发表机构
School of Mechanical Engineering, Shanghai Jiao Tong University; Faculty of Engineering, The University of Hong Kong（上海交通大学机械工程学院; 香港大学工程学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对抓地到漂移的连续过渡问题，提出BE-LMPC方法，通过单圈优化使漂移在附着系数0.6时涌现，明确漂移是极限操控的条件性延续。
AI 中文摘要
现有自动漂移控制器通常跟踪预设的漂移平衡点、侧滑参考或轨迹，这些方案明确了如何执行漂移，但在接近操控极限时从抓地驾驶到漂移的连续过渡问题仍未解决。本文将漂移涌现定义为重复的单圈时间最小化任务，其中控制器目标或奖励均不包含显式的漂移参考。边界探索学习模型预测控制器（BE-LMPC）基于已完成的单圈构建经验安全集和局部偏移的终端代价，通过在固定全局速度约束下迭代优化空间速度分配，逐步探索更大的侧滑和横摆率包络，同时保持可恢复性。随着单圈性能提升，持续侧滑和明显的横摆运动涌现，后轴接近饱和。分析表明，当外部条件平滑变化时，轮胎附着力到滑动的过渡本身不会导致轮胎力或车辆状态的突变，组合滑动Fiala模型在该过渡处满足连续性条件。在轮胎路面附着系数为0.6时，单圈时间从第3圈的49.95秒降至第12圈的25.50秒，漂移首次在第11圈涌现，第12圈达到16.5°侧滑和0.894后轴利用率。相比之下，附着系数0.8至1.2时未检测到漂移，1.2时达到类似峰值速度，仅后轴利用率为0.483。这些结果表明，漂移是极限操控的条件性延续，在性能需求提升至接近可用轮胎容量时涌现，而非单独预设的运动模式。
英文摘要
Automated drift controllers commonly track a prescribed drift equilibrium, sideslip reference, or trajectory. These formulations establish how to execute drift, whereas the continuous transition from grip driving to drift near the handling limit remains unresolved. This paper defines drift emergence in a repetitive lap time minimization task, where neither the controller objective nor the reward contains an explicit drift reference. A boundary exploration learning model predictive controller (BE-LMPC) constructs an empirical safe set and a locally shifted terminal cost from completed laps. By iteratively improving spatial speed allocation under a fixed global speed bound, the controller progressively explores larger sideslip and yaw rate envelopes while preserving recoverability. As lap performance improves, sustained sideslip and pronounced yaw motion emerge while the rear axle approaches saturation. Analysis shows that, when external conditions vary smoothly, the transition from tire adhesion to sliding does not itself cause abrupt changes in tire force or vehicle state. The combined-slip Fiala model satisfies this continuity condition at the transition. At a tire road friction coefficient of 0.6, lap time decreases from 49.95 s on Lap~3 to 25.50 s on Lap~12, with drift first emerging on Lap~11. Lap~12 reaches 16.5$^\circ$ sideslip and 0.894 rear axle utilization. In contrast, no drift is detected for friction coefficients from 0.8 to 1.2; at 1.2, a similar peak speed is achieved with only 0.483 rear axle utilization. These results characterize drift as a conditional continuation of limit handling that emerges when increasing performance demand approaches the available tire capacity, rather than as a separately prescribed motion mode.
