scholarly journals 3D Analysis of Low-Voltage Gas-Filled DC Switch Using Simplified Arc Model

2019 ◽  
Vol 6 (1) ◽  
pp. 65-68 ◽  
Author(s):  
S. Gortschakow ◽  
D. Gonzalez ◽  
S. Yu ◽  
F. Werner
Keyword(s):  
High Speed ◽  
Low Voltage ◽  
Black Box ◽  
Optical Observations ◽  
3D Analysis ◽  
High Speed Camera ◽  
Plasma Model ◽  
Arc Model ◽  
Arc Current ◽  
Electro Magnetic

Electro-magnetic simulations have been used for the visualization of distribution of Lorentz force acting on a DC switching arc in low-voltage contactor. A simplified plasma model (black-box model) was applied for the description of arc conductivity. Arc geometry was gained from the high-speed camera images. Influence of arc position, arc current and of external magnetic field has been studied. Results have been compared with optical observations of the arc dynamics.

scholarly journals Stability, spatial extension and extinction of an electric arc in aeronautical conditions of pressure under 540 V DC

2019 ◽  
Vol 87 (3) ◽  
pp. 30901
Author(s):  
Romaric Landfried ◽  
Mohamed Boukhlifa ◽  
Thierry Leblanc ◽  
Philippe Teste ◽  
Jonathan Andrea
Keyword(s):  
High Speed ◽  
Electric Arc ◽  
High Speed Camera ◽  
Arc Length ◽  
Electrode Gap ◽  
Arc Current ◽  
The Mean ◽  
The Stability ◽  
Energy Dissipated

This work deals with the characterization of DC electric arcs in aeronautical conditions of pressure (from 104 Pa to 105 Pa). Observations have been made with the help of a high speed camera and various characteristics of electric arc under 540 V DC have been studied: the stability arc length, the extinction gap, the arc duration and the mean energy dissipated in the arc. The arc current intensity range is 10–100 A. The obtained results show that the arc stability length, extinction electrode gap, arc duration and energy dissipation in the arc have a direct correlation with the pressure and the current in the circuit.

scholarly journals Experimental Studies of Arc Motion Between Two Parallel Runners with Splitter Plates

2020 ◽  
Vol 7 (1) ◽  
pp. 16-20
Author(s):  
J. Lu ◽  
J.-J. Gonzalez ◽  
P. Freton ◽  
M. Benmouffok ◽  
P. Fort ◽  
...  
Keyword(s):  
High Speed ◽  
Low Voltage ◽  
Voltage Drop ◽  
Circuit Breaker ◽  
Experimental Studies ◽  
Experimental Setup ◽  
High Speed Camera ◽  
Electrical Measurements ◽  
Arc Voltage ◽  
Splitter Plates

In this paper, we present an experimental study in a simplified arc chamber geometry of Low-Voltage Circuit Breaker (LVCB). The influence of vent aperture on arc motion and the influence of splitter plates on arc voltage drop and arc motion are studied. The arc chamber is composed by two parallel arc runners and following the configuration chosen by one or two splitter plates. The experimental setup is completed by a generator (capacitor bench with triggered switch), a high-speed camera and electrical measurements. The arc ignition, arc displacement, arc splitting and arc re-strike have been observed. The results will be described and discussed for different experimental configurations.

scholarly journals Multi-fidelity black-box optimization for time-optimal quadrotor maneuvers

2021 ◽  
pp. 027836492110333
Author(s):  
Gilhyun Ryou ◽  
Ezra Tal ◽  
Sertac Karaman
Keyword(s):  
Real World ◽  
High Speed ◽  
Analytical Approximation ◽  
Black Box ◽  
Bayesian Optimization ◽  
Optimization Framework ◽  
Quadrotor Aircraft ◽  
Time Optimal ◽  
Feasibility Constraints ◽  
Generation Problem

