Shaking-Table Control by Real-Time Compensation of the Reaction Force Caused by a Nonlinear Specimen

2004 ◽  
Vol 126 (1) ◽  
pp. 122-127 ◽  
Author(s):  
Yoshihiro Dozono ◽  
Toshihiko Horiuchi ◽  
Hideo Katsumata ◽  
Takao Konno
Keyword(s):  
Real Time ◽  
Control Method ◽  
Reaction Force ◽  
Shaking Table ◽  
Transfer Characteristics ◽  
Series Of Experiments ◽  
The Difference ◽  
Do So

An improved shaking-table control method has been developed. This method compensates the reaction force caused by a nonlinear specimen in real time, and thus maintains a desired table acceleration. To do so, it identifies the difference between the desired and the actual transfer characteristics of the shaking table, then compensates for the difference. Because the required time for this combination of identification and compensation is less than one second, the method can compensate, in real time, for the disturbance caused by a nonlinear specimen. By means of a series of experiments, it is confirmed that the method can maintain a desired table acceleration even when a nonlinear specimen is under excitation.

scholarly journals Mixed Sensitivity-Based Robust H∞ Control Method for Real-Time Hybrid Simulation

Symmetry ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 840
Author(s):  
Xizhan Ning
Keyword(s):  
Real Time ◽  
Control Method ◽  
Weighting Function ◽  
Hybrid Simulation ◽  
Shaking Table ◽  
Transfer System ◽  
Hydraulic Actuator ◽  
Earthquake Excitation ◽  
Engineering Structures ◽  
Weighting Functions

Real-time hybrid simulation (RTHS), dividing the emulated structure into numerical substructures (NS) and physical substructures (PS), is a powerful technique to obtain responses and then to assess the seismic performance of civil engineering structures. A transfer system, a servo-hydraulic actuator or shaking table, is used to apply boundary conditions between the two substructures. However, the servo-hydraulic actuator is inherently a complex system with nonlinearities and may introduce time delays into the RTHS, which will decrease the accuracy and stability of the RTHS. Moreover, there are various uncertainties in RTHS. An accurate and robust actuator control strategy is necessary to guarantee reliable simulation results. Therefore, a mixed sensitivity-based H∞ control method was proposed for RTHS. In H∞ control, the dynamics and robustness of the closed-loop transfer system are realized by performance weighting functions. A form of weighting function was given considering the requirement in RTHS. The influence of the weighting functions on the dynamics was investigated. Numerical simulations and actual RTHSs were carried out under symmetric and asymmetric dynamic loads, namely sinusoidal and earthquake excitation, respectively. Results indicated that the H∞ control method used for RTHS is feasible, and it exhibits an excellent tracking performance and robustness.

Shaking table control via real-time inversion of hydraulic servoactuator linear state-space model

2021 ◽  
pp. 095965182110072
Author(s):  
José Ramírez-Senent ◽  
Jaime H García-Palacios ◽  
Iván M Díaz
Keyword(s):  
State Space ◽  
Real Time ◽  
Feedback Linearization ◽  
Control Method ◽  
State Space Model ◽  
Shaking Table ◽  
Time Inversion ◽  
Space Model ◽  
Control Command ◽  
Linear State

In this work, a Model-Based Control method for a single horizontal degree of freedom shaking table is presented. The proposed approach relies on the real-time inversion of a previously identified linear state-space model of the hydraulic servoactuator which drives the table. The inputs to the model are the control command and the force exerted on servoactuator rod. The latter contains all the relevant information related to the external actions acting on the servoactuator, thus making control system performance independent from the specimen with which the table is loaded and enabling it to cope with specimen non-linear behavior and eventual external forces exerted on it. A parallel proportional integral derivative controller, which accounts for non-modeled dynamics and a feedback linearization scheme, aimed at minimizing servovalve flow non-linearity, complement the previous architecture. The effectiveness of the method has been assessed numerically. According to the simulation results, the performance of the proposed technique appears quite promising; however, several factors must be carefully considered to achieve successful actual implementation.

