基于挠性圆盘的甘薯裸苗类水平栽植运动分析与试验

针对目前挠性圆盘在甘薯裸苗栽植中无法满足水平栽植农艺要求的问题，结合农艺要求，对挠性圆盘夹持甘薯裸苗栽植过程进行运动学分析，构建裸苗触地弯曲与苗根运动的数学模型，利用台架和EDEM软件仿真试验验证模型，对裸苗弯曲朝向的影响因素与触地后裸苗根部的运动轨迹进行研究。结果表明:1)裸苗理论弯曲朝向由圆盘旋转中心距地面高度、机具前进速度与圆盘转速决定，裸苗根部会在触地后先向前移动一段距离；2)当机具前进速度为0.25 m/s时，裸苗实际弯曲朝向与圆盘转速相关，圆盘转速为1.4 rad/s时，甘薯裸苗弯曲实际朝向与理论朝向的符合率达到98%。当圆盘转速大于1.2 rad/s后，裸苗根部在触地后先向前移动的距离小于10 mm。田间试验表明在机具前进速度为0.25 m/s，圆盘转速为1.4 rad/s的情况下，甘薯裸苗在挠性圆盘的夹持下能够实现类水平栽植，栽植深度合格率达到95.6%，栽植姿态合格率达到87.8%。

Kinematics analysis and experiment of horizontal planting of sweet potato naked seedlings based on flexible disc

In view of the problem that the flexible disc can not meet the agronomic requirements of horizontal planting in cultivation of sweet potato naked seedlings at present, according to the agronomic requirements, the kinematics analysis was used to investigate the planting process of sweet potato naked seedlings clamped by flexible discs. A mathematical model of sweet potato naked seedlings bending and root movement was constructed. The influencing factors of sweet potato naked seedlings bending orientation were verified by using the method of bench and EDEM software simulation test and the movement track of sweet potato naked seedlings root after touching the ground were studied. The results showed that: 1)The theoretical bending orientation of sweet potato naked seedlings is determined by the height from the rotating center of the disc to the ground, the forward speed of the machine and the rotating speed of the disc. The root of sweet potato naked seedlings moves forward for a certain distance after touching the ground; 2)When the machine speed is 0. 25 m/s, the actual bending orientation of sweet potato naked seedlings is related to the disc speed. When the disc speed is 1. 4 rad/s, the coincidence rate between the actual bending orientation and the theoretical orientation of sweet potato naked seedlings reaches 98%. When the rotational speed of the disc was greater than 1. 2 rad/s, the distance of the root of the sweet potato naked seedlings moving forward is less than 10 mm after touching the ground. In conclusion, under the condition of the machine speed of 0. 25 m/s and the disc speed of 1. 4 rad/s, the sweet potato naked seedlings is planted horizontally, the qualified rate of planting depth is 95. 6%, and the qualified rate of planting posture reaches 87. 8%.