【作者】 周俊峰；

【导师】 谭建平；

【作者基本信息】 中南大学 ， 机械电子工程， 2006， 博士

【摘要】 随着世界经济和科学技术的发展，薄板带材的需求量不断增加，特别是在铝加工行业，为实现铝薄板加工生产过程中板材厚度、板形、板凸度的高精度控制，对在线检测装置的检测精度提出了更高的要求，并促进检测装置向智能化方向发展。但目前的检测设备在经济性以及功能性等方面均存在着不足。本文以国家高技术研究发展计划(863计划)课题“铝薄板高精度板凸度在线检测装置”(课题编号：2002AA423190)为背景。开发了基于激光检测技术的铝薄板板凸度在线检测装置，通过理论分析和试验研究，深入研究了高精度板凸度激光检测装置整体及各子系统的误差规律，从误差避免和误差补偿的角度，综合运用有限元优化技术、小波信号分析与处理技术，解决了系统精度保证及精度控制的关键问题。在此基础上，结合薄板带的快速铸轧工业试验，对板凸度激光检测装置的性能进行了工业试验验证。表明该装置具有成本低、精度高、稳定性好的特点，对于提高我国铝带材的产品质量，增强市场竞争力具有重要的意义。同时文中所用理论和方法也适用于其它检测装置，本文的研究具有重要的理论意义和应用价值。论文的主要研究内容和成果如下：1．通过对高精度板凸度激光检测装置整体及各子系统深入的精度分析，在比较不同方案的基础上，根据项目要求的移动式、高精度的核心目标，设计了基于双束激光差动测量方法的扫描式激光板凸度检测方案，确定了以C型扫描框架为主体的装置的总体结构造型，实现了低成本、高精度的板厚、板凸度同时测量。2．研究了板凸度激光检测装置实现智能化检测的自动测量策略，对双束激光差动测量系统中的传感器位置关系与测量有效性的规律进行了研究，建立了不同被测板材厚度条件下的最佳传感器位置调节目标。基于该目标，提出了板凸度激光检测的调节策略，仿真试验证明了自动调节策略的可行性。3．研究了高精度板凸度激光检测系统的静态误差传递规律，分析机械装配精度等因素造成的系统中传感器平动位置误差、旋转角度误差等对系统精度的影响规律，建立了系统装置的机械加工及装配精度所致的误差分析模型，形成系统加工、装配精度的控制准则，为系统标定与静态误差修正提供理论依据。4．基于试验研究，通过工业现场的环境振动测试试验，不同振动激励下框架的动力学性能试验，不同扫描检测状态下板凸度检测精度的影响规律试验，分析了不同振动参数、扫描参数对检测精度的影响规律，建立了系统装置的动态误差分析模型，为通过误差避免和误差补偿以保证检测精度奠定了基础。5．在分析移动框架静态、动态变形以及不良振型对检测精度的影响规律的基础上，提出了通过对检测装置关键部件C型框架的进行模态优化实现精度控制的方法。在通用有限元软件ANSYS的基础上，利用APDL语言对框架力学性能分析与动态优化设计，包括静态(强度、刚度)优化分析，模态优化分析，动力学响应分析等，并进行了设计变量的灵敏度分析，提出了C型移动框架的优化设计结构。6．研究了基于小波原理的板凸度激光检测信号振动误差抑制的方法，针对板凸度激光检测信号的多频特性，通过多分辨小波分析与处理方法，采用小波信号分解—重构，来剔除检测信号中的谐波性振动误差成分，确定了最佳小波基函数和小波分解层数。通过仿真试验和现场试验表明，本方法可以减少因振动和各种环境扰动等原因造成的误差，检测精度得到了明显的提高。7．研究了板凸度激光扫描参数因素作用引起的误差补偿方法，针对该类误差多参数耦合、非线性的特点，采用神经网络的方法，建立扫描参数与动态误差之间的非线性神经网络模型，通过对动态误差的预测，实现动态误差的补偿。通过工业试验比表明，本方法有效地消除了由于扫描状态不同引起的随机误差，提高了检测精度。8．进行了板凸度激光检测系统的技术集成，对该装置的硬件组成和软件系统进行了详细的分析研究。设计制造了我国首台扫描式铸轧板带板凸度激光检测装置样机。经现场应用表明，装置的检测精度、系统功能完全能够满足铸轧板凸度检测与控制的要求。更多还原

