单行自走式电动采茶机履带底盘设计与行驶性能试验

Design and Travel Performance Test of Crawler Chassis for Single-row Self-propelled Electric Tea Picker

摘要:

针对丘陵茶园行间距窄、地形坡大等特点和现有跨垄式底盘难以进入以及采摘设备适应性差等问题，本文设计了一款单行自走式电动采茶机。首先，结合丘陵山地茶园实际情况以及茶树种植农业现状，确定采茶机设计参数。采用Solidworks对整机结构进行三维模拟建模，建立履带底盘直线行驶速度模型与转向动力学模型，分析了同向差速、单边制动、反向差速3种转向工况的阻力特性;对采茶机横向、纵向稳定性以及越障性能进行了理论分析，求解出最大横向倾翻角为19.3°和最大爬坡角为31.0°;通过RecurDyn开展多体动力学仿真，仿真结果表明，当地面附着系数为0.67、样机行驶速度为0.4 m/s时，整机可在横向角为18°时未倾翻，纵向最大爬坡角为34°，表明整机横向稳定性、纵向爬坡性能均可满足设计需求。最后，经田间试验测得，履带底盘在15 m水泥地面直线行驶偏移量为248.4 mm，偏移率为1.67%;实际横向极限倾翻角为15°;可顺利通过15°~33.5°纵向斜坡;原地转向直径为1 318 mm，圆心偏移量为81.2 mm，满足采茶机在丘陵山地茶园的工作需求。研究结果可为丘陵山地茶园采摘装备研究和参数优化奠定基础。

Abstract:

Aiming at the characteristics of narrow row spacing and large terrain slope of hilly tea gardens, as well as the poor adaptability of existing picking equipment, a single-row self-propelled electric tea picker was designed. Firstly, combined with the actual conditions of hilly and mountainous tea gardens and the agricultural status of tea tree planting, the design parameters of the tea picker were determined systematically. Solidworks software was adopted for three-dimensional (3D) simulation modeling of the whole machine structure, and the linear driving speed model and steering dynamics model of the crawler chassis were established. On this basis, the resistance characteristics of three steering conditions, namely, co-directional differential speed, single-side braking and reverse differential speed, were analyzed in detail. In order to ensure the operational safety of tea picker in complex hilly terrain, the transverse stability, longitudinal stability and obstacle surmounting performance of the tea picker were theoretically analyzed, and the maximum transverse tipping angle was 19.3° and maximum climbing angle was 31.0°. Subsequently, multi-body dynamics simulation was carried out by using RecurDyn software. The simulation results showed that when the ground coefficient was set to 0.67 and the driving speed of the prototype was 0.4 m/s, the maximum transverse tipping angle of the whole machine was 18° and the maximum longitudinal climbing angle was 31.0°, indicating that both the transverse stability and longitudinal climbing performance of the whole machine can meet the pre-designed requirements. Finally, field tests were conducted to verify the performance of the crawler chassis. The test results showed that the linear driving deviation of the crawler chassis on a 15-meter cement ground was 248.4 mm, with a deviation rate of 1.67%;the actual maximum transverse tipping angle was 15°;the tea picker can smoothly pass through longitudinal slopes ranging from 15° to 33.5°;the in-situ steering diameter was 1 318 mm, and the center offset was 81.2 mm. The test results were roughly consistent with the simulation results, which verified the rationality of the design. The research results can lay a theoretical and experimental foundation for the research and parameter optimization of picking equipment in hilly and mountainous tea gardens.