*********************** All users be aware: UWSpace has been experiencing unusually long wait times during the depositing process. If you are a graduate student depositing a thesis, it is recommended that while the browser is loading that you do not try to close the connection. If you receive an error or a timeout message, please logout and then log back in. Please do not recreate and resend a new thesis deposit. In most cases, despite the error message, your deposit has successfully been sent to be reviewed. You can verify this by checking under the ‘deposits being reviewed page’. We apologize for the inconvenience. We are working hard to resolve this issue quickly. ***********************
Reconfigurable Integrated Vehicle Stability Control Using Optimal Control Techniques
MetadataShow full item record
The motivation for the development of vehicle stability control systems comes from the fact that vehicle dynamic behavior in unfavorable driving conditions such as low road-tire adhesion and high speed differs greatly from its nominal behavior. Due to this unexpected behavior, a driver may not be successful in controlling the vehicle in challenging driving situations based only on her/his everyday driving experience. Several noteworthy research works have been conducted on stability control systems over the last two decades to prevent car accidents due to human error. Most of the resultant stability controllers contain individual modules, where each perform a particular task such as yaw tracking, sideslip control, or wheel slip control. These design requirements may contradict each other in some driving scenarios. In such situations, inconsistent control actions can be generated with individual modules. The development of a stability controller that can satisfy diverse and often contradictory requirements is a great challenge. In general, transferring a control structure from one vehicle to another with a different drivetrain layout and actuation system configuration requires remarkable rectifications and repetition of tuning processes from the beginning to achieve a similar performance. This can be considered to be a serious drawback for car manufacturing companies since it results in extra effort, time, and expenses in redesigning and retuning the controller. In this thesis, an integrated controller with a modular structure has been designed to concurrently provide control of the vehicle chassis (yaw rate and sideslip control) and wheel stability (wheel slip ratio control). The proposed control structure incorporates longitudinal and lateral vehicle dynamics to decide on a unified control action. This control action is an outcome of solving an optimization problem that considers all the control objectives in a single cost function, so integrated wheel and vehicle stability is guaranteed. Moreover, according to the particular modular design of the proposed control structure, it can be easily reconfigured to work with different drivetrain layouts such as all-wheel-drive, front-wheel-drive, and rear-wheel-drive, as well as various actuators such as torque vectoring, differential braking, and active steering systems. The high-level control module provides a Center of Gravity (CG) based error analysis and determines the required longitudinal forces and yaw moment adjustments. The low-level control module utilizes this information to allocate control actions optimally at each vehicle corner (wheel) through a single or multi-actuator regime. In order to consider the effect of the actuator dynamics, a mathematical description of the auction system is included in distribution objective function. Therefore, a legitimate control performance is promised in situations requiring shifting from one configuration to another with minimal modifications. The performance of the proposed modular control structure is examined in simulations with a high-fidelity model of an electric GM Equinox vehicle. The high-fidelity model has been developed and provided by GM and the use of the model is to reduce the number of labor-intensive vehicle test and is to test extreme and dangerous driving conditions. Several driving scenarios with severe steering and throttle commands, then, are designed to evaluate the capability of the proposed control structure in integrated longitudinal and lateral vehicle stabilization on slippery road condition. Experimental tests also have been performed with two different electric vehicles for real-time implementation as well as validation purposes. The observations verified the performance qualifications of the proposed control structure to preserve integrated wheel and vehicle chassis stability in all track tests.
Cite this work
Seyedeh Asal Nahidi (2017). Reconfigurable Integrated Vehicle Stability Control Using Optimal Control Techniques. UWSpace. http://hdl.handle.net/10012/12381
Showing items related by title, author, creator and subject.
Development of an Integrated Control Strategy Consisting of an Advanced Torque Vectoring Controller and a Genetic Fuzzy Active Steering Controller Jalali, Kiumars; Uchida, Thomas; McPhee, John; Lambert, Steve (SAE International, 2013-04-08)The optimum driving dynamics can be achieved only when the tire forces on all four wheels and in all three coordinate directions are monitored and controlled precisely. This advanced level of control is possible only when ...
A New Control Strategy for Coordinated Control of Ground Vehicle Vertical Dynamics via Control Allocation Binder, Michael Karl (University of Waterloo, 2014-08-08)The scope of this thesis concerns the basic research and development of a coordinated control system for the control of vehicle roll and pitch dynamics using suspension forces as actuators. In this thesis, the following ...
Unified power flow controller, modeling, stability analysis, control strategy and control system design Sreenivasachar, Kannan (University of Waterloo, 2001)