Precision Force Measurement Using the Levitation Mass Method (LMM)

2010 ◽  
Vol 36 ◽  
pp. 41-51
Author(s):  
Yusaku Fujii ◽  
Koichi Maru ◽  
Tao Jin ◽  
Takao Yamaguchi
Keyword(s):  
Doppler Shift ◽  
Force Measurement ◽  
Inertial Force ◽  
Force Sensor ◽  
Sensor Calibration ◽  
Future Prospects ◽  
Shift Frequency ◽  
The Stability ◽  
Calibration Material ◽  
Structure Test

This paper reviewed the present status and the future prospects of a method for precision mass and force measurement based on levitation mass method (LMM). The LMM has been proposed and improved by the author The mass which levitated using a pneumatic linear bearing in LMM is used to producte a inertial force which used as the reference force applied to the objects under test, such as to force sensor calibration, material and structure test. The inertial force is calibrated only from Doppler shift frequency. The stability of laser’s wavelength has improved in the LMM. The futhure work and the method to improve the precision have described.

Precision Force Measurement Using the Levitation Mass Method (LMM)

2011 ◽  
Vol 103 ◽  
pp. 1-8
Author(s):  
Yusaku Fujii ◽  
Akihiro Takita ◽  
Jakrapong Kaewkhao ◽  
Mitra Djamal ◽  
Takao Yamaguchi
Keyword(s):  
Laser Beam ◽  
Doppler Shift ◽  
Measurement Method ◽  
Force Measurement ◽  
Inertial Force ◽  
High Accuracy ◽  
Optical Interferometer ◽  
Future Prospects ◽  
Mechanical Measurement ◽  
Shift Frequency

This paper reviews the present status and future prospects of the levitation mass method (LMM), which is a precision mechanical measurement method. The LMM has been proposed and improved by the author for 10 years. The force generated by the actuator is measured as the inertial force of the mass levitated with sufficiently small friction using an aerostatic linear bearing and connected to the moving part of the actuator. During the measurement, the Doppler shift frequency of the laser beam reflected by the mass is measured with a high accuracy with the help of an optical interferometer. Subsequently, the velocity, position, acceleration, and inertial force of the mass are calculated using based on this frequency. Simultaneously, the current and voltage supplied to the actuator are measured.

scholarly journals Circuit Design of Surface Acoustic Wave Based Micro Force Sensor

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Yuanyuan Li ◽  
Wenke Lu ◽  
Changchun Zhu ◽  
Qinghong Liu ◽  
Haoxin Zhang ◽  
...  
Keyword(s):  
Acoustic Wave ◽  
Surface Acoustic Wave ◽  
Circuit Design ◽  
Force Measurement ◽  
Pressure Sensors ◽  
Force Sensor ◽  
Piezoresistive Sensor ◽  
Detection Circuit ◽  
Micro Force Sensor ◽  
The Stability

Pressure sensors are commonly used in industrial production and mechanical system. However, resistance strain, piezoresistive sensor, and ceramic capacitive pressure sensors possess limitations, especially in micro force measurement. A surface acoustic wave (SAW) based micro force sensor is designed in this paper, which is based on the theories of wavelet transform, SAW detection, and pierce oscillator circuits. Using lithium niobate as the basal material, a mathematical model is established to analyze the frequency, and a peripheral circuit is designed to measure the micro force. The SAW based micro force sensor is tested to show the reasonable design of detection circuit and the stability of frequency and amplitude.

Research on Axis Piezoelectric Six-Component Force/Moment Sensor Clamp Device

2013 ◽  
Vol 427-429 ◽  
pp. 1217-1222
Author(s):  
Ning Xu ◽  
Han Neng Ren ◽  
Ying Jun Li
Keyword(s):  
Force Feedback ◽  
Simulation Analysis ◽  
Force Measurement ◽  
Surface Friction ◽  
Force Sensor ◽  
Structure Design ◽  
Sensor Calibration ◽  
Force Transmission ◽  
Finite Element Software ◽  
Component Force

The six-component force measurement and real-time force feedback is not only the basis of multi-equipment coordination of operational control and the force comply with the control, but also to develop the technical basis of the overloaded operators, equipment and other heavy equipment. This article designed a fastening device based on the swelling principle of surface friction, for the six-component force sensor with parallel axis rigid connection. Analysis the six-component force sensor measurement principle, study the blessing device dynamometer performance of six-component force sensor. Use the finite element software for modeling and simulation analysis of the structure. Design of the loading experiments, the experiments show that the fastening technology based on the principle of swelling of the surface friction, to solve the six-component force sensor axis fixed and force transmission, interference of swelling structure to the sensor calibration is relatively small, both achieve effective clamping, but also improves the transfer efficiency of the power flow. With good positioning, highly repetitive assembly and disassembly, convenient adjusting device, etc.

scholarly journals Performance Evaluation of Capacitive Based Force Sensor for Electroencephalography Head Caps

2020 ◽  
Vol 2 ◽  
pp. 4-8
Author(s):  
Warsito I.F. ◽  
Hunold A. ◽  
Haueisen J. ◽  
Supriyanto E.
Keyword(s):  
Performance Evaluation ◽  
Force Measurement ◽  
Force Sensor ◽  
Signal Measurement ◽  
Repeatability Error ◽  
The Stability

Accurate electrode signal measurement using EEG head caps can only be achieved through sufficient contact or force. A flexible force sensor is required to obtain accurate force measurement underneath EEG head caps. In this study, we evaluate the performance of a capacitive based sensor including its accuracy, repeatability, hysteresis, and stability. The result shows that accuracy error and repeatability error were 3.03±2.8 % and 3.84±2.92 %, respectively. The stability errors were 2.37±0.15 %(10 gram), 2.54±0.00 % (50 gram), 2.37±0.15 % (100 gram), 5.07±1.16 % (150 gram), 7.27±0.39 % (200 gram). The hysteresis error of the sensor was 4.48±0.47 %. Based on the results, the capacitive based force sensor provides sufficiently low errors in accuracy, repeatability, stability, and hysteresis and is thus suitable for measuring adduction force in EEG cap applications

