基于准零刚度原理控制水稻脱粒过程诱发滚筒振动的方法研究

Combine harvester disturbed vibration of rice threshing cylinder emerge as the beginning of rice threshing, changes as the diversification of feeding rate, disappears as the end of threshing. It is difficult to control vibration due to the time - varying vibration characteristics. Straw winding constraints, variable mass process, time varying feeding rate are taken into researches. The mechanism of vibration and mechanism of disturbance induced by rice threshing will be revealed. A method of controlling vibration and suppressing resonance will be developed. The research content includes: 1) Winding constraint characteristics of rice straw on threshing cylinder will be researched based on the variable mass model in threshing process. The vibration generation mechanism of threshing cylinder will be revealed by the analysis of eccentric additional mass equivalent method on threshing cylinder. 2) The law of change of eccentric additional mass at both sides of feeding and draining ends will be researched based on the feeding rate time-varying characteristics. Disturbance mechanism of vibration characteristics in cylinder threshing process will be expounded. 3) Controllable negative stiffness will be developed based on the shaft end pre-stressed side. Vibration characteristics of both sides of feeding and draining ends in cylinder threshing process will be researched. Disturbed vibration control method of quasi-zero stiffness beam will be developed. The aim of this project will reveal the mechanism of vibration and the mechanism of disturbance induced by rice threshing. Design method of quasi-zero stiffness will be developed for controlling disturbed vibration of cylinder threshing process. All this research result will improve the cylinder threshing performance and reliability.

联合收割机水稻脱粒过程诱发的滚筒振动随脱粒开始而产生、随喂入量波动而变化、随脱粒结束而消失，振动特性瞬变且难以控制。本项目从滚筒脱粒过程中受稻秆旋绕约束、变质量过程、时变喂入量等影响因素入手，研究诱发滚筒振动的机理及扰动机制，建立控制脱粒过程中滚筒振动及抑制共振的方法。研究内容：1）研究滚筒水稻脱粒过程中的变质量模型，解析脱粒稻秆对滚筒的旋绕约束特性，采用偏心附加质量等效法揭示脱粒过程诱发滚筒振动的机理；2）研究滚筒脱粒过程中的喂入量时变特性，解析滚筒喂入与排草两端偏心附加质量的变化规律，阐明时变喂入量对滚筒脱粒过程振动特性的扰动机制；3）研究脱粒过程中滚筒两轴端的振动特性，提出采用轴端预应力方法构建可控负刚度屈梁，建立正负刚度并联的准零刚度复梁受扰振动控制方法。本项目旨在揭示水稻脱粒过程诱发滚筒受扰振动产生机理，建立控制滚筒脱粒过程振动的准零刚度复梁设计方法，提高滚筒脱粒性能及可靠性。

针对联合收割机水稻脱粒过程诱发滚筒振动随脱粒开始而产生、随喂入量波动而变化、随脱粒结束而消失，振动特性瞬变且难以控制等难题，本项目研究了诱发滚筒振动的机理及扰动机理，建立控制脱粒过程中滚筒振动及抑制共振的方法，获得了控制滚筒脱粒过程振动的准零刚度复梁设计模型和参数，提高了滚筒脱粒性能及可靠性。. 依据项目研究内容及目标，主要开展了三方面的研究：（1）研究滚筒水稻脱粒过程中的变质量模型，解析脱粒稻秆对滚筒的旋绕约束特性，采用偏心附加质量等效法揭示脱粒过程诱发滚筒振动的机理。通过对水稻脱粒过程中茎秆的受力和旋绕约束特性开展研究，发表SCI论文3篇，申请发明专利2件、 PCT专利1件，授权发明专利1件，获2018年中国专利奖金奖。（2）研究滚筒脱粒过程中的喂入量时变特性，解析滚筒喂入与排草两端偏心附加质量的变化规律，阐明时变喂入量对滚筒脱粒过程振动特性的扰动机制。针对脱粒过程中的水稻喂入量时变特性研究，发表SCI论文3篇，申请发明专利2件、PCT专利1件，授权发明专利2件，获2018年教育部科学技术进步一等奖、2019年神农中华农业科技奖二等奖。（3）研究脱粒过程中滚筒两轴端的振动特性，提出采用轴端预应力方法构建可控负刚度屈梁，建立正负刚度并联的准零刚度复梁受扰振动控制方法。针对脱粒过程中滚筒两轴端的振动特性研究，发表SCI论文3篇，申请发明专利1件，授权发明专利1件。通过本研究，揭示了水稻脱粒过程诱发滚筒振动的机理，建立了联合收割机滚筒脱粒过程中的振动控制方法，为解决联合收割机滚筒脱粒过程产生振动的难题奠定基础。. 在本项目资助下共发表了SCI收录论文9篇、申请发明专利9件（授权了4件）、申请PCT专利2件、作为主要完成人获得了2019年神农中华农业科技奖二等奖（排名第8）、2018年中国专利奖金奖（排名第二）、2018年教育部科学技术进步一等奖（排名第四），培养了硕士研究生3人。