scholarly journals Automated Angle Measurement Instrument Calibration Method for Preliminary Ground Setup of Navigation Elements

2014 ◽  
Vol 2014 (8) ◽  
pp. 225-230
Author(s):  
E Bezvesilna ◽  
◽  
Y Kyrychuk ◽  
L Chepyuk ◽  
A Ostapchuk
Keyword(s):  
Measurement Instrument ◽  
Calibration Method ◽  
Angle Measurement ◽  
Instrument Calibration

scholarly journals Automatic anatomical calibration for IMU-based elbow angle measurement in disturbed magnetic fields

2017 ◽  
Vol 3 (2) ◽  
pp. 167-170 ◽  
Author(s):  
Daniel Laidig ◽  
Philipp Müller ◽  
Thomas Seel
Keyword(s):  
Motion Analysis ◽  
Degrees Of Freedom ◽  
Homogeneous Magnetic Field ◽  
Calibration Method ◽  
Angle Measurement ◽  
Human Motion ◽  
Human Motion Analysis ◽  
Indoor Environments ◽  
Sensor Orientation ◽  
Optical Motion

AbstractInertial Measurement Units (IMUs) are increasingly used for human motion analysis. However, two major challenges remain: First, one must know precisely in which orientation the sensor is attached to the respective body segment. This is commonly achieved by accurate manual placement of the sensors or by letting the subject perform tedious calibration movements. Second, standard methods for inertial motion analysis rely on a homogeneous magnetic field, which is rarely found in indoor environments. To address both challenges, we introduce an automatic calibration method for joints with two degrees of freedom such as the combined radioulnar and elbow joint. While the user performs arbitrary movements, the method automatically identifies the sensor-to-segment orientations by exploiting the kinematic constraints of the joint. Simultaneously, the method identifies and compensates the influence of magnetic disturbances on the sensor orientation quaternions and the joint angles. In experimental trials, we obtain angles that agree well with reference values from optical motion capture. We conclude that the proposed method overcomes mounting and calibration restrictions and improves measurement accuracy in indoor environments. It therefore improves the practical usability of IMUs for many medical applications.

scholarly journals Evaluating the Properties of a Coating Material with Polycaprolactone-Degradable Fluorinated Silicon-Containing Waterborne Polyurethane

2020 ◽  
Vol 12 (9) ◽  
pp. 3745 ◽  
Author(s):  
Yao-Tang Hsu ◽  
Wen-Hsin Wang ◽  
Wei-Hsi Hung
Keyword(s):  
Thermal Stability ◽  
Tensile Strength ◽  
Functional Groups ◽  
Tensile Testing ◽  
Testing Machine ◽  
Measurement Instrument ◽  
Gel Permeation Chromatography ◽  
Waterborne Polyurethane ◽  
Angle Measurement ◽  
Tensile Testing Machine

This study successfully synthesized fluorinated silicon-containing waterborne polyurethanes (FSWPUs) by using polycaprolactone (PCL) diol, 2,2,3,3-Tetrafluoro-1,4-butanediol, and [3-(2-Aminoethylamino)propyl] trimethoxysilane (AEAPTES ). The FSWPU’s particle size was examined using dynamic light scattering. After the FSWPUs were processed into a dry film, their molecular weight and basic properties were analyzed using gel permeation chromatography (GPC), Fourier-transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDS). Additionally, the thermal stability of the FSWPUs was inspected by thermogravimetric analysis and dynamic mechanical analysis. The tensile strength and elongation at the break of the FSWPUs before and after hydrolysis were also analyzed, using a tensile testing machine. Subsequently, FSWPU emulsions were cast between the tiles, and hydrophilicity, hydrophobicity, and surface tension were then measured on a contact-angle measurement instrument. The tensile testing machine was again employed to test the sheer strength of the FSWPUs between the tiles, and a tape test was conducted to analyze their adhesion to the tiles. The results revealed that AEAPTES functional groups can reinforce the thermal stability, tensile strength, and water resistance of FSWPUs. Moreover, the AEAPTES functional groups increased the adhesion of FSWPUs to the tiles and reduced the surface energy of the tiles.

