Vibration fixtures, at times, have resonant frequencies that exist in the frequency range needed for conducting vibration tests. These resonant frequencies can cause significant problems when running vibration tests over ranges which include these resonances. A test engineer will attempt to control the shaker system through a feedback accelerometer which controls the level of vibration input in...

Abstract: Passive vibration control solutions are often limited to working reliably at one design point. Especially applied to lightweight structures, which tend to have unwanted vibration, active vibration control approaches can outperform passive solutions. To generate dynamic forces in a narrow frequency band, passive single-degree-of-freedom oscillators are frequently used as vibration abso...

Passive vibration shunt control using piezoelectric materials and an electrical network can remove vibration energy from structures. However, the vibration shunt control efficiency relies on the optimization of the vibration energy transfer between a structure and a Lead-Zirconate-Titanate piezoelectric ceramic material. We present an analytical study of a parallel resistor-inductor piezoelectr...

A hybrid control scheme for vibration reduction of flexible spacecraft during rotational maneuvers is investigated by using variable structure output feedback control (VSOFC) for attitude control and smart materials for active vibration suppression. The proposed control design process is twofold: design of the attitude controller using VSOFC theory acting on the hub and design of an independent...

For active vibration control in linear systems, structural response of the controlled structure is the superposition of the response caused by external disturbances, which is defined as the primary response, and the response caused by the active vibration controller, which is defined as the control response. This structural vibration can be cancelled if the control response has equal amplitude ...

background: deficiency of attention and concentration is one of great reasons of traffic incidents and it covers between 20 to 50 percent of events due to careless and mindedness. studies show that attention and concentration are considered as one of important cognitive components in safe driving. vibration is an important physical effect in all vehicles. till now has not been any organized stu...

In order to motivate the use of active vibration control, consider the future interferometric missions planned by NASA or ESA (one such a mission, called ”Terrestrial Planet Finder” aims at detecting earth-sized planets outside the solar system; other missions include the mapping of the sky with an accuracy one order better than that achieved by Hypparcos). The purpose is to use a number of sma...

Experience in the design of steel and concrete floor systems to control vibrations suggests that a floor system’s vibration characteristics are often fundamental to its acceptable performance. In such cases, serviceability drives the design instead of strength. This is particularly true for laboratory floors that support sensitive equipment and floor girders that fall within certain spans. This...

Vibration control of rotating machinery is tougher and a challenging challengerical technical problem. There are two major categories of vibration control techniques for rotating machinery such as direct control using vibration isolators and balancing control using vibration dampers. This chapter presents the simulation of a PID control scheme and calculation of tuning parameters. These paramet...