scholarly journals Real-Time Cable Force Calculation beyond the Wrench-Feasible Workspace

Robotics ◽  
2020 ◽  
Vol 9 (2) ◽  
pp. 41 ◽  
Author(s):  
Roland Boumann ◽  
Tobias Bruckmann
Keyword(s):  
Real Time ◽  
Parallel Robot ◽  
The Novel ◽  
Set Point ◽  
Numerical Efficiency ◽  
Cable Force ◽  
Cable Forces ◽  
Special Circumstances ◽  
Force Calculation ◽  
Iterative Structure

Under special circumstances, a cable-driven parallel robot (CDPR) may leave its wrench-feasible-workspace. Standard approaches for the computation of set-point cable forces are likely to fail in this case. The novel nearest corner method for calculating appropriate cable forces when the CDPR is outside of its wrench-feasible-workspace was introduced in former work of the authors. The obtained cable force distributions aim at continuity and generate wrenches close to the desired values. The method employs geometrical operations in the cable force space and promises real-time usability because of its non-iterative structure. In a simplified simulation, a cable break scenario was used to carry out more detailed testing of the method regarding different parameters, a higher number of cables, and the numerical efficiency. A brief discussion about the continuity of the method when entering the wrench-feasible-workspace is presented.

Application of Quadratic Programming Method to Cable Force Calculation of Cable Erection Arch Bridge

2014 ◽  
Vol 587-589 ◽  
pp. 1364-1369
Author(s):  
Cheng Wu ◽  
Jin Yu Liu ◽  
Shui Xing Zhou
Keyword(s):  
Quadratic Programming ◽  
High Precision ◽  
Steel Tube ◽  
Influence Matrix ◽  
Calculation Process ◽  
Cable Force ◽  
Quadratic Programming Method ◽  
Cable Forces ◽  
Force Calculation ◽  
Number Of Iterations

Taking the bare arch deformation under gravity as target alignment, the influence matrix that associates the cable forces with segment deformation is obtained via ANSYS program, and the cable force is quickly calculated by MATLAB quadratic programming toolbox. It is illustrated with an example of Guizhou Zong-xi River Bridge, which is a 360-meter concrete filled steel tube bridge in construction, and the calculation process is given. The results show that, this new method has the advantages of high precision and less number of iterations.

scholarly journals Online Learning Algorithms for the Real-Time Set-Point Tracking Problem

2021 ◽  
Vol 11 (14) ◽  
pp. 6620
Author(s):  
Arman Alahyari ◽  
David Pozo ◽  
Meisam Farrokhifar
Keyword(s):  
Decision Making ◽  
Power Systems ◽  
Real Time ◽  
Demand Response ◽  
Tracking Problem ◽  
Smart Meters ◽  
Set Point ◽  
Point Tracking ◽  
Power Set ◽  
Decision Making Framework

With the recent advent of technology within the smart grid, many conventional concepts of power systems have undergone drastic changes. Owing to technological developments, even small customers can monitor their energy consumption and schedule household applications with the utilization of smart meters and mobile devices. In this paper, we address the power set-point tracking problem for an aggregator that participates in a real-time ancillary program. Fast communication of data and control signal is possible, and the end-user side can exploit the provided signals through demand response programs benefiting both customers and the power grid. However, the existing optimization approaches rely on heavy computation and future parameter predictions, making them ineffective regarding real-time decision-making. As an alternative to the fixed control rules and offline optimization models, we propose the use of an online optimization decision-making framework for the power set-point tracking problem. For the introduced decision-making framework, two types of online algorithms are investigated with and without projections. The former is based on the standard online gradient descent (OGD) algorithm, while the latter is based on the Online Frank–Wolfe (OFW) algorithm. The results demonstrated that both algorithms could achieve sub-linear regret where the OGD approach reached approximately 2.4-times lower average losses. However, the OFW-based demand response algorithm performed up to twenty-nine percent faster when the number of loads increased for each round of optimization.

scholarly journals Implementation and intelligent gain tuning feedback–based optimal torque control of a rotary parallel robot

2021 ◽  
pp. 107754632110191
Author(s):  
Farzam Tajdari ◽  
Naeim Ebrahimi Toulkani
Keyword(s):  
Real Time ◽  
Tracking Error ◽  
Parallel Robot ◽  
Torque Control ◽  
Test Bed ◽  
Linear Quadratic ◽  
Control Effort ◽  
The Real ◽  
Unknown Disturbances ◽  
Quadratic Integral

Aiming at operating optimally minimizing error of tracking and designing control effort, this study presents a novel generalizable methodology of an optimal torque control for a 6-degree-of-freedom Stewart platform with rotary actuators. In the proposed approach, a linear quadratic integral regulator with the least sensitivity to controller parameter choices is designed, associated with an online artificial neural network gain tuning. The nonlinear system is implemented in ADAMS, and the controller is formulated in MATLAB to minimize the real-time tracking error robustly. To validate the controller performance, MATLAB and ADAMS are linked together and the performance of the controller on the simulated system is validated as real time. Practically, the Stewart robot is fabricated and the proposed controller is implemented. The method is assessed by simulation experiments, exhibiting the viability of the developed methodology and highlighting an improvement of 45% averagely, from the optimum and zero-error convergence points of view. Consequently, the experiment results allow demonstrating the robustness of the controller method, in the presence of the motor torque saturation, the uncertainties, and unknown disturbances such as intrinsic properties of the real test bed.

