基于STM32的气液压力装置定时充排系统设计

设计了一种基于STM32的4路双对通道定循环次数气动或液动压力装置定时充排系统,主要对管路中的电磁阀进行定时开或关。在STM32中移植了FATFS文件系统、UCOSIII操作系统和emWIN图形设计系统,系统设置的数据保存在W25Q64中,采用电阻式触摸屏和LCD进行界面操作和显示。设计制作了系统桌面、屏幕校准、监视器、系统设置、手动操作和关于系统共6个界面。通过操作系统定时函数和定时计数,全局变量设计了两种定时逻辑,可进行高压和低压两种定时模式的选择,而在手动操作模式下,系统关闭充电磁阀,只进行充排过程定时。结果表明,系统运行良好,能够根据设置准确地完成定时充排任务,可应用于多种气动或液动压力装置中。     

气力输送流型与压力信号关系研究

以压缩空气作为介质,在内径为65 mm的管中分别进行稀相与密相气力输送实验,并据此研究了压力信号与流型的关系.通过分析压力信号的波动和功率谱密度,发现压力信号与颗粒输送流型存在密切关联.研究表明:密相气力输送系统压力信号的波动范围和波动标准差均远大于稀相输送;并且密相气力输送系统压力信号的概率密度分布分散,总体呈现典型...     

高压气动球阀状态监测与性能评估试验研究

阀是流体输送系统中的关键部件, 准确地掌握其状态、性能对于确保系统安全可靠地工作非常重要。以高压气动球阀为对象, 开展状态监测与性能评估试验研究。构建球阀状态监测试验系统并开展实验, 利用获取的阀进气口与出气口压力、阀执行机构转动角度等有关信息, 对球阀的性能进行分析。结果表明:该方法能够将球阀工作过程的稳态与瞬态特征相融合, 很好地实现了对球阀动态过程和工作性能的评估。     

一种气动自动压力补偿装置的实现

为满足压力自动补偿的实时性和准确性要求,介绍了一种采用气动方式实现压力补偿的方法。以外部压力反馈或上位机所发送压力数据作为目标压力实现压力实时补偿。系统内气体总量可循环利用,避免从外界循环补充气体,根据目标压力与剩余气体压力关系确定气路系统的工作模式,大大地缩短了压力补偿的调节时间。试验验证,可实现2 MPa以下的压力快速补偿,在产品应用中取得了良好效果。     

基于气体激励的压电俘能技术及其在气动系统中的应用与展望

气动技术正朝着智能化、无线化的方向发展,越来越多的智能传感器引入到气动系统来实现监测与反馈,因此实现传感器长期稳定的供能是当前气动系统亟待解决的关键问题之一。研究表明,利用压电材料可产生毫瓦级的电能输出,能量级数可以满足低功耗传感器的能耗需求,因此该技术有望作为一种新型的供电技术为电池续航,使低功耗传感器长时间稳定地工作。基于此,介绍了压电能量收集技术的起源,气体激励下的压电俘能器结构与研究现状,以及气动系统压力能转化为电能的相关工作。研究结果表明,压电材料可以将气体压力能直接转化为电能,其单片最大输出功率接近10 mW,通过对电能的整理与存储可使气动系统中磁性开关正常工作。该技术可增大电池的使用寿命,甚至将来或可成为气动系统低功耗传感器能量的主要来源。     

一种双联式气-液复合传动增压装置

介绍了一种新型的双联式气 液复合传动增压装置,分析了其整个系统的工作原理,并给出了高、低压下输出流量和输出压力的计算公式。该增压装置以压缩空气为动力源,无液压站和高速泵,符合绿色制造的理念,并且成本低、结构简单、功能完善,与现有同类装置相比,工作效率提高了2倍。 关键词：气液复合传动;增压装置;双级压力;节能环保     

特种车辆油气弹簧漏气故障的识别与预测

针对特种车辆实现基于状态的维修和自主保障需求,首次对特种车辆悬挂系统的核心部件油气弹簧进行了基于数据驱动方法的状态识别和故障预测研究。对油气弹簧的主要故障模式和机理进行了分析,针对发生频率最高的漏气故障,提出了一种适用于不同工况下的基于相同位移下气压变化的特征提取方法。提出了一种基于支持向量分类机和回归机的故障识别和预测框架,采用该框架能适应实车应用环境的要求,无需增加额外传感器,只利用车辆现有的测试环境就能实现油气弹簧漏气故障的实时监测和预防性维护,与其他基于振动信号的方法相比更具有实用性。在试验室内进行了模拟状态退化试验,利用采集的数据验证了方法的可行性,可用于特种车辆油气悬架的在线状态监控和预测。     

