西门子S7-200在自动调平中的应用实践

以西门子S7-200PLC核心,以松下A系列交流伺服驱动为执行机构的自动调平控制系统,该控制系统可推广应用于三点式自动调平及液压自动调平系统。     

自动调平技术研究

自动调平系统主要用于雷达车、战车等车辆的自动调平,也可应用于其他地面设备的自动调平.机电式自动调平系统采用机械式4点支撑结构,调平时4条支腿自动伸缩调整载体至水平,保证调平后载体的水平和稳定;自动调平技术通过水平传感、调平控制将电气和机械融合成为一个有机的整体,使机电自动调平系统快速、平稳、准确、可靠,满足了高精度自动调平的需要.     

一种面向液压储能器的122 GHz FMCW 测距雷达

针对液压储能器活塞位移测量过程中存在的高温、高压、油污等影响问题,提出了基于122 GHz FMCW 测距雷达的活塞位移测量方案。在分析雷达系统结构和工作原理的基础上,分别对调制信号单元、T/ R 收发单元、调理单元和ARM 实时处理单元进行了详细设计,一方面采用集成设计思路缩小了系统体积,满足了液压储能器内安装测试需求,另一方面通过设计聚焦透镜,提高了122 GHz 毫米波在液压储能器内部的穿透能力。实验结果表明,在2 m 液压储能器活塞测试中,122 GHz FMCW 测距雷达能够耐压30 MPa,测距误差不超过2 cm。     

六点支撑自动调平系统关键技术研究

本文对车载自动调平系统进行了详细的描述与讨论,列举了目前典型自动调平系统的类型和特点,通过对六点自动调平系统的受力模型分析,得出了车载上装设备的结构布局设计的指导原则。文中重点研究了六点支撑共同参与调平过程的控制策略,并利用设计实例得出了撑腿在自动调平过程中的伸长量计算方法。另外,对自动调平系统中的关键技术,如虚腿、安全性等问题也进行了梳理和总结。本文讨论的内容和涉及的方法均来源于实际工程系统,对自动调平系统工程设计人员具有一定的参考价值。     

六点支撑自动调平系统关键技术研究

本文对车载自动调平系统进行了详细的描述与讨论,列举了目前典型自动调平系统的类型和特点,通过对六点自动调平系统的受力模型分析,得出了车载上装设备的结构布局设计的指导原则。文中重点研究了六点支撑共同参与调平过程的控制策略,并利用设计实例得出了撑腿在自动调平过程中的伸长量计算方法。另外,对自动调平系统中的关键技术,如虚腿、安全性等问题也进行了梳理和总结。本文讨论的内容和涉及的方法均来源于实际工程系统,对自动调平系统工程设计人员具有一定的参考价值。     

某雷达自动调平机构的设计分析

某雷达在作战前需要进行雷达车的架设调平工作，采用电动自动调平是一种快速可靠的调平方法。它同以往的手动，液压传动调平相比有许多优点：如调平时间短，调平精度高，可靠性高等。本文着重就调平机构的结构设计进行分析，探讨其系统的高效性和可靠性。     

P87C591单片机在座车平台液压调平系统中的应用

设计了一套基于P87C591的四点支撑液压调平控制系统,该系统可用于座车平台的自动调平。应用P87C591内部集成的CAN,SIO0,SIO1独立串口,分别实现了控制系统所需的CAN总线通讯、RS 485通讯I、C总线方式的I/O口扩展。本系统能完成支撑腿落地自动检测,支撑腿自动锁紧、解锁,自动调平,自动撤收,水平监测和显示等功能。     

雷达载车调平支腿机械设计

机动雷达一般是通过自动调平系统实现雷达载车自动调平的。随着机动雷达的广泛应用,作为雷达载车自动调平系统的重要组成部分,调平支腿设计的成功与否会直接或间接地影响到雷达整机的工作性能。本文介绍了一种机电式自动调平系统的调平支腿的机械设计,其机械部分具有结构紧凑、可靠性高、维护简单等特点。     

基于油压检测的雷达车全自动调平策略

实现对雷达载车的全自动调平,已成为机动雷达的重要功能.文中针对采用液压控制的重型雷达载车系统,指出了调平腿虚支撑的危害,提出基于油压检测原理解决虚支撑的策略,阐述了油压检测在一键式全自动调平中的重要作用,对如何利用油压检测实现着地后的可靠支撑检测、如何利用油压检测改善全自动调平策略及避免调平后的虚支撑现象、如何提高油压检测的可靠性等进行了详尽的描述,同时提供了油压检测测试曲线及自动调平的电路实现方案.     

