起重机智能超载限制器的研制

发布时间：2018-04-11 02:33

本文选题：超载限制器 + AT89S52　；参考：《西南交通大学》2011年硕士论文

【摘要】：电子技术在称重方面的应用,促进了称重技术向自动化、集成化、功能多样化和智能化方向发展。起初应用于起重机械(如桥式、门式等)的超载限制器大多是机械式的,因其体积大,结构较复杂,故现已被电子式的取代。人们对测量、控制精度及准确性要求越来越高的同时,在系统的性能及可靠性方面也提出了更高的要求。因此,在保证现有限制器功能的前提下,提高系统的集成性及可靠性,成为提高产品品质的关键。现有的超载限制器都是采用屏蔽电缆线将称重传感器采集的信号传输到后一级,然后再进行处理(如放大、A/D转换、单片机控制等),这样会引起信号的衰减,降低整个系统的灵敏度；再者,在工业现场,由于环境因素和工作性质的影响,屏蔽电缆线易受到损坏,严重的情况下会失去传输信号的能力,又因屏蔽电缆线的安装特点,不宜去检测(或判断)故障源所在,这就给检测与维护带来了困难。本设计超载限制器采用短距离无线传输模块nRF24L01来替代屏蔽电缆线,克服了采用屏蔽电缆线易引起的问题。本文首先阐明了论文的研究背景和意义,然后分析了国内外超载限制器的研究现状,概述了本论文的主要研究内容和工作。论文针对提出的需求,设计了超载限制器的主、副钩称重传感器部分,分析了传感器的安装方案,保证了所采集信号的准确性,也为信号的后级处理奠定了基础。在第2章提出了两种设计方案,在确定方案的前提下,分别设计了超载限制器的发送端和接收端硬件电路,总体上采用模块化的设计思想。在发送端将称重传感器模块、放大电路模块、A/D转换模块、单片机(AT89S52)及外围电路模块、无线模块nRF24L01、电源模块等模块集成为一体(谓之功能集成传感器)。详细分析了各模块的设计；接收端也同样采用了AT89S52作为核心控制芯片,分析设计了继电器控制模块、电源模块、无线模块nRF24L01、声光报警模块,在扩展8255A的基础上设计了数码管显示模块。根据模块化的设计思想编译了软件系统的相应软件。无线通信系统的一个关键问题是防止同频段的其它设备的干扰,本设计基于nRF24L01的可选工作频道及很短的频道切换时间,采用跳频展频技术(FHSS, Frequency-Hopping Spread Spectrum)来解决由Bluetooth、Wi-Fi、ZigBee等2.4G频段设备引入的无线传输干扰问题。
[Abstract]:The application of electronic technology in weighing promotes the development of weighing technology towards automation, integration, function diversification and intelligence.The overload limiter used in crane (such as bridge type, door type, etc.) is mostly mechanical. Because of its large volume and complicated structure, it has been replaced by electronic type.As the accuracy and accuracy of measurement, control and control are becoming higher and higher, the performance and reliability of the system are also required.Therefore, under the premise of ensuring the function of the existing limiter, improving the integration and reliability of the system becomes the key to improve the product quality.The existing overload limiter uses shielded cable to transmit the signal collected by the weighing sensor to the next level, and then processes it (such as amplifying the A / D conversion, controlling by the single chip microcomputer, etc.), which will cause the signal to attenuate.Reducing the sensitivity of the whole system; moreover, at the industrial site, due to the influence of environmental factors and working properties, shielding cables are vulnerable to damage, and in serious cases they will lose the ability to transmit signals, and because of the installation characteristics of shielded cables,It is unsuitable to detect (or judge) the fault source, which brings difficulties to detection and maintenance.In this design, the short-range wireless transmission module nRF24L01 is used to replace the shielded cable, which overcomes the problems caused by the use of shielded cable.In this paper, the research background and significance of the thesis are expounded, then the research status of overload limiter at home and abroad is analyzed, and the main research contents and work of this paper are summarized.In this paper, the main and secondary hooks of the overload limiter are designed, and the installation scheme of the sensor is analyzed, which ensures the accuracy of the collected signal and lays a foundation for the post-stage processing of the signal.In chapter 2, two design schemes are proposed. On the premise of determining the scheme, the hardware circuits of the transmitter and receiver of the overload limiter are designed respectively, and the modular design idea is adopted in general.At the sending end, the weighing sensor module, the amplifying circuit module and the A / D conversion module, the single chip microcomputer AT89S52) and the peripheral circuit module, the wireless module nRF24L01, the power supply module, etc.The design of each module is analyzed in detail, the receiving end also adopts AT89S52 as the core control chip, the relay control module, the power supply module, the wireless module nRF24L01, the acousto-optic alarm module, the relay control module, the power supply module and the acousto-optic alarm module are analyzed and designed.The digital tube display module is designed on the basis of 8255A extension.The corresponding software of the software system is compiled according to the modular design idea.One of the key problems of wireless communication system is to prevent interference from other devices in the same frequency band. In this paper, the optional working channel based on nRF24L01 and the short channel switching time are designed.FHSS (Frequency-Hopping Spread Spectrum) is used to solve the problem of wireless transmission interference introduced by Bluetooth Wi-Fi Fig ZigBee and other 2.4G band devices.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH21;TP273

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