Date of Award
Master of Science in Engineering
Mechanical and Aerospace Engineering
Jennifer Hudson, Ph. D.
Richard Meyer, Ph. D.
Koorosh Naghshineh, Ph. D.
Masters Thesis-Open Access
This thesis is the second part of a two-part study focused on improving Continuous Variable Transmission (CVT) ratio management and control. The objective of the overall project was to develop a methodology for a vehicle with a CVT and a downsized gasoline engine to deliver the maximum vehicle fuel economy within drivability and performance constraints. The first part of this study, as described in , focuses on developing a cycle driven model for optimizing the CVT ratio. The study presented in this paper focuses on developing a velocity driven model to simulate the real-time behavior of a vehicle. The results from the optimization schedule presented in backward-looking velocity driven model were utilized to develop a new powertrain optimal operating line (hereafter referred to as P-OOL) which considers powertrain (engine and CVT) efficiency. This P-OOL was created to ensure that the control strategies utilized in the forward- looking model could be used in a real-time vehicle. The proposed P-OOL has been simulated in the model using the Federal Test Procedure (FTP-75) test cycle. Simulation results show that the engine operating points deviate away from the P-OOL. The reasons for deviation of operating points from the P-OOL are vehicle dynamics and powertrain response lag. A control algorithm was simulated which considers powertrain loss and inertia torque due to CVT ratio changes to minimize powertrain response lag. Simulations show a significant improvement in the fuel economy by applying the powertrain response lag compensation algorithm.
Deshmukh, Paresh, "Forward-Looking, Velocity-Driven, Powertrain Modeling and Optimal Control for Continuous Variable Transmission" (2018). Master's Theses. 3425.