基于压电陶瓷的主被动一体化作动器及多维隔振系统研究

发布时间：2018-06-10 20:29

本文选题：主被动一体化隔振 + 压电陶瓷作动器　；参考：《哈尔滨工业大学》2017年博士论文

【摘要】：在现代航天工程领域中,航天器的系统组成越来越复杂,航天器在轨运行时各部件,如动量轮、控制力矩陀螺、太阳帆板等正常工作引起的不可避免的振动不仅会造成航天器自身结构的振动响应,也会干扰航天器敏感仪器设备正常工作,影响它们的精度和可靠性,导致测控导航、姿态指向和观测瞄准等重要指标下降,甚至导致敏感仪器工作异常或失效,严重影响航天器机动性能、数据传输稳定性,最终可能导致飞行任务失败的严重后果。因此,本文结合国家自然基金项目及国家重点基础研究发展计划子课题,对航天器上敏感仪器设备的多自由度精密隔振问题进行系统深入研究,提出了多维主被动一体化隔振的设计方法,研制了适合特殊空间环境的主被动一体化作动器,并设计了一种基于主被动一体化作动器的隔振平台,建立了面向敏感有效载荷的多自由度精密隔振策略,减小振动对敏感仪器正常工作的影响,为其提供安静的力学环境。针对传统被动隔振与主动隔振各自的优缺点,提出了一种基于压电陶瓷和粘弹性材料的主被动一体化作动器。该作动器具有结构紧凑,尺寸小和重量轻的优点,同时细杆状外型有利于与航天器结构集成设计,减小运动干涉。根据其动力学特性需求,完成了作动器原型的设计与实验测试,并搭建实验系统完成了性能实验。实验结果表明提出的基于压电陶瓷的主被动一体化作动器在低频段和高频段都具有较好的隔振效果,其中低频段隔振和谐振峰值的抑制主要通过主动隔振部分实现,而高频段的隔振功能由被动部分承担。在主动部分出错或完全失效的情况下,被动部分仍能够正常工作,此时可以获得不差于单纯采用被动隔振器的隔振效果,客观提高了系统的可靠性。提出的主被动一体化作动器采用通过一定工艺叠合而成的压电陶瓷堆,它在输出位移与驱动电压之间存在多值对应的迟滞现象,是智能材料的固有特性。这种迟滞将限制主被动一体化作动器的响应速度及控制精度。针对这一问题,基于Bouc-Wen模型建立了能描述基于压电陶瓷的主被动一体化作动器迟滞特性的数学模型,并提出了相应参数辨识方法,通过实验验证迟滞模型及参数辨识方法的有效性。提出了两种基于该迟滞数学模型的线性化控制方法,分别为前馈补偿和前馈补偿-PI反馈复合控制,仿真分析验证了两种线性化控制方法的有效性,结果表明,两种方法均能实现主被动一体化作动器的线性化控制,复合控制的线性化效果优于前馈控制。主被动一体化作动器的线性化控制为其应用于多自由度隔振平台,完成振动主动实时控制奠定基础。为实现敏感有效载荷的六自由度隔振,提出了使用基于压电陶瓷的主被动一体化作动器为支撑杆件,以正交结构为原型的两杆正交隔振模块。由于航天器敏感有效载荷受到的扰动振幅较小,且基于压电陶瓷的主被动一体化作动器输出量程为微米级,因此铰链间隙影响被放大。针对此种情况采用一种无间隙式球铰,并应用于正交隔振模块。基于该正交隔振模块,针对质量大、直径大、安装空间受限、直径与安装高度比极大的航天器敏感有效载荷,设计了一种三个正交隔振模块组成的六维正交隔振平台,基于拉格朗日方程建立所设计的六维正交隔振平台的动力学方程,为后续对六维正交隔振平台的动力学特性分析做准备。基于建立的采用主被动一体化作动器的六维隔振平台的动力学方程,考虑系统存在的非结构不确定性,如动力学建模时的简化处理、模型误差等,设计了鲁棒H∞控制器,保证隔振系统在不确定因素存在时依然有良好的隔振性能。针对动力学模型中存在的结构不确定性,建立了含有刚度、阻尼不确定的参数摄动模型,提出基于μ综合理论的鲁棒控制器,大大降低H∞控制器对于结构不确定性模型控制的保守性。对控制器进行仿真分析,结果表明采用鲁棒控制的六维正交隔振平台对于各种形式的激励信号均能有效衰减,有效隔振频带宽10Hz~+∞范围,能够完全消除一阶谐振峰值,且随着激励频率增大,衰减效果增强。为验证理论分析的有效性,进行了六维正交隔振平台隔振性能实验。针对敏感有效载荷各项性能指标要求,设计并研制有效载荷模拟件。完成实验样机研制及机械系统搭建,基于快速控制原型技术,建立了隔振平台实时控制系统,完成了硬件及软件调试,以竖直方向信号为激励信号,完成隔振性能测试。实验结果表明,主被动一体化控制下的六维隔振平台能够在18Hz~+∞范围内,有效衰减振动,能够完全衰减系统一阶谐振峰值。该实验进一步验证基于压电陶瓷的主被动一体化六维正交隔振平台能够提高整个系统的稳定性和可靠性、降低能耗,即使主动控制环节失效,隔振平台自身被动结构仍具有一定的隔振能力。
[Abstract]:In the field of modern space engineering, the system composition of the spacecraft is becoming more and more complex. The inevitable vibration caused by the normal work of the components, such as the momentum wheel, the control moment gyro, the solar panel and other normal work, will not only cause the vibration response of the spacecraft itself, but also interfere with the normal work of the spacecraft's sensitive instrument and equipment. Their accuracy and reliability are affected by the reduction of important indicators such as measurement and control navigation, attitude pointing and observation aiming, and even the abnormal or failure of the sensitive instruments, which seriously affect the maneuverability of the spacecraft, the stability of the data transmission, and the serious consequences of the failure of the flight mission. Therefore, this paper combines the national natural fund project. The problem of multi degree of freedom and precision vibration isolation of sensitive instrument and equipment on spacecraft is systematically studied, and the design method of multi-dimensional and passive integrated vibration isolation is proposed. A passive and integrated actuator suitable for special space environment is developed, and a kind of one based on the main and passive integration is designed. Based on the vibration isolation platform of the actuator, a multi degree of freedom precision vibration isolation strategy for sensitive payload is established to reduce the effect of vibration on the normal work of the sensitive instrument and provide a quiet mechanical environment. In view of the advantages and disadvantages of the traditional passive vibration isolation and active vibration isolation, a kind of passive and passive materials based on the main and passive materials of piezoelectric ceramics and viscoelastic materials is proposed. The actuator has the advantages of compact structure, small size and light weight. At the same time, the thin rod shape is advantageous to the integrated design of the spacecraft structure and reduces the motion interference. According to its dynamic characteristics, the design and experimental test of the actuator prototype are completed, and the experimental system has been set up to complete the performance experiment. The experimental result table is completed. The active and passive integrated actuator based on piezoelectric ceramics has good vibration isolation effect in low frequency and high frequency segments, in which the suppression of the vibration isolation and the peak value of the low frequency section is mainly realized by active vibration isolation, while the vibration isolation function of the high frequency section is borne by the passive part. The dynamic part can still work normally. At this time, the vibration isolation effect of the passive vibration isolator can be obtained, and the reliability of the system is improved objectively. The proposed passive integrated actuator adopts a piezoelectric ceramic stack formed by a certain process. It has a hysteresis between the output displacement and the driving