Contactless control of suspended loads for offshore installations: Proof of concept using magnetic interaction

Current offshore wind turbine installation and positioning methods require mechanical equipment attached on the lifted components and human intervention. The present paper studies the development of a contactless motion compensation technique by investigating a magnetically controlled pendulum. The technique involves the interaction of a...

Data-based modal space control for active damping

This research presents a novel data-based modal control method for actively dampening the flexible mode in a multi-input multi-output (MIMO) system. Traditional passive damping methods add significant mass to the system, making recent advances in sensor and actuator technology, such as lightweight piezoelectric materials, a more appealing...

Optimal Active Damping Performance in Presence of Disturbance and Electronic Noise Sources

Vibration attenuation in lightly damped blade-like systems such as cantilevers or end-effectors of robot manipulators can be dampened using Active Vibration Control (AVC). Piezoelectric patches in a collocated setup measure and control the bending modes of such a cantilever system using Positive Position Feedback (PPF). Tuning methods for PPF...

Fractional-Order Negative Position Feedback for Vibration Attenuation

In this paper, a fractional-order extension of a negative position feedback (NPF) controller for active damping is proposed. The design of the controller is motivated by the frequency-domain loop shaping analysis, and the controller dynamics are defined to maintain the high-pass characteristics of an integer-order NPF. The proposed controller...

Input and state estimation for compliant motion stages: Estimating modal contribution for guidance flexures

To improve Active Vibration control methods like Independent Modal Space Control (IMSC), an estimate of the modal contribution of vibrational eigenmodes of compliant structures is required. In this work, three Recursive Bayesian input and state estimation algorithms previously introduced in civil engineering are evaluated for use on on high-tech...

Vibration suppression of a state-of-the-art wafer gripper

Vibration suppression of flexible end-effectors has become one of the great challenges within the semiconductor industry to achieve the precision required to produce chips. These end-effectors tend to be prone to vibrations due to their lightweight design and low thickness, whilst they still should have high accuracy and precision. This...

Active Unit-Cell Structures for Vibration Control: Conceptual Design of Hexapod Struts

In this paper, the implementation of an active unit-cell metamaterial used for vibration control is discussed. The active unit-cell metamaterial is designed for implementation in a hexapod strut. As each of the unit-cells can be sensed and actuated, over-sensing and over-actuation are introduced in the system. This can be used to create...

Time-division multiplexing is used as a method to reduce the number of amplifiers needed in active vibration control systems that use piezoelectric actuators

The high-tech industry is constantly searching for methods to make more efficient, more accurate, and faster machines. One of the methods to improve the performance of these machines is active vibration control(AVC) which can help to achieve faster transient responses. One of the ways to achieve this is better controllability which means more...

Active Vibration Control: using over-sensing and over-actuation

The demand for faster production times and higher precisions in the industrial automation is ever-increasing. Resonance modes caused by flexural elements in these machines are limiting the maximum bandwidth. Because of this, high-precision motion systems in industrial machines are limited in the maximum operating speed and precision. To improve...

Multi-scale experimental testing on variable stiffness and damping components for semi-active structural control

This paper presents experimental testing of a new semi-active vibration control device comprising a shape memory polymer (SMP) core that is reinforced by an SMP-aramid composite skin. This control device works as a load-transfer component that can be integrated into truss and frame structures in the form of a joint. At the material level,...

Novel Designs to Improve Support Stiffness during Large Strokes in Compliant Mechanism

The precision, speed, and stroke of mechatronic machines need continuous improvement. Compliant mechanisms are widely used in the precision machines, but they do not have larger strokes due to their limited deformation. In the present time, various applications also require high speed and more problems appear due to the dynamics of the compliant...

A fractional-order positive position feedback compensator for active vibration control

In this paper a novel Active Vibration Control (AVC) strategy based on fractional-order calculus is developed. A fractional-order Positive Position Feedback (PPF) compensator is proposed to overcome the limitations of the commonly used integer-order PPF such as: frequency spillover, amplitude amplification in the quasi-static region of the...