Principle Error Analysis of Three-Point Supporting Type Barycenter Measurement System

2012 ◽  
Vol 605-607 ◽  
pp. 951-954
Author(s):  
Yong Xing Hao ◽  
Ya Hui Liu ◽  
Song Wei Yang ◽  
Hai Tao Cheng
Keyword(s):  
Theoretical Analysis ◽  
Measurement System ◽  
Tilt Angle ◽  
Simplified Model ◽  
Calculation Formula ◽  
Geometrical Analysis ◽  
Simulation Experiments ◽  
Elastic Deformations ◽  
Measured Object ◽  
Angle Calculation

Taking elastic deformations of the platform and sensors into consideration, a simplified model of three-point supporting type barycenter measurement system was built. The tilt-angle calculation formula of the measured object caused by elastic deformations was obtained through the physical and geometrical analysis. Then the principle error of barycenter eccentricity was calculated in measurement process. On study of the principle error expression, it was concluded that measurement value of barycenter eccentricity is greater than the actual; the value of the principle error is proportional to the weight, the barycenter height and the actual barycenter eccentricity of the measured object, and is inversely proportional to the square of the distributing radius of sensors, the synthetic stiffness of the stacking part of platform and sensor. But the principle error has nothing to do with the phase angle of barycenter. Finally, simulation experiments were done using Adams. The experimental results agree well with the conclusions of theoretical analysis.

Vibrations of a Helicopter Rotor-Fuselage System Induced by the Main Rotor Blades in Flight

1955 ◽  
Vol 22 (3) ◽  
pp. 355-360
Author(s):  
M. Morduchow ◽  
S. W. Yuan ◽  
H. Reissner
Keyword(s):  
Theoretical Analysis ◽  
Natural Frequencies ◽  
Rotor Blades ◽  
Helicopter Rotor ◽  
Simplified Model ◽  
Main Rotor ◽  
Numerical Examples ◽  
The Masses

Abstract Based on a simplified model of the hub-fuselage structure, a theoretical analysis is made of the response of the hub and fuselage of a helicopter in flight to harmonic forces transmitted by the rotor blades to the hub both in, and normal to, the plane of rotation. The assumed structure is in the form of a plane framework with masses concentrated at the joints. Simple expressions are derived for the vibration amplitudes of the mass points as functions of the masses and natural frequencies of the hub and the fuselage. The pertinent nondimensional parameters are determined, and simple explicit conditions of resonance are derived. Numerical examples are given to illustrate the results.

scholarly journals Measuring the diameter of a cylinder with automatic calibration

2021 ◽  
Vol 2057 (1) ◽  
pp. 012086
Author(s):  
S V Dvoynishnikov ◽  
G V Bakakin ◽  
V G Meledin ◽  
V V Rahmanov ◽  
O Yu Sadbakov
Keyword(s):  
Light Source ◽  
Measurement System ◽  
Automatic Calibration ◽  
Shadow Method ◽  
Measured Object ◽  
Calibration And Verification

Abstract The work aims at developing a method for measuring the diameter of cylindrical objects, eliminating the need for calibration and verification of the measurement system during operation. The system for measuring the diameter of cylindrical objects contains a photodetector and a light source located on opposite sides of the measured object to implement the shadow method. The proposed method is based on the measurement of two reference cylinders located in the measuring area for automatic calibration of the system at each measurement. It is shown that the proposed method provides stable reliable measurements with an error of less than 2 μm for the diameter of the measured cylindrical objects of up to 10 mm.

scholarly journals Method to Increase the Accuracy of Large Crankshaft Geometry Measurements Using Counterweights to Minimize Elastic Deformations

2020 ◽  
Vol 10 (14) ◽  
pp. 4722 ◽  
Author(s):  
Leszek Chybowski ◽  
Krzysztof Nozdrzykowski ◽  
Zenon Grządziel ◽  
Andrzej Jakubowski ◽  
Wojciech Przetakiewicz
Keyword(s):  
Elastic Deformation ◽  
Measurement System ◽  
Design Solution ◽  
Structural Elements ◽  
Elastic Deformations ◽  
Elastic Deflection ◽  
Reaction Forces ◽  
Geometry Measurement

Large crankshafts are highly susceptible to flexural deformation that causes them to undergo elastic deformation as they revolve, resulting in incorrect geometric measurements. Additional structural elements (counterweights) are used to stabilize the forces at the supports that fix the shaft during measurements. This article describes the use of temporary counterweights during measurements and presents the specifications of the measurement system and method. The effect of the proposed solution on the elastic deflection of a shaft was simulated with FEA, which showed that the solution provides constant reaction forces and ensures nearly zero deflection at the supported main journals of a shaft during its rotation (during its geometry measurement). The article also presents an example of a design solution for a single counterweight.

