Comparison of force measurement systems for hand tools

2000 ◽  
Vol 2 (3) ◽  
pp. 191-200
Author(s):  
Tanja Niemel\"a ◽  
Markku Lepp\"anen ◽  
Minna P\"aivinen ◽  
Markku Mattila

Ergonomic properties of a pair of pruning shears were tested using a new laboratory measurement system for non-powered hand tools. With this system, it is possible to measure simultaneously the EMG activity of two muscles, the opening angle of hand tool blades by means of a potentiometer and, by means of strain gages, the force transmitted to the handle. A measurement system was tested by comparing the forces needed to cut wood of a certain diameter, and the actual force required, as measured by a material-testing system. The correlation between forearm flexor muscle activity and the compression force created by the user was investigated. The evaluation of the experimental testing system for non-powered hand tools has shown that there are methods for the measurement of force demand and opening angle. However, some improvements are recommended before this measurement system is used widely in the field.

Author(s):  
Tanja Niemelä ◽  
Markku Leppänen ◽  
Minna Päivinen ◽  
Markku Mattila

During the Eurohandtool Project an experimental testing system for non-powered hand tools was developed for laboratory testing. With this system, it is possible to measure simultaneously (1) the EMG activity of two muscles, (2) the opening angle of hand tool blades by means of a potentiometer and, (3) by means of strain gages, the force transmitted to the handle. The first part of evaluation of the system was to determine its time of warming-up, reliability, linearity and repeatability. This paper concentrates on the second part, during which the aim was to test the measurement system by comparing the forces needed to cut wood of a certain diameter, and the actual force required, as measured by a material-testing system. The correlation between forearm flexor muscle activity and the compression force created by the user was investigated. The evaluation of experimental testing system for non-powered hand tools has shown that there are methods to measure force demand, opening angle and EMG-activity simultaneously. However, it is recommended to make some improvements before this measurement system can be taken into widespread use.


Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 588
Author(s):  
Benjamin C. Smith ◽  
Brett C. Ramirez ◽  
Steven J. Hoff

Many climate-controlled agricultural buildings use direct gas-fired circulating heaters (DGFCH) for supplement heat. There is no standardized test to calculate thermal efficiency for these heaters. This study aimed to develop a measurement system and analytical analysis for thermal efficiency, quantify the measurement uncertainty, and assess economics of DGFCH efficiency. The measurement system developed was similar to the ASHRAE 103 standard test stand with adaptations to connect the apparatus to the DGFCH. Two different propane measurement systems were used: input ratings < 30 kW used a mass flow system and input ratings > 30 kW used a volumetric gas meter. Three DGFCHs (21.9, 29.3, 73.3 kW) were tested to evaluate the system. Thermal efficiencies ranged from 92.4% to 100.9%. The resulting uncertainty (coverage factor of 2; ~95% Confidence Interval) ranged from 13.1% to 30.7% for input ratings of 56.3 to 11.4 kW. Key sources of uncertainty were propane and mass flow of air measurement. The economic impact of 1% difference in thermal efficiency ranged from USD $61.3 to $72.0 per heating season. Refinement of the testing system and procedures are needed to reduce the uncertainty. The application of this system will aid building designers in selection of DGFCHs for various applications.


Sensors ◽  
2019 ◽  
Vol 19 (11) ◽  
pp. 2641 ◽  
Author(s):  
Junghoon Park ◽  
Sangjoon Kim ◽  
Youngjin Na ◽  
Yeongjin Kim ◽  
Jung Kim

Wearable ground reaction force (GRF) measurement systems make it possible to measure the GRF in any environment, unlike a commercial force plate. When performing kinetic analysis with the GRF, measurement of multiaxial GRF is important for evaluating forward and lateral motion during natural gait. In this paper, we propose a bendable GRF measurement system that can measure biaxial (vertical and anterior-posterior) GRF without interrupting the natural gait. Eight custom small biaxial force sensors based on an optical sensing mechanism were installed in the proposed system. The interference between two axes on the custom sensor was minimized by the independent application of a cantilever structure for the two axes, and the hysteresis and repeatability of the custom sensor were investigated. After developing the system by the installation of force sensors, we found that the degree of flexibility of the developed system was comparable to that of regular shoes by investigating the forefoot bending stiffness. Finally, we compared vertical GRF (vGRF) and anterior-posterior GRF (apGRF) measured from the developed system and force plate at the same time when the six subjects walked, ran, and jumped on the force plate to evaluate the performance of the GRF measurement system.


