Lateral Tracking and Stability Control for Automated Vehicles

This thesis studies the lateral tracking and stability control problem of ground vehicle in the context of autonomous automated vehicle system. An autonomous vehicle platoon is composed of a human-driven lead vehicle and several automated following ones. A full set of vehicle operating states is analyzed and it is found that they can be covered by either a tracking controller or a stability control. Lateral tracking control design in normal driving condition and lateral stability control design in emergency situations are examined then. A cooperative control structure using feedforward information of the lead vehicle is implemented in tracking control design in the proposed Leader-Dependent Coordinate System. The tracking performance is much improved compared to classical pursuit algorithm by using this cooperative information and knowledge of road pattern in tracking scenarios. A Modified-LuGre type dynamic tire model is proposed and used in the design of direct yaw moment control. This thesis solves the problem of optimal usage of tire traction in the application of vehicle stability control by using the 2-D Modified LuGre tire model. Since the model captures 2-D tire friction force distribution dynamically, the derived yaw moment controller is coordinated with the existing steering control without over-demanding a longitudinal slip ratio that the tire can not provide. The designed yaw moment control is also adaptive to surface friction condition that can prevent tire from skidding due to over-command braking torque. To analyzed the stability control problem in a large region of state, a point-wise linearized model along vehicle state is derived by introducing a concept of generalized tire cornering stiffness. A three-layer time-optimal yaw moment control architecture is provided to stabilize the vehicle in the shortest time. The designed yaw moment controller provides the maximum stabilizing moment for individual axle so it can be used in stability control problems for both passenger vehicles and heavy duty vehicles.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Mechanical Engineering

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2015

Author dc:creator

• Liang, Wei

Contributors dc:contributor

• Andrew Alleyne

• Engineering, Mechanical

Language dc:language

eng

Identifier

(MiAaPQ)AAI3301184

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/83899