Measurement of the Depth Distance Based on the Binocular Stereo Vision

2012 ◽  
Vol 468-471 ◽  
pp. 1895-1898 ◽  
Author(s):  
A Lin Hou ◽  
Ying Geng ◽  
Xue Cui ◽  
Wen Ju Yuan ◽  
Feng Guang Shi
Keyword(s):  
Camera Calibration ◽  
Stereo Vision ◽  
Measurement System ◽  
Measuring Method ◽  
Simulation Experiments ◽  
Camera Imaging ◽  
Binocular Stereo Vision ◽  
Binocular Stereo ◽  
Image Pairs

The measurement system of the depth distance based on binocular stereo vision is proposed. The model of camera imaging is established and the process of camera calibration is described. Interior and external parameters of two cameras are calculated by HALCON. Then the depth distance can be obtained by the parallax measurement of the image pairs. The simulation experiments have been done and the results demonstrated that the measuring method is feasible.

Study on Parameters of Deep-Hole Loose Blasting under the Condition of High Stress

2014 ◽  
Vol 644-650 ◽  
pp. 646-649
Author(s):  
Zhi Tao Zheng ◽  
Ying Xu
Keyword(s):  
Theoretical Analysis ◽  
Coal Mine ◽  
High Stress ◽  
Calculation Formula ◽  
Rock Blasting ◽  
Deep Hole ◽  
Design Work ◽  
Hole Wall ◽  
Deep Rock ◽  
Reference Design

The hole wall crushed and fractured zones length has been derived theoretically,and put forward the calculation formula of blasting crushing circle and radius of the corresponding fracture zone.Corresponding to the deep rock blasting parameters design on the basis of theoretical analysis,then lead to the reasonable parameters.These can provide certain reference design work for coal mine deep rock blasting parameters.

Theoretical Analysis on the Ultimate Bearing Capacity for Steel Tubular Transmission Tower’s Joints with Annular Plate

2014 ◽  
Vol 664 ◽  
pp. 175-181 ◽  
Author(s):  
Zhi Juan Rong ◽  
Xue Ming Wang ◽  
Bao Hua Lv ◽  
Xin Yue Zhang ◽  
Ling Zhang
Keyword(s):  
Theoretical Analysis ◽  
Bearing Capacity ◽  
Annular Plate ◽  
Ultimate Bearing Capacity ◽  
Simplified Model ◽  
Force Distribution ◽  
Element Analysis ◽  
Energy Principle ◽  
State Of Stress ◽  
Principle Theory

The aim of this paper is to study the ultimate bearing capacity of steel tubular transmission tower’s joint with annular plate based on the theoretical analysis. A simplified model of annular plate joints was performed to investigate the force distribution of the tube-gusset joints. To obtain the state of stress and ultimate bearing capacity, the annular plate with clamped boundary condition on the inner edges and subjected to diametric loading is employed in this study by the direct integration and thin plate energy principle theory. Experiment and finite element analysis are carried out and the results show that both are the similar.

scholarly journals An underground three-dimensional displacement measurement system

2018 ◽  
Vol 232 ◽  
pp. 02053
Author(s):  
Yifeng Cheng ◽  
Qing Li ◽  
Nanying Shentu ◽  
Chao Zhang
Keyword(s):  
Measurement System ◽  
Tilt Angle ◽  
Group Structure ◽  
Three Dimensional ◽  
Horizontal Displacement ◽  
Vertical Displacement ◽  
Displacement Sensor ◽  
Monitoring Methods ◽  
Geological Disaster ◽  
On Line

With the development of society, the damage of geological disaster to people's life and property is more serious, so the improvement of monitoring means of geological disaster is particularly urgent, there are some shortcomings in traditional monitoring methods, and it is impossible to measure the three-dimensional displacement of underground. The authors have designed an integrated three-dimensional displacement sensor to measure underground horizontal displacement and vertical displacement and tilt angle, and realize the real-time on-line monitoring of underground three-dimensional displacement visually through multi-group structure co-measurement.

Theoretical Analysis of Shearing Capacity of U-Section Steel-Encased Concrete Composite Beams with the Full Connection Design

2011 ◽  
Vol 94-96 ◽  
pp. 958-961
Author(s):  
Xue Jun Zhou ◽  
Ting Zhang
Keyword(s):  
Theoretical Analysis ◽  
Composite Beams ◽  
Vertical Shear ◽  
Calculation Formula ◽  
Shear Connectors ◽  
Shear Connection ◽  
Shear Performance ◽  
Weak Plane ◽  
Connection Design ◽  
Relative Slippage

In this article, by studying the horizontal and vertical shear performance, the calculation formula for the fully shear connection is proposed. In order to avoid the overall vertical relative slippage between the steel and concrete, the vertical slippage formula is proposed to calculate the required number of the shear connectors for the first weak plane and second weak plane.

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