Zheng Lufeng, Lu Yongjie, Wang Jianxi, Li Haoyu
Department of Mechanical Engineering, Shijiazhuang Tiedao University, Shijiazhuang, 050043, China.
State Key Laboratory of Mechanical Behavior in Traffic Engineering Structure and System Safety, Shijiazhuang Tiedao University, Shijiazhuang, 050043, China.
Sci Rep. 2024 Nov 30;14(1):29802. doi: 10.1038/s41598-024-80854-9.
Considering the fault tolerance of EMB (Electro-Mechanical-Brake) braking failure and anti-rollover control at the same time is one of the urgent problems to be solved in the driving safety of X-by-wire vehicles. Accurate rollover index is a key part of anti-rollover control. Aiming at the problem that the traditional rollover index reflects that the unsprung mass of the vehicle is insufficiently affected by road excitation, a tripped vehicle rollover dynamic model is established based on single-wheel braking failure, and a rollover evaluation index NLTR (New Load-Transfer-Rate) suitable for braking failure is proposed. In order to improve the lateral safety of the vehicle when the line control fails, a hierarchical anti-rollover controller based on road adhesion coefficient identification, SM-ABS (Sliding-Mode-ABS) control and DBR (Differential-Braking-Redistribution) control is designed. Taking the rollover index threshold as the controller trigger condition, the controller effects under NLTR, traditional RI2 and standard LTR indicators are compared respectively. Simulation and HIL test show that the traditional index controller has failure risk under extreme conditions. The designed NLTR index controller can accurately evaluate the rollover risk of the vehicle, control the vehicle in time, and improve the vehicle stability by 68.18% under Fish-Hook condition.
同时考虑电子机械制动(EMB)制动失效的容错性和防侧翻控制是线控车辆行驶安全中亟待解决的问题之一。精确的侧翻指标是防侧翻控制的关键部分。针对传统侧翻指标对路面激励下非簧载质量影响反映不足的问题,基于单轮制动失效建立了绊倒车辆侧翻动力学模型,并提出了一种适用于制动失效的侧翻评估指标NLTR(New Load-Transfer-Rate,新负载转移率)。为提高线控失效时车辆的横向安全性,设计了一种基于路面附着系数识别、滑模防抱死制动系统(SM-ABS)控制和差动制动重新分配(DBR)控制的分层防侧翻控制器。以侧翻指标阈值作为控制器触发条件,分别比较了NLTR、传统RI2和标准LTR指标下控制器的效果。仿真和硬件在环测试表明,传统指标控制器在极端条件下存在失效风险。所设计的NLTR指标控制器能够准确评估车辆的侧翻风险,及时对车辆进行控制,在鱼钩工况下可将车辆稳定性提高68.18%。