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At present, the lane changing technology for a single driving environment has been relatively mature, but the actual situations are much more complicated, such as the changing curvature and the changes in road conditions. In this paper, a new lane changing obstacle avoidance control strategy for the variable curvature road was proposed. It has two stages including path planning for variable curvature lane changing and inverse system decoupling (ISD) control for path tracking. The first stage established the lane changing path models for the variable curvature road. A longitudinal-lateral safe distance model was proposed to constrain the safe boundary of the lane changing path. The second stage proposed a dynamic decoupling method for longitudinal and lateral motion based on the inverse system decoupling, a direct yaw moment and active front wheel steering coordinated control method was designed. The inverse system decoupling algorithm can correct the single point preview (SPP) method to improve the stability and the path tracking accuracy in the lane changing obstacle avoidance process. The strategy was simulated by CarSim/Simulink co-simulation, and the experiments were carried out on the hardware-in-the-loop platform. The results show that the proposed control strategy can effectively avoid obstacles when the vehicle is driving on the variable curvature road. Besides, for the different road conditions and the strong non-linearity generated during the lane changing process, the control strategy can reduce the tracking error by a maximum of 32.7%, both the yaw rate and side slip angle can be controlled in a smaller range. [ABSTRACT FROM AUTHOR]

This paper proposes a novel dynamic path planning and path following control method for collision avoidance, which works based on an improved piecewise affine tire model. The main contribution of this work is the design of a dynamic path planning method based on model predictive control, where it replans a maneuverable path to avoid moving obstacle in real time. A hierarchical control framework contains a high-level path replanning model predictive control and a low-level path following model predictive control. A collision avoidance cost function in the high hierarchies was designed to calculate the relative dynamic distance, which copes with the sudden obstacle. Moreover, the replanning path is the optimized output according to reference trajectory, obstacle, and handling stability. The control objective of the low hierarchies is to accurately track the replanning path, especially for the increased nonlinearity of large tire sideslip angle. For this reason, an improved piecewise affine tire model is designed and used for model predictive control to improve the path following performance and reduce calculated burden. The main improvement of the piecewise affine tire model is that the varied lateral stiffness coefficients adapt to the change of the tire sideslip angle in different tire regions. Based on the CarSim and Simulink platform, the dynamic path planning and path following simulations are designed to test the proposed method. The simulation results demonstrate the effectiveness of the proposed method. [ABSTRACT FROM AUTHOR]

In this paper, a new curve-lane recognition algorithm is proposed. The algorithm uses edge point curvature voting to determine the region of interest based on near-vision straight-lane information. First, information is detected in the near-vision area regarding the straight lines to the left and right of the current lane. Near-vision lane-line extraction includes lane image filtering, as well as edge detection of the region of interest below the vanishing line. The vanishing point is positioned by determining the position of the edge point and distribution of the direction angle. In addition, the straight line is extracted based on the position of the vanishing point. The straight lines that are constructed for the current lane in this way are selected and used as supplementation, in combination with the lane model. Next, the road curvature range isometry is divided into multiple subdivision regions. The near-vision lane straight-line curvature parameters extending from each edge point in the region of interest are computed by combining the straight-line near-vision lane information with the curve lane model in the pixel coordinate system. Subsequently, voting and counting are carried out for the curvature regions of each edge point to which the corresponding curvature computing values belong. Finally, the counting maximum from the corresponding curvature regions of the straight lines located to the left and right of the current lane are searched for, and the curvature region is converted, to obtain the lane line corresponding to the curvature parameter values. Experimental results indicate that the proposed curve-lane recognition algorithm can effectively detect the curve lanes of different curvatures. The results also indicate that the proposed curve detection method is highly accurate, and the algorithm is very robust in different environments. [ABSTRACT FROM AUTHOR]

In-wheel motor drive vehicles have many advantages such as more efficient, energy-saving, large space, and flexible control. But the increase of four-wheel actuators and sensors makes the probability of wheel motor fault increase and brings risk to the safety and reliability of the system. For in-wheel motor drive vehicles, the motor torque output fault happens frequently, which seriously affects the stability and safety of the vehicle. The stability control under the single-motor fault condition is considered in this paper, and the vehicle model with a single-motor fault and the fault diagnosis observer are established. Then, combined with the fault observation, a stability control method is formulated based on the different states of the controlled object of the vehicle. At the stage of low speed and small steering, a torque compensation controller including steady state/feedforward/feedback control is designed for the fault motor based on the triple-step method to ensure the vehicle staying in a stable driving state. At the stage of high-speed, large-steering, or large-torque output, the vehicle stability control based on torque distribution is carried out for the sound wheel, which is composed of a torque tracking controller and a torque optimal distribution controller. The former can make the vehicle get rid of the fault state quickly, and the latter can effectively keep the stability of the vehicle and make the vehicle maintain a certain driving response ability. Finally, the control method proposed in this paper is simulated and tested on the CarSim/Simulink joint simulation platform and the CarSim/LabVIEW hardware-in-loop experiment bench. The results show that after the single-motor fault occurs, the stability control system can effectively suppress the instability of the vehicle caused by the single-motor fault and ensure the stability and safety of the vehicle. [ABSTRACT FROM AUTHOR]

A 3-degree of freedom (DOF) nonlinear model including yaw, lateral, and roll motions was constructed, and a numerical simulation of chaotic behavior was performed using the Lyapunov exponent method. The vehicle motion is complex, manifesting double-periodic, quasi-periodic, and chaotic phases, which negatively affects the vehicle lateral stability. To control this chaotic behavior, a controller was designed based on the sliding mode variable structure control (SM-VSC) method. To decrease chattering and further improve lateral stability of the vehicle under extreme operating conditions, the adaptive power reaching law was realized by using a fuzzy control method. The performance of the SM-VSC system was simulated by using Matlab/simulink. The simulation results including the uncontrol, SM-VSC control, and adaptive-reaching SM-VSC control were compared, which demonstrated that the adaptive-reaching SM-VSC control method is more effective in suppressing the chaotic phase of the vehicle lateral motion. The approach proposed in this paper can significantly improve a vehicle's lateral stability under extreme operating conditions. [ABSTRACT FROM AUTHOR]