals A Rule-Based Energy Management Strategy Based on Dynamic Programming for Hydraulic Hybrid Vehicles

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Haicheng Zhou ◽  
Zhaoping Xu ◽  
Liang Liu ◽  
Dong Liu ◽  
Lingling Zhang
Keyword(s):  
Dynamic Programming ◽  
Energy Management ◽  
Management Strategy ◽  
Optimal Solution ◽  
Hybrid Vehicles ◽  
Engine Control ◽  
Energy Management Strategy ◽  
Rule Based ◽  
Hydraulic Hybrid ◽  
Global Optimal

Energy management strategy is very important for hydraulic hybrid vehicles to improve fuel economy. The rule-based energy management strategies are widely used in engineering practice due to their simplicity and practicality. However, their performances differ a lot from different parameters and control actions. A rule-based energy management strategy is designed in this paper to realize real-time control of a novel hydraulic hybrid vehicle, and a control parameter selection method based on dynamic programming is proposed to optimize its performance. Firstly, the simulation model of the hydraulic hybrid vehicle is built and validated by the data tested from prototype experimental platform. Based on the simulation model, the optimization method of dynamic programming is used to find the global optimal solution of the engine control for the UDDS drive cycle. Then, the engine control parameters of the rule-based energy management strategy are selected according to the engine control trajectory of the global optimal solution. The simulation results show that the 100 km fuel consumption of the proposed rule-based energy management strategy is 12.7L, which is very close to the global optimal value of 12.4L and is suboptimal.

scholarly journals Energy Management of Hybrid Power System in UUV Based on Pontryagin’s Minimum Principle

2020 ◽  
Vol 182 ◽  
pp. 03001
Author(s):  
Huizhong Gao ◽  
Junguang Wang ◽  
Jun Lu ◽  
Xiao Zong
Keyword(s):  
Power System ◽  
Energy Management ◽  
Power Distribution ◽  
Minimum Principle ◽  
Proton Exchange ◽  
Pontryagin’S Minimum Principle ◽  
Energy Management Strategy ◽  
Hybrid Power System ◽  
Hybrid Power ◽  
Pontryagin's Minimum Principle

Hybrid power system which consists of a proton exchange membrane fuel cell and a battery has great perspective for Unmanned Underwater Vehicles (UUVs). As fuel cell’s working point has a direct relationship with its efficiency and lifetime, a key concern of the hybrid power system is the power distribution between the two parts. Aiming at minimizing the equivalent hydrogen cost, this work presents an optimal real-time energy management strategy based on the Pontryagin’s minimum principle. Compared with some other methods, this method possesses shorter calculation time and smaller storing space, which is helpful for online optimization in actual applications. In this research, a typical UUV working profile is tested with different initial co-state values to evaluate the proposed method, and the results indicate good robustness and effectiveness.

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