Active vibration control of a multi-degree-of-freedom system via twin rotor damper

2021 ◽  
pp. 1-43
Author(s):  
Richard Terrill ◽  
Uwe Starossek
Keyword(s):  
Vibration Control ◽  
Power Efficiency ◽  
Active Vibration Control ◽  
Degree Of Freedom ◽  
Control Force ◽  
Efficient Manner ◽  
Active Mass ◽  
Power Efficient ◽  
Continuous Rotation ◽  
Twin Rotor

Abstract The twin rotor damper (TRD), an active mass damping device, is used for the vibration control of a multi-degree-of-freedom (MDOF) system of oscillators. A single TRD unit consists of two eccentric control masses rotating about two parallel axes. In its principle mode of operation, the continuous rotation mode (CRM), the control masses rotate with a constant angular velocity in opposite directions; producing a monofrequent harmonic control force in an energy and power efficient manner. Extensive research has shown the effectiveness of the TRD in the CRM for systems with a single dominate mode of vibration. In this paper, the application of a single and multiple TRD units operating in the CRM is investigated for the control of MDOF system of oscillators. The influence of the monofrequent control force produced by the TRD on the MDOF system of oscillators is investigated analytically. Subsequently, the analysis is inverted and the influence of the MDOF system of oscillators on the TRD is studied, in particular its power efficiency and damping performance. Finally, the power efficiency and damping performance of the TRD for the control of a system with two modes of vibration is analytically compared to that of a conventional active mass damping device. It is shown that in most cases, the TRD achieves greater damping performance in a more power efficient manner than a conventional active mass damper of similar size and mass.

Active Vibration Control of a Triple Flexible Structures Combined With Actuators

1995 ◽  
Author(s):  
Kazuto Seto ◽  
Yoshihiro Toba ◽  
Fumio Doi
Keyword(s):  
Vibration Control ◽  
Large Scale ◽  
Active Vibration Control ◽  
Flexible Structures ◽  
Low Frequency ◽  
Tall Buildings ◽  
Control Force ◽  
Active Vibration ◽  
Strong Winds ◽  
Lq Control

Abstract In order to realize living comfort of tall buildings by reducing the vibration of higher floors by strong winds, this paper proposes a new method of vibration control for flexible structures with a large scale. The higher a tall building the lower its natural frequency. Since obtaining sufficient force to control the lower frequency vibrations of tall buildings is a difficult task, controlling the vibration of ultra-tall buildings using active dynamic absorbers is nearly impossible. This problem can be overcome by placing actuators between a pair of two or three ultra-tall buildings and using the vibrational force of each building to offset the vibrational movement of its paired mate. Therefore, it is able to obtain enough control force under the low frequency when the proposed method is used. In this paper, a reduced-order model expressed by 2DOF system under taking into consideration for preventing spillover instability is applied to control each flexible structure. The LQ control theory is applied to the design of such a control system. The effectiveness of this method is demonstrated theoretically as well as experimentally.

scholarly journals A Comparative Study Based on Different Control Algorithms for Suppressing Multistage Gear Transmission System Vibrations

2018 ◽  
Vol 2018 ◽  
pp. 1-16
Author(s):  
Wenhao Sun ◽  
Feng Zhang ◽  
Weidong Zhu ◽  
Han Wang ◽  
Shunan Luo ◽  
...  
Keyword(s):  
Vibration Control ◽  
Active Vibration Control ◽  
Transmission System ◽  
Gear Transmission ◽  
Control Algorithms ◽  
Control Force ◽  
The Finite Element Method ◽  
Control Schemes ◽  
Gear Transmission System ◽  
Active Vibration

A modal analysis (MA) was preconsidered to determine a novel active vibration control (AVC) structure of multistage gear transmission system (MGTS) and an appropriate actuating position for the piezoelectric actuator (PZT); the results of the calculating method and the finite element method (FEM) were compared to validate the reliability of MA. The controllers based on different control algorithms were designed to drive the PZTs to output the control force for suppressing the host structure vibrations. To analyze the feasibility of the applied control schemes and discuss the control effects dominated by the different control algorithms, a series of active vibration control numerical simulations were studied. The cosimulation results validate the practicability of the proposed control schemes and provide a forcible guidance for the further experimental works.

Active Vibration Control of the Axially Moving String Using Space Feedforward and Feedback Controllers

1996 ◽  
Vol 118 (3) ◽  
pp. 306-312 ◽  
Author(s):  
S. Ying ◽  
C. A. Tan
Keyword(s):  
Vibration Control ◽  
Feedforward Control ◽  
Active Vibration Control ◽  
Upstream Region ◽  
Control Force ◽  
Feedback Controllers ◽  
Axially Moving String ◽  
Downstream Region ◽  
Active Vibration ◽  
Axially Moving

Active vibration control of an axially moving string using space feedforward and feedback controllers is presented. Closed-form results for the transverse response of both the uncontrolled and controlled string are given in the s domain. The space feedforward controller is established by employing the idea of wave cancellation. The proposed control law indicates that vibration in the region downstream of the control force can be cancelled. With the space feedforward control, the mode shapes of the axially moving string are changed such that the free response tends to zero in the downstream region. An interesting physical interpretation is that the control force acts effectively as a holder (active support) which limits the vibration of the string to the upstream region and eliminates any vibration in the downstream region. Simulation results show that the response of the string to both sinusoidal and random excitations is suppressed by applying the space feedforward control. The feedback controller is introduced to attenuate the response of the string due to undesired disturbances in the downstream.

scholarly journals Cellular IOT using nRF9160kit

2020 ◽  
Vol 16 (15) ◽  
pp. 34
Author(s):  
Arvind Vishnubhatla
Keyword(s):  
Power Efficiency ◽  
Low Cost ◽  
Wind Farms ◽  
Global Market ◽  
System Capacity ◽  
Battery Life ◽  
Automated Driving ◽  
Efficient Manner ◽  
Power Efficient ◽  
Small Form Factor

The current vision of internet of things aims at connecting anything with everything. It is estimated that there will be 18 billion connected devices in 2022. Applications   like utility meters, robotics, smart street lighting, process automation, solar and wind farms are expected to grow. High end requirements for automated driving, industrial automation and e-health exist. Cellular IOT is expected to bring new use cases to address latest requirements in the market. There is a need to provide large coverage in a power efficient manner while providing a high battery life. There is a need to have a kit which connects seamlessly and has a small form factor. The requirements on latency and throughput are relaxed in some cases while stringent in others. Stringent requirements make use of more radio resources. There is increased demand for system capacity and network availability. In this paper we make use of nRF9160 kit a low-cost device where a reduction in the cost and complexity has been achieved. The performance objectives of coverage, throughput, latency, capacity, power efficiency and complexity are met. This kit provides a reliable and future proof solution in the long term. The kit is built for the global market and allows roaming over multiple networks.

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