主动粘弹性控制抗冲击扰动

根据粘弹性材料耗能减振性能较好的特点,针对高频扰动、冲击扰动,本文提出了主动粘弹性控制的方法,定义了主动粘弹性控制技术的基本架构.根据粘弹性材料的耗能计算模型,提出了粘弹性控制律的选取原则.结合广义Maxwell模型,提出了3种粘弹性控制律(viscoelastic control law,VCL).并将粘弹性比例–微分(proportional derivative,PD)控制、粘弹性比例–积分–微分(proportional integral derivative,PID)控制、粘弹性自抗扰控制(active disturbance rejection control,ADRC)应用到常见的二阶系统中.研究结果表明,主动粘弹性控制技术抗高频扰动、抗冲击扰动的性能特别优异.由于主动控制的响应速度快,主动粘弹性控制的抗扰性能好,本文提出了主动控制与主动粘弹性控制相切换的控制方法,并对切换控制策略进行了研究.研究结果表明,切换控制可同时兼顾抗扰性能与响应速度.

支座刚度对液压粘弹性控制系统（HVES）减震效果的影响

在考虑支座变形的条件下．建立了液压粘弹性控制系统（ＨＶＥＳ）与受控结构所组成的控制体系的运动方程；通过计算分析，探讨了支座刚度对ＨＶＥＳ减震效果的影响规律，以及该规律随ＨＶＥＳ参数的变化情况；在此基础上，给出了支座刚度的下限临界值，从而为ＨＶＥＳ支座的工程设计提供了依据。

Controller design based on viscoelasticity dynamics model and experiment for flexible drive unit

In order to ensure that the system has the advantage of light weight and vibration absorption, the steel rope is used as a flexible transmission part. A flexible drive unit(FDU) is developed, whose features are guided by steel rope, increasing force by the movable pulley group, modular, convenient and flexible. Dynamics model for controller is deduced based on the constitutive equation of viscoelasticity. Controller is designed for position control and is based on the viscoelasticity dynamics model compensation control strategy proposed. The control system is based on the TURBO PMAC multi-axis motion control card.Prototype loading experiments and velocity experiments results show that the FDU can reach 2 Hz with no load and the max speed of 30(°)/s. The FDU has the capability of the load torque 11.2 N·m and the speed of 24(°)/s simultaneously, and the frequency response is 1.3 Hz. The FDU can be used to be the pitch joint of hip for biped robot whose walking speed is 0.144 km/h theoretically.

Optimal Vibration Control of Adjacent Building Structures Interconnected by Viscoelastic Dampers

The objective of this paper is to investigate the dynamic characteristics of two adjacent building structures interconnected by viscoelastic dampers under seismic excitations. The computational procedure for an analytical model including the system model formulation, complex modal analysis and seismic time history analysis is presented for this purpose. A numerical example is also provided to illustrate the analytical model. The complex modal analysis is conducted to determine the optimal damping ratio, the optimal damper stiffness and the optimal damper damping of the viscoelastic dampers for each mode of the system. For the damper stiffness and damping with optimal values, the responses can be categorized into underdamped and critically damped vibrations. Furthermore, compared to the viscous dampers with only the energy dissipation mechanism, the viscoelastic dampers with both the energy dissipation and redistribution mechanisms are more effective for increasing the damping ratio of the system. The seismic time history analysis is conducted to assess the effectiveness of the viscoelastic dampers for vibration control. Based on the optimal damping ratio, the optimal damper stiffness, the optimal damper damping of the viscoelastic dampers for a certain mode of the system, and the viscoelastic dampers can be used to effectively suppress the root-mean-square responses as well as the peak responses of the two adjacent buildings.

Passive vibration control of truss-cored sandwich plate with planar Kagome truss as one face plane

Kagome based high authority shape morphing structure is a kind of truss-cored sandwich metal plate with a planar Kagome truss as one of its face plane. The planar Kagome truss can achieve arbitrary in-plane nodal displacements with minimal internal resistance when its rods are deformed. Moreover, the in-plane deflection of the planar Kagome truss may induce the lateral deflection of the whole sandwich plate. In this paper, the feasibility to enhance the damping of the truss-cored sandwich plate through the replacement of a very small portion of rods in the planar Kagome truss by cylindrical viscoelastic dampers is exploited. The Biot model is chosen to simulate the behavior of the viscoelastic material in the dampers, and the fraction of axial modal strain energy of the rods in the planar Kagome truss is adopted as the index to decide the positions of the dampers. Through complex modal analysis and time-domain simulation, it is shown that the passive vibration control approach is very effective for the vibration reduction of this kind of truss-cored sandwich plates.