2012 ◽  
Vol 463-464 ◽  
pp. 684-688
Author(s):  
Daniel Popescu ◽  
Stefan Buzatu ◽  
Raluca Gavrila ◽  
Marian Popescu

The paper presents two measurement systems for the dynamic components of the grinding forces in case of robots that perform finishing operations. The optimization of the measurement system is performed at the force measurement captor level using a special structure elastic element within the digital command robot driving system.


Author(s):  
Francesco Braghin ◽  
Federico Cheli ◽  
Emiliano Giangiulio ◽  
Federico Mancosu

The measurement of tyre-road contact forces is the first step towards the development of new control systems for the improvement of vehicle safety and performances. At present, tyre-road contact force measurement systems are very expensive and modify the non suspended vehicle inertia due to their high mass and rotational inertia moment. Thus, vehicle dynamics is significantly affected. The measured contact forces are therefore not fully representative of the contact forces that the tyres will experience during real working conditions. A new low-cost tyre-road contact force measurement system has been developed that is installable on any type of wheel. Its working principle is based on the measurement of three deformations of the wheel. Through a dynamic calibration of the instrumented wheel it is possible to reconstruct all three contact force and torque components once per wheel turn. These forces are then sent to the vehicle chassis and may be used by on-board active control systems to improve vehicle safety and performances. Validation tests were carried out with a vehicle having all four wheels equipped with the low-cost tyre-road contact force measurement system. It was possible to reconstruct contact forces once per wheel turn in any working condition with a precision that is comparable to that of existing high-cost measurement systems ([1], [2], [3], [4], [5]).


Sensor Review ◽  
2022 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Xiang Li ◽  
Keyi Wang ◽  
Yan Lin Wang ◽  
Kui Cheng Wang

Purpose Plantar force is the interface pressure existing between the foot plantar surface and the shoe sole during static or dynamic gait. Plantar force derived from gait and posture plays a critical role for rehabilitation, footwear design, clinical diagnostics and sports activities, and so on. This paper aims to review plantar force measurement technologies based on piezoelectric materials, which can make the reader understand preliminary works systematically and provide convenience for researchers to further study. Design/methodology/approach The review introduces working principle of piezoelectric sensor, structures and hardware design of plantar force measurement systems based on piezoelectric materials. The structures of sensors in plantar force measurement systems can be divided into four kinds, including monolayered sensor, multilayered sensor, tri-axial sensor and other sensor. The previous studies about plantar force measurement system based on piezoelectric technology are reviewed in detail, and their characteristics and performances are compared. Findings A good deal of measurement technologies have been studied by researchers to detect and analyze the plantar force. Among these measurement technologies, taking advantage of easy fabrication and high sensitivity, piezoelectric sensor is an ideal candidate sensing element. However, the number and arrangement of the sensors will influence the characteristics and performances of plantar force measurement systems. Therefore, it is necessary to further study plantar force measurement system for better performances. Originality/value So far, many plantar force measurement systems have been proposed, and several reviews already introduced plantar force measurement systems in the aspect of types of pressure sensors, experimental setups for foot pressure measurement analysis and the technologies used in plantar shear stress measurements. However, this paper reviews plantar force measurement systems based on piezoelectric materials. The structures of piezoelectric sensors in the measurement systems are discussed. Hardware design applied to measurement system is summarized. Moreover, the main point of further study is presented in this paper.


1991 ◽  
Vol 35 (2) ◽  
pp. 366-380
Author(s):  
Toshimitsu Iinuma ◽  
Nobuhito Gionhaku ◽  
Yoshihiko Moriya ◽  
Koji Takeuchi ◽  
Hideaki Takeuchi ◽  
...  

2006 ◽  
Author(s):  
Kihyo Jung ◽  
Heecheon You ◽  
Ochae Kwon

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Andrea Cristina de Lima-Pardini ◽  
Raymundo Machado de Azevedo Neto ◽  
Daniel Boari Coelho ◽  
Catarina Costa Boffino ◽  
Sukhwinder S. Shergill ◽  
...  

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