A New Approach to Water Velocity Estimation and Correction

2009 ◽  
Author(s):  
C. V. Carvill
Keyword(s):  
Water Velocity ◽  
Velocity Estimation ◽  
New Approach ◽  
Estimation And Correction

scholarly journals An Illustrated Guide to Estimation of Water Velocity in Unregulated River for Hydrokinetic Performance Analysis Studies in East Malaysia

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1330
Author(s):  
Almalik Mohd Saupi ◽  
Nashiren Mailah ◽  
Mohd Mohd Radzi ◽  
Kamarul Mohamad ◽  
Saiful Ahmad ◽  
...  
Keyword(s):  
Regression Model ◽  
Water Level ◽  
Rural Areas ◽  
Electrical Energy ◽  
Peninsular Malaysia ◽  
Water Velocity ◽  
Velocity Estimation ◽  
Coefficient Of Determination ◽  
Velocity Data ◽  
Model Equations

Electrification coverage in Sarawak is the lowest at 78.74%, compared to Peninsular Malaysia at 99.62% and Sabah at 82.51%. Kapit, Sarawak, with 88.4% of its population located in rural areas and mostly situated along the main riverbanks, has great potential to generate electrical energy with a hydrokinetic system. Yearly water velocity data is the most significant parameter with which to perform a hydrokinetic analysis study. Nevertheless, the data retrieved from local river databases are inadequate for river energy analysis, thus hindering its progression. Instead, flow rates and rainfall data had been utilized to estimate the water velocity data. Till present, there is still no publication has been found on estimating of water velocity data in unregulated river using water level. Therefore, a novel technique of estimating the daily average water velocity data in unregulated rivers is proposed. The modelling of regression equation for water velocity estimation was performed and two regression model equations were generated to estimate both water level and water velocity on-site and proven to be valid as the coefficient of determination values had been R2 = 87.4% and R2 = 87.9%, respectively. The combination of both regression model equations can be used to estimate long-term time series water velocity data for type-C unregulated river in remote areas.

Velocity Estimation of Motion Systems Based on Low-Resolution Encoders

2012 ◽  
Vol 135 (1) ◽  
Author(s):  
Hongzhong Zhu ◽  
Toshiharu Sugie
Keyword(s):  
Angular Position ◽  
Velocity Estimation ◽  
Position Sensor ◽  
Low Resolution ◽  
New Approach ◽  
Numerical Examples ◽  
Fitting Method ◽  
Sensor Resolution ◽  
Speed Range ◽  
Incremental Encoder

This paper proposes a new approach to estimate the velocity of mechanical system in the case where the optical incremental encoder is used as the position sensor. First, the actual angular position is reconstructed via moving horizon polynomial fitting method by taking account of quantization feature and the plant dynamics. Then, the reconstruction signal is applied to a classical observer to obtain the velocity estimation. Its robustness against the position sensor resolution and the degree of the polynomial is discussed by some numerical examples. Experiments with very low-resolution encoder in low speed range also confirm its effectiveness.

scholarly journals Optical Ortho-Rectification for Image-Based Stream Surface Flow Observations Using a Ground Camera

2021 ◽  
Vol 3 ◽  
Author(s):  
Ryota Tsubaki ◽  
Runye Zhu
Keyword(s):  
Optical System ◽  
Image Acquisition ◽  
Field Measurements ◽  
Surface Flow ◽  
Velocity Estimation ◽  
Image Resolution ◽  
Direction Parallel ◽  
New Approach ◽  
Stream Surface ◽  
Raster Image

Image-based stream flow observation consists of three components: (i) image acquisition, (ii) ortho-rectification, and (iii) an image-based velocity estimation. Ortho-rectification is a type of coordinate transformation. When ortho-rectifying a raster image, pixel interpolation is needed and causes the degradation of image resolution, especially in areas located far from the camera and in the direction parallel to the viewing angle. When measuring the water surface flow of rivers with a wide channel width, reduced and distorted image resolution limits the applicability of image-based flow observations using terrestrial image acquisition. Here, we propose a new approach for ortho-rectification using an optical system. We employed an optical system embedded in an ultra-short throw projector. In the proposed approach, ortho-rectified images were obtained during the image acquisition phase, and the image resolution of recorded images was almost uniform in terms of physical coordinates. By conducting field measurements, characteristics of the proposed approach were validated and compared to a conventional approach.

scholarly journals Hydrokinetic Energy Assessment in Unregulated River for Hydrokinetic Performance Analysis Studies in East Malaysia

