Vehicular Adaptive Cruise Control With Lane Change Assist

Adaptive Cruise Control (ACC) system has been proved to enhance vehicle safetyand reduce driver’s workload. However, the conventional ACC can’t detect driver’s lanechange intent when the host vehicle is approaching the leading vehicle, and it controlsthe host vehicle remaining following the leading vehicle in the originating lane. Thiswill increase driver’s intervention frequency and reduce system’s applicability. Toaddress these problems, this thesis proposes a novel ACC system with Lane Changeassist function (LCACC). First, the driver’s lane change characteristics are analyzedbased on the field experimental data. Second, a warning algorithm for lane change isstudied considering the surrounding vehicles. Furthermore, the LCACC’s controlalgorithm is designed with coordination of double-target tracking, multi-vehicle safetydriving and the longitudinal ride comfort. Finally, the system’s performances arevalidated with driving simulator.To verify the research necessity of LCACC system, and make the system’sperformance meet driver’s lane change request, driver’s lane change characteristics arestudied based on the field experimental data. Driving decision when approaching isanalyzed by extracting lane change road segments from approaching road segments, thestate parameters’ distributions of vehicular and inter-vehicle are described mainly byAnalysis of Variance (ANOVA), lane change behaviors are studied involving lanechange frequency, turn signal usage and rear mirror checking.A lane change warning algorithm integrating multi-vehicle information isdeveloped to judge the lane change risk and ensure safety. After the design of the systemstructure, the Minimum Longitudinal Safety Spacings (MSS) among the host vehicleand its surrounding vehicles are separately analyzed with the goals of safe followingand emergency collision avoidance, driving style factor is introduced to modify theMSS so that the warning timing can accord with the risk awareness of the individualdriver.To coordinate the tracking, safety and comfort issues, the thesis proposes amulti-objective coordinated control algorithm for the LCACC system using ModelPredictive Control (MPC) theory. The tracking performance is designed based on therelative velocity and distance error of the lane change vehicle and the two leading vehicles in the originating lane and destination lane, the safety performance is designedconsidering the safe following distances of the lane change vehicle and its surroundingvehicles, the comfort performance is ensured by limiting the longitudinal acceleration.In the design process of the tracking performance, fuzzy logic method is used to adjustthe car-following weights and realize the double-target tracking.After designing nine lane change conditions through the scene simulation systemand two controllers for the control platform, the LCACC system’s performances areinvestigated with driving simulator. It is concluded that compared with conventionalACC system, the proposed LCACC system can timely assist driver to change lane, andrealize the coordination of double-target tracking, multi-vehicle safety driving andlongitudinal ride comfort performance.