Chaotic Systems Based Real-Time Implementation of Visual Cryptography Using LabVIEW

2020 ◽  
Vol 37 (4) ◽  
pp. 639-645
Author(s):  
Gülden Günay Bulut ◽  
Mehmet Cem Çatalbaş ◽  
Hasan Güler
Keyword(s):  
Real Time ◽  
Secure Communication ◽  
Chaotic Systems ◽  
Control Method ◽  
Visual Cryptography ◽  
Real Time Simulation ◽  
The Real ◽  
Time Simulation ◽  
The Difference ◽  
Different Chaotic Systems

In recent years, chaotic systems have begun to take a substantial place in literature due to increasing importance of secure communication. Chaotic synchronization which has emerged as a necessity for secure communication can now be performed with many different methods. This study purposes the Master-Slave synchronization via active controller and real time simulation of five different chaotic systems such as Lorenz, Sprott, Rucklidge, Moore-Spiegel, Rössler. Master slave synchronization was performed because of synchronization realized between the same type of chaotic systems with different initial parameters and also because of the systems were expected to behave similarly as a result of synchronization. Active control method was used to amplify the difference signal between master and slave systems which have different initial parameters and to return back synchronization information to the slave system. The real time simulation and synchronization of the master and slave systems performed successfully in LabVIEW environment. Furthermore, for the real time implementation, analogue outputs of NI-DAQ card used and real time results also were observed on an oscilloscope and secure communication application using sinusoidal signal and an image encryption application achieved successfully.

Improvement in Shaking-Table Control Performance by Real-Time Compensation of Reaction Force Caused by a Specimen

2007 ◽  
Vol 2 (2) ◽  
pp. 327-334
Author(s):  
Yoshihiro DOZONO ◽  
Toshihiko HORIUCHI ◽  
Hideo KATSUMATA ◽  
Takao KONNO
Keyword(s):  
Real Time ◽  
Reaction Force ◽  
Shaking Table ◽  
Control Performance

Adjectives and their keyness: a corpus-based analysis of tourism discourse in English

Corpora ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. 351-378 ◽  
Author(s):  
Isabel Durán-Muñoz
Keyword(s):  
Domain Specific ◽  
Adventure Tourism ◽  
Frequency Of Use ◽  
Relevant Reference ◽  
The Difference ◽  
Do So

This paper attempts to shed some light on the importance of adjectives in the linguistic characterisation of tourism discourse in English in general and in adventure tourism in particular as well as to prove how significant the difference in usage is compared to the general language. It seeks to understand the role that adjectives play in this specific subdomain and to contribute to the linguistic characterisation of tourism discourse in this respect. It also aims to confirm or reject previous assumptions regarding the use, and frequency of use, of adjectives and adjectival patterns in this specialised domain and, in general, to promote the study of adjectivisation in domain-specific discourses. To do so, it proposes a corpus-based study that measures the keyness of adjectives in promotional texts of the adventure tourism domain in English by comparing their usage in the compiled corpus to the two most relevant reference corpora of English (coca and the bnc).

Control of coagulation process by dual wavelength article analyzer

1997 ◽  
Vol 36 (4) ◽  
pp. 135-142 ◽  
Author(s):  
Norihito Tambo ◽  
Yoshihiko Matsui ◽  
Ken-ichi Kurotani ◽  
Masakazu Kubota ◽  
Hirohide Akiyama ◽  
...  
Keyword(s):  
Water Quality ◽  
Control System ◽  
Predictive Control ◽  
Control Method ◽  
Feedforward Control ◽  
Raw Water ◽  
Floc Size ◽  
Coagulation Process ◽  
Series Of Experiments ◽  
Size Data

A coagulation process for water purification plants mainly uses feedforward control based on raw water quality and empirical data and requires operator's help. We developed a new floc sensor for measuring floc size in a flush mixer to be used for floc control. A control system using model predictive control was developed on the floc size data. A series of experiments was performed to confirm controllability of settled water quality by controlling flush mixer floc size. An automatic control with feedback from the coagulation process was evaluated as practical and reliable. Finally this new control method was applied for actual plant and evaluated as practical.

scholarly journals ‘Youthification’ of drama through real-time storytelling: A production study of blank and the legacy of SKAM

2021 ◽  
Vol 16 (2) ◽  
pp. 145-162
Author(s):  
Vilde Schanke Sundet
Keyword(s):  
Real Time ◽  
Public Service ◽  
Production Study ◽  
Do So

This article explores the ‘youthification’ of television through real-time storytelling. It draws on a study of the online youth drama blank (2018–2019), NRK’s first follow-up after the hit show SKAM (2015–2017). It finds that real-time drama brings unique opportunities to broadcasters aiming to reconnect with younger audiences, but also substantial challenges. This insight is essential, as previous studies have highlighted the format’s advantages while downplaying its problems and dilemmas. Furthermore, the article emphasises the continuous need for innovation in youth storytelling, especially at public service broadcasters with the mandate and ability to do so.

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