Most active vibration isolation systems that try to a provide quiescent acceleration environment for space-science experiments have utilized linear design methods. In this paper, we address adaptive control augmentation of an existing classical controller that combines a high-gain acceleration inner-loop feedback together with a low-gain position outer-loop feedback to regulate the platform abo...

This paper presents the initial investigation of nonlinear control for a magnetic spring. The combination of a magnet pair in repulsion and a magnet pair in attraction create a spring with a quadratic force curve. At its nominal position, it is a marginally stable system that has interesting vibration isolation properties. Non-linear control is shown to be effective in stabilising the system.

The paper presents a mathematical model for an industry inspired problem of vibration isolation applied to a cluster of elastic fluid-filled containers. We develop a systematic approach employing full fluid-solid interaction and Floquet-Bloch waves in periodic multi-scale systems. The analytical findings are accompanied by numerical simulations, including frequency response analyses and computa...

An effective wide band active control law through one kind of the Dynamic Vibration Absorber (DVA) is proposed and studied in this paper. With the help of mechanical impedance method, active DVA control law is formulated based on the passive mechanical model. The electrical DVA can generate multi-mode active damping to the structure. The host structure is an aluminum plate and acceleration sign...

To effectively improve the tire grounding behaviors of wheelchair robots, an analytical method is proposed to analyze and optimize the tire grounding safety. Firstly, taking the cushion and tires as the vibration isolation elements with stiffness and damping, the vertical vibration model of the human-wheelchair robot is established. Then, taking the random excitation as the typical input, the f...

We present design details and test results for the first short-term frequency standard to achieve ultra-high stability (oy < without he use of liquid helium. Technical features include vibration isolation by atmospheric helium gas and a new sapphire resonator design with adjustable compensation operating at 8-10K.

Nondestructive testing and defect detection using optical techniques has been extensively investigated. This communication presents a simple method for defect detection in deformed circular plates using moiré deflectometry. The experimental arrangement is simple, inexpensive and does not require elaborate vibration isolation requirements.