Seminar - System Modeling and Control Strategy Development for a Series Hydraulic Hybrid Vehicle by Prof. Chih-Keng Chen
Date: 19 October 2015 (Monday)
Time: 4:00 pm – 5:00 pm
Venue: EF305, The Hong Kong Polytechnic University
Series hydraulic hybridization is a promising way to achieve better fuel economy improvement. This improvement depends strongly on the vehicle type, size, control strategy, and driving schedule. The main goal of this work is to develop a comprehensive methodology for modeling and designing control system for a series hydraulic hybrid vehicle.
For evaluating the performance of control strategies, a forward-facing closed-loop simulation model based on physical features is initially derived by using Simscape toolbox. Then a mathematical approach is applied in order to estimate a control-oriented model to the development of the control system. The behaviors of the two models are compared with the same open-loop control signal. The simulation results show that the control oriented-model captures essential features adequate to design the controller.
The complexity of the control system is managed by decomposing it into two control level system, the supervisory and actuator levels. The main function of the supervisory controller is to determine desired reference values for engine torque and engine speed to a given vehicle velocity demand. The actuator controller calculates the amount of fuel mass injected into cylinder of the engine, the displacements of hydraulic pump and pump/motor to drive the outputs of the SHHV to their corresponding references. This work proposes two different rule-based supervisory controllers, called Thermostatic and Modulated-pressure. The former supervisory uses only current pressure as the feedback variable to determine the desired output power of the engine. The later one uses current speed in addition to current pressure. Model predictive control (MPC) framework is applied to build the actuator controller. The performance of the MPC actuator controller is compared with conventional multi-PID controller.
Professor Dr.-Ing. Chih-Keng Chen received his B.S. and M.S. degrees in Mechanical Engineering from Cheng-Kung University, Tainan, Taiwan in 1986 and 1988, and Ph.D. degree in systems and control engineering from Case Western Reserve University, Cleveland, USA in 1993. He is currently a professor in Department of Mechanical and Automation Engineering, Da-Yeh University(DYU) of Taiwan. From 2009 to 2012, Prof. Chen was the chairman in the same department and vice dean of engineering college in DYU. Currently, he is in charge the office of Foreign Affairs in DYU. Since 2009, Prof. Chen received the award of the distinguished professor in DYU. His current research interests are in vehicle dynamics, braking control, hydraulic hybrid vehicle and control applications for two-wheeled vehicles.