scholarly journals Design and Testing of Inertial System for Landslide Displacement Distribution Measurement

Sensors ◽  
2020 ◽  
Vol 20 (24) ◽  
pp. 7154
Author(s):  
Yongquan Zhang ◽  
Huiming Tang ◽  
Guiying Lu ◽  
Yuansheng Wang ◽  
Changdong Li ◽  
...  
Keyword(s):  
Pitch Angle ◽  
Measurement Accuracy ◽  
Measurement Instrument ◽  
Deformation Monitoring ◽  
Displacement Measurement ◽  
Roll Angle ◽  
Lateral Direction ◽  
Landslide Evolution ◽  
Gravity Platform ◽  
And Control

Landslide displacement monitoring plays a fundamental role in the study of landslide evolution mechanisms, forecasting, risk assessment, prevention, and control. To fill the deficiencies of traditional instrumentation for measuring landslide displacement distributed along lateral direction, a landslide displacement measurement method based on deformation-coupled pipeline trajectory measurement is proposed, and a pipeline trajectory inertial measurement instrument is developed. The developed instrument, primarily comprised of a single shaft gyro, two axis accelerometers, and an external roller encoder, is designed as an axial half strapdown-radial half platform structure combined with a mechanical gravity platform. This structure avoids the singularity of pitch angle and roll angle and can expediently calculate a pipeline trajectory with an Eulerian transformation when obtaining several basic physical variables, e.g., the axial linear velocity, pitch angle, roll angle, and azimuth angle. Additionally, the pipeline trajectory, measured at different times, possesses the ability to reflect the displacement evolution feature of landslides. The results of prototype simulation tests imply a single measurement accuracy of a 12 cm/100 m span and a singly periodic multiple (more than five times) measurement accuracy of a 3 cm/100 m span, which meets medium-precision displacement measurement requirements for a landslide. Additionally, the finished instrument has been successfully applied to the deformation monitoring of the Majiagou I# landslide, which further verifies its feasibility and offers a reference for similar landslides.

scholarly journals Calibration and Accuracy Determination of a Microwave Type Sensor for Measuring Grain Flow

2014 ◽  
Vol 931-932 ◽  
pp. 1592-1596
Author(s):  
Renny Eka Putri ◽  
Azmi Yahya ◽  
Nor Maria Adam ◽  
Samsuzana Abd Aziz ◽  
Tajudeen Abiodun Ishola
Keyword(s):  
Real Time ◽  
Pitch Angle ◽  
Measurement Errors ◽  
Measurement Accuracy ◽  
Evaluation Study ◽  
Flow Sensor ◽  
Roll Angle ◽  
Flow Measurements ◽  
Solid Flow ◽  
Grain Flow

Impact type grain flow sensor for crop yield monitoring is known to have problem of some thrown grain by the elevator conveyor in a combine not hitting the sensing impact plate. New technology of microwave solid flow sensor was used to solve the problem of impact-type sensor. A calibration stand with its instrumentation systems to stimulate the actual operation of the clean grain auger in a rice combine had been designed and constructed in this study for the purpose of conducting the calibration and evaluation study of the sensor. Two different solid flow sensor orientations and three different solid flow sensor extrusions were investigated in order to find the best positioning of the sensor on the chute for the measurement. Results from the conducted tests indicates that the best sensor positioning is on totally flat ground at 180o orientation and 8 cm extrusion of the chute cross section (R2=0.9400). Then, the solid flow sensor was tested at seven chute pitch angle positions (i.e-4.5o, -3.0o, -1.5o, 0o, +1.5o, + 3.0o, and +4.5 o), seven chute roll angle positions (i.e-4.5o,-3.0o, -1.5 o, 0o, +1.5o, +3.0 o, and +4.5o). Finally, accuracy tests undertaken to compare the real time measurements against the average flow measurements. ANOVA test shows that both pitch angle and roll angle positions have significant effects on the measurement accuracy of the sensor. The measurement errors increased with increasing roll angles and increasing pitch angle. Conclusively, this conducted laboratory study was able to quantify the measurement accuracy of the SWR Solid Flow sensor for real-time measurement of grain flow under a simulated laboratory rice combine test set-up.