voltage. It is an inherent characteristic of intelligent materials. This hysteresis will limit the response speed and control precision of the passive and passive integrated actuator. Based on the Bouc-Wen model, a mathematical model which can describe the hysteresis characteristics of the active passive integrated actuator based on the piezoelectric ceramics is established, and the corresponding parameter identification method is proposed. The experimental verification is carried out by the experiment. The validity of the hysteresis model and the parameter identification method. Two linearized control methods based on this hysteresis model are proposed, which are feedforward compensation and feedforward compensation -PI feedback compound control respectively. The effectiveness of the two linearized control methods is verified by simulation analysis. The results show that the two methods can achieve the active and passive integrated actuator. Linearization control, the linearization effect of the compound control is better than the feedforward control. The linearization control of the active and passive integrated actuator is the basis for its application to the multi degree of freedom vibration isolation platform and the active real time vibration control of the vibration. In order to realize the six degree of freedom vibration isolation of the sensitive payload, the application of the active and passive integration based on the piezoelectric ceramic is proposed. A two bar orthogonal vibration isolation module with an orthogonal structure as the support bar. The disturbance amplitude of the sensitive payload of the spacecraft is smaller and the output range of the piezoelectric ceramic is based on the main and passive integration of the actuator and the output range of the actuator is micron, so the effect of the hinge gap is amplified. Based on the orthogonal vibration isolation module, based on the orthogonal vibration isolation module, a six dimension orthogonal vibration isolation platform composed of three orthogonal vibration isolation modules is designed for the large mass, large diameter, limited space of installation space and high sensitivity to the installation height of the spacecraft. Based on the Lagrange equation, the designed six dimensional orthogonal vibration isolation is established. The dynamic equation of the platform is prepared for the analysis of the dynamic characteristics of the six dimensional orthogonal vibration isolation platform. Based on the dynamic equations of the six dimensional vibration isolation platform based on the active and passive integrated actuator, the robust H infinity control is designed, considering the unstructured uncertainty of the system, such as the simplified treatment of the dynamic modeling, the model error and so on. It ensures that the vibration isolation system still has good vibration isolation performance when the uncertain factors exist. According to the structural uncertainty in the dynamic model, a parameter perturbation model with stiffness and damping uncertainty is established, and a robust controller based on the muon synthesis theory is proposed, which greatly reduces the H infinity controller for structural uncertainty model control. The simulation analysis of the controller shows that the six dimensional orthogonal vibration isolation platform with robust control can effectively attenuate all kinds of excitation signals and effectively eliminate the first order resonance peak in the range of 10Hz~+ infinity of vibration frequency bandwidth, and the attenuation effect is enhanced with the increase of the frequency of excitation. The effectiveness of the six dimensional orthogonal vibration isolation platform isolation performance experiment. Aiming at the requirements of the sensitive payload performance requirements, design and develop the payload simulator. Complete the experimental prototype development and mechanical system construction. Based on the rapid control prototype technology, the Ge Zhenping platform real-time control system is established, and the hardware and software debugging are completed. The vibration isolation performance test is completed with the vertical direction signal as the excitation signal. The experimental results show that the six dimensional vibration isolation platform under the integrated control of the main and passive control can effectively attenuate the vibration and completely attenuate the first harmonic peak of the system in the 18Hz~+ infinity range. This experiment further verifies the six dimensional orthogonal isolation based on the passive integration of the piezoelectric ceramics. The vibration platform can improve the stability and reliability of the whole system, reduce the energy consumption. Even if the active control link fails, the passive structure of the vibration isolation platform still has a certain vibration isolation capability.
【学位授予单位】：哈尔滨工业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：V414;V441

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