Research of Magnetic Grid Rail Splicing Technology Based on Phase Difference Detection Method

2013 ◽  
Vol 278-280 ◽  
pp. 905-914
Author(s):  
Wen Tao Gu ◽  
Shao Kun Lei ◽  
Fang Li ◽  
Shao Wei Zhou
Keyword(s):  
Real Time ◽  
Phase Difference ◽  
Detection Algorithm ◽  
Initial Position ◽  
Signal Frequency ◽  
Simulation Test ◽  
Signal Phase ◽  
Difference Detection ◽  
Phase Errors ◽  
New Type

To meet the high real-time performance and high accuracy requirements of signal detection in the rail splicing process, this paper proposes a new type of magnetic grid rail splicing method based on accurately zeroing output signal phase difference of two magnetic grid reading heads, thus establishing two reading heads “shift” rules. The accurate zero setting technology of phase difference is based on Nuttall window algorithm, which doesn’t need to give the exact signal frequency beforehand and sample periodically, and can effectively eliminate phase errors. So this algorithm is suitable for detecting signal phase difference when reading heads go over buff joints with any speed at any initial position. Additionally, simulation test and experimental verification were performed on this detection algorithm and “shift” rules. The results show that, the method mentioned in this paper can real-time detect the phase difference by “shift” rules, when reading heads go over buff joints with any speed or any acceleration.

The Analysis and Correction of Time-Delay in the Precise Acoustic Measurement System

2013 ◽  
Vol 333-335 ◽  
pp. 236-242
Author(s):  
Zhi Gang Huang ◽  
Chun Jie Qiao ◽  
Chao Ma ◽  
Shen Zhao
Keyword(s):  
Time Delay ◽  
Phase Difference ◽  
Measurement System ◽  
Group Delay ◽  
Phase Delay ◽  
Signal Frequency ◽  
Acoustic Measurement ◽  
Signal Phase ◽  
Acoustic Transducer ◽  
Good Consistency

The acoustic transducer is a nonlinear system, which will cause a time delay to signals. The system group and phase delay have a large influence on the results in the transmit-time measurement. In order to solve the problem, this paper proposes to use the signal phase difference to eliminate the phase delay, and precisely determine the group delay by the method of experiment. At first, this paper theoretically proves that the group delay of the acoustic measurement system is constant, and the phase delay changes over signal frequency, then it analyzes the influence of group and phase delay on the measuring results and meanwhile puts forward a method to use the multi-frequency signal phase difference to eliminate group delay .Finally, it achieves the group delay through experiments, and there is a good consistency between the experimental results and theoretical analysis.

scholarly journals Real-time 2D–3D door detection and state classification on a low-power device

2021 ◽  
Vol 3 (5) ◽  
Author(s):  
João Gaspar Ramôa ◽  
Vasco Lopes ◽  
Luís A. Alexandre ◽  
S. Mogo
Keyword(s):  
Low Power ◽  
Real Time ◽  
Object Classification ◽  
Semantic Segmentation ◽  
Detection Algorithm ◽  
Power Device ◽  
Indoor Environments ◽  
State Classification ◽  
Segmentation Algorithms ◽  
Indoor Spaces

AbstractIn this paper, we propose three methods for door state classification with the goal to improve robot navigation in indoor spaces. These methods were also developed to be used in other areas and applications since they are not limited to door detection as other related works are. Our methods work offline, in low-powered computers as the Jetson Nano, in real-time with the ability to differentiate between open, closed and semi-open doors. We use the 3D object classification, PointNet, real-time semantic segmentation algorithms such as, FastFCN, FC-HarDNet, SegNet and BiSeNet, the object detection algorithm, DetectNet and 2D object classification networks, AlexNet and GoogleNet. We built a 3D and RGB door dataset with images from several indoor environments using a 3D Realsense camera D435. This dataset is freely available online. All methods are analysed taking into account their accuracy and the speed of the algorithm in a low powered computer. We conclude that it is possible to have a door classification algorithm running in real-time on a low-power device.

A New Method for Phase Difference Estimation Based on Time-Varying Signal Model

2013 ◽  
Vol 333-335 ◽  
pp. 650-655
Author(s):  
Peng Hui Niu ◽  
Yin Lei Qin ◽  
Shun Ping Qu ◽  
Yang Lou
Keyword(s):  
Signal Processing ◽  
Real Time ◽  
Phase Difference ◽  
Time Signal ◽  
Time Interval ◽  
Time Varying ◽  
Signal Model ◽  
Time Frequency ◽  
Mass Flowmeter ◽  
Coriolis Mass Flowmeter

A new signal processing method for phase difference estimation was proposed based on time-varying signal model, whose frequency, amplitude and phase are time-varying. And then be applied Coriolis mass flowmeter signal. First, a bandpass filtering FIR filter was applied to filter the sensor output signal in order to improve SNR. Then, the signal frequency could be calculated based on short-time frequency estimation. Finally, by short window intercepting, the DTFT algorithm with negative frequency contribution was introduced to calculate the real-time phase difference between two enhanced signals. With the frequency and the phase difference obtained, the time interval of two signals was calculated. Simulation results show that the algorithms studied are efficient. Furthermore, the computation of algorithms studied is simple so that it can be applied to real-time signal processing for Coriolis mass flowmeter.

Voltage Phase Difference Detection for Superconductor Quench

2014 ◽  
Vol 933 ◽  
pp. 82-85
Author(s):  
Shi Feng Wang ◽  
Yi Xiang Yue ◽  
Jin Fang
Keyword(s):  
Phase Difference ◽  
Detection Method ◽  
Phase Detection ◽  
Test Results ◽  
Development Platform ◽  
Advantages And Disadvantages ◽  
Difference Detection ◽  
Protection Systems ◽  
Actual Operation ◽  
Voltage Phase

In this paper, the actual operation of the superconducting motor and electrical parameters, a detailed analysis of the advantages and disadvantages of the existing quench detection method. After that I proposed an innovative detection method - voltage phase difference detection. On this basis, the design phase detection method based on the voltage difference quench detection and protection systems, based on stand-alone test and NI development platform test results, we verify its feasibility of the voltage phase difference detection method, and great superiority.

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