scholarly journals Roll Angle Estimation Algorithm of Geomagnetic/Gyro Combination Based on an Interacting Multiple-Model Kalman Filter

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jian-li Su ◽  
Hua Wang
Keyword(s):  
Kalman Filter ◽  
Measurement Accuracy ◽  
Angular Rate ◽  
Estimation Algorithm ◽  
Roll Angle ◽  
Interacting Multiple Model ◽  
Multiple Model ◽  
Calculation Results ◽  
Gyroscope Sensor ◽  
And Control

The knowledge of the geomagnetic and gyro information that can be used for projectile roll angle is decisive to apply trajectory correction and control law. In order to improve the measurement accuracy of projectile roll angle, an interacting multiple-model Kalman filter (IMMKF) algorithm using gyro angular rate information to geomagnetic sensor information is proposed. Firstly, the data acquisition module of the geomagnetic sensor and the gyroscope sensor is designed, and the test data of the sensors are obtained through the semiphysical experiments. Furthermore, according to the measurement accuracy of each sensor, the algorithm performs the IMMKF process on the geomagnetic/gyro information to get the roll angle. It can be proven by experiments and calculation results that the error of the roll angle obtained after processing by the IMMKF algorithm is close to 2°, which is better than the 5° calculated by adopting the Kalman filter directly with geomagnetic information.

Method of Attitude Measurement Based on the Geomagnetic and Gyroscope

2013 ◽  
Vol 336-338 ◽  
pp. 180-184 ◽  
Author(s):  
Li Long ◽  
He Zhang
Keyword(s):  
Pitch Angle ◽  
Measurement Accuracy ◽  
Performance Test ◽  
Detection System ◽  
Roll Angle ◽  
Angle Error ◽  
Blind Area ◽  
Trajectory Correction ◽  
Yaw Angle ◽  
Attitude Detection

The trajectory correction capability of the Simple guided munitions is directly affected by measurement accuracy of attitude angle. A gesture detection method based on geomagnetic gyro combination is proposed in this paper in order to detect the projectile flight attitude, The yaw angle of the projectile is solved by using runge-kutta algorithm with angle information of MEMS gyro. Then roll angle and pitch angle of the projectile is solved by magnetic field component of the three-axis magnetic sensor. Finally, the whole attitude detection system is installed in three-axis non-magnetic turntable to have a performance test. Experimental results show that the attitude solution results error is small. Nearby blind area, the roll angle error reduced to 5° and the pitch angle error reduced to 4°. In other locations, the roll angle error reduced to 2° and the pitch angle error reduce to 1°. The measurement accuracy increased nearly tenfold, can satisfy the trajectory correction demand of simple guidance ammunition.

A Design of High-Accuracy Displacement Measurement Instrument from Principles of Optics

2012 ◽  
Vol 170-173 ◽  
pp. 2924-2928
Author(s):  
Sheng Biao Chen ◽  
Yun Zhi Tan
Keyword(s):  
Measurement Instrument ◽  
High Accuracy ◽  
Mechanical Tests ◽  
Total Reflection ◽  
Displacement Measurement ◽  
New Method ◽  
Water Volume ◽  
Water Drainage ◽  
Accuracy Of Measurement ◽  
Better Than

In order to measure the water drainage volume in soil mechanical tests accurately, it develop a new method which is based on principles of optics. And from both physical and mathematic aspects, it deduces the mathematic relationship between micro change in displacement and the increment projected on screen. The result shows that total reflection condition is better than refraction condition. What’s more, the screen could show the water volume micro variation clearly, so it can improve the accuracy of measurement.

