【作者】 梁巍；

【导师】 刘长生；

【作者基本信息】 中南林业科技大学 ， 森林工程， 2007， 硕士

【摘要】 电液比例控制技术,是在近30多年迅速发展起来的介于普通开关控制技术与伺服控制技术之间的新型电液控制技术分支。它是针对伺服控制存在的诸如功率损失大、对油液过滤要求苛刻、制造和维护费用高,而提供的快速性在一般工业设备中又往往用不着的情况研发出来的。电液比例控制技术具有对介质污染不敏感,控制原理简单,工作可靠,重复精度高,价格适中,成批产品的性能一致性好等优点。因而,电液比例控制技术受到人们普遍重视,也使该技术得到飞速发展。基于电液比例控制技术的特点,把此技术用在推土机工作装置自动控制上非常适合。随着科学技术的发展,人们对工程机械的要求越来越高,如操纵轻便、安全舒适等。但目前我国绝大多数推土机工作装置的升降,是由推土机司机手动操作进行。在作业过程中对推土机外负荷的变化完全凭人的感觉(视觉和听觉)预测,因而不可避免的存在较大的迟缓性和不确定性,从而导致推土机的作业效率较低,作业质量较差,操作人员的劳动强度大和使推土机使用寿命变短等缺陷。本课题的研究就是为了解决这一难题。文中综合分析了目前国内外在推土机自动控制方面的发展趋势,设计了一套从发动机转速、滑转率检测到控制工作装置自动升降的双通道控制系统,保证了推土机在不同的地面附着系数下都能实现工作装置自动控制。本文还阐述了该系统各组成部分(传感器、信号处理系统、控制器、执行器)的详细结构和设计方法。设计了控制器外围电路(时序电路、复位电路、电压电源电路)和有源滤波器外围电路。考虑到干扰的存在,设计出看门狗电路来实现抗干扰。研究了推土机工作装置的液压系统,在原有液压系统的基础上,并接了铲刀、松土齿电液比例自动控制系统,最终实现了推土机的铲刀和松土齿在不同工况下自动调节到合理的位置。最后,利用Mathworks公司的Matlab/Simulink软件对系统进行仿真,并提出了本设计进一步的改进方案和措施。更多还原

【Abstract】 The proportional control technology of Electricity and Fluid is rapidly develops in the nearly more than 30 years. It is the new branch of the proportional control technology of Electricity and Fluid that situated between the ordinary switch control technology and the servo-control technology. Its study is aims at some problem such as the big power loss, the strict request for liquor filters, the high cost of manufacture and the maintenance, useless of the rapidity in the general industrial equipment. It has some merits such as insensitive to the medium pollution, simple control principle, reliable work, high redundant precision, reasonable price, the product performance is more consistent. Therefore, it receives the people generally value. This technology also obtains the rapid development. Based on the character of proportional control technology of Electricity and Fluid, it is extremely appropriately to use it in the equipment automatic control of the bulldozer works.Along with science and technology development, people set the more and more request to the project machinery, such as operates facilely, safe and comfortable, and so on. But, at present, most fluctuation of bulldozer work installment is manual operated by the bulldozer driver in our country. The change of the bulldozer’s outside shoulders are forecasted completely depends on person’s feeling (vision and hearing) in the work process. So many flaws are existence inevitably. For example, slowness and not determinism, the low efficiency of Bulldozer work, worse work quality, operators’heavy labor intensity, shortens of bulldozer’s service life.This study is for solve this difficult problem. The article analysis and study the present development tendency of bulldozer automatic control in domestic and overseas. In the article I designed a set of double channel control system, which works from the examination of the engine speed, the rate of Skid and the rotation to the control work equipment power elevation. It guaranteed the bulldozer can realize the work equipment automatic control under all the different coefficient of ground adhesion. The article elaborated detailed structure and design method of each constituent in the system, just as sensor, signal processing system, controller and execution. I designed the controller periphery electric circuit (sequence circuit, repositioned electric circuit, voltage power circuit) and the active filter periphery electric circuit. Considered the existence of disturbance, I designed the "dog that guards the door" electric circuit to resistance disturbance. I studied the hydraulic system of the bulldozer shovel. Based on original hydraulic system, I connected the proportional control system of electricity and fluid of the shovel and the loose earth teeth. Finally the system has realized that the bulldozer shovel and the loose earth teeth automatically adjust to reasonable position under the different operating situation. I has processed the simulation of the system by the software of Matlab/Simulink in Mathworks Corporation. I proposed the further program and measure of this design to improvement.更多还原