AIProVE – Adjustable Impedance Elements for Product Validation in Compliant Environments

机械系统在动态载荷下的验证需要考虑系统的运行环境，因为边界条件对系统的行为有很大的影响。为了获得可重复的结果，需要在试验台上进行测试，以定义、控制和测量参数。针对实际系统阻抗可变而试验台阻抗不变的情况，研究了可调阻抗元件(AIE)作为试验台的机械元件以及电动工具和飞机轻量化结构设计的指导思想。在电动工具测试中，使用者的手的动态行为会受到使用者的异质性、不同的姿势或在使用过程中肌肉张力的变化，从而导致不同的结果。在第二种情况下，由于机舱中不同的安装位置，机舱部件(如厨房或洗手间)的动态行为受到不同的连接阻抗的高度影响。在这两种情况下，都可以通过在测试活动期间使用AIE调整测试环境的刚度和阻尼来获得更真实的测试结果，并且可以进行系统研究来改进产品设计。AIE是允许独立调整其机械刚度和阻尼性的机械元件。到目前为止，人们已经研究了各种可调刚度元件(ASE)和可调阻尼元件(ADE)。但很少有研究涉及可调刚度和可调阻尼器在AIEs中的组合应用。不同的尺寸、操作范围和测量技术使基于文献研究的比较变得复杂。该项目首先对ASES和ADE的不同工作原理以及它们的静态和动态特性进行了实验研究。将ASES和ADE组合成AIE样机，并对其在高、低频段的特性、刚度和阻尼行为进行分析。在研究的基础上，开发了模块化的AIE设计目录，该目录涵盖了不同的要求，如不同的频率范围和负载，以及合适的工作原理的选择过程。该目录支持研究AIE的科学家和需要特定AIE进行测试应用的科学家。为了展示AIE的潜力，我们选择了两个AIE进行电动工具和机舱内部的测试。这两个测试装置涵盖了不同范围的要求，从具有高激励力的低频段到具有低激励力的高频段。因此，这两个场景代表了对模块化AIE设计目录的应用研究。为更真实地测试电动工具(包括广泛的用户阻抗变化)和飞机轻量化结构(包括不同的连接阻抗)提供了指导方针，以便为产品开发提供新的知识。

Validation of mechanical systems under dynamic loads requires the consideration of the system’s operation environment, since the boundary conditions have a major impact on the system’s behavior. For repeatable results, tests are conducted on test rigs to define, control and measure parameters. Systematic deviations occur inevitably, if the impedance of the real system is variable, but the test rig’s impedance is not.In this project, Adjustable Impedance Elements (AIEs) are researched as machine elements for test benches and guidelines on the examples of power tool and aircraft lightweight structures. In power tool testing the dynamic behaviour of the user’s hand is subjected to heterogeneity of users, different postures or changes in muscle tension during the application, which leads to different results. In a second case, the dynamic behaviour of aircraft cabin components, like galleys or lavatories are highly affected by different joint impedances, due to variable installation positions in the cabin. In both cases more realistic test results can be achieved by adjusting the stiffness and damping of the test environment with an AIE during test campaigns and systematic studies are possible to improve product design. The AIEs are machine elements that allow an independent adjustment of their mechanical stiffness and damping properties. So far, a variety of adjustable stiffness elements (ASEs) and adjustable damping elements (ADEs) have been investigated. But only little research addressed the combined application of adjustable stiffness and adjustable damping in AIEs. Different dimensions, operation ranges and measurement techniques complicate comparisons based on literature research.The project starts with an experimental investigation of different working principles for ASEs and ADEs as well as their static and dynamic characterization. The ASEs and ADEs are combined to AIE prototypes and then analyzed regarding their characteristic stiffness and damping behavior at high and low frequency bands. Based on the research a modular AIE design catalogue is developed, that covers different requirements, e.g. different frequency ranges and loads for the dimensioning as well as the selection process of suitable working principles. The catalogue supports scientists researching AIEs and scientists requiring specific AIEs for testing application.To demonstrate the potential of AIEs, two AIEs are chosen and investigated for tests of power tools and cabin interior. The two test set ups cover different ranges of requirements from low frequency band with high excitation forces and a high frequency band with low excitation forces. Thus, the two scenarios represent an application study on the modular AIE design catalogue. Guidelines for more realistic testing of power tools, including a wide range of user impedance variation, and aircraft lightweight structures, including different joint impedances, are derived to enable new knowledge for product development.