压电式MEMS传感器的稳健设计研究

发布时间：2018-03-15 08:18

本文选题：MEMS传感器　切入点：稳健设计　出处：《北方工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着微机械加工技术的发展,MEMS传感器的研究受到广泛重视。其中压电式MEMS传感器因可实现多功能化、智能化、集成化和无需辅助电源等优势,有着极高的应用前景。然而MEMS传感器的特征尺寸在纳、微米量级,使得其力学行为和运动规律等与宏观机械系统有很大不同。传统机械设计理论不再适用于MEMS器件的设计,本文在压电式MEMS传感器的设计中引入稳健设计思想,对压电式MEMS传感器的稳健设计方法进行了理论研究、数值计算和仿真验证。本文分别研究了基于随机模型、容差模型和模糊模型的微传感器的稳健设计原理和建模方法。通过对单根纳米纤维压电性能的稳健设计研究,建立了其基于容差模型和随机模型的稳健设计数学模型,得到单根纳米纤维结构设计参数的优化解,有效提高其压电性能。对比发现其容差和随机稳健优化结果具有较好的一致性,表明稳健设计在MEMS传感器敏感元件结构优化设计中的重要意义,为后续压电双晶梁MEMS传感器的稳健设计提供了思路和方法。为了避免压电双晶梁MEMS传感器的稳健设计过程中的盲目性,提高MEMS传感器的设计效率。采用ANSYS仿真分析了压电双晶梁结构参数对其输出电压的影响,合理选取压电双晶梁MEMS传感器的稳健设计变量。通过ANSYS仿真讨论压电双晶梁结构参数对其最大位移的影响,将压电双晶梁最大位移的ANSYS仿真结果与Simts理论值对比发现两者误差率小于9%,说明ANSYS仿真结果正确可靠,为有限元仿真验证稳健设计结果提供理论依据。利用本文所提到的三种稳健设计模型研究了压电双晶梁MEMES传感器的优化设计。详细地分析了压电双晶梁中的可控和不可控因素,考虑稳健设计参数的不确定性(随机性和模糊性)和MEMS工艺中存在的加工偏差;以保证压电双晶梁边界约束、应力约束和应变约束的稳健可行性为基础,建立了压电双晶梁MEMS传感器的稳健设计数学模型并求解。设计结果与原方案相比较,表明稳健设计能提高MEMS传感器的质量性能,控制其加工成本;当MEMS传感器实际加工尺寸与稳健设计参数发生变差(在一定范围内)时能保持性能稳定,提升MEMS传感器微加工的成品率,验证了稳健设计方法的实用性和有效性。应用ANSYS仿真验证了压电双晶梁MEMS传感器的稳健设计结果正确可靠。ANSYS仿真验证还表明稳健设计在提高MEMS传感器质量性能的基础上,不仅压电双晶梁整体结构尺寸下降,压电双晶梁的最大位移也减小,提高MEMS传感器的安全性。
[Abstract]:With the development of micromachining technology, the research of MEMS sensors has been paid more and more attention. Among them, piezoelectric MEMS sensors have the advantages of multifunction, intelligence, integration and no auxiliary power supply. However, the characteristic size of MEMS sensor is in the order of nanometers and microns, which makes its mechanical behavior and motion law very different from macroscopic mechanical system. The traditional mechanical design theory is no longer suitable for the design of MEMS devices. In this paper, the robust design idea of piezoelectric MEMS sensor is introduced, and the robust design method of piezoelectric MEMS sensor is studied theoretically, numerically and simulated. The robust design principle and modeling method of micro sensor based on tolerance model and fuzzy model are studied. The robust design mathematical model based on tolerance model and stochastic model is established by studying the robust design of piezoelectric properties of a single nanofiber. The optimal solution of the design parameters of a single nanofiber structure is obtained, and the piezoelectric properties of the nanofiber are improved effectively. It is found that the results of tolerance and stochastic robust optimization are in good agreement with each other. The results show that robust design is of great importance in the structural optimization of MEMS sensors. In order to avoid the blindness in the robust design of piezoelectric double crystal beam MEMS sensor, the method is provided for the subsequent robust design of piezoelectric double crystal beam MEMS sensor. The design efficiency of MEMS sensor is improved. The effect of the structure parameters of piezoelectric double crystal beam on the output voltage is analyzed by ANSYS simulation. The robust design variables of piezoelectric double crystal beam MEMS sensor are reasonably selected. The influence of structural parameters of piezoelectric double crystal beam on its maximum displacement is discussed by ANSYS simulation. By comparing the ANSYS simulation results of the maximum displacement of piezoelectric double crystal beams with the theoretical values of Simts, it is found that the error rate between the two is less than 9, which shows that the ANSYS simulation results are correct and reliable. This paper provides a theoretical basis for the finite element simulation to verify the robust design results. Using the three robust design models mentioned in this paper, the optimal design of piezoelectric twin beam MEMES sensor is studied. The controllable and uncontrollable factors in piezoelectric double crystal beam are analyzed in detail. Considering the uncertainty (randomness and fuzziness) of the robust design parameters and the machining deviation in MEMS process, the robust feasibility of boundary constraint, stress constraint and strain constraint of piezoelectric double crystal beam is ensured. The mathematical model of robust design of piezoelectric double crystal beam MEMS sensor is established and solved. The results show that the robust design can improve the quality performance of MEMS sensor and control its processing cost. When the actual machining size of the MEMS sensor and the robust design parameters become worse (within a certain range), the performance of the MEMS sensor can be kept stable, and the finished product rate of the MEMS sensor can be increased. The practicability and validity of the robust design method are verified. The results of robust design of piezoelectric double crystal beam MEMS sensor are verified by ANSYS simulation. The simulation results also show that the robust design is based on improving the quality of MEMS sensor. Not only the structure size of piezoelectric double crystal beam is decreased, but also the maximum displacement of piezoelectric double crystal beam is reduced, which improves the safety of MEMS sensor.
【学位授予单位】：北方工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH-39;TP212

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