Collaborative Research: Hybrid Control of Gear System Vibration with Time-Varying Dynamics via Piezo-Composite Array

康涅狄格大学、田纳西大学和田纳西州立大学的合作项目的研究目标是创造新的理论和潜在的变革性技术，以有效控制齿轮系统引起的振动传播。在齿轮系统中，多音调振动是由于齿啮合刚度的参数变化引起的，这是由接触齿数和齿灵活性的运动变化引起的。在这个项目中，我们计划开发一种多层混合控制方法，通过同时进行被动隔离和主动控制，实现参数时变齿轮系统动力学的多音调振动抑制。具体而言，我们将开发具有频率可调阻带的双周期伸扭耦合压电/复合支撑，以阻止高频振动的传播，同时在支撑中使用压电换能器实现基于Floquet分解的双环自适应前馈/时变反馈控制策略，以主动抑制自激振动。通过这些创新，新方法将严格解决齿轮系统振动控制中的主要挑战，例如广谱多音调振动，参数激励的时变动力学和非平稳响应。齿轮是许多能源、飞机、汽车和船舶系统的关键部件。如果这项研究取得成功，不仅可以提高这些系统的耐久性、可靠性和效率，还可以改善人类的操作和生活环境。特别是，减少齿轮引起的振动和相关的噪音排放可以在风能开发中发挥关键作用。通过执行教育任务，专业人员将通过课堂教学、社区外展和让代表性不足和少数群体的学生参与顶点项目来传播研究成果，从而为劳动力培训做出重大贡献。

The research objective of this collaborative project by University of Connecticut, University of Tennessee and Tennessee State University is to create new theories and a potentially transformative technology to effectively control the gear system-induced vibration propagation. In gear systems, multi-tonal vibrations are induced as a result of parametric variations in tooth mesh stiffness caused by kinematic variations in the number of teeth in contact and tooth flexibility. In this project, we plan to develop a multi-layered, hybrid control methodology to enable multi-tonal vibration suppression of parametric time-varying gear system dynamics via simultaneous passive isolation and active control. Specifically, we will develop bi-periodic extension-twist coupled piezoelectric / composite struts with tunable frequency stop-bands to block high frequency vibration propagation, and in the meantime employ the piezoelectric transducers in the struts to realize a dual-loop adaptive feedforward / time-varying feedback control strategy based on Floquet decomposition that provides active suppression of self-exited vibrations. With these innovations, the new methodology will rigorously address the major challenges in gear system vibration control, e.g. wide spectrum multi-tonal vibrations, time-varying dynamics with parametric excitations, and non-stationary responses. Gears are critical components in many energy, aircraft, automobile, and marine/ship systems. If successful, the outcome of this research can lead to not only increased durability, reliability and efficiency of those systems, but also improved human operating and living environment. Particularly, reduction of gear-induced vibration and associated noise emissions can play a critical role in wind energy development. By carrying out the educational tasks, the PIs will disseminate the research findings through classroom teaching, community outreach, and involving under-represented and minority group students in capstone projects, thereby contributing significantly to workforce training.