基于自适应调节双负电容压电分流阻尼的桨－轴系－船体耦合系统振动传递控制机理与方法

The vibration and resultant underwater sound radiation of propeller-shaft-hull coupled system induced by the fluctuating propeller pressures is one of the principal contributors at low frequency range for underwater vehicles. Vibration transmission control of fluctuating pressures through the shaft is an important measure to control low-frequency noise radiation. Aimed at this problem, the project has presented a new control scheme by employing an adaptive tuning piezoelectric shunt with two negative capacitances. For theoretical analyses, modeling of the Electro-mechanical coupling system consisting of the propeller-shaft-hull and the adaptive tuning piezoelectric shunt is carried out; the multiple mode broadband control mechanism and the effects of parameters on the responses are investigated; optimal parameters of the piezoelectric shunt are obtained; circuit analysis and implementation on piezoelectric shunt circuit with two negative capacitances is studied; negative capacitance is constructed based on high-voltage Operational Amplifier(OpAmp); adaptive tuning is realized by an electronically tunable resistor, which is employed to change the value of the negative capacitance to the best fit for the present condition; the capability of the proposed shunt to increase the general electromechanical coupling factor for small strain, to enhance the anti-saturation performance even at high vibration level and to develop the adaptability of optimal parameters under varying operation conditions is analyzed. For experimental investigation, electrical impedance measurement of the piezostructure and vibration responses tests on a scaled propeller-shaft-hull/plate coupled system with/without the adaptive tuning piezoelectric shunt are carried out to verify the modeling method, the control mechanism as well as the effect of the proposed method under different rotation speeds and excitation amplitudes. The investigation will give a sound theoretical reference to the design of adaptive tuning piezoelectric shunt in a propeller-shaft-hull coupled system.

螺旋桨脉动压力引起桨－轴系－船体耦合系统的振动声辐射是水下航行器低频声辐射的主要贡献者。利用振动传递控制减小脉动压力通过轴系对船体的激励是控制其低频声辐射的重要措施。针对该问题，提出一种基于自适应双负电容压电分流阻尼的控制方法。理论方面，通过建立含分流阻尼电路的桨－轴系－船体机电耦合系统力学模型和开展稳定性分析，揭示其多模态宽带振动控制机理，获得分流阻尼电路的最优参数；通过对基于高电压运算放大器的双负电容压电分流电路、基于电路可控电阻调节负电容参数的自适应控制电路的设计和分析，实现弱应变下广义机电耦合系数增强、大激励下运算放大器抗饱和以及复杂环境下最优参数自适应调节。试验方面，开展负电容压电分流电路的阻抗特性测试、施加压电分流阻尼控制的桨－轴系－船体/板缩比模型的响应对比测试，对建模方法、不同转速和激励幅值下的控制机理和效果进行验证。研究成果将为该方法的实际工程应用提供坚实的理论基础。

针对螺旋桨通过轴系激励船体这一重要传递途径，提出一种基于自适应双负电容压电分流阻尼的控制方法。理论方面，建立了含分流阻尼电路的桨－轴系－船体机电耦合系统力学模型，基于机电类比获得了针对特定被控模态下的最优参数，明确了和被控模态的相关的并联和串联负电容稳定性参数条件，揭示了并联负电容增强机电耦合系数、串联负电容减少电感需求的机理；设计了电路可控电阻调节负电容参数的自适应控制电路，分析结果表明自适应控制电路可对单模态实施自适应控制；提出了利用能量法建立双负电容-电阻-电感压电分流电路动能均值、热能均值与电路元件关系的多模态耦合寻优算法，结果表明该算法能够针对电路元件快速寻优实现宽频段振动控制，适用于变工况、大规模压电阵列等场合；考虑压电片的串联和并联寄生电阻开展了负电容压电分流对单模态控制的仿真分析。试验方面，一方面，基于差分电路和NI平台，将传递函数转化为差分方程，利用IIR滤波器或比例积分微分电路实现了双负电容-电阻-电感压电分流电路，另一方面基于高电压运算放大器和负阻抗变换电路研制了串联负电容及并联负电容；完成了压电片的电学特性测试分析、负电容压电分流电路的特性测试。在梁板结构、桨轴试验系统中开展了充分的试验研究，1）针对悬臂梁、复合材料悬臂梁结构完成了负电容压电分流吸振试验，试验结果表明：负电容压电分流吸振对梁板结构具有良好的控制效果，且多个压电片可以分别控制多个模态而互不影响且同时控制单个模态时控制效果会进一步提升。2）完成了舱段结构上负电容压电分流电路振动控制试验，通过舱壁上压电片分流控制，可同时抑制舱壁和壳体上的振动，单个并联负电容压电分流电路可将舱壁和壳体在低频耦合模态处下降超过3dB。3）针对桨-轴-船体耦合系统开展了基于压电堆负电容压电分流动力吸振的试验，试验结果表明：该布置下的压电堆负电容压电分流电路对桨叶上激励产生的轴系和壳体的振动控制都有效果。3）完成了桨-轴试验系统试验台架的设计，开展了试验台架的模态测试、负电容压电分流电路的振动控制效果测试，测试结果表明，RL分流电路在缩比结构中控制效果较差，基本没有控制效果；负电容压电分流电路对阻尼较小的弯曲振动控制效果较好，对刚度较大的纵向振动控制效果较差。试验研究结果发现负电容在达到理想的稳定性临界值之前即开始电路失稳、双负电容电路存在稳定性问题，经初步分析，上述稳定性问题和电路参数非理想性有关，是后