RTCONTACT: An Efficient Wheel-Rail Contact Algorithm for Real-Time Dynamic Simulations

2012 ◽  
Author(s):  
N. Bosso ◽  
A. Gugliotta ◽  
N. Zampieri
Keyword(s):  
Real Time ◽  
Computational Efficiency ◽  
Simulation Models ◽  
Experimental Tests ◽  
Contact Forces ◽  
Dynamic Simulations ◽  
Time Dynamic ◽  
Contact Algorithm ◽  
Complex Simulation ◽  
Precise Representation

Determination of contact forces exchanged between wheel and rail is one of the most important topics in railway dynamics. Recent studies are oriented to improve the existing contact methods in terms of computational efficiency on one side and on the other side to develop more complex and precise representation of the contact problem. This work shows some new results of the contact code developed at Politecnico di Torino identified as RTCONTACT; this code, which is an improvement of the CONPOL algorithm, is the result of long term activities, early versions were used in conjunction with MBS codes or in Matlab® environment to simulate vehicle behaviour. The code has been improved also using experimental tests performed on a scaled roller-rig. More recently the contact model was improved in order to obtain a higher computational efficiency that is a required for the use inside of a Real Time process. Benefit of a Real Time contact algorithm is the possibility to use complex simulation models in diagnostic or control systems in order to improve their performances. This work shows several comparisons of the RTCONTACT contact code respect commercial codes, standards and benchmark results.

Real-time control strategies for predenitrification - nitrification activated sludge plants biodegradation control

2001 ◽  
Vol 43 (1) ◽  
pp. 209-216 ◽  
Author(s):  
J. Suescun ◽  
X. Ostolaza ◽  
M. Garcia-Sanz ◽  
E. Ayesa
Keyword(s):  
Real Time ◽  
Pilot Plant ◽  
Control Strategies ◽  
Average Concentration ◽  
Real Time Control ◽  
Dynamic Simulations ◽  
Set Point ◽  
The Real ◽  
Time Dynamic ◽  
Time Control

This paper presents the real-time control strategies developed to regulate both the ammonia and nitrate concentration in the effluent of the new Vitoria WWTP (Spain). Nitrate control aims at the optimal use of the denitrification potential at any moment. For this purpose, the proposed control algorithm continuously adapts the internal recycle flow in order to maintain a desired nitrate set-point in the anoxic zone. Ammonia control aims at maintaining the required average concentration of ammonia in the effluent by manipulating the Dissolved Oxygen (DO) set-point. The control strategies have been based on a hierarchical structure where a high-level or supervisory control selects the set-point of the low-level or conventional controllers. The design of the controllers was carried out using the Quantitative Feedback Theory QFT for the design of robust control systems. Moving average values of some variables have been introduced in order to eliminate the perturbations associated with the daily 24-hour profiles. The controllers have been verified using long-time dynamic simulations based on a mathematical model previously calibrated in pilot plant. Influent load and temperature used in the simulations correspond to the real values measured in the full-scale WWTP during 12 months. The results obtained in the simulations show the good performance and stability of the control strategies independently from external disturbances. A short-time experimental verification of the controllers in pilot plant with real wastewater is also presented.

scholarly journals Analysis of a Smart Sensor Based Solution for Smart Grids Real-Time Dynamic Thermal Line Rating

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7388
Author(s):  
Yuming Liu ◽  
Jordi-Roger Riba ◽  
Manuel Moreno-Eguilaz ◽  
Josep Sanllehí
Keyword(s):  
Wind Speed ◽  
Real Time ◽  
Smart Grids ◽  
Experimental Tests ◽  
Power Lines ◽  
Smart Sensor ◽  
Time Dynamic ◽  
Weather Stations ◽  
Thermal Line ◽  
Maximum Transmission