Mandibular deviations in TMD and non-TMD groups related to eye dominance and head posture

2002 ◽  
Vol 25 (2) ◽  
pp. 147-155 ◽  
Author(s):  
N. Pradham ◽  
G. White ◽  
N. Mehta ◽  
A. Forgione
Keyword(s):  
Head Rotation ◽  
Lateral Direction ◽  
Head Posture ◽  
Control Subjects ◽  
Eye Dominance ◽  
Pain Center ◽  
And Control ◽  
Female Subjects

This study was designed to determine whether eye-dominance affects head posture (rotation) and in turn, whether head posture is associated with mandibular frenum midline deviation, in both TMJ and control subjects. Eye dominance was determined using three tests:Porta, Hole, Point tests. Natural head posture was evaluated using the Arthrodial protractor. Mandibular frenum deviation was recorded as left, right or no deviation. Fifty female subjects were included in the study, 25 TMJ patients attending the Gelb Craniomandibular Pain Center and 25 non-TMJ control subjects. The findings indicate that eye dominance and direction of head rotation are strongly associated in both TMJ and control subjects. Further, in TMJ subjects mandibular deviation occurred in greater frequency than in controls and tends to occur in the contra lateral direction of head rotation.

Signal Sampling and Accuracy Analysis of Large Gear’s Angular Displacement Measuring its Deviation On-Machine

2011 ◽  
Vol 189-193 ◽  
pp. 4201-4204
Author(s):  
Jia Qi Jin ◽  
Hui Li
Keyword(s):  
Measurement Accuracy ◽  
Angular Displacement ◽  
Total Error ◽  
Measuring Method ◽  
Displacement Measurement ◽  
Signal Acquisition ◽  
Accuracy Analysis ◽  
Friction Disc ◽  
Large Gear ◽  
Circular Grating

To solve the critical problem of large gear deviation on-machine: angle displacement measurement that is how to get signal acquisition and accuracy analysis of angle displacement. A new measuring method is proposed, which applies the dividing mechanism (it is composed of friction disc and circular grating) to ensure index and pick up signal of gear corner correctly and strictly according to the principle of angular displacement measurement. Furthermore, the main error which affects measurement accuracy is analyzed, and accuracy is analyzed with geometrical theory such as Fourier series and error synthesis principle etc. The experimental results indicate that angel dividing and signal samplings are easier and more efficient by the dividing mechanism, furthermore, the accuracy is in the range of total error that is permitted by verification, and the mechanism can also meet the requirement of high accuracy, so the method is significance that assessing transmission accuracy of involutes gear.

Optocontact mini-displacement measurement instrument

1998 ◽  
Author(s):  
Bo Liu ◽  
Ling Yang ◽  
Jian Zhang ◽  
Jian-Ying Fan
Keyword(s):  
Measurement Instrument ◽  
Displacement Measurement

scholarly journals Analysis of Parameter Sensitivity Using Robust Design Techniques for a Flatfish Type Autonomous Underwater Vehicle

2009 ◽  
Vol 2009 ◽  
pp. 1-10 ◽  
Author(s):  
M. Santhakumar ◽  
T. Asokan ◽  
T. R. Sreeram
Keyword(s):  
Robust Design ◽  
Pitch Angle ◽  
High Performance ◽  
Autonomous Underwater Vehicle ◽  
Controller Design ◽  
Autonomous Underwater Vehicles ◽  
Angle Variation ◽  
Hydrodynamic Parameters ◽  
And Control ◽  
Design Techniques

Hydrodynamic parameters play a major role in the dynamics and control of Autonomous Underwater Vehicles (AUVs). The performance of an AUV is dependent on the parameter variations and a proper understanding of these parametric influences is essential for the design, modeling, and control of high-performance AUVs. In this paper, the sensitivity of hydrodynamic parameters on the control of a flatfish type AUV is analyzed using robust design techniques such as Taguchi's design method and statistical analysis tools such as Pareto-ANOVA. Since the pitch angle of an AUV is one of the crucial variables in the control applications, the sensitivity analysis of pitch angle variation is studied here. Eight prominent hydrodynamic coefficients are considered in the analysis. The results show that there are two critical hydrodynamic parameters, that is, hydrodynamic force and hydrodynamic pitching moment in the heave direction that influence the performance of a flatfish type AUV. A near-optimal combination of the parameters was identified and the simulation results have shown the effectiveness of the method in reducing the pitch error. These findings are significant for the design modifications as well as controller design of AUVs.

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