【作者】 张勋；

【导师】 朱瑞祥；

【作者基本信息】 西北农林科技大学 ， 农业机械化工程， 2009， 硕士

【摘要】 我国耕地面积仅占世界耕地的7%,而化肥施用量却高达占世界的25.14%,是世界平均施用水平的2.81倍,我国已成为世界上最大的化肥生产和消费国。化肥的施用,在提高耕作土壤的肥力、保障了国家粮食安全的同时,也带来一些环境问题。研究表明,长期过量和不科学施用化肥,会引起土壤物理性质恶化、水生生态系统的酸化、富营养化及降低物种多样性等。本研究针对玉米作物保护性模式下,施肥作业中易发生机具堵塞及肥料利用率低等问题,提出了一种穴播穴施肥技术,并对其机械装置和相应的控制系统进行设计分析。本研究的主要工作及取得的成果有:(1)在分析常见玉米播种及种肥施用方式的基础上,论证了保护性耕作条件下施用缓/控释肥作为种肥时一次性施肥的合理性;并对种肥高效利用的施肥方式进行分析,提出了穴播穴施肥技术,对施肥技术的农业技术要求、施肥参数及种子肥料的物料特性进行了分析。(2)为了实现本研究提出的穴播穴施肥技术,分析了种子及肥料的成穴方式,提出了一次定位成穴法和多次定位成穴法。针对种子一次成穴方式介绍了水平圆盘精密排种器和窝眼轮式排种器,针对肥料一次成穴方式设计了活塞式一次定位成穴装置和圆盘式一次定位成穴装置。并分别设计了种子及肥料的多次定位成穴装置,研究表明其明显优于一次定位成穴方式。为了保证种肥间距符合农艺要求,设计了多次定位成穴的种、肥联动机械机构;通过机械式和电磁式驱动方式的对比分析,本研究采用电磁铁直接驱动种子、肥料的多次定位成穴装置。(3)根据控制系统的功能要求,设计了相应的控制模块。选取8051单片机作为其控制芯片,在对种子检测传感器、种箱肥箱余量检测传感器、固态继电器等重要的元器件选择的基础上,对控制系统的稳压电源、传感器检测电路、电磁铁驱动电路、故障报警电路等主要硬件模块进行设计。(4)分析了软件系统的整体结构,并选用汇编语言、以Keil C51μVision2为平台进行编程开发;设计了系统初始化模块、LED显示控制模块、外部中断处理模块、定时中断模块、故障报警模块等功能软件;通过调试,整个控制系统满足穴播穴施肥的功能要求。更多还原

【Abstract】 China’s arable land accounts for only 7% of the world’s arable land, but fertilizer application rate is as high as the 25.14% of the world, and application level is of the world’s average level of 2.81 times. China has become the world’s largest producer and consumer of chemical fertilizers. Application of chemical fertilizers in farming has improved our soil fertility and ensured the national food security, but also brought about some environmental issues. Studies have shown that long-term excessive and unscientific using of chemical fertilizers can cause the deterioration of the soil physical properties, acidification of aquatic ecosystems, eutrophication and reduce species diversity.In order to solve the problem of blockage when fertilization is carried out and improve fertilizer application rate in maize conservation agriculture, this paper brings forward a technology named hill-drop drill and fertilization. The mechanical devices and corresponding control system is designed and analyzed. The main purpose of this study and the results are as follows:(1) Under the conditions of analyzing the types of maise seeders and fertilizer application in common way, the paper proves that it is rationality to use slow/controlled release fertilizer as a one-time application of fertilizer in maize conservation agriculture. After analyzing the influencing factors of efficient use of fertilizer, hill-drop drill and fertilization was put forward. Fertilization technical requirements for agricultural technology, application parameters and material properties of seeds and fertilizer were issued.(2) In order to achieve hill-drop drill and fertilization mentioned in the research, methods of making seeds or fertilizer in a hole is discussed. Based on the material properties of seeds and fertilizer, this paper puts forward two methods: being located at a time and located at multiple times when seeding or fertilizing. For seeds located at a time, horizontal disc precision meter and cell-seed distributor are introduced; and for fertilizer located at a time, piston hole fertilization positioning device and hole fertilization positioning disc are designed. For seeds or fertilizer in a hole located at multiple times, the device is considered and proved better than method of being located at a time. Analytically, in order to ensure the distance beween seeds and fertilizer meet the the agronomic requirements, this paper design mechanical linkage institutions for being located at multiple times. By comparing mechanical and electromagnetic driving means, this paper chooses electromagnet direct driving the institutions.(3) According to the functional requirements of the control system, corresponding implementations of modules are devised. 8051 single-chip is selected as the control system’s chip. In the basis of analyzing the seed detection sensor, quantity left in the seed box or fertilizer box detection sensor, Solid State Relays and other important components, this paper designs the control system stabilized power supply, sensor detection circuit, solenoid driver circuit, failure alarm circuit and other major hardware modules.(4) Giving analysis of the overall structure of software system, the program is development by assembly language in Keil C51μVision2 platform. The paper designs the system initialization module, LED display control module, external interrupt handling module, timer interrupt module, fault alarm module and other functional software. Through debugging, the entire control system can meet the requirements of hill-drop drill and fertilization.更多还原