scholarly journals Estimation of 3D Knee Joint Angles during Cycling Using Inertial Sensors: Accuracy of a Novel Sensor-to-Segment Calibration Procedure Based on Pedaling Motion

Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2474 ◽  
Author(s):  
Sébastien Cordillet ◽  
Nicolas Bideau ◽  
Benoit Bideau ◽  
Guillaume Nicolas
Keyword(s):  
Knee Joint ◽  
Inertial Sensor ◽  
External Rotation ◽  
Calibration Method ◽  
Calibration Procedure ◽  
Angle Measurement ◽  
Measurement Unit ◽  
Joint Angles ◽  
Calibration Methods ◽  
Flexion Extension

This paper presents a novel sensor-to-segment calibration procedure for inertial sensor-based knee joint kinematics analysis during cycling. This procedure was designed to be feasible in-field, autonomously, and without any external operator or device. It combines a static standing up posture and a pedaling task. The main goal of this study was to assess the accuracy of the new sensor-to-segment calibration method (denoted as the ‘cycling’ method) by calculating errors in terms of body-segment orientations and 3D knee joint angles using inertial measurement unit (IMU)-based and optoelectronic-based motion capture. To do so, 14 participants were evaluated during pedaling motion at a workload of 100 W, which enabled comparisons of the cycling method with conventional calibration methods commonly employed in gait analysis. The accuracy of the cycling method was comparable to that of other methods concerning the knee flexion/extension angle, and did not exceed 3.8°. However, the cycling method presented the smallest errors for knee internal/external rotation (6.65 ± 1.94°) and abduction/adduction (5.92 ± 2.85°). This study demonstrated that a calibration method based on the completion of a pedaling task combined with a standing posture significantly improved the accuracy of 3D knee joint angle measurement when applied to cycling analysis.

scholarly journals A Novel Calibration Method of Articulated Laser Sensor for Trans-Scale 3D Measurement

Sensors ◽  
2019 ◽  
Vol 19 (5) ◽  
pp. 1083 ◽  
Author(s):  
Jiehu Kang ◽  
Bin Wu ◽  
Xiaodeng Duan ◽  
Ting Xue
Keyword(s):  
Measurement Instrument ◽  
Calibration Method ◽  
High Accuracy ◽  
Industrial Applications ◽  
Laser Beams ◽  
Laser Sensor ◽  
3D Measurement ◽  
System Parameters ◽  
Laser Sensing ◽  
Processing Techniques

The articulated laser sensor is a new kind of trans-scale and non-contact measurement instrument in regular-size space and industrial applications. These sensors overcome many deficiencies and application limitations of traditional measurement methods. The articulated laser sensor consists of two articulated laser sensing modules, and each module is made up of two rotary tables and one collimated laser. The three axes represent a non-orthogonal shaft architecture. The calibration method of system parameters for traditional instruments is no longer suitable. A novel high-accuracy calibration method of an articulated laser sensor for trans-scale 3D measurement is proposed. Based on perspective projection models and image processing techniques, the calibration method of the laser beam is the key innovative aspect of this study and is introduced in detail. The experimental results show that a maximum distance error of 0.05 mm was detected with the articulated laser sensor. We demonstrate that the proposed high-accuracy calibration method is feasible and effective, particularly for the calibration of laser beams.

Research on Key Technologies of Precise Measurement of Geographic Coordinates of Subsea Pipelines

2021 ◽  
Author(s):  
Li Jian ◽  
Wang Jialin ◽  
Zhao Jianyuan ◽  
Li Mingze ◽  
Huang Xinjing
Keyword(s):  
Pitch Angle ◽  
Precise Measurement ◽  
Oil And Gas ◽  
Calibration Method ◽  
Angle Measurement ◽  
Continuous Increase ◽  
Ac Servo ◽  
Main Work ◽  
Ac Servo Motor ◽  
Subsea Pipelines

