Abstract: In order to further improve the upgrading, assembly and maintenance efficiency of quadrotor  agricultural UAVs and expand the application scope of agricultural UAVs, a modular design method for agricultural UAVs is proposed. Firstly, the correlation between any parts in the quadrotor agricultural UAV at the level of connection fixation, function and geometric parameters is comprehensively analyzed, the part relationship diagram is constructed, the highly correlated parts are clustered into parts, and the correlation matrix of the parts at each level is calculated. Secondly, using the AHP to give different weights to each level, calculate the comprehensive strength correlation matrix between components, and merge parts according to the module evaluation principle. Finally, the module structure is established, the corresponding modules are combined according to the job requirements, and the static and dynamic characteristics of the key functional modules are analyzed. The results show that:  This modular design method simplifies 28 drone parts into 6 independent modules. When the UAV is updated, only the corresponding changed modules need to be redesigned and manufactured. The independence of the module simplifies the assembly process and reduces the maintenance cost. The 6 modules can be combined into spraying drones or spreading drones, so that drones are not only suitable for pesticide spraying, but also for seed and fertilizer sowing. Through the finite element analysis of the central cabin module, its maximum stress is 23.889MPa, which is much smaller than the maximum tensile strength of carbon fiber 4780MPa, the natural frequency of the first four orders is greater than the maximum frequency of 32.75Hz when the UAV is working, and its maximum morphological variable is 0.0046359mm, which meets the deformation requirements under the extreme working conditions of the UAV.

Key words:  , agricultural UAV, modular approach, quadrotor correlation matrix, static and dynamic analysis

摘要： 为进一步提高四旋翼农业无人机的升级、装配和维修效率，拓展农业无人机的应用范围，提出一种针对农业无人机的模块化设计方法。首先，综合分析四旋翼农业无人机中任意零件间在连接固定、功能和几何参数层面的相关关系，构建零件关系图，将相关性强的零件聚类成部件，并计算部件在各层面的相关性矩阵。其次，利用AHP赋予各层面不同权值，计算部件间综合强度相关性矩阵，依据模块评判原则合并部件。最后，建立模块结构，根据作业需求组合相应模块，并对关键功能模块进行静动态特性分析。研究结果表明：该模块化设计方法将28个无人机零件简化为6个独立的模块；无人机更新换代时，只需对相应发生改变的模块进行重新设计制造；模块的独立性简化装配的工艺流程，降低维修成本；6个模块可以组合成喷洒无人机或播撒无人机，使无人机不仅适用于农药的喷洒，也适用于种子和肥料的撒播；通过对中央舱模块的有限元分析，其最大应力为23.889 MPa，远小于碳纤维最大抗拉强度4 780 MPa，前四阶固有频率都大于无人机工作时最高频率32.75 Hz，以及其最大形变量为0.004 635 9 mm，满足无人机极限工况下的形变要求。

关键词: 农业无人机, 模块化方法, 四旋翼, 相关性矩阵, 静动态分析