Dynamic thermal line rating (DTLR) allows us to take advantage of the maximum transmission capacity of power lines, which is an imperious need for future smart grids. This paper proposes a real-time method to determine the DTLR rating of aluminum conductor steel-reinforced (ACSR) conductors. The proposed approach requires a thermal model of the line to determine the real-time values of the solar radiation and the ambient temperature, which can be obtained from weather stations placed near the analyzed conductors as well as the temperature and the current of the conductor, which can be measured directly with a Smartconductor and can be transmitted wirelessly to a nearby gateway. Real-time weather and overhead line data monitoring and the calculation of DTLR ratings based on models of the power line is a practical smart grid application. Since it is known that the wind speed exhibits important fluctuations, even in nearby areas, and since it plays a key role in determining the DTLR, it is essential to accurately estimate this parameter at the conductor’s location. This paper presents a method to estimate the wind speed and the DTLR rating of the analyzed conductor. Experimental tests have been conducted to validate the accuracy of the proposed approach using ACSR conductors.

scholarly journals Real-time dynamic substructuring in a coupled oscillator–pendulum system

2006 ◽  
Vol 462 (2068) ◽  
pp. 1271-1294 ◽  
Author(s):  
Y.N Kyrychko ◽  
K.B Blyuss ◽  
A Gonzalez-Buelga ◽  
S.J Hogan ◽  
D.J Wagg
Keyword(s):  
Real Time ◽  
Experimental Tests ◽  
Quantitative Agreement ◽  
Physical Structure ◽  
Transfer System ◽  
Neutral Delay ◽  
Pendulum System ◽  
Time Dynamic ◽  
Dynamic Substructuring ◽  
Delay Differential

Real-time dynamic substructuring is a powerful testing method, which brings together analytical, numerical and experimental tools for the study of complex structures. It consists of replacing one part of the structure with a numerical model, which is connected to the remainder of the physical structure (the substructure) by a transfer system. In order to provide reliable results, this hybrid system must remain stable during the whole test. A primary mechanism for destabilization of these type of systems is the delays which are naturally present in the transfer system. In this paper, we apply the dynamic substructuring technique to a nonlinear system consisting of a pendulum attached to a mechanical oscillator. The oscillator is modelled numerically and the transfer system is an actuator. The system dynamics is governed by two coupled second-order neutral delay differential equations. We carry out local and global stability analyses of the system and identify the delay dependent stability boundaries for this type of system. We then perform a series of hybrid experimental tests for a pendulum–oscillator system. The results give excellent qualitative and quantitative agreement when compared to the analytical stability results.

scholarly journals Modelling real-time dynamic substructuring using partial delay differential equations

2007 ◽  
Vol 463 (2082) ◽  
pp. 1509-1523 ◽  
Author(s):  
Y.N Kyrychko ◽  
S.J Hogan ◽  
A Gonzalez-Buelga ◽  
D.J Wagg
Keyword(s):  
Real Time ◽  
Virtual Environment ◽  
Experimental Tests ◽  
Beam Equation ◽  
Real Time Control ◽  
Oscillator System ◽  
Time Dynamic ◽  
Time Control ◽  
Dynamic Substructuring ◽  
Delay Differential

Real-time dynamic substructuring is a new component testing method for simulating the dynamics of complex engineering systems. The physical component is tested within a computer-generated ‘virtual’ environment using real-time control techniques. Delays in communication which occur between the component and the virtual environment can potentially destabilize the simulation. In this paper, the mechanism for this instability is examined using a beam-oscillator system as a case study. We will show how the stability and the amplitude response of the system change with the time delay. Numerical simulations of the reduced system as well as a full-delayed beam equation are performed. A series of experimental tests is carried out on a beam-oscillator system. Comparison of the theoretical, numerical and experimental results is presented and these agree remarkably well.

Control Model Constructing on Real-Time Dynamic Reversible Lane in Condition of Connected Vehicle

CICTP 2020 ◽  
2020 ◽  
Author(s):  
Lina Mao ◽  
Wenquan Li ◽  
Pengsen Hu ◽  
Guiliang Zhou ◽  
Huiting Zhang ◽  
...  
Keyword(s):  
Real Time ◽  
Control Model ◽  
Connected Vehicle ◽  
Time Dynamic
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