Abstract With the continuous increase of offshore oil and gas exploitation activities, the number of subsea pipelines is becoming larger and larger, which leads to frequent occurrence of subsea pipeline accidents. Long-term safe operation of subsea pipelines can be ensured by regular defect detection. The premise of locating and disposing defects is to accurately measure the geographic coordinates of subsea pipelines. Our research group has put forward a kind of pipeline spherical internal detector (SD), which has the advantages of convenient implementation, low risk to jam. For the SD, this paper has carried out research on the key technology of precise measurement of subsea pipelines’ geographic coordinates using the internal magnetic fields. The main work is as follows: (1) Magnetic tensor invariant calibration method for magnetometer array has been studied and L-M algorithm is taken to solve the parameters, which is efficient and accurate. Field calibration experiment has proved this method is effective and has good robustness. (2) A new method of measuring pipeline’s pitch angle is proposed. Under the experimental condition of using AC servo motor to drive the sensor instead of the SD to rotate, the pitch angle measurement error is less than 0.2°. (3) Magnetic anomaly of spiral weld and buckling pipeline are used as new mark points to calibrate the geographic coordinates of subsea pipelines. Experimental results show that the newly designed SD can successfully identify spiral welds and buckling pipeline.

scholarly journals Development of Brewster angle measurement instrument using microcontroller unit

2019 ◽  
Vol 1204 ◽  
pp. 012098
Author(s):  
Ahmad Marzuki ◽  
Lintang Bongkar Girana ◽  
Mahmudah Salwa Gianti ◽  
Fendi Aji Purnomo
Keyword(s):  
Measurement Instrument ◽  
Angle Measurement ◽  
Brewster Angle ◽  
Microcontroller Unit

Research and Characterization of Water and Oil Repellent Finishing Auto Interior Materials

2011 ◽  
Vol 239-242 ◽  
pp. 837-842
Author(s):  
Zhao Fang Du ◽  
Xian Sheng Cheng ◽  
Fu Rong Huang
Keyword(s):  
Monomer Concentration ◽  
Measurement Instrument ◽  
Angle Measurement ◽  
Optimum Process ◽  
Process Conditions ◽  
Temperature Plasma ◽  
Low Surface Energy ◽  
Processing Power ◽  
Oil Repellent

The treatment of resist water and oil by low-temperature plasma technology for recycled polyethylene terephthalate(PET)fiber automotive interior carpet was studied.The best process conditions were optimized:low-temperature plasma processing power was 150W,vacuum was 30Pa, time was 10 min,perfluorooctylsulfonyl amide(C8H2F17NO2S)monomer concentration was 15%.With angle measurement instrument,scanning electron microscopy and infrared spectroscopy,the performance of PET interior carpet on the condition of optimum process was tested and analysed.The result showed:there was cross-linked esterification between C8H2F17NO2S monomer and PET molecules,some C-F groups with low surface energy appeared on the fiber surface.Namely, C8H2F17NO2S monomer was effectively grafted onto the surface of PET fiber.The PET interior carpet had a better effect on resisting water and oil.

A Simplified Self-Calibration Method for Cylindrical Grating

2017 ◽  
Vol 868 ◽  
pp. 99-104
Author(s):  
Wen Ying Zhang ◽  
Wei Hu Zhou ◽  
Da Bao Lao ◽  
Hao Ran Zhu
Keyword(s):  
High Precision ◽  
Calibration Method ◽  
Relative Displacement ◽  
Angle Measurement ◽  
Random Errors ◽  
Angle Sensor ◽  
Measuring Device ◽  
Self Calibration ◽  
Angle Measuring ◽  
System Errors

Cylindrical grating angle sensor is a common angle measuring device with high precision. Due to the reflecting arc surface of the cylindrical grating the effects of relative displacement of graduation line and gap variation will interact. Significant residual errors still exist even with high precision cylindrical grating and multiple reading heads around the scale disc .In this paper, based on the principle of circumference closure, the principle of self-calibration is deduced and analyzed in detail. The calibration curve is obtained by obtaining the deviation between the certain position and an ideal position of the graduation line position in real time. A simple self-calibration method of cylindrical grating is acquired. It can calibrate random errors and system errors with time and improve the angle measurement accuracy. The method has the advantages of simple structure and strong maneuverability, and provides technical means for the miniaturization and high precision of cylindrical grating.

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