A Design of a Monitoring Expert System of Flight Parameter

2013 ◽  
Vol 791-793 ◽  
pp. 874-877
Author(s):  
Yan Song Zhang ◽  
Hui Feng Zhang ◽  
Wei Ye ◽  
Chao Jiang Wang ◽  
Zhen Dong Xu
Keyword(s):  
Expert System ◽  
Real Time ◽  
Flight Test ◽  
Information Control ◽  
Digital Information ◽  
Video Information ◽  
Test Technology ◽  
Flight Controls ◽  
Flight Parameters ◽  
Special Circumstances

In order to meet the trend for flight test technology, this paper presents a monitoring expert system of flight parameters based on embedded technology , which can achieve real-time interpretation of flight data air and provide the parameters for the AHRS, engines, flight controls for aircraft crew members as well as the disposal of the special circumstances operating. It can be used for real-time collection and record a variety of digital information, control information and video information transmitting by the missiles and fiber during the fly testing process.

scholarly journals Increased Delay Discounting on a Novel Real-Time Task among Girls, but not Boys, with ADHD

2015 ◽  
Vol 22 (1) ◽  
pp. 12-23 ◽  
Author(s):  
Keri S. Rosch ◽  
Stewart H. Mostofsky
Keyword(s):  
Real Time ◽  
Delay Discounting ◽  
Diagnostic Group ◽  
Group Differences ◽  
The Novel ◽  
Typically Developing ◽  
Subjective Ratings ◽  
Time Discounting ◽  
Children With Adhd ◽  
Girls With Adhd

AbstractThe aim of this study was to examine delay discounting in girls and boys with ADHD-Combined type (ADHD-C) relative to typically developing (TD) children on two tasks that differ in the extent to which the rewards and delays were experienced by participants. Children ages 8–12 years with ADHD-C (n=65; 19 girls) and TD controls (n=55; 15 girls) completed two delay discounting tasks involving a series of choices between smaller, immediate and larger, delayed rewards. The classic delay discounting task involved choices about money at delays of 1–90 days and only some of the outcomes were actually experienced by the participants. The novel real-time discounting task involved choices about an immediately consumable reward (playing a preferred game) at delays of 25–100 s, all of which were actually experienced by participants. Participants also provided subjective ratings of how much they liked playing the game and waiting to play. Girls with ADHD-C displayed greater delay discounting compared to boys with ADHD-C and TD girls and boys on the real-time discounting task. Diagnostic group differences were not evident on the classic discounting task. In addition, children with ADHD-C reported wanting to play the game more and liking waiting to play the game less than TD children. This novel demonstration of greater delay discounting among girls with ADHD-C on a discounting task in which the rewards are immediately consumable and the delays are experienced in real-time informs our understanding of sex differences and motivational processes in children with ADHD. (JINS, 2016, 22, 12–23)

scholarly journals Shaping Streamflow Using a Real-Time Stormwater Control Network

Sensors ◽  
2018 ◽  
Vol 18 (7) ◽  
pp. 2259 ◽  
Author(s):  
Abhiram Mullapudi ◽  
Matthew Bartos ◽  
Brandon Wong ◽  
Branko Kerkez
Keyword(s):  
Real Time ◽  
Control Strategies ◽  
Low Cost ◽  
Control Network ◽  
Monitoring And Control ◽  
Set Point ◽  
Smart Water ◽  
Decay Times ◽  
Retention Basins ◽  
Scale Control

“Smart” water systems are transforming the field of stormwater management by enabling real-time monitoring and control of previously static infrastructure. While the localized benefits of active control are well-established, the potential for system-scale control of watersheds is poorly understood. This study shows how a real-world smart stormwater system can be leveraged to shape streamflow within an urban watershed. Specifically, we coordinate releases from two internet-controlled stormwater basins to achieve desired control objectives downstream—such as maintaining the flow at a set-point, and generating interleaved waves. In the first part of the study, we describe the construction of the control network using a low-cost, open-source hardware stack and a cloud-based controller scheduling application. Next, we characterize the system’s control capabilities by determining the travel times, decay times, and magnitudes of various waves released from the upstream retention basins. With this characterization in hand, we use the system to generate two desired responses at a critical downstream junction. First, we generate a set-point hydrograph, in which flow is maintained at an approximately constant rate. Next, we generate a series of overlapping and interleaved waves using timed releases from both retention basins. We discuss how these control strategies can be used to stabilize flows, thereby mitigating streambed erosion and reducing contaminant loads into downstream waterbodies.

Quantitative real-time RT-PCR data analysis: current concepts and the novel “gene expression’s C T difference” formula

2006 ◽  
Vol 84 (11) ◽  
pp. 901-910 ◽  
Author(s):  
Jan H. Schefe ◽  
Kerstin E. Lehmann ◽  
Ivo R. Buschmann ◽  
Thomas Unger ◽  
Heiko Funke-Kaiser
Keyword(s):  
Data Analysis ◽  
Real Time ◽  
The Novel ◽  
Rt Pcr ◽  
Novel Gene ◽  
Difference Formula
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