Comparative Study of Energy Management Strategies for Hydraulic Hybrids

2014 ◽  
Vol 137 (4) ◽  
Author(s):  
Timothy O. Deppen ◽  
Andrew G. Alleyne ◽  
Jonathan J. Meyer ◽  
Kim A. Stelson
Keyword(s):  
Energy Management ◽  
Design Method ◽  
Tracking Error ◽  
Management Strategies ◽  
Stochastic Dynamic ◽  
Drive Cycle ◽  
Hybrid Powertrain ◽  
Hydraulic Hybrid ◽  
System A ◽  
Factorial Design Of Experiments

The sensitivity of energy management strategies (EMS) with respect to variations in drive cycle and system parameters is considered. The design of three strategies is presented: rule-based, stochastic dynamic programming (SDP), and model predictive control (MPC). Each strategy is applied to a series hydraulic hybrid powertrain and validated experimentally using a hardware-in-the-loop system. A full factorial design of experiments (DOE) is conducted to evaluate the performance of these controllers under different urban and highway drive cycles as well as with enforced modeling errors. Through this study, it is observed that each EMS design method represents a different level of tradeoff between optimality and robustness based on how much knowledge of the system is assumed. This tradeoff is quantified by analyzing the standard deviation of system specific fuel consumption (SSFC) and root mean square (RMS) tracking error over the different simulation cases. This insight can then be used to motivate the choice of which control strategy to use based on the application. For example, a city bus travels a repeated route and that knowledge can be leveraged in the EMS design to improve performance. Through this study, it is demonstrated that there is not one EMS design method which is best suited for all applications but rather the underlying assumptions of the system and drive cycle must be carefully considered so that the most appropriate design method is chosen.

Real-World Robustness for Hybrid Vehicle Optimal Energy Management Strategies Incorporating Drivability Metrics

2014 ◽  
Vol 136 (6) ◽  
Author(s):  
Daniel F. Opila ◽  
Xiaoyong Wang ◽  
Ryan McGee ◽  
R. Brent Gillespie ◽  
Jeffrey A. Cook ◽  
...  
Keyword(s):  
Energy Management ◽  
Fuel Economy ◽  
Real World ◽  
Power Flow ◽  
Design Method ◽  
Management Strategies ◽  
Hybrid Vehicle ◽  
Stochastic Dynamic ◽  
Real World Data ◽  
Industrial Controller

Hybrid vehicle fuel economy and drive quality are coupled through the “energy management” controller that regulates power flow among the various energy sources and sinks. This paper studies energy management controllers designed using shortest path stochastic dynamic programming (SP-SDP), a stochastic optimal control design method which can respect constraints on drivetrain activity while minimizing fuel consumption for an assumed distribution of driver power demand. The performance of SP-SDP controllers is evaluated through simulation on large numbers of real-world drive cycles and compared to a baseline industrial controller provided by a major auto manufacturer. On real-world driving data, the SP-SDP-based controllers yield 10% better fuel economy than the baseline industrial controller, for the same engine and gear activity. The SP-SDP controllers are further evaluated for robustness to the drive cycle statistics used in their design. Simplified drivability metrics introduced in previous work are validated on large real-world data sets.

Predictive Energy Management for Parallel Hydraulic Hybrid Passenger Vehicle

2010 ◽  
Author(s):  
Timothy O. Deppen ◽  
Andrew G. Alleyne ◽  
Kim A. Stelson ◽  
Jonathan J. Meyer
Keyword(s):  
Energy Management ◽  
Hybrid Vehicle ◽  
Management Problem ◽  
Transfer Energy ◽  
Hybrid Powertrain ◽  
Engine Torque ◽  
Engine Simulation ◽  
Hydraulic Hybrid ◽  
Displacement Pump ◽  
Hydraulic Hybrid Vehicle

In this paper, a model predictive control (MPC) approach is presented for solving the energy management problem in a parallel hydraulic hybrid vehicle. The hydraulic hybrid vehicle uses variable displacement pump/motors to transfer energy between the mechanical and hydraulic domains and a high pressure accumulator for energy storage. A model of the parallel hydraulic hybrid powertrain is presented which utilizes the Simscape/Simhydraulics toolboxes of Matlab. These toolboxes allow for a concise description of the relevant powertrain dynamics. The proposed MPC regulates the engine torque and pump/motor displacement in order to track a desired velocity profile while maintaining desired engine conditions. In addition, logic is applied to the MPC to prevent high frequency cycling of the engine. Simulation results demonstrate the capability of the proposed control strategy to track both a desired engine torque and vehicle velocity.

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.