Development of Material Tester Using Pendulum

2011 ◽  
Vol 497 ◽  
pp. 176-181
Author(s):  
Hironori Ebara ◽  
Akihiro Takita ◽  
Tomohiko Azami ◽  
Yusaku Fujii
Keyword(s):  
Doppler Shift ◽  
Mechanical Characteristics ◽  
Inertial Force ◽  
Inertia Force ◽  
Materials Testing ◽  
Optical Interferometer ◽  
Measured Time ◽  
Small Force ◽  
Shift Frequency ◽  
Measuring Force

The requirements for evaluating the mechanical characteristics of materials have increased in the various industrial, research and the applications such as materials testing. Therefore, the authors have proposed a method for measuring force acting a material using pendulum [1]. In the Material tester, the mechanical characteristics of material against small force are measured by means of the pendulum mechanism based on the levitation mass method (LMM) [2,3,4].In the LMM, the Doppler shift frequency is measured for measuring the inertial force. The Doppler shift frequency of a laser beam reflected from the mass is accurately measured by using optical interferometer. The velocity, position, acceleration and inertia force of the mass are calculated from the measured time-varying Doppler shift frequency. Thus, the accurate measure of frequency makes that of force.

scholarly journals VirtualCPR: Virtual Reality Mobile Application for Training in Cardiopulmonary Resuscitation Techniques

Sensors ◽  
2021 ◽  
Vol 21 (7) ◽  
pp. 2504
Author(s):  
Francisco Javier García Fierros ◽  
Jesús Jaime Moreno Escobar ◽  
Gabriel Sepúlveda Cervantes ◽  
Oswaldo Morales Matamoros ◽  
Ricardo Tejeida Padilla
Keyword(s):  
Virtual Reality ◽  
Cardiopulmonary Resuscitation ◽  
Mobile Application ◽  
Force Measurement ◽  
Heart Diseases ◽  
Medical Knowledge ◽  
Public Health Problem ◽  
Force Sensor ◽  
Previous Training ◽  
Color Indicator

Deaths due to heart diseases are a leading cause of death in Mexico. Cardiovascular diseases are considered a public health problem because they produce cardiorespiratory arrests. During an arrest, cardiac and/or respiratory activity stops. A cardiorespiratory arrest is rapidly fatal without a quick and efficient intervention. As a response to this problem, the VirtualCPR system was designed in the present work. VirtualCPR is a mobile virtual reality application to support learning and practicing of basic techniques of cardiopulmonary resuscitation (CPR) for experts or non-experts in CPR. VirtualCPR implements an interactive virtual scenario with the user, which is visible by means of employment of virtual reality lenses. User’s interactions, with our proposal, are by a portable force sensor for integration with training mannequins, whose development is based on an application for the Android platform. Furthermore, this proposal integrates medical knowledge in first aid, related to the basic CPR for adults using only the hands, as well as technological knowledge, related to development of simulations on a mobile virtual reality platform by three main processes: (i) force measurement and conversion, (ii) data transmission and (iii) simulation of a virtual scenario. An experiment by means of a multifactorial analysis of variance was designed considering four factors for a CPR session: (i) previous training in CPR, (ii) frequency of compressions, (iii) presence of auditory suggestions and (iv) presence of color indicator. Our findings point out that the more previous training in CPR a user of the VirtualCPR system has, the greater the percentage of correct compressions obtained from a virtual CPR session. Setting the rate to 100 or 150 compressions per minute, turning on or off the auditory suggestions and turning the color indicator on or off during the session have no significant effect on the results obtained by the user.

A novel approach to estimating the Doppler shift frequency from quadrature mixer output

2017 ◽  
Vol 88 (7) ◽  
pp. 073503 ◽  
Author(s):  
M. Y. Wang ◽  
A. D. Liu ◽  
C. Zhou ◽  
J. Q. Hu ◽  
H. Li ◽  
...  
Keyword(s):  
Doppler Shift ◽  
Novel Approach ◽  
Shift Frequency

Robust Impedance Control of Manipulators Carrying a Heavy Payload

2010 ◽  
Vol 132 (5) ◽  
Author(s):  
Farhad Aghili
Keyword(s):  
Force Measurement ◽  
Impedance Control ◽  
Stability And Convergence ◽  
Robot Dynamics ◽  
Control Input ◽  
Heavy Load ◽  
Impedance Model ◽  
Force Moment ◽  
Loop Feedback ◽  
The Stability

A heavy payload attached to the wrist force/moment (F/M) sensor of a manipulator can cause the conventional impedance controller to fail in establishing the desired impedance due to the noncontact components of the force measurement, i.e., the inertial and gravitational forces of the payload. This paper proposes an impedance control scheme for such a manipulator to accurately shape its force-response without needing any acceleration measurement. Therefore, no wrist accelerometer or a dynamic estimator for compensating the inertial load forces is required. The impedance controller is further developed using an inner/outer loop feedback approach that not only overcomes the robot dynamics uncertainty, but also allows the specification of the target impedance model in a general form, e.g., a nonlinear model. The stability and convergence of the impedance controller are analytically investigated, and the results show that the control input remains bounded provided that the desired inertia is selected to be different from the payload inertia. Experimental results demonstrate that the proposed impedance controller is able to accurately shape the impedance of a manipulator carrying a relatively heavy load according to the desired impedance model.

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