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Title: A novel approach to hydrostatic transmission control in a forklift truck : modelling, simulation and testing
Author: Bradley, Conor
Awarding Body: Queen's University Belfast
Current Institution: Queen's University Belfast
Date of Award: 2017
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The purpose of this thesis is to describe the steps undertaken in a “proof-of-concept” project aimed at improving the fuel efficiency of forklift trucks. In this study, a prototype forklift truck was developed which employs a continuously variable hydrostatic transmission in place of the traditional torque converter drivetrain. Through the application of backward- and forward-facing simulation techniques, a novel vehicle control system was created to target maximum drivetrain efficiency, while still working within the constraints of the prototype hardware and the demands of the driver. Different control strategies were designed to optimise the efficiency of the drivetrain in both steady-state and transient conditions, while several performance mode settings were included to allow the driver to adjust the trade-off between fuel consumption and maximum productivity. The prototype truck was tested in accordance with both VDI 2198 and VDI Turnover tests. When the quantity of work was fixed (i.e. during the VDI 2198 test), the control system and its various strategies proved to be functioning as desired by minimising the amount of fuel consumed to complete the task, regardless of the selected performance mode. When the quantity of work was not fixed (i.e. during the VDI Turnover test), a clear trend was demonstrated between fuel consumption and productivity depending on the selected performance mode, again proving that the control system was functioning as desired When compared to the current production truck of the same rated capacity, the prototype truck consumed an average of 36% less fuel over the VDI 2198 cycle. Additionally, the prototype vehicle also showed a 35% increase in effectivity (i.e. the number of loads moved per kilogram of fuel consumed) during the VDI Turnover test Finally, a forward-facing model of the prototype truck was created and partially validated using an industry-standard automotive simulation package with a view to allowing for future developments to be made through detailed vehicle simulation.
Supervisor: Not available Sponsor: Not available
Qualification Name: Thesis (Ph.D.) Qualification Level: Doctoral
EThOS ID:  DOI: Not available