Hybrid Electric Vehicle Torque Split Algorithm for Reduction of Engine Torque Transients

George, Derek

doi:10.33915/etd.7179

Cited by 4 publications

(12 citation statements)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…• Golden section search -Iteratively finds a minima or maxima of a given non-linear function by successively narrowing the range of values inside which the extrema is known to exist. A golden section search algorithm is easily implementable but does not however guarantee an optimal convergence [19].…”

Section: Various Algorithm Objectives and Overviewmentioning

confidence: 99%

“…Alternatively, as SOC deviates above the target SOC, the shift lines will move to the left which promotes higher gears (lower gear ratios) to place the engine in a more efficient region for torque production subsequently decreasing the amount of fuel consumed during discharge events. Note, this generation method assumes that the engine torque will be reduced by the torque split algorithm when SOC is above the target SOC and the engine torque will be increased by the torque split algorithm when SOC is below the target SOC to charge the batteries [19]. The generation method used for the SOC dependent shift schedules assumes the torque split algorithm will select the optimal engine torque necessary for a vehicle operating point and only controls the engine speed placement to most efficiently produced that engine torque.…”

Section: Shift Schedule Theorymentioning

confidence: 99%

“…This data will not be provided in this paper as it is GM sensitive information not disclosed to the public. The engine and electric motor mechanical power produced is calculated from the product of the component torque in newton-meters and component speed in radians per second as shown in Equation (19) and Equation 20…”

Section: Shift Schedule Generation Soc Independent Shift Schedule Genmentioning

confidence: 99%

“…Notably, the engine torques with the highest fitness are the ideal engine torques needed to maximize the fitness function during vehicle operation. It is assumed that the torque split algorithm [19] within the overall control algorithm of the vehicle will calculate the ideal engine torques within a reasonable tolerance as the output commanded torque. The highest fitness along the k-axis (transmission gear)…”

Section: Shift Schedule Generation Soc Independent Shift Schedule Genmentioning

confidence: 99%

“…However, these trends may not be a result of the shift schedule used but rather the torque split algorithm that was developed for the vehicle [19]. Additional results from SIL testing for the sensitivity analysis are also shown in Appendix C: Additional SIL Results.…”

Section: Areamentioning

confidence: 99%

See 4 more Smart Citations

Generation and Sensitivity Analysis of Transmission Shift Schedule for Hybrid-Electric Vehicle

Connelly¹

View full text Add to dashboard Cite

The increased concern of global climate change and lack of sustainability of fossil fuels in the projected future has prompted further research into alternative fuel vehicles, or advanced vehicles, in an effort to combat vehicle emissions and fuel consumption. One of the many areas of advanced vehicles being researched includes the electrification and hybridization of vehicles. As the technology for hybrid-electric vehicles has increased, so has the need for more advanced control scheme for the vehicles. This includes the development and optimization of a shift schedule for the automatic transmission in a hybrid powertrain. The focus of this work is to demonstrate how to develop and analyze the benefits and shortcomings of two different shift schedules for a position 3 parallel hybrid-electric vehicle: a traditional two-parameter shift schedule that operates as a function of the driver's accelerator position and the vehicle's speed (SOC independent shift schedule), and a three-parameter shift schedule that also adapts to fluctuations in the state of charge of the high voltage batteries (SOC dependent shift schedule). The shift schedules were generated using an exhaustive search coupled with a fitness function to evaluate all possible vehicle operating points. The generated shift schedules were then tested in the software-in-the-loop (SIL) environment and the vehicle-in-the-loop (VIL) environment and compared to each other, as well as to the stock 8L45 8-speed transmission shift schedule. The results show that both generated shift schedules improved upon the stock transmission shift schedule used in the hybrid powertrain in component efficiency, vehicle efficiency, engine fuel economy, and vehicle fuel economy. However, there were few differences between the two shift schedules. A sensitivity analysis was then performed on the generated SOC dependent shift schedule by varying the initial SOC in the SIL environment in an attempt to explore more of the shift schedule's solution space. The sensitivity analysis showed little difference in vehicle energy consumption, engine fuel economy, and vehicle fuel economy during the executed driving cycle as initial SOC varied. Additionally, the analysis showed that the gear commanded from the SOC dependent shift schedule between the three cases were almost identical with the exception of at the start of the simulation. Once the control algorithm achieved and sustained the target SOC, the SOC dependent shift schedule contributed little as deviations in SOC were minute. iii DEDICATION This thesis is dedicated to my old family, new family, and friends. I want to thank my dad, James Connelly, for his patience with me and constant support through my college career. Without him I would not be where I am today. I want to thank my mom, Judi Connelly, who has been a pillar of support and always believed I can be better than I am. I want to thank my little sister, Sarah, for always keeping me on the right track.