如何用虚拟仪器测量灰气比

灰气比是衡量气力输送系统效率的重要指标,但灰气比的测量一直是难点,特别是气量的精确测量更难。主要是因为气体品质受温度、压力、时间影响较大,是个时变的量．传统仪器几乎无法做到精确测量和记录。采用虚拟仪器进行测量,不但成本低而且精确度高：在沙角电厂的实测中,通过记录各电场的瞬时流量曲线,找出了如何正确调整各电场发送逻辑,改善了用气量,解决了原气源不足的难题．     

Asymmetric Fuzzy Control of a Positive and Negative Pneumatic Pressure Servo System

The pneumatic pressure control systems have been used in some fields. However, the researches on pneumatic pressure control mainly focus on constant pressure regulation. Poor dynamic characteristics and strong nonlinearity of such systems limit its application in the field of pressure tracking control. In order to meet the demand of generating dynamic pressure signal in the application of the hardware-in-the-loop simulation of aerospace engineering, a positive and negative pneumatic pressure servo system is provided to implement dynamic adjustment of sealed chamber pressure. A mathematical model is established with simulation and experiment being implemented afterwards to discuss the characteristics of the system, which shows serious asymmetry in the process of charging and discharging. Based on the analysis of the system dynamics, a fuzzy proportional integral derivative (PID) controller with asymmetric fuzzy compensator is proposed. Different from conventional adjusting mechanisms employing the error and change in error of the controlled variable as input parameters, the current chamber pressure and charging or discharging state are chosen as inputs of the compensator, which improves adaptability. To verify the effectiveness and performance of the proposed controller, the comparison experiments tracking sinusoidal and square wave commands are conducted. Experimental results show that the proposed controller can obtain better dynamic performance and relatively consistent control performance across the scope of work (2–140 kPa). The research proposes a fuzzy control method to overcome asymmetry and enhance adaptability for the positive and negative pneumatic pressure servo system.     

基于LabVIEW的弹簧拉压力测试系统

文中分析和设计了基于LabVIEW的弹簧拉压力测试系统。系统硬件以AT89C52作为微处理控制芯片;键盘设计成4×4矩阵型式,利用软件编程实现键码扫描;显示方式为液晶显示,采用基于T6963芯片驱动的240×128液晶显示屏,系统字库自行设计;系统参数存储体存储芯片AT24C64,系统大部分控制单元均采用I2C总线,硬件时序用软件模拟。系统软件采用LabVIEW图形化编程环境,通过交互式图形化前面板来控制系统,并显示结果。由于是基于计算机技术的测试系统,从而使系统的功能可以灵活定义,便于满足用户要求。系统具有良好的人机界面,操作方便,数据曲线动态显示,系统参数自动记忆,同上位机实时交换数据,亦可独立工作。     

新型热驱动气压泵及其性能分析

采用热驱动气压泵代替溶液泵完成对制冷系统内浓溶液从低压到高压的输送过程,分析了热驱动气压泵4个主要工作过程的工作原理,并在无回热的情况下,气压缸体积2.5L,单次输送液体2L,以发生温度100℃,冷凝温度36℃,吸收温度36℃,蒸发温度0℃对热驱动气压泵代替溶液泵完成液体增压输送进行分析,得出整个制冷系统的COP为0.48的结论。最后分析了单次放入气压缸内的浓氨水体积与热驱动气压泵效率之间的关系,得出单次放入气压缸内的浓氨水体积越大,获得单位质量氨在气压缸内的受热量越少的结论。     

气动系统换向冲击压电俘能特性

为充分利用气动系统管路产生的压力冲击,提出了一种基于压电材料的正压电效应压电俘能器,搭建了基于该俘能器的实验测试系统,研究了气体压力、换向时间对该俘能器俘能特性的影响。结果表明,在气体动载荷激励下,压电俘能器内的压电片产生了弯曲形变,俘能电压与形变变化密切相关;气体压力值增大时,峰值电压、峰值功率升高;而随着换向时间的改变,峰值电压、峰值功率未有显著变化。     

Configurable monitoring system for industrial process control

A data-centered architecture for an industrial process monitoring system (PMS) is proposed. In such a system, the elements of graphical user interface (GUI) can be used to simulate the working process of practical devices by their state data, because a change of devices’ state will cause some properties of graphic elements to vary. And by operating the graphic elements, the user can first handle the monitoring data, and then operate the devices indirectly since the changed monitoring data will be inputted into the devices, and ensure their control. A configurable platform, which consists of tools such as project manager, GUI developer, system builder, etc., is developed to customize a specific PMS for different types of devices. The procedure of configuring a specific PMS with the platform is detailed. Then, the reconstructing and working process of the specific PMS is described.     

