高精度温盐检定恒温槽控制系统的设计与研究

发布时间：2018-01-15 22:24

本文关键词：高精度温盐检定恒温槽控制系统的设计与研究　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：海洋仪器是人们感知海洋特征物理量的重要工具,为海洋科学研究提供了基本依据。海洋仪器的正常使用离不开计量校准工作。海水温盐检定恒温槽是海洋仪器温度校准装置的重要组成部分。本文的主要研究内容为温盐检定恒温槽的控制系统设计,包括控制系统工作原理、硬件电路设计、控制算法选择、软件设计编制以及系统性能测试。在温度测量方面,使用了实验室精密测温线路(四线制接法)接入NTC热敏电阻和精密电阻的方法,结合高性能的模数转化与处理器计算,实现了对微小温度变化量的测量,其中测温灵敏度可达0.0001℃,测温精度可达±0.01℃。控制系统实现了多点定时控温功能,为操作人员提供了极大的便利。恒温槽的温度控制可分为快速控制和微调控制两个阶段,其中微调控制使用了单相交流可控硅和半导体制冷片作为分立的热量调节机构,使得控制作用更加快速灵活且精确。在控制算法上,采用了变速积分PID调节方式,相比普通PID调节获得了更好的动态响应特性。PID参数的整定过程中使用了基于饱和继电反馈的PID参数自整定方法,提高了对临界信息的辨识精度。依照JJF1030-2010《恒温槽技术性能测试规范》测试了恒温槽温场的波动性与均匀性,结果表明两者均满足设计要求。系统设计中将温度的测量与控制集成在一起,并在硬件平台上移植了嵌入式实时操作系统,使其具备了一定的多任务管理功能,另外预留了以太网接口,这些都符合工业测控设备集成化、智能化、网络化的发展趋势。此外,系统使用触摸屏作为人机界面装置,相对传统上使用的LCD液晶屏和机身自带操作按键,更加可视化、标准化、易于操作。
[Abstract]:Marine equipment is an important tool for people to perceive marine features of physical quantity, provides the basis for marine scientific research. The normal use of marine instruments cannot do without calibration. CTW verification thermostat is an important component of the marine instrument temperature calibration device. The main contents of this paper for the design of control system of temperature and salt temperature test the slot, including the working principle of control system, hardware circuit design, control algorithm selection, design of software and system performance test. In the temperature measurement, using the laboratory precision temperature measurement circuit (four wire) method for accessing NTC thermistor and precision resistors, combined with analog-to-digital conversion and processor of high performance computing, implementation the measurement of small temperature variation, the measurement sensitivity can reach 0.0001 degrees, temperature measurement accuracy of up to + 0.01 degrees. The control system realizes the multi point temperature control. To provide a great convenience to the operator. The temperature control of the thermostat can be divided into fast control and fine control in two stages, the fine tuning control using single-phase AC thyristor and the semiconductor refrigeration piece adjusting mechanism as a discrete heat, make the control more flexible and fast accurate. In the control algorithm, the the variable integral PID control mode, compared with the ordinary PID regulation won the tuning process better dynamic response characteristics of.PID parameters used in the parameters of PID saturation based on relay feedback self-tuning method, improve the precision of identification of critical information. In accordance with the technical performance of thermostat JJF1030-2010< test specification test > volatility thermostat temperature the results show that the uniformity of both meet the design requirements. The system design of the temperature measurement and control are integrated together, and transplant the embedded in the hardware platform. The real-time operating system, which has a multi task management function, also reserved the Ethernet interface, which is in line with the industrial control equipment integrated, intelligent, networked development trend. In addition, the system uses touch screen as man-machine interface device, compared with the traditional use of LCD LCD screen and the body comes with buttons more visual, standardized, easy to operate.

【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P716;TP273

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