show abstract

Section: Various Algorithm Objectives and Overviewmentioning

confidence: 99%

Section: Shift Schedule Theorymentioning

confidence: 99%

Section: Shift Schedule Generation Soc Independent Shift Schedule Genmentioning

confidence: 99%

Section: Shift Schedule Generation Soc Independent Shift Schedule Genmentioning

confidence: 99%

Section: Areamentioning

confidence: 99%

See 3 more Smart Citations

Generation and Sensitivity Analysis of Transmission Shift Schedule for Hybrid-Electric Vehicle

Connelly¹

View full text Add to dashboard Cite

show abstract

Implementation of Radial Basis Function Artificial Neural Network into an Adaptive Equivalent Consumption Minimization Strategy for Optimized Control of a Hybrid Electric Vehicle

Harris¹

View full text Add to dashboard Cite

This thesis is dedicated especially to my mom, dad, and sister. I thank them for their unwavering support in all my decisions regarding my education. I especially thank Dad for keeping me grounded when things were rough.This thesis is also dedicated to my extended family. I thank them for all their continuous encouragement and support. I especially thank my aunt, Rebecca Bland, and my uncle, Brian Richards, for their wisdom and direction regarding my education.

show abstract

Generation and Analysis of Hybrid-Electric Vehicle Transmission Shift Schedules with a Torque Split Algorithm

Connelly¹,

George²,

Nix³

et al. 2020

JTTs

View full text Add to dashboard Cite

The increased concern over global climate change and lack of long-term sustainability of fossil fuels in the projected future has prompted further research into advanced alternative fuel vehicles to reduce vehicle emissions and fuel consumption. One of the primary advanced vehicle research areas involves electrification and hybridization of vehicles. As hybrid-electric vehicle technology has advanced, so has the need for more innovative control schemes for hybrid vehicles, including the development and optimization of hybrid powertrain transmission shift schedules. The hybrid shift schedule works in tandem with a cost function-based torque split algorithm that dynamically determines the optimal torque command for the electric motor and engine. The focus of this work is to develop and analyze the benefits and limitations of two different shift schedules for a position-3 (P3) parallel hybrid-electric vehicle. a traditional two-parameter shift schedule that operates as a function of vehicle accelerator position and vehicle speed (state of charge (SOC) independent shift schedule), and a three-parameter shift schedule that also adapts to fluctuations in the state of charge of the high voltage batteries (SOC dependent shift schedule). The shift schedules were generated using an exhaustive search coupled with a fitness function to evaluate all possible vehicle operating points. The generated shift schedules were then tested in the software-in-the-loop (SIL) environment and the vehicle-in-the-loop (VIL) environment and compared to each other, as well as to the stock 8L45 8-speed transmission shift schedule. The results show that both generated shift schedules improved upon the stock transmission shift schedule used in the hybrid powertrain comparing component efficiency, vehicle efficiency, engine fuel economy, and vehicle fuel economy.

show abstract

Hybrid Electric Vehicle Torque Split Algorithm for Reduction of Engine Torque Transients

Cited by 4 publications

References 18 publications

Generation and Sensitivity Analysis of Transmission Shift Schedule for Hybrid-Electric Vehicle

Generation and Sensitivity Analysis of Transmission Shift Schedule for Hybrid-Electric Vehicle

Implementation of Radial Basis Function Artificial Neural Network into an Adaptive Equivalent Consumption Minimization Strategy for Optimized Control of a Hybrid Electric Vehicle

Generation and Analysis of Hybrid-Electric Vehicle Transmission Shift Schedules with a Torque Split Algorithm

Contact Info

Product

Resources

About