基于LPC1343的气密性检测系统

气密性检测系统的核心包括压力、流量的测量,气路控制,指示灯控制及各开关器件的检测。系统选择高性能的基于ARM CoretexM3的LPC1343微控制器,通过I2C接口和ADC实现压力和流量的数据采集;使用UART接口与LCD HMI人机接口模块通信,实现系统的参数设置及实时数据的显示;使用GPIO口和驱动电路对各器件进行控制,实现了器件气密性自动化检测。     

气动式制动能量回收技术研究

建立了一种通用气动式制动能量回收系统的数学模型。针对不同汽车制动的初始平均速度及高压储气罐预冲压力、容积等关键参数,在MATLAB中进行了仿真计算,通过分析系统工作过程中汽车的车速变化及系统高压储气罐的气压变化,研究系统的可行性及其能量回收效率。结果表明:系统的制动能回收效率与高压储气罐的预充压力成正比,与高压储气罐的容积成反比,合理地确定高压储气罐预充压力和容积,系统回收效率可达20%;当汽车速度较低时,车辆仅依靠气动式制动系统,可满足汽车对制动距离的标准规定。     

Using two servovalves to improve pneumatic force control in industrial cylinders

Pneumatic actuation systems present several advantages like low cost, high force/volume ratios, and the absence of significant heat or magnetic field generation. However, its use in complex control tasks is hindered by their highly nonlinear behavior. This drawback is caused not only by the nonlinear behavior of phenomena like friction but also by the large variation of some of the system proprieties with the system state. One of such proprieties is the fluidic stiffness of the actuator, which may suffer significant changes with the piston velocity when the pressure dynamics of both actuator chambers are coupled due to the use of only one servovalve. This dependency can be eliminated if the pressure (or pneumatic force) inside each chamber is independently controlled using two servovalves. In this paper, two pneumatic force allocation strategies are proposed and analyzed. In the first one, the stiffness of the actuator becomes independent of the pneumatic force reference. In the second one, the pneumatic forces are devised to avoid early pressure saturation of the cylinder chambers. Based on an experimental test rig, both strategies are compared against each other and against the use of only one servovalve.     

数控机床中气动系统的故障诊断与维修

论文阐述了气动系统在数控机床上的应用以及气动系统的维护与保养,并针对HT6350卧式加工中心气动系统的几例故障进行了诊断与维修。     

A data acquisition and control system in the MISS electronics standard for the detector on drift tubes

A structure of the data acquisition and control system (DAQC) in the MISS electronics standard for a multichannel detector on drift tubes is described. Its special feature is the use of the specialized LE-83 controller for communications with the computer and LE-83T controller-timer, which fulfills off-line all functions of storing data in its inner memory buffers in real time without an obligatory external trigger launching signal. The rewriting of stored data from the buffer into the computer memory and their transmission via the local network occur periodically in program-specified time intervals. The received data are processed on-line to control the equipment, alert, if a fault is detected, and produce physical results directly to the operator, who interacts with the system through the graphic interface with a possibility of the setup configuration. The system is built as a set of interacting processes, which can operate both on one computer or be distributed on several computers (within the frameworks of the local network).     

基于气液转换器的气动汽车动力系统能效优化

随着能源和环境问题日益严重,基于气液转换器的气动汽车逐渐被关注。然而,以压缩空气为动力来源的气液转换器在工作时能量效率低下,直接影响了气动汽车的发展。设计了一种驱动气动汽车的气液转换器系统,建立数学模型,对气液转换器的工作过程进行仿真,分析了关键结构参数对该系统能效的影响。并搭建基于此气液转换器的汽车动力系统实验平台进行验证,得到优化系统能效的方法,结果表明：当输入压力在0.5~0.55 MPa之间变动时,或者活塞的有效面积比为4~6之间,系统的效率将会超过30%。活塞行程对效率的影响小,随着活塞行程的变化,效率保持在30%几乎不变;活塞行程对输出功率影响大,活塞行程增加时,输出功率下降;输入压力和活塞有效面积比增加时,输出功率也会增加。结果表明：为气液转换器的结构设计和性能优化提供了依据。     

Analysis of Power Matching on Energy Savings of a Pneumatic Rotary Actuator Servo-Control System

When saving energy in a pneumatic system, the problem of energy losses is usually solved by reducing the air supply pressure. The power-matching method is applied to optimize the air-supply pressure of the pneumatic system, and the energy-saving effect is verified by experiments. First, the experimental platform of a pneumatic rotary actuator servo-control system is built, and the mechanism of the valve-controlled cylinder system is analyzed. Then, the output power characteristics and load characteristics of the system are derived, and their characteristic curves are drawn. The employed air compressor is considered as a constant-pressure source of a quantitative pump, and the power characteristic of the system is matched. The power source characteristic curve should envelope the output characteristic curve and load characteristic curve. The minimum gas supply pressure obtained by power matching represents the optimal gas supply pressure. The comparative experiments under two different gas supply pressure conditions show that the system under the optimal gas supply pressure can greatly reduce energy losses.