A new contact-type on-machine measurement system is designed and developed for the evaluation of a micro cutting edge profile. The measurement system is composed of a compact probe unit having a ...sharp stylus mounted on a flexible beam, an inner displacement sensor for the detection of the stylus displacement, and a two-axis precision positioning system. For the evaluation of tool faces having a steep slope, a new probing procedure with the enhancement of the inner displacement sensor integrated into the probe unit is newly proposed. After the design and development of the probe unit, the feasibilities of the developed measurement system and the proposed probing procedure are demonstrated through some basic experiments. Regarding the out-of-straightness and angular error motion of the two-axis positioning system employed in the developed measurement system, a pair of length gauges is newly employed to reduce the influences of error motions of the stage system. The topographic profile of the micro cutting edge obtained by the measurement system with the modified probe unit is then compared with those obtained by a commercial stylus profiler and a laser confocal microscope. The feasibility and effectiveness of the developed on-machine tool edge profile measurement system are also demonstrated through uncertainty analysis based on the GUM with the Monte-Carlo method.
•A contact-type on-machine cutting edge measurement system is developed.•A stylus on a flexible beam has been used for low force measurement.•A probing procedure with an inner displacement sensor has been proposed.•Uncertainty of apex angle measurement has been analyzed based on GUM.•An expanded uncertainty of 0.14° has successfully been achieved.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Purpose:
Decreased prostatic compliance as a result of benign prostatic enlargement can result in bladder outlet obstruction. This changes the urethral