重载多模态电磁激振器的特性分析及逆模型补偿研究

发布时间：2018-07-31 16:48

【摘要】：炮塔等军用装备的性能高低在国防建设中具有举足轻重的地位。但这些装备通常处于非常恶劣的外部环境和复杂的工况中，工作时受到强烈振动，容易引发各种问题，如瞄准具损坏、紧固件断裂或松脱、零部件磨损和疲劳损坏等，进而影响射击精度，甚至带来事故或使装备失去工作能力。因此有必要对其进行振动试验，找出潜在问题，进而实现可靠性设计和最优化设计。然而长期以来我国大型军用装备振动试验台的研制工作却跟不上国防建设的需求，这种局面严重制约了我国的国防现代化建设。为满足国防建设的需求，本文设计了一种应用于大型军用装备的振动试验台，针对其重载、空间狭小等特点，结合各种激振器的优缺点和适用范围，提出了液压结合电磁激振的总体方案，其中液压激振器承担50Hz以下的低频大振幅振动，而电磁激振器负责50Hz以上的较高频率小振幅振动，本文重点研究了电磁激振部分。本文首先通过查阅相关文献资料了解重载激振器的特点、发展现状及前景，并根据某炮塔激振试验台的要求，结合各类激振器的优缺点和适用场合，设计了液压结合电磁激振的总体方案，并提出以多模态谐振机构的共振作用放大整体振幅的结构方案。根据动铁式电磁激振器的工作原理，以电磁铁为基础，通过理论计算及有限元静力分析和模态分析，设计了相应的谐振机构，完成了原理验证装置的结构设计。利用Ansys对该装置进行电磁分析，得到了电磁激振器的静态吸力特性曲线，反映了电磁吸力与工作气隙和电流之间的关系。利用Matlab/Simulink分别建立该装置的电路、磁路及机械运动部分的数学模型，其中电磁部分包含了非线性因素，机械部分是多模态系统，并通过仿真对该模型进行了动态特性分析，分析结果表明多模态系统具有放大幅值的作用。针对多模态系统响应波动过大，且难以用反馈消除的缺陷，本文提出了逆模型补偿控制方法，结合被控对象的具体情况，建立了几种不同的逆模型，并分析了逆模型控制的有效性。仿真表明逆模型具有显著作用，不仅可使输出对输入信号保持良好的跟随性，且共振区的幅值得到较好补偿，输出响应平稳。由于逆模型的补偿作用受模型参数准确性的影响，本文通过改变各参数进行仿真，得到了逆模型对各参数的敏感程度，，作为后续参数修正的依据。针对本课题设计了基于TMS320F2812的DSP应用系统，利用Simulink的自动代码生成技术结合CCS的代码开发调试功能将控制算法写入DSP，实现电磁激振器的控制。由扫频实验证明装置存在多模态，并由此修正了模型参数；通过逆模型控制实验验证了逆模型控制对主模态共振频率特性具有较好的补偿作用。
[Abstract]:The performance of turret and other military equipment plays an important role in national defense construction. However, these equipment are usually in very bad external environment and complex working conditions, and are subjected to strong vibration while working, which can easily lead to various problems, such as sight damage, fastener breakage or loosening, parts wear and fatigue damage, etc. This will affect the accuracy of the shooting, even bring accidents or make the equipment incapacitated. Therefore, it is necessary to carry out vibration test to find out the potential problems and to realize reliability design and optimization design. However, for a long time, the development of large scale military equipment vibration test-bed in China has not kept up with the demand of national defense construction. This situation has seriously restricted the modernization of national defense in our country. In order to meet the needs of national defense construction, this paper designs a kind of vibration test-bed which is applied to large-scale military equipment. Aiming at its characteristics of heavy load and narrow space, combined with the advantages and disadvantages and applicable range of various vibration exciters, A general scheme of hydraulic combined electromagnetic excitation is proposed in which the hydraulic exciter is responsible for the low frequency and large amplitude vibration below 50Hz, while the electromagnetic exciter is responsible for the high frequency and small amplitude vibration above 50Hz. This paper focuses on the electromagnetic excitation part. In this paper, the characteristics, development status and prospect of heavy load vibration exciter are studied by referring to relevant literature. According to the requirements of a turret vibration test rig, the advantages and disadvantages of all kinds of vibration exciters are combined with the applicable situation. The overall scheme of hydraulic combined electromagnetic excitation is designed, and the structure scheme of amplifying the whole amplitude by the resonance action of multi-mode resonant mechanism is proposed. According to the working principle of the moving iron type electromagnetic vibration exciter, based on the electromagnet, through theoretical calculation, finite element static analysis and modal analysis, the corresponding resonant mechanism is designed, and the structure design of the principle verification device is completed. The static suction characteristic curve of the electromagnetic exciter is obtained by electromagnetic analysis with Ansys, which reflects the relationship between the electromagnetic suction and the working air gap and current. The mathematical models of the circuit, magnetic circuit and mechanical motion part of the device are established by using Matlab/Simulink, in which the electromagnetic part contains nonlinear factors, the mechanical part is a multi-modal system, and the dynamic characteristics of the model are analyzed by simulation. The results show that the multimodal system can amplify the amplitude. Aiming at the defect that the response of multimodal system is too fluctuating and it is difficult to eliminate it with feedback, this paper presents a compensation control method for inverse model. According to the concrete situation of the controlled object, several different inverse models are established. The effectiveness of inverse model control is analyzed. Simulation results show that the inverse model can not only make the output follow the input signal well, but also compensate the amplitude of the resonance region well, and the output response is stable. Because the compensation effect of the inverse model is affected by the accuracy of the parameters of the model, the sensitivity of the inverse model to each parameter is obtained by changing the parameters and the sensitivity of the inverse model to each parameter is obtained, which can be used as the basis for the subsequent revision of the parameters. A DSP application system based on TMS320F2812 is designed in this paper. The control algorithm is written into the DSP by using the automatic code generation technology of Simulink and the code development and debugging function of CCS to realize the control of the electromagnetic exciter. It is proved by the frequency sweep experiment that there are many modes in the device and the model parameters are corrected. The inverse model control experiment proves that the inverse model control can compensate the resonance frequency characteristics of the main mode.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TJ06;TB534.2

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