A Hardware-in-the-Loop Platform for a Series Hybrid Powertrain Featuring Two Equivalent Consumption Minimization Strategies

2014 ◽  
Author(s):  
Sara Mohon ◽  
Satadru Dey ◽  
Beshah Ayalew ◽  
Pierluigi Pisu
Keyword(s):  
Energy Management ◽  
Control Strategies ◽  
Management Strategies ◽  
Electrical Energy ◽  
Hardware In The Loop ◽  
Real Time Control ◽  
Hybrid Powertrain ◽  
Time Control ◽  
Equivalence Factor ◽  
And Performance

Hardware-in-the-loop (HIL) platforms enable rapid evaluation of different system configurations and energy management strategies for electrified/hybrid powertrains without building full vehicle prototypes. This paper outlines a HIL platform for a series hybrid powertrain and discusses particular control strategies. The main hardware components of the platform are a gasoline generator, a lead acid battery pack, a bi-directional dc/dc converter, a programmable dc load, strain gauges, and a rotary encoder. Along with these hardware components, a real-time control prototyping system is used to implement energy management strategies and monitor several signals form the HIL platform. The effectiveness and performance of this platform is demonstrated by implementing two versions of the Equivalent Consumption Minimization Strategy (ECMS). The first version uses a constant equivalence factor for weighting the cost of electrical energy storage, while the second version uses an adaptive equivalence factor based on the deviation of battery state of charge (SOC) from a reference SOC.

scholarly journals Enery management in Mobile Hydraulics

2013 ◽  
Vol 135 (06) ◽  
pp. S4-S6
Author(s):  
Andrew Alleyne ◽  
Timothy Deppen ◽  
Jonathan Meyer ◽  
Kim Stelson
Keyword(s):  
Energy Management ◽  
Control Strategies ◽  
Management Strategies ◽  
Electrical Power ◽  
Cost Effective ◽  
Transportation Systems ◽  
Fluid Power ◽  
Energy Management Strategy ◽  
Hybrid Powertrain ◽  
Wide Range

This paper explores research into hydraulic hybrids that span a wide range of applications from heavy-duty vehicles, such as city buses, to small passenger vehicles. This case study also highlights the importance of having a well-designed energy management strategy if one is to maximize benefit of the hybrid powertrain. There is potential for hydraulic hybrid vehicles to offer a cost-effective solution to the need for increased efficiency in transportation systems. The high-power density of fluid power makes it a natural choice for energy storage in urban driving environments where there are frequent starts/stops and large acceleration/braking power demands. Because the opportunities and challenges of fluid power are different than those of electrical power, unique control strategies are needed and a summary of common energy management strategies (EMS) design methods for hydraulic hybrids has been presented.

Modeling and Design of a Hydraulic Hybrid Powertrain for Passenger Vehicle

2017 ◽  
Author(s):  
Haoxiang Zhang ◽  
Feng Wang ◽  
Kim A. Stelson
Keyword(s):  
Energy Management ◽  
Management Strategy ◽  
Controller Design ◽  
Mechanical Transmission ◽  
Passenger Vehicle ◽  
Energy Management Strategy ◽  
Hybrid Powertrain ◽  
Hydraulic Hybrid ◽  
Hydraulic Accumulator ◽  
Pressure Controlled

A hydraulic hybrid powertrain for passenger vehicle is studied in this paper. The hydraulic hybrid powertrain consists of a hydro-mechanical transmission and a hydraulic accumulator. The key component of this hydro-mechanical transmission is a pressure-controlled hydraulic transmission. It combines pumping and motoring function in one unit and is potentially more competitive in terms of both energy efficiency and cost effectiveness than a conventional hydrostatic transmission. By feeding the output flow of the pressure-controlled hydraulic transmission to a variable displacement motor coupled to the transmission output shaft, a more compact and simpler hydro-mechanical transmission is constituted. In this paper the systematic approach of applying the hydraulic hybrid powertrain to a passenger vehicle is studied. A dynamic simulation model is developed in Simulink and the U.S. EPA’s urban cycle is used as the test driving cycle. A rule-based energy management strategy (EMS) for the hydraulic hybrid powertrain has also been developed. The system parameter design, controller design and the energy management strategy are evaluated through simulation.

scholarly journals Simultaneous Optimization of Supervisory Control and Gear Shift Logic for a Parallel Hydraulic Hybrid Refuse Truck Using Stochastic Dynamic Programming

2011 ◽  
Author(s):  
Rajit Johri ◽  
Simon Baseley ◽  
Zoran Filipi
Keyword(s):  
Dynamic Programming ◽  
Power Management ◽  
Stochastic Dynamic Programming ◽  
Management Strategies ◽  
Infinite Horizon ◽  
Simultaneous Optimization ◽  
System Level ◽  
Stochastic Dynamic ◽  
Gear Shift ◽  
Hydraulic Hybrid

The power management controller of a hybrid vehicle orchestrates the operation of onboard energy sources, namely engine and auxiliary power source with the goal of maximizing performance objectives such as the fuel economy. The paper focuses on optimization of the power management strategy of the refuse truck with parallel hydraulic hybrid powertrain. The high power density of hydraulic components and high charging/discharging efficiency of accumulator with no power constraint make hydraulic hybrid an excellent choice for heavy-duty stop and go application. Two power management strategies for a parallel hydraulic hybrid refuse truck are compared; heuristic and stochastic dynamic programming based optimal controller. For designing a SDP based controller, an infinite horizon problem is setup with power demand from driver modeled as random Markov process. The objective is to maximize system level efficiency by optimizing (i) the power split between engine and hydraulic propulsion unit, and (ii) gear shift schedule. This combines the optimization of powertrain parameters with power management design.

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