轮履切换式作物表型信息感知机器人底盘设计与试验

Design and Experiment of Wheel-crawler Switching Chassis for Crop Phenotyping Information Perception Robot

摘要:

为解决大田作物表型信息感知机器人底盘损伤作物、灵活性不足和通过性差等问题，结合我国稻麦的种植农艺模式和生长特点，设计了一种具有轮履切换和轮距无级调节功能的大田作物表型信息感知机器人底盘。对底盘的整机结构和工作原理进行了阐述，设计了刚性叶轮、充气橡胶轮和三角履带3种可快速切换的行走装置和四轮独立驱动及四轮独立转向的部件，以及轮距无级精确调节装置。并对机器人底盘转向性能、稳定性和通过性进行了理论分析，结果表明机器人底盘性能满足设计要求。对车架进行了有限元仿真分析，结果表明车架强度和刚度均能满足设计要求，并能够有效避免因地形激励产生的共振。样机试制后田间试验结果表明，机器人底盘具有良好的行驶性能，3种形态底盘在田间地面直线最大行驶速度分别为1.02、0.98、0.73 m/s，加速度为0.3、0.33、0.18 m/s2，行驶平均偏移率分别为2.35%、1.18%、1.89%；轮式底盘、三角履带式底盘最小转弯半径分别为2 306、1 432 mm；刚性叶轮式底盘纵向爬坡角为30°，横向爬坡角为28°；翻越垂直障碍高度为350 mm，田间越埂高度为308 mm，能够满足大田场景表型信息感知作业要求。

Abstract:

Aiming to address the issues of crop damage, insufficient flexibility, and poor passability associated with chassis systems in field crop phenotyping information perception robots, a chassis was designed that integrated wheel-crawler switching and stepless wheelbase adjustment functionalities, taking into account the agronomic practices and growth characteristics of rice and wheat cultivation in China. The overall structure and operational principles of the chassis were elaborated, and three types of easily switchable locomotion devices, i.e., a rigid impeller, inflatable rubber wheels, and triangular tracks were developed. Additionally, components for independent four-wheel drive and four-wheel steering, along with a device for precise stepless adjustment of wheelbase, were designed. The steering performance, stability, and passability of the robot chassis were theoretically analyzed, with results confirming that the performance met the design requirements. Finite element analysis was conducted on the chassis frame, demonstrating that both the strength and stiffness met the design specifications and that resonance induced by terrain excitation can be effectively mitigated. Field tests conducted on the prototype indicated that the robot chassis exhibited excellent driving performance, with maximum linear travel speeds of 1.02 m/s, 0.98 m/s, and 0.73 m/s across the three configurations, while accelerations were recorded at 0.3 m/s2, 0.33 m/s2, and 0.18 m/s2, respectively. The average deviation rates during travel were 2.35%, 1.18%, and 1.89%, respectively. The minimum turning radii for the wheeled and triangular tracked configurations were 2 306 mm and 1 432 mm, respectively. The rigid impeller configuration achieved a longitudinal climbing angle of 30° and a lateral climbing angle of 28°. The robot successfully traversed vertical obstacles up to 350 mm in height and negotiated field ridges of 308 mm, thereby meeting the operational requirements for phenotyping information perception in large field scenarios.