复杂激励作用下甘蔗收获机切割系统振动性能的研究

It is a significant strategy to realize the mechanization of the sugarcane harvesting for promoting Chinese sugar industry development, while high broken biennial root rate is the main bottleneck problem that impede it . Based on the previous research, it is found that the broken biennial root rate can be effectively reduced by suppressing the vibration of cutting system. But, there are various excitation sources which incentive regulation are complex when the sugarcane harvester is working . Then the vibration performance of the cutting system which is acted by multiple excitation sources is an urgent problem to be solved. The dynamic analysis model of cutting system is built by studying the rules of road excitation in the sugarcane field, reaction incentive by the cane rod, driven power incentive, and their fitting function. A variety character of nonlinear vibration is studied by equation and virtual prototype simulation method. And then, get the internal relationship between the broken biennial root rate and the structure parameters, operating parameters and the cutting system vibration. Subsequently, reduce the broken biennial root rate by means of optimizing the parameters and reducing vibration measures. Through a series of simulation tests in the laboratory and experiments on the prototype of sugarcane harvester in the field, the theoretical analytic results are verified. Then a new design theory of the sugarcane harvester which may reduce the broken biennial root rate will be set up.

实现甘蔗机械化收割对促进我国蔗糖业发展具有重要战略意义，而甘蔗宿根破头率偏高是阻碍应用研究的主要瓶颈难题。据前期研究发现，抑制切割系统的振动能有效降低甘蔗宿根破头率。但甘蔗收获机械工作时所受激励源繁多,激励规律复杂,在多激励源共同作用下切割系统的振动性能是亟待研究的关键问题。本项目从蔗地路面激励、蔗杆反作用力激励、驱动动力源激励等的规律和拟合函数入手，建立收割机切割系统动态分析模型，由此解析方程和虚拟样机仿真技术研究系统的各种非线性振动特性，获得系统结构参数、工况参数等与切割系统振动的内在关系, 及对甘蔗宿根破头率的影响规律;通过结构参数优化、减振等措施减小甘蔗宿根破头率;通过实验室模拟及实验样机田间试验,验证理论研究的结论;建立可降低甘蔗宿根破头率的甘蔗收获机械设计新理论。

实现甘蔗生产机械化收割对促进我国蔗糖业发展和食糖安全具有重要战略意义，但目前我国的甘蔗收获机的应用率仅<5%,而甘蔗宿根破头率高是影响其推广应用的主要瓶颈之一。. 本项目研究发现，切割系统的动态响应特性与甘蔗宿根破头率存在较强的相关性, 取得下列成果:（1）本项目以切割系统动态特性对甘蔗破头率的影响为切入点，通过多体动力学的解析模型研究、虚拟样机仿真分析、模态测试与动态分析、激励实验平台试验研究、刀盘和甘蔗在相对振动状态下切割实验研究等多种研究方法，研究了在蔗地路谱、蔗杆反作用力、动态切割力、驱动力源等激励源耦合作用下切割系统的动态特性对甘蔗宿根破头率影响的机理，其中甘蔗路谱对刀架振动具有显著影响；基本摸清了各主要激励源特征及甘蔗收获机切割器系统振动响应特性（2）通过仿真与实验研究了甘蔗蔗芯蔗皮的力学特性及微观状态下的切割机理和破损特性；（3）分析了切割系统结构参数、工作参数及模态参数等对切割系统的影响关系;（4）通过系列仿真分析和试验研究：发现了（刀盘）切割系统的轴向振动是甘蔗宿根破头率的重要影响因素，相对于切割工艺参数，其对甘蔗切割质量具有更显著的影响的重要规律。（5）初步研究了切割系统的结构动态特性(振动幅值、频谱分析、传递函数分析)等表征办法；（6）采用DA_SVM（蜻蜓算法）群智能方法，构建了切割系统轴向振动对甘蔗宿根破头率的预测模型，均方误差为：9.99E－05，拟合率为：99．99%，相比较其具有较优的预测精度。（7）通过拓扑优化，探讨了以降低切割器系统轴向振动为目标的结构优化;分别对刀架、刀盘、物流架进行结构优化，并通过实验室实验平台测试实验研究, 可有效地提高系统的动态刚度，降低切割系统的轴向振动。发表论文27篇(EI收录5篇),获授权专利17项。. 综上所述，该项目达到了预期的目标，完成了主要的研究任务，发现了重要的机理和规律，初步探讨了切割系统的部分动态设计准则，为实现低甘蔗破头率的甘蔗收获机械设计提供了应用研究理论基础和参考依据。