基于故障树分析的某雷达自动调平系统故障研究

本文从雷达自动调平技术基础出发,详细研究了自动调平的运行原理和控制机理,对其故障产生的根源进行了深入的探究。通过收集故障信息和故障产生的机理,并对其进行了深入的分析,建立了自动调平系统的故障模型,并以自动调平系统失效为顶事件,层层分析展开,设计了详实完整的故障树,故障树的底事件数量达到了50个以上,基本涵盖了机械结构、伺服驱动、电气控制和软件逻辑等各个方面的故障信息,并对故障树进行了定性和定量分析,求解了其最小割集,对底事件重要度进行了分析。     

Sensorless position control with a hydraulic stepper drive — Concept,compression modeling and experimental investigation

This paper presents a new type of a linear hydraulic stepper drive for sensorless positioning tasks in hydraulics. The drive transforms pulses sent to switching valves into quite precise motion steps. The drive is realized by a hydraulic cylinder piston unit which displaces defined fluid quantums by limited forward strokes of that piston.A test rig (hydraulic cylinder with a hydraulic stepper unit) was built and experiments were performed to study the positioning accuracy, repeatability, linearity and scattering range of the proposed stepper drive concept. Two different step sizes (5 µm and 15 µm) were tested and investigated. Also a computation model was developed for sensorless position estimation and verified by measurements. The results show the quite good accuracy of the model for all tested operating conditions.An application example is studied, the sensorless control of the deflection of an elastic beam. Its experimental testing was done by hardware in the loop simulation, where the computed beam force is imposed to the physical stepper drive via a controlled hydraulic force. The results proof the practical suitability of the drive concept.     

Novel bulk modulus model to estimate stiffness in fluid power systems

A precise evaluation of the bulk modulus is essential for the efficient simulation and accurate design of hydraulic circuits. The compression and dissolution of air bubbles in hydraulic oil can affect the density as well as the effective bulk modulus during corresponding operation. To address this phenomenon, this study presents a novel model for the bulk modulus. The representation does not rely on the tangent or the secant definition of the bulk modulus, but on the assumption of compression as a polytropic process. The results are compared to various experimental studies, showing that the new model can properly reproduce the experimental data. In addition, a model based on new bulk modulus and a model based on a commercial software are used for the simulation of four-chamber cylinder in digital fluid power circuits. These simulations verify that the LMS model can be reliable though a discrepancy exists in reproducing the position of piston, which will be increased by time.     

Measuring system for development of stroke-sensing cylinder forautomatic excavator

In order to develop a stroke-sensing cylinder for automatic excavators equipped with Hall sensors of GaAs type, a measuring test facility is set up and used in investigating the design parameters. The measuring system itself is a kind of XZ table with two moving axes in X and Z directions, respectively, on which sensing parts, including Hall sensors, are installed. Furthermore, to attain a high precision of movement of the measuring system, a new sliding mode control is introduced, which diminishes chattering in the control loop by setting two dead zones along the switching line. The unknown parameters for sliding mode control are estimated by a signal compression method. The output signal from a Hall sensor was analyzed by using a measuring instrument. In particular, the detected signal according to the Hall sensor's movement on the piston rod, which has a magnetic scale, was investigated and the vertical distance between the Hall sensor and the piston rod, which gives direct effects on the detected signal, was obtained. Based on these results, the stroke-sensing cylinder was designed and fabricated     

基于ATmega16L的电液伺服控制系统设计

针对电液伺服闭环控制过程中,设定信号不断发生变化,电液阀门位置定位精确度较低的难题.采用AT-mega16L作为核心控制器,并配有高精度A/D、D/A转换器,通过对阀门开度控制信号和位置反馈信号进行采集、转换、计算和比较,发出控制信号决定并执行换向阀的换向、交流伺服电动机的起停运转,推动液压缸推杆的伸缩,进而对阀门转角大小、开度百分比进行精确定位.     

