A Study on Velocity Decay of φ6mm Tungsten Ball Fragment

2014 ◽  
Vol 1042 ◽  
pp. 154-158
Author(s):  
Chun Lin Yi ◽  
De Ren Kong ◽  
Yi Zhao Li ◽  
Li Ping Li ◽  
Jin Qiu Zhang ◽  
...  
Keyword(s):  
High Speed ◽  
Least Square Method ◽  
Least Square ◽  
Experimental Results ◽  
Measuring System ◽  
Low Speed ◽  
Velocity Decay ◽  
Velocity Attenuation ◽  
Attenuation Models ◽  
Velocity Measuring

In order to explore the velocity attenuation law and model of φ6mm tungsten ball fragment, theory analysis combined with tests is employed to study its velocity experimental results. First of all, a fragment velocity measuring system including 12 groups of cutting device is established. Then the attenuation experiments of φ6mm tungsten ball fragment in high speed and low speed velocity are performed by the measuring system. Based on the least-square method, MATLAB software is adopted to analysis the experimental data and obtained the high speed and low speed velocity attenuation models. The results show that φ6mm tungsten ball fragment speed attenuation coefficient is consistent in high speed and low. Thus, the analysis on velocity experimental results verifies that the established model is reasonable.

An Algorithm and Design for RFID Velocity Measurement Based on Least Square Method

2011 ◽  
Vol 317-319 ◽  
pp. 1573-1576
Author(s):  
Lin Ying Jiang ◽  
Heng Zhang ◽  
Han Qing Tan
Keyword(s):  
Great Degree ◽  
Velocity Measurement ◽  
Least Square Method ◽  
Least Square ◽  
Measuring System ◽  
Rfid Technology ◽  
Velocity Measuring ◽  
The Cost

This paper comes up with an algorithm and application for velocity measurement based on RFID technology. This measurement can reduce the cost of velocity-measuring system to a great degree, and improve the accuracy of velocity measurement on the basis of the algorithm.

Cutting Force Empirical Model of High-Speed Precision Hard Cutting GCr15

2009 ◽  
Vol 69-70 ◽  
pp. 301-305
Author(s):  
Jing Shu Hu ◽  
Yuan Sheng Zhai ◽  
Fu Gang Yan ◽  
Yu Fu Li ◽  
Xian Li Liu
Keyword(s):  
Cutting Force ◽  
Empirical Model ◽  
High Speed ◽  
Orthogonal Design ◽  
Cutting Speed ◽  
Least Square Method ◽  
Cutting Parameters ◽  
Least Square ◽  
Physical Parameters ◽  
Hard Cutting

In the cutting process, cutting force is one of the important physical parameters, which affects the generation of cutting heat, tool life and surface precision of workpiece directly. In this paper an orthogonal design of experiment and subsequent data is analyzed using high speed finish hard cutting GCr15 whose hardness is 65HRC. Cutting speed is 200-400m/min, to study the influence of cutting parameters on cutting force, cutting force empirical model has obtained from least square method.

Determination of Johnson Cook Material Model Constants and Their Influence on Machining Simulations of Tungsten Heavy Alloy

2018 ◽  
Author(s):  
Chithajalu Kiran Sagar ◽  
Amrita Priyadarshini ◽  
Amit Kumar Gupta ◽  
Sidharth Kumar Shukla
Keyword(s):  
Least Square Method ◽  
Material Model ◽  
Least Square ◽  
Experimental Results ◽  
Tungsten Heavy Alloy ◽  
Fe Model ◽  
Abc Algorithm ◽  
Bee Colony ◽  
Aircraft Manufacturing ◽  
Heavy Alloys

Tungsten Heavy Alloys (WHA) are used in counterbalance and ballast weights for aerodynamic balancing in fixed and rotary wing aircraft. Manufacturing these components for closer tolerances using machining is a challenging task. The present work aims to develop a 2D Finite Element (FE) model to simulate the chip formation process during machining of WHA using Johnson Cook Material Model (JCMM). The model constants for 95%WHA are determined based on the high strain rate test data using least square method. The calculated values are further optimized using Genetic Algorithm (GA) and Artificial Bee Colony (ABC) algorithm, which are then used as material inputs for FE simulation of machining WHA. The predicted results such as cutting force, chip geometry, shear stress, shear angle are presented and compared with the experimental results under similar cutting conditions. It has been observed that the constants obtained from ABC algorithm show minimum error in the cutting performance measures for all the experimental results.

Localization of Mobile Robot Based on Least Square Method

2013 ◽  
Vol 347-350 ◽  
pp. 808-811
Author(s):  
Jia Lu Li ◽  
Lin Bing Long ◽  
Bao Feng Zhang
Keyword(s):  
Motion Estimation ◽  
Mobile Robot ◽  
Mobile Robots ◽  
Least Squares ◽  
Least Square Method ◽  
Least Square ◽  
Experimental Results ◽  
Sift Algorithm ◽  
Key Techniques ◽  
Point Detection

Localization is the basis for navigation of mobile robots. This paper focuses on key techniques of localization for mobile robots based on vision. Firstly, the specific measures and steps of the algorithm are analyzed and researched in depth. In the study, SIFT algorithm combined with epipolar geometry constraint is used on the environment feature point detection, matching and tracking. And the method of RANSAC combined with the least squares is used to obtain accurate results of the motion estimation. Then the necessary experiments are carried out to verify the correctness and effectiveness of algorithms. The experimental results verified the accuracy of the improved algorithm.

