A vehicle multi-objective coordinated lane change assist adaptive cruise control method

Abstract

The invention relates to a vehicle multi-target coordinating lane changing assisting adaptive cruise control method. The method comprises the following steps that 1) LCACC combination property indexes are set according to two-front-vehicle traceability, multi-vehicle movement safety and longitudinal driving comfort requirements, and the LCACC combination property indexes comprise a cost function and I / O constraints; 2) a multi-target coordinating optimal control problem is built, solving is carried out through a rolling time domain optimization algorithm, the optimal control quantity is obtained, and optimal control is achieved. The LCACC cost function is set according to the following steps that a) a traceability cost function is built through a two-norm linear combination of the vehicle distance errors and vehicle speed errors of the own vehicle and two front vehicles; b) a comfort cost function is built by restraining longitudinal acceleration. The LCACC I / O constraints are set according to the steps that a) in the respect of tracking performance, vehicle following error constraints which are used for limiting the vehicle speed errors and the vehicle distance errors and allowed by a driver are obtained through driver experimental data in a statistic mode; b) in the respect of safety performance, the safety distance between the own vehicle and multiple surrounding vehicles is restrained in the view of vehicle following and collision avoidance; c) in the respect of comfort performance, the expected longitudinal acceleration data range is restrained.

Description

technical field [0001] The invention relates to a vehicle longitudinal dynamics control method, in particular to a vehicle multi-objective coordinated lane-changing auxiliary adaptive cruise control method based on model predictive control theory. Background technique [0002] As one of the typical representatives of driver assistance systems (DAS, Driver Assistance Systems), adaptive cruise control system (ACC, Adaptive Cruise Control System) can improve driving safety, improve traffic congestion and relieve driving fatigue, and has been widely recognized and concerned by research institutions and automobile companies . However, the research on the existing ACC system is mainly carried out based on straight-line driving. Under the lane-changing driving, the existing ACC system shows certain limitations, and even interferes with the normal driving of the vehicle. For example, when the driver performs a lane change under the condition of approaching the vehicle in front, the...

AI Technical Summary

Problems solved by technology

However, the research on the existing ACC system is mainly carried out based on straight-line driving. Under lane-changing driving, the existing ACC system shows certain limitations, and even interferes with the normal driving of the vehicle.

For example, when the driver performs a lane change under the condition of approaching the vehicle in front, the conventional ACC system cannot recognize the lane change intention and continues to follow the vehicle ahead in the original lane, thereby interfering with the driver's lane change behavior and increasing the driver's concern about the lane change. System Intervention Frequency

[0003] In the process of lane changing, there are multi-objective coordination optimization problems in three aspects: the tracking performance between the self-vehicle and the two vehicles in front, the safety between the self-vehicle and the surrounding vehicles, and the driver's longitudinal comfort. The existing ACC cannot To meet this requirement, the tracking problem is reflected in: before the start of the lane change, the follow-up target of the conventional ACC is the vehicle in front of the original lane; The driver’s intention to change lanes causes obstacles; during the cross-lane process, the conventional ACC suddenly changes the following target, which not only causes a sudden change in the expected acceleration, but also makes the driver feel uncomfortable; The following control of the car in front of the lane requires a long time to adjust the following relationship with the car in front of the target lane

The safety problem is reflected in: during the lane changing process, the state fluctuation of the lane changing vehicle itself will cause certain interference to the front and rear vehicles in the original lane and the target lane, which may cause rear-end collision accidents

The comfort problem is reflected in: when the absolute value of the acceleration output by the ACC is large, the driver will feel uncomfortable

Aiming at the problem that conventional ACC hinders lane changing, some scholars have proposed to add an automatic lane changing function to the conventional ACC system, but automatic lane changing involves lateral dynamics and needs to control the steering wheel, which is quite different from the system structure and control algorithm of ACC; In addition, automatic lane changing only controls a single vehicle to complete the lane changing behavior, and lacks consideration of the movement coordination between the lane changing vehicle and the surrounding vehicles, making it difficult to ensure the safety of lane changing

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