Vehicle Dynamics Control (VDC) systems (also known as Active Chassis
systems) are mechatronic systems developed for improving vehicle comfort,
handling and/or stability. Traditionally, most of these systems have been
individually developed and manufactured by various suppliers and utilised by
automotive manufacturers. These decentralised control systems usually
improve one aspect of vehicle performance and in some cases even worsen
some other features of the vehicle.
Although the benefit of the stand-alone VDC systems has been proven,
however, by increasing the number of the active systems in vehicles, the
importance of controlling them in a coordinated and integrated manner to
reduce the system complexity, eliminate the possible conflicts as well as
expand the system operational envelope, has become predominant. The
subject of Integrated Vehicle Dynamics Control (IVDC) for improving the
overall vehicle performance in the existence of several VDC active systems has
recently become the topic of many research and development activities in both
academia and industries
Several approaches have been proposed for integration of vehicle control
systems, which range from the simple and obvious solution of networking the
sensors, actuators and processors signals through different protocols like CAN
or FlexRay, to some sort of complicated multi-layered, multi-variable control
architectures. In fact, development of an integrated control system is a
challenging multidisciplinary task and should be able to reduce the complexity,
increase the flexibility and improve the overall performance of the vehicle.
The aim of this thesis is to develop a low-cost control scheme for integration of
Electric Power-Assisted Steering (EPAS) system with Enhanced Stability
Program (ESP) system to improve driver comfort as well as vehicle safety. In
this dissertation, a systematic approach toward a modular, flexible and
reconfigurable control architecture for integrated vehicle dynamics control
systems is proposed which can be implemented in real time environment with
low computational cost. The proposed control architecture, so named
“Integrated Vehicle Control System (IVCS)”, is customised for integration of
EPAS and ESP control systems.
IVCS architecture consists of three cascade control loops, including high-level
vehicle control, low-level (steering torque and brake slip) control and smart
actuator (EPAS and EHB) control systems. The controllers are designed based
on Youla parameterisation (closed-loop shaping) method. A fast, adaptive and
reconfigurable control allocation scheme is proposed to coordinate the control
of EPAS and ESP systems. An integrated ESP & ESP HiL/RCP system
including the real EPAS and Electro Hydraulic Brake (EHB) smart actuators
integrated with a virtual vehicle model (using CarMaker/HiL®) with driver in the
loop capability is designed and utilised as a rapid control development platform
to verify and validate the developed control systems in real time environment.
Integrated Vehicle Dynamic Control is one of the most promising and
challenging research and development topics. A general architecture and
control logic of the IVDC system based on a modular and reconfigurable control
allocation scheme for redundant systems is presented in this research. The
proposed fault tolerant configuration is applicable for not only integrated control
of EPAS and ESP system but also for integration of other types of the vehicle
active systems which could be the subject of future works