面向微振信号的驻极体减振俘能装置设计与建模
DESIGN AND MODELING OF ELECTRET VIBRATION SUPPRESSION AND ENERGY HARVESTING DEVICE ORIENTED TO MICRO-VIBRATION SIGNALS
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摘要: 随着航天工程的飞速发展以及先进制造业对加工精度要求的持续提高, 对低频微振信号的控制与利用越发受到关注. 本文采用驻极体材料, 参考动力减振器理论, 开发了一种面向低频微振环境的减振俘能一体化装置, 建立了驻极体减振俘能装置的机电耦合模型. 为兼顾减振和俘能的双重要求, 本文分析和等效了静电力对系统动力学特性的影响, 并进行了参数的评估, 提出了适用于驻极体减振俘能的优化方法. 建立了AMEsim和Simulink的联合仿真环境, 对模型和结果进行了仿真验真. 建模和仿真的结果表明, 本文建立的驻极体减振俘能装置的机电耦合模型可以准确描述装置的运动过程, 建模与仿真的误差在5%以内. 驻极体减振俘能装置对参数变化十分敏感, 且副结构刚度、初始间距等对减振俘能性能的影响都明显强于副结构阻尼. 经过优化, 本文设计的驻极体减振俘能装置, 能够兼顾减振和俘能需求, 可以实现接近于理想动力减振器的减振效果, 也可以在牺牲15%减振效果前提下, 获得1700 V输出电压和3.1 mW俘能功率. 本文建立的机电耦合模型和动态静电力解析模型, 有助于理解驻极体减振俘能机构的工作原理, 揭示了非线性静电力的变化过程和作用机理.Abstract: With the rapid development of space technology, and the continuous improvement of the processing precision requirements of advanced manufacturing, the control and utilization of low-frequency micro-vibration signals have attracted more and more attention. Using electret materials, we developed an integrated device to solve these problems, aiming to vibration suppression and energy harvesting, for low-frequency micro-vibration environments, and established the electromechanical coupling model of the electret vibration suppression and energy harvesting device, referring to the theory of dynamic vibration absorber (DVA). In order to meet the dual requirements of vibration suppression and energy harvesting, the influence of electrostatic force on the dynamic characteristics of the system was analyzed and equivalent, the parameters of the electret vibration suppression and energy harvesting device were evaluated and an optimization method for vibration suppression and energy harvesting was presented. We established a co-simulation environment of AMEsim and Simulink, and verified the model and results by simulation. The results of modeling and simulation showed that, the electromechanical coupling model of the electret energy harvesting device established in this paper can accurately describe its motion process, and the error of modeling and simulation is less than 5%. The vibration suppression and energy harvesting device is sensitive to the changes in parameters, and electrode spacing and stiffness of the secondary structure have stronger influence on the performance than the damping. Using our proposed optimization method for different usage scenarios, the device we designed can achieve the ability of ideal dynamic vibration absorber, or obtain 1700 V output voltage and 3.1 mW energy harvesting power sacrificing 15% of vibration suppression. The electromechanical coupling model and dynamic electrostatic force analytical model established in this paper are helpful to understand the working principle of the electret vibration suppression and energy harvesting mechanism, and reveal the change process and action mechanism of the nonlinear electrostatic force.