We consider the problem of generating a time-optimal quadrotor trajectory for highly maneuverable vehicles, such as quadrotor aircraft. The problem is challenging because the optimal trajectory is located on the boundary of the set of dynamically feasible trajectories. This boundary is hard to model as it involves limitations of the entire system, including complex aerodynamic and electromechanical phenomena, in agile high-speed flight. In this work, we propose a multi-fidelity Bayesian optimization framework that models the feasibility constraints based on analytical approximation, numerical simulation, and real-world flight experiments. By combining evaluations at different fidelities, trajectory time is optimized while the number of costly flight experiments is kept to a minimum. The algorithm is thoroughly evaluated for the trajectory generation problem in two different scenarios: (1) connecting predetermined waypoints; (2) planning in obstacle-rich environments. For each scenario, we conduct both simulation and real-world flight experiments at speeds up to 11 m/s. Resulting trajectories were found to be significantly faster than those obtained through minimum-snap trajectory planning.

scholarly journals Asymmetric Ge/SiGe coupled quantum well modulators

Nanophotonics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1765-1773
Author(s):  
Yi Zhang ◽  
Jianfeng Gao ◽  
Senbiao Qin ◽  
Ming Cheng ◽  
Kang Wang ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Quantum Well ◽  
Quantum Wells ◽  
High Speed ◽  
Low Voltage ◽  
Extinction Ratio ◽  
High Frequency Response ◽  
Modulation Format ◽  
Silicon Photonic ◽  
Coupled Quantum Well

Abstract We design and demonstrate an asymmetric Ge/SiGe coupled quantum well (CQW) waveguide modulator for both intensity and phase modulation with a low bias voltage in silicon photonic integration. The asymmetric CQWs consisting of two quantum wells with different widths are employed as the active region to enhance the electro-optical characteristics of the device by controlling the coupling of the wave functions. The fabricated device can realize 5 dB extinction ratio at 1446 nm and 1.4 × 10−3 electrorefractive index variation at 1530 nm with the associated modulation efficiency V π L π of 0.055 V cm under 1 V reverse bias. The 3 dB bandwidth for high frequency response is 27 GHz under 1 V bias and the energy consumption per bit is less than 100 fJ/bit. The proposed device offers a pathway towards a low voltage, low energy consumption, high speed and compact modulator for silicon photonic integrated devices, as well as opens possibilities for achieving advanced modulation format in a more compact and simple frame.

scholarly journals Tracking by Deblatting

2021 ◽  
Author(s):  
Denys Rozumnyi ◽  
Jan Kotera ◽  
Filip Šroubek ◽  
Jiří Matas
Keyword(s):  
High Speed ◽  
High Performance ◽  
Motion Blur ◽  
Velocity Estimation ◽  
High Speed Camera ◽  
Trajectory Function ◽  
Novel Approach ◽  
Blind Deblurring ◽  
Object Trajectories ◽  
Complex Trajectories

AbstractObjects moving at high speed along complex trajectories often appear in videos, especially videos of sports. Such objects travel a considerable distance during exposure time of a single frame, and therefore, their position in the frame is not well defined. They appear as semi-transparent streaks due to the motion blur and cannot be reliably tracked by general trackers. We propose a novel approach called Tracking by Deblatting based on the observation that motion blur is directly related to the intra-frame trajectory of an object. Blur is estimated by solving two intertwined inverse problems, blind deblurring and image matting, which we call deblatting. By postprocessing, non-causal Tracking by Deblatting estimates continuous, complete, and accurate object trajectories for the whole sequence. Tracked objects are precisely localized with higher temporal resolution than by conventional trackers. Energy minimization by dynamic programming is used to detect abrupt changes of motion, called bounces. High-order polynomials are then fitted to smooth trajectory segments between bounces. The output is a continuous trajectory function that assigns location for every real-valued time stamp from zero to the number of frames. The proposed algorithm was evaluated on a newly created dataset of videos from a high-speed camera using a novel Trajectory-IoU metric that generalizes the traditional Intersection over Union and measures the accuracy of the intra-frame trajectory. The proposed method outperforms the baselines both in recall and trajectory accuracy. Additionally, we show that from the trajectory function precise physical calculations are possible, such as radius, gravity, and sub-frame object velocity. Velocity estimation is compared to the high-speed camera measurements and radars. Results show high performance of the proposed method in terms of Trajectory-IoU, recall, and velocity estimation.

Sign in / Sign up

Export Citation Format

Share Document