Date of Award
Master of Science in Engineering
Mechanical and Aerospace Engineering
Jennifer Hudson, Ph. D.
Richard Meyer, Ph. D.
Koorosh Naghshineh, Ph. D.
Optimal control, automotive, powertrain, continuous variable transmission (CVT), response log compensation
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.