【Abstract】 With the development of economy and technology, the requirement ofthin sheet increased largely. Especially in aluminum industry, to realizehigh accuracy control of aluminum thin sheet’s thickness, flatness andconvexity, the higher measurement precision of the on line measureequipment, and that will promote measure equipment become moreintelligent. But the actual measure equipment has shortage in economicand functional aspects.Funded by the National High Technology Research and DevelopmentProgram("863"Program) of China—"The On-line High-precisionConvexity Measurement Equipment for Thin Aluminum Sheet"(No.2002AA423190). An on-line high-precision convexity measurementequipment for thin aluminum sheet based on laser measurementtechnology. With theory analysis and experiment research, the error rulesof whole system and subsystem of high-precision convexity measurementequipment using a laser system are studied. The key technologies toguarantee and control the measuring precision of the measurement systemby use of finite element method and wavelet signal analysis andprocessing method, which includes error avoidance and error restraint.Combined with the high-speed thin-gauge roll casting industrialexperiment, the capabilities of high-precision sheet convexity using alaser measuring system are validated by the industry test. The experimentshows that the system has advantages of low-cost, high-precision andgood-stability, and that is very important to improve production quality ofdomestic aluminum sheet and boost up market competition ability. At thesame time, the theory and means are also used in other measurementequipment. All those study of this paper are very important both in theoryand application.In this paper, the main research work and achievement as follows:1. After errors analysis of whole system and subsystem ofhigh-precision convexity measurement equipment using a laser system,and compare different projects, according to the main program goal of moving and high-precision measurement, a scanning project to measurethe convexity of thin-sheet is developed, that is based on the differencemeasurement theory of a pair of laser beams, and the whole structure ofequipment is designed, which is C-frame structure. It is realized that sheetthickness and convexity are measured together with low-cost andhigh-precision.2. The automatic measurement strategy is studied, which is used torealize intelligent measurement for convexity measurement equipmentusing a laser system. The rule between sensor’s position relation andmeasurement validity of difference measurement system with a pair oflaser beams is studied; the optimal position adjusting aim under differentthickness conditions of sheet to be measured is set up. According to thisaim, the adjustment strategy in sheet convexity measurement system withlaser is brought forward, and the differentia sensor’s position adjustingmechanism is designed. The measurement simulation experimental showsthat automatic measurement strategy is feasibility.3. The static errors transfer rules of high-precision convexitymeasurement using a laser system is studied. The rule that is howhorizontal position errors of sensor and rotational angle errors of sensor,etc. caused by mechanism assembly precision affect system precision isstudied. The analysis model of errors caused by mechanism process andassembly precisions is set up, and the control rule of system processassembly is fashioned, which could provide the theory foundation ofsystem calibration and static errors modification.4. Based on experimental studies, which include the environmentvibrations testing experiment under industrial conditions, the experimentof the frame dynamics capability excited by the different vibrations, andthe rule experiment of how different scanning status affect measurementprecision, the rule of how vibrations with different parameters affect themeasurement is investigated, the dynamics errors analysis model is set up,which set up the foundation of guarantee measuring precision of themeasurement system by use of error avoidance and error restraint.5. After the rule of how static distortions, dynamic distortions and ill modes shapes of moving-frame affect the system’s measuring precision isstudied, the method to guarantees the measuring precision of theequipment by structure optimization of the C-frame which is key part ofmeasurement system is brought forward. With the universal finite elementanalysis software-ANSYS, by the use of APDL language, the analysis ofthe frame’s mechanics characteristic and dynamic structure optimizationof the frame is carried out, which include static (intensity and stiffness)optimum analysis, modal optimum analysis and dynamic responseanalysis, etc. The sensitivity analysis of design variable is also carried out.So that, the optimum structure of moving frame with C-shape is putforward.6. The method of vibration error restraint for sheet convexitymeasuring signal based on wavelet signal multi-resolution analysis isstudied. According to multi-frequency characteristic of sheet convexitymeasuring signal and by use of the wavelet multi-resolution analysismethod, with wavelet decomposition and restoration method, theconvexity measuring signal is decomposed into single components andafter a restraining algorithm is used, the wavelet restoration of validcomponents of the measured signal is carried out and vibration errors areeliminated. The optimum wavelet primary function and the optimumwavelet decomposition level number are determined. By the simulationtesting and experiment, it is showed that errors caused by vibration andsome environment disturbance could be reduced and measuring precisionis increased obviously.7. The errors compensation for sheet convexity measuring, which arecaused by the factor of scanning parameters is studied. According to thecharacteristic of multi-parameter coupling and non-linear, by use of neuralnetwork (NN) method, the non-linear NN model between scanningparameters and dynamic errors is created. By means of dynamic errorsforecasting, dynamic errors compensation is realized. By industrial testing,it is showed that errors caused by different scanning parameters areeliminated effectively and measurement precision is increased.8. The technology integration of high-precision convexity measurement using laser is carried out. The detailed analysis and study ofhardware composing and software structure for the measurementequipment are carried out. The device of convexity measurement withlaser for thin-gauge roll casting is designed and developed, which is firstone in our country. The application shows that the measurement precisionand the system functions of device can satisfy measurement and control ofthe convexity for thin-gauge roll casting and system.更多还原