摘要 针对茶园拖拉机（tractor in tea plantation，TTP）在作业时进行避障转弯极易发生侧翻、倾覆等安全问题，提出一种基于Bezier曲线优化的避障稳定路径控制方法.首先，从作业场景和运行稳定性两个方面进行运动学分析，系统分析了TTP安全作业特点；然后，针对TTP设计了一种避障路径规划系统方案及Bezier曲线路径优化控制方法，该方法拟合出的路径具有路径光滑、曲率连续、初末位置曲率相同等优点；最后，在CarSim仿真平台搭建TTP模型和坡道避障作业的环境模型，验证并分析横摆角速度、质心侧偏角两项重要的操稳性参数.结果表明：TTP在Bezier曲线拟合的避障路径控制方法下当运行速度小于转向极限速度时，运行稳定性良好,当转向速度超过极限速度的65.1%，其横摆角速度和质心侧偏角的超调量变化率分别达到了50.3%和78.6%；同时在该避障控制方法下，随着坡度的增加，即使速度保证在极限速度以下，TTP稳定性也会进一步恶化；在极限坡度角范围内，坡度角增大10°，其横摆角速度和质心侧偏角的超调量变化率平均达到了32.8%和14.5%.
Abstract：To solve the safety problems of tractors in tea plantation (TTP) in obstacle avoidance turning with rollover and overturn, an obstacle avoidance stable path control method was proposed based on Bezier curve optimization. The kinematics analysis was carried out according to operation scene and operation stability, and the safety operation characteristics of TTP were systematically analyzed. The obstacle avoidance path planning system framework and the Bezier curve path optimization method were designed. The path fitted by this method had the advantages of smooth path, continuous curvature with the same curvature at the beginning and end. TTP model and ramp obstacle avoidance environment model were established on CarSim simulation platform to verify and analyze two important operation stability parameters of yaw velocity and sideslip angle. The results show that TTP has good running stability when the running speed is less than the steering limit speed under the path fitted by Bezier curve. When the steering speed exceeds 65.1% of the steering limit speed, the overshooting rates of yaw velocity and the centroid sideslip angle reach 50.3% and 78.6%, respectively. At the same time, with the increasing of slope, TTP stability can be further deteriorated even if the speed is kept below the limit speed. When the slope angle is increased by 10°, the overshoot rates of yaw velocity and the centroid sideslip angle reach 32.8% and 14.5% on average，respectively.
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