【作者】 刘明；

【导师】 章青；

【作者基本信息】 天津大学 ， 机械制造及其自动化， 2009， 硕士

【摘要】 随着海洋开发的不断深入,超大型结构物屡见不鲜。在预制的过程中,由于设备、设计修改以及焊接材料的诸多因素的影响,使结构物的重量和重心与设计值往往存在较大误差。大型结构物在海上安装过程中,受到作业机具吊装能力等因素的影响,需要准确的结构物重量和重心数值。为了能够确保工程的安全,在预制完毕后对结构物进行称重,确定结构物准确的重量和重心十分必要。对大型结构物称重系统精度分析,同时通过补偿技术提高称重系统的精度就重要的意义和工程价值。大型结构物称重系统是由液压系统、电气控制系统、传感器与数据采集系统以及计算机控制系统等组成的复杂系统。本文对构成称重系统的关键设备如千斤顶、位移传感器、压力传感器等的精度进行系统分析,建立了影响称重系统精度分析的补偿模型,利用VB软件开发了相应的计算软件包,对称重误差进行了系统的补偿,大幅度地提高了整个系统的测量精度。具体工作主要包括以下几个方面:1.通过研究大型结构物称重系统工作原理,重点分析影响称重系统精度的关键因素千斤顶摩擦力特性、千斤顶保压特性、千斤顶工作面积、压力传感器精度、位移传感器精度、数据采集器精度和千斤顶位置、不同步精度;2.根据重量、重心计算模型,通过误差全微分分析方法,对影响重量精度的灵敏度、精度进行了系统分析,同时对总体影响重心精度的千斤顶位置、顶升过程的不同步精度进行了全面分析;3.建立了称重误差补偿模型,重点考虑千斤顶摩擦力特性、千斤顶保压特性、千斤顶工作面积,使计算模型精度得到大幅度提高;4.根据补偿模型,利用VB软件开发了相应的计算软件包;5.结合实际称重工程,进行了称重系统精度分析和试验研究,结果表明通过称重误差补偿模型可以有效提高大型结构物称重系统的精确性。更多还原

【Abstract】 Accompanying deeper exploitation of the sea, large structures have become very common. During the pre-fabricating process, affected by equipment, design modification and welding material such factors, the actual weight and gravity-center of the structures are deviated from the design values. During the installation of large structures on the sea, the weight and gravity-center values of the structures should be very accurate, considering the lifting capability of the operating apparatus. To secure the work safety, it is very important to weigh the structures after the prefabrication, to determine their exact weight and gravity-center. As a result, analyzing the accuracy of weighing system for the large structures and improving the accuracy of weighing system through compensation techniques are of great significance and engineering benefits.The weighing system for the large structures is a complicated system consisting of hydraulic system, electric control system, sensors and data collecting system, and computer controlling system. This article systematically analyzes the accuracy of jacks, displacement sensors, and pressure sensors such key equipment forming the weighing system, establishes the analyzing and compensating module affecting the weighing system accuracy, developing relevant calculating software package applying VB software, systematically compensating the error of weighing, which as a result improve significantly the overall measuring accuracy of the whole system. The general procedure is listed below:1. Based on the working principles of the weighing system for the ultra-large structures, focus on analyzing the major factors affecting the weighing system accuracy such as, friction characteristics of jack, pressure-sustaining characteristics of jack, service area of jack, accuracy of pressure sensor, accuracy of displacement sensor and accuracy of data collecting system, as well as jack location and desynchrony accuracy.2. According to the weight and gravity-center calculation model, through error total differential analyzing method, analyze systematically the sensitivity and accuracy affecting the accuracy of weight. At the same time, analyze comprehensively the jack location and desynchrony during jacking affecting the gravity-center accuracy. 3. Establish the weighing error compensation model, which substantially increases the calculation accuracy. It focuses on the friction characteristics of jack, pressure-sustaining characteristics of jack, and service area of jack.4. Based on the compensation model, the corresponding package co-software has been developed using VB.5. Accuracy analysis and test researches have been carried out combining the actual weighing project. The results show that the accuracy of weighing system for the large structures has been effectively improved when use the weighing error compensation model. .更多还原