2018 ◽  
Author(s):  
Almalik Faisel Mohd Saupi ◽  
Nashiren Farzilah Mailah ◽  
Mohd Amran Mohd Radzi ◽  
Saiful Zuhaimi Ahmad ◽  
Azimi Che Soh
Keyword(s):  
Regression Model ◽  
Water Level ◽  
Rural Areas ◽  
Electrical Energy ◽  
Peninsular Malaysia ◽  
Water Velocity ◽  
Velocity Estimation ◽  
Coefficient Of Determination ◽  
Velocity Data ◽  
Model Equations

Electrification coverage in Sarawak is the lowest at 78.74%, compared to Peninsular Malaysia at 99.62% and Sabah at 82.51%. Kapit, Sarawak with its 88.4% populations located in rural areas and mostly situated along the main riverbanks has great potential to generate electrical energy by hydrokinetic system. Yearly water velocity data is the most significant parameter to perform hydrokinetic analysis study. Nevertheless, the data retrieved from local river databases are inadequate for river energy analysis, thus hindering its progression. Instead, flow rates and rainfall data had been utilised to estimate the water velocity data. This signifies no estimation of water velocity in an unregulated river by using water level data had been made. Therefore, a novel technique of estimating the daily average water velocity data in unregulated rivers is proposed. The modelling of regression equation for water velocity estimation was performed and two regression model equations were generated to estimate both water level and water velocity on-site and proven to be valid as the coefficient of determination values had been R2 = 87.4% and R2=87.9%, respectively. The combination of both regression model equations can be used to estimate long-term time series water velocity data for type-C unregulated river in remote areas.

scholarly journals Comparison of sound velocity estimation and classification methods for ultrasonic testing of cheese

2016 ◽  
Vol 12 (1) ◽  
pp. 51-62
Author(s):  
I. Kertész ◽  
J. Felföldi
Keyword(s):  
Wavelet Decomposition ◽  
Information Criterion ◽  
Velocity Estimation ◽  
Classification Methods ◽  
New Approach ◽  
Linear Discriminant ◽  
Ultrasonic Measurements ◽  
Long Time ◽  
Time Average ◽  
Short Time

Testing of two methods novel to ultrasonic measurements was carried out on cheese samples to estimate the Time-of-Flight (TOF) parameter. The Short Time Average/Long Time Average (STA/LTA) method and the Autoregressive Akaike Information Criterion Picker (AR-AIC picker) method are used mainly in seismology for earthquake event detection. The STA/LTA method proved to be ineffective with such noise level that is present during ultrasonic measurements, but the AIC picker algorithm yielded reliable results. A new approach for classification was tested on two types of samples, those were matching in composition, but different in treatment and texture. The method used is based on the results of wavelet decomposition, and after retrieving sufficient spectral data, a linear discriminant analysis (DA) resulted in 100% correct classification, which was compared to the DA classification results based on other methods.

Increasing interpretation accuracy: A new approach to interval velocity estimation

1988 ◽  
Vol 7 (9) ◽  
pp. 13-16 ◽  
Author(s):  
David Hadley ◽  
Jeff Thorson ◽  
Shannon Maher
Keyword(s):  
Velocity Estimation ◽  
New Approach ◽  
Interval Velocity

Precise Velocity Estimation with a Stand-Alone GPS Receiver

2011 ◽  
Vol 64 (2) ◽  
pp. 311-325 ◽  
Author(s):  
Weidong Ding ◽  
Jinling Wang
Keyword(s):  
Field Test ◽  
Test Data ◽  
Carrier Phase ◽  
Velocity Estimation ◽  
Gps Receiver ◽  
Differential Gps ◽  
New Approach ◽  
Estimation Algorithms ◽  
Computational Load

A scrutiny of the existing time differencing carrier phase (TDCP) velocity estimation algorithms has revealed several shortcomings that could be further improved. One of these is that the velocity estimation at epoch t would require the receiver positions at epoch t+Δt or more are available. Another is the usage of satellite velocities in the calculations which would increase the receiver computational load and degrade the accuracy. In this paper, an improved TDCP velocity estimation approach has been proposed and tested. The new approach depends only on receiver position at epoch t and satellite positions at epoch t and t+Δt. Satellite velocities are not required in this calculation. This proposed algorithm has been validated using static and kinematic field test data, showing that equivalent velocity accuracy achievable by using differential GPS techniques can be made possible with the proposed standalone GPS method.

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