植保机喷杆位置变增益滑模控制系统设计

关薪 李树江

摘要：大型喷杆式植保机在现代农业生产过程中被广泛应用，但由于路面不平、车体震动等原因，喷杆位置难于精准控制，会产生喷洒药液不匀的问题。由于植保机的喷杆悬架系统本身具有强非线性、时滞性和不确定性等特点的存在，使用传统控制方法的最终效果并不理想。为了解决未知干扰和建模误差的问题。建立了植保机双钟摆型悬架的动力学模型，引入滑模控制结合随机配置网络（SCN）预测补偿的方法设计控制器，该控制器在保证动态性能的前提下，降低了抖振。解决了控制效果并不理想的问题，同时降低了系统误差和未知干扰对系统的影响。系统通过仿真模型验证了控制器的稳定性，仿真结果表明该控制器动态性能和鲁棒性方面表现良好。

关键词： 植保机;位置控制;随机配置网络;滑模控制;喷杆悬架

中图分类号：TP273    文献标识码：A

文章编号：1009-3044（2021）32-0117-04

Design of Sliding Mode Control System for the Position of Spray Bar of Plant Protection Machine with Variable Gain

GUAN Xin， LI Shu-jiang

（Shenyang University of Technology， Shenyang 110870， China）

Abstract： Large-scale spray-rod type plant protection machine is widely used in the process of modern agricultural production， but due to uneven road surface， vehicle body vibration and other reasons， the position of spray rod is difficult to accurately control， which will produce the problem of uneven spraying liquid. Due to the strong non-linearity， time delay and uncertainty of the spray rod suspension system of plant protection machine， the final effect of using the traditional control method is not ideal. In order to solve the problems of unknown disturbance and modeling error， the dynamic model of plant protection machine double pendulum suspension was established. The sliding mode control combined with stochastic configuration networks （SCN） prediction and compensation method was introduced to design the controller. The chattering of the controller was reduced on the premise of ensuring the dynamic performance. The problem that the control effect is not ideal is solved and the influence of system error and unknown disturbance is reduced. The stability of the controller is verified by the simulation model， and the simulation results show that the controller performs well in dynamic performance and robustness.

Key words： plant protection machine; position control; random configuration network; sliding mode control; Spray bar suspension

1 引言

我国是一个农业大国，但生产效率很低。其原因主要在于植物保护环节消耗人力巨大，机械化程度低。大型植保机械的推广使用可以有效改善这一现象[1]。农机产品主流是尾部加装喷杆的大型拖拉机，喷杆臂展大，成本低适合大规模田地的作物保护。但这种机型存在药液喷洒均匀的问题，产生原因主要是大田作业环境非常复杂，而且存在随机扰动，农机喷杆只有被动悬架与车身相连无法抵消这些干扰，轻则造成药液喷施不均效果降低，重则造成喷杆倾斜机身损坏等严重后果。……