Nonlinear Dynamics and Control of a Pneumatic Vibration Isolator
Nonlinear Dynamics and Control of a Pneumatic Vibration Isolator
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DOI：
10.1115/1.2128642
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发表时间：
2006-08
期刊：
影响因子：
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通讯作者：
M. Heertjes;N. Wouw
中科院分区：
文献类型：
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作者：
M. Heertjes;N. Wouw
对单自由度气动隔振器的非线性动力学进行了研究。在物理模型的基础上，用非对称的刚度非线性来描述隔振器的刚度特性。对于一个完全非线性的气动隔振器模型，研究了两种不同类型的扰动的响应：施加在隔离有效载荷上的力和基础振动。利用广义力-导纳函数研究了有效载荷受到扰动时隔振器的动态行为，并分析了其稳态响应和超谐共振共存的特征。在广义传递率函数的基础上，对隔振器传递的基础振动进行了研究，再次显示出丰富的非线性动力学行为。非对称非线性的存在也会导致高能低频响应的多重高频激励。对于这两种激励，非线性行为严重影响了隔离器的性能。为了避免任何形式的非线性表现，同时提高被动隔振器的性能，提出了一种全面的非线性控制设计。它由一个基于线性PID的控制器和一个非线性计算力矩控制器(CTC)组成。无论是线性控制还是非线性控制，隔振器的性能都可以用广义力的导纳和传递率来量化。后者特别关注多个高频激励。
The nonlinear dynamics of a single-degree-of-freedom pneumatic vibration isolator are studied. Based on a physical model, a nonsymmetric stiffness nonlinearity is derived to describe the stiffness property of the isolator. For a full nonlinear pneumatic isolator model, the response to two different types of disturbances is studied: forces applied to the isolated payload and base vibrations. The dynamic behavior of the isolator in case of a disturbance applied to the payload is studied using the generalized force-mobility function and features coexisting steady-state responses and a superharmonic resonance. Base vibrations transmitted via the isolator are studied on the basis of the generalized transmissibility function again showing rich nonlinear dynamic behavior. The presence of a nonsymmetric nonlinearity also induces high-energy low-frequency response to multiple high-frequency excitation. For both types of excitation, the nonlinear behavior is seriously compromising the performance of the isolator. To avoid any expression of nonlinearity whatsoever and, at the same time, to enhance the performance of the passive isolator, an overall nonlinear control design is proposed. It consists of a linear PID-based controller together with a nonlinear computed torque controller (CTC). For either linear or nonlinear control, the isolator performance is quantified in terms of generalized force mobility and transmissibility. The latter with a special focus on multiple high-frequency excitation.