大型喷灌机喷头PWM变量脉冲的实现  

The Realization of PWM Variable Pulse for the Sprinkler of Large-scale Irrigation Machine

作　　者：陶帅 李文涛 黄小林 李彦明[1] 莫锦秋[1] Tao Shuai;Li Wentao;Huang Xiaolin;Li Yanming;Mo Jinqiu(School of Mechanical Engineering,Shanghai Jiao Tong University,Shanghai 200240,China)

机构地区：[1]上海交通大学机械与动力工程学院,上海200240

出　　处：《农机化研究》2021年第5期18-22,共5页Journal of Agricultural Mechanization Research

基　　金：“十三五”国家重点研发计划项目(2017YFD0700504-2)。

摘　　要：独立喷头变量喷灌(IS-VRI)能够实现更精细化的地块管理,提高水资源利用率。目前,针对IS-VRI的研究多集中于流量分配及分解算法,考虑分配和分解结果的具体执行,给出了对大型喷灌机上众多喷头进行独立PWM变量控制的具体实现。首先,结合大型变量喷灌机存在的复杂解算与实时控制并存、受控电磁阀分布跨度大且数量多,以及行走约束等实际情况,介绍了由无线透传中继有线的串行总线构成的分级分布控制系统;然后,基于该系统,给出从机发出多路独立PWM脉冲的硬件设计和软件处理流程;最后,从大型喷灌机整体性能角度,阐述采用在一个计量周期中配置不同占空比的PWM脉冲来取得均化后较低的变量比下限和变量比分辨率的方法,且针对PWM脉冲带来的机械激振和压力脉动,给出了站间错相和站内错相两种缓解措施。通过实物实施,验证了所述系统和方法的正确性和有效性。Individual sprinkler variable rate irrigation(IS-VRI)can manage the land more precisely and improve the utilization rate of water resources.Existing researches are focused on the algorithms of flow distribution and decomposition.The realization of the independent PWM Variable Control of many sprayers on the large-scale irrigation machine is present in this paper.Due to the complex solution and real-time control coexisting for the large-scale variable sprinkler,the large distribution span and a large number of the controlled solenoid valves,the walking constraints of the sprinkler,a hierarchical distributed control system,which is based on a serial bus with wireless transmission relay cable,is given in this paper.Then,the hardware design and software processing flow of independent PWM pulses producing in the slave station are described.From the perspective of the overall performance of the large-scale sprinkler,different PWM duty ratios are used in a metering cycle to get a lower limit and variable resolution in the view of homogenization.In this paper,inter-station and in-station phase stagger are used to reduce the mechanical vibration and pressure pulsation caused by PWM pulse.The system and method described in this paper have been implemented and verified.

关 键 词：变量喷灌 分级分布控制 脉宽调制 相位错开 

分 类 号：S277.94[农业科学—农业水土工程] S491[农业科学—农业工程]