Research Insterests

Advanced Vehicle Control Systems (including active safety, driver assist, warning and intervention), Alternative Fuel Vehicles, Manual Control Systems and Human Interaction, Powertrain System Modeling and Control, Robust and Robust/Adaptive Control, Modeling and Identification of Mechanical Systems, Mechatronics.

I joined the National Taiwan University of Science and Technology in Feb. 2004. My past research experiences are mostly related to the vehicle dynamics and control, with special focus on the human driver modeling and interactions. In recent years I have been involved in the Optical Mechatronics Research Center in our school and some of my research focus has shifted to the automation and manufacturing process control. Below are brief descriptions of the research directions:

1. Vehicle Control Interaction Between Drivers and Active Safety Systems

This topic investigates the driver-controller interaction issues in the vehicle active safety systems. The variation of driver’s steering behavior was identified as the interaction issue to be addressed. A system identification approach was employed to obtain the driver model and model uncertainty in that project. Based on the identified models, a robust control approach was proposed to handle the driver model uncertainty. However, due to large model uncertainty involved, robust performance was not achieved. Only robust stability can be guaranteed under the given model uncertainty. Preliminary human-in-the-loop driving simulator experiments were also conducted to evaluated the proposed robust controller.

2. Investigation of a Co-pilot Steering Controller for Articulated Vehicles

Although the number of heavy-duty trucks is less than the number of passenger vehicles, however, the severity of crashes involving heavy trucks is usually more serious. In the literature, the research effort on safety system design for heavy trucks is not as emphasized as passenger vehicles. This topic proposes to investigate the rearward amplification problem for a tractor-semitrailer configuration. The problem formulation is first quantified by associated driver and vehicle models. A differential braking steering controller is designed to address the unique rearward amplification problem. The designed system will be first evaluated on the PC using computer simulations with the formulated models. A scaled version of the tractor-semitrailer vehicle is constructed, with the function of differential braking implemented. Experiments with this scaled articulated vehicle will be conducted to provide meaningful validation for the proposed control system.

3. Control of Industrial Robot for Maintaining Contact Force During Path Following

In many machining processes the cutting force is of primary concern to ensure machining quality and efficiency. The automation of the manufacturing plant leads to large scale introduction of industrial robots to handle more complicated tasks. Consequently, the industrial robots face even more challenging requirements in the automation processes, including the force regulation during a path following task. The traditional force compliance control has been successfully applied to the contact force regulation for a steady contact during smooth transition. However, when the robots are required to perform a task to follow a designated path while maintaining regulated force, the requirements from the trajectory tracking error and force regulation error may become conflicting. It is very interesting how the trade-off between the tracking of trajectory and the force influence each other. In this task a state dependent LQ approach is proposed to negotiate the trade-off between the two conflicting requirements, and the polishing and deburring processes are chosen as the validating platform.