Subpixel Edge Detection Algorithm of the Glass Bottle Based on Zernike Moments

2011 ◽  
Vol 80-81 ◽  
pp. 1345-1349
Author(s):  
Hao Yang ◽  
Lei Pei
Keyword(s):  
Edge Detection ◽  
Fast Algorithm ◽  
Least Square Method ◽  
Threshold Value ◽  
Detection Algorithm ◽  
Zernike Moments ◽  
Least Square ◽  
Measuring System ◽  
Zernike Moment ◽  
Glass Bottle

The accuracy of edge detection determines the accuracy of actual dimension measurement，in order to improve the measuring accuracy, this paper proposes a fast algorithm of detecting the glass bottle dimension based on Zernike moments. Firstly, combines the traditional Zernike moment-based method with Otsu adaptive threshold algorithm and a new fast algorithm for edge detection is proposed. Then uses this fast algorithm to detect the edge of glass bottle with subpixel-level and uses the least square method to fit ellipses formed by the glass bottle mouth and bottom. Calibrated the system with standard gauge block and obtain the actual dimension at last. Experimental results show that the improved algorithm not only can make the edge detection reach the subpixel-level accuracy, but also can avoid the edge misidentification and inefficient causing by repeatedly manual adjustments to select the threshold value when detecting the edge. Making a rapid, accurate, non-contact measuring system becomes a reality.

Comparing of Coordinate Transformation Based on Total Least Squares and Least Squares

2014 ◽  
Vol 522-524 ◽  
pp. 1211-1214
Author(s):  
Qing Wu Meng ◽  
Lu Meng
Keyword(s):  
Least Squares ◽  
Coordinate Transformation ◽  
Least Square Method ◽  
Coefficient Matrix ◽  
Total Least Squares ◽  
Least Square ◽  
Experimental Results ◽  
Transformation Models ◽  
Total Least Square

The coordinate transformation models based on least square method and total least square are built and discussed. The least square model only includes the errors of observation vectors, the total least square model simultaneously takes into consideration to the errors of observation vectors and the errors of coefficient matrix. The both models are verified and compared in experiment. The experimental results showed that the model of total least square is more in line with actual, and more reasonable than by least square theoretically, and the coordinate transformation solution result of total least square with least square is more near.

Design of a Multijet Omnidirectional Propulsion System for Small Jet-Boats

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
David Foley ◽  
Jean-Sebastien Plante
Keyword(s):  
High Speed ◽  
Flow Model ◽  
Open Loop ◽  
Propulsion System ◽  
Experimental Results ◽  
Control Algorithms ◽  
Control Laws ◽  
Low Speed ◽  
Advanced Control ◽  
Design Requirements

Jet-boats perform remarkably well at high-speed but lack low speed maneuverability for tight maneuvers such as docking. This paper presents a joystick controlled omnidirectional propulsion system for jet-boats. The concept uses a set of fixed jet nozzles disposed around the hull. When a force is commanded by the joystick, valves on each nozzle modulate the flow so that the sum of nozzle thrusts correspond to the commanded force. The positions and angles of the nozzles are optimized with an index of omnidirectionality quality based on the projection of a set of force solutions on a shell with the shape of a desired force space. The choice of valve positions and engine speeds is done by the numerical inversion of an internal viscous flow model. A 3D simulator, backed by experimental results, serves to (1) evaluate the ability of the proposed concept in meeting its design requirements and (2) develop control algorithms. Experimental results show that the proposed omnidirectional system is effective for low speed maneuverability with open-loop force control. The present work also offers an effective omnidirectional propulsion system that is easy to enhance with advanced control laws. Velocity feedback control is given as an example and shows important improvement of maneuverability and robustness to miscalibration.

Signal Conditioning of Low-Cost Gyroscope Using Kalman Filter and Nonlinear Least Square Method

2012 ◽  
Vol 622-623 ◽  
pp. 1519-1523
Author(s):  
C. Saraporn ◽  
T. Dolwichai ◽  
J. Srisertpol ◽  
K. Teeka
Keyword(s):  
Kalman Filter ◽  
Motion Control ◽  
Low Cost ◽  
Least Square Method ◽  
Scaling Factor ◽  
Least Square ◽  
Experimental Results ◽  
Signal Conditioning

Gyroscopes are important sensors in motion control in equipment such as airplanes, missiles and Segway. Low-cost gyroscopes have problems in signals such as bias, noise and scaling factor that decrease the efficiency of motion control. Therefore this paper is to present signal conditioning of low-cost gyroscopes using a Kalman filter to remove unwanted noise and nonlinear least square method to estimate parameters for compensation errors to the model by comparison with the encoder. The experimental results is shown that Kalman filter and nonlinear least square method can be used in signal conditioning of low-cost gyroscope for a more accurate signal.

Combined Phase Unwrapping Method Using 2D Image Information in PMP 3D Measurement

2013 ◽  
Vol 765-767 ◽  
pp. 2148-2152 ◽  
Author(s):  
Yue Hua Gao ◽  
Bing Luo ◽  
Zhong Yu Sun ◽  
Su Fang Zhao
Keyword(s):  
Basic Principle ◽  
Least Square Method ◽  
Phase Unwrapping ◽  
Least Square ◽  
Experimental Results ◽  
Solder Paste ◽  
3D Measurement ◽  
Image Information ◽  
Practical Engineering ◽  
Break Area

In SMT solder paste deposit 3D measurement based on PMP, conventional phase unwrapping method suffered from shadow, noise and holes. Considering practical engineering condition, phase unwrapping method can be improved using 2D image information: basic principle method was applied to smooth area, quality-guided unwrapping and least-square method were taken in shadow or break area for phase unwrapping respectively. Experimental results show that desired phases can be correctly and quickly unwrapped in proposed method.

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