一种基于压电陶瓷的新型灵巧液压泵

提出了一种基于压电陶瓷的高频惯性单向阀液压泵。该泵利用压电陶瓷堆在推动活塞隔膜压缩油腔时控制活塞的位置、速度和加速度,利用惯性力帮助非惯性系下的特殊单向阀开合,突破了普通单向阀频率响应低的瓶颈。对高频惯性单向阀液压泵进行建模仿真,结果表明这种液压泵在原理上是可实现的。     

一例船舶发电机滑油日耗量增加故障分析

船舶发电副机系统滑油耗量异常增加时, 过多的滑油窜入燃烧室会造成燃烧恶化, 严重污染活塞、气缸、 气阀、排气道, 甚至结焦造成活塞环卡死, 影响安全生产。以某型号船舶发电副机滑油日耗不断增加的故 障为例, 分析滑油油耗增加的常见原因, 进行故障排查, 得出该型号船舶发电副机滑油油耗的增加并非滑 油系统自身的原因, 而是由于活塞环制作工艺不完善造成的。因此, 在备件的购置和验收时要加强审核, 择优选用。日常要对滑油消耗量、吊缸检查、活塞环搭口间隙、磨损测量等进行检查, 及时发现故障, 排 除故障, 确保船舶航行安全。     

汽车转向缸试验两侧轮载模拟方法

为了完成某汽车转向缸耐久试验中转向缸两侧轮载的模拟加载要求,提出了两侧液压伺服加载的方法。该方法无需真实轮胎以及重力载荷模拟系统,具有结构简单,加载一致性好的特点。论述了该方法的原理,建立了转向缸运动与加载系统的耦合关系数学模型,给出了解耦控制算法。经仿真和几十万次耐久试验结果表明,所给出的转向缸载荷模拟方法满足转向缸耐久试验的载荷模拟要求。     

基于AMESim的铅电解阴极抽棒电液比例控制系统仿真分析

在铅电解生产中,需在电解完成后将阴极板上的阴极导电棒进行抽取、收集以便再次利用。目前大多数国内厂家在此工序上仍采用人工的方式进行抽取。文中采用电液比例技术,设计了一台快速、稳定、有效的自动化铅电解阴极棒抽取设备。利用AMESim软件,对拍棒、翻板、出口举升三个重要系统进行了仿真分析。仿真结果显示:拍棒油缸1.5 s伸出,1.5 s收回,伸出量为300 mm;翻板机构最大转角91.8°,运行周期9 s;举升油缸运行为间歇运动,每次下降10 mm,间隔1.5 s;各阶段系统输出均大于设备的最大需求。仿真结果表明,系统定位准确、时间把控精准、输出充足,可完全达到设计需要。     

Coupling Leveling Control Based on Fuzzy PID for Synchronous Loading System of Load-Bearing Test Bed

This paper describes a 4-cylinder hydraulic circuit system controlled by a new cross-coupled fuzzy PID, and its leveling algorithm is designed to meet the demand of the loading system for test bed. In order to enable synchronous loading and implement precise leveling control, the output displacement derived from a theoretical model, called ˙Zn, is tracked in real-time. Using AMEsim software, the reliability of the scheme designed by master-slave control and fuzzy PID cross coupling control have been confirmed, and have drawn a conclusion that the more serious the inconsistencies of the load for 4-cylinder are, the more size corresponding synchronization errors will be. Further, leveling experiments have demonstrated that the synchronization performance of leveling system can be improved significantly by adjusting the load values for the 4-cylinder so as to meet the demand of its un-synchronization.     

The Research on Characteristics of Hydraulic Support Advancing Control System in Coal Mining Face

This paper researches the electro hydraulic control system of two-column shield hydraulic supports, takes the hydraulic support base advancing loop as the position servo control system, and studies its dynamic characteristics. It establishes the power amplifier, position sensor, hydraulic cylinder and loading mathematical model of the position servo control system, determines the model parameters of the advancing control system according to the shield hydraulic support used in the 1315 working face of GuoTun coal mine, and derives the opening loop transfer function of the valve controlled advancing cylinder. This paper also analyzes the stability of the control system of the advancing loop with the modern design method, and verifies the stability of the electro-hydraulic control system loop according to the simulation curve and the stability. By comparing with the valve core displacement and system flow curve while the system opening or closing, this paper explains the application effect of servo control system. It provides a new research idea and method for the study of the overall stability and effectively reduces the failure rate of electro-hydraulic control system of the hydraulic support. It also plays practical significance and value to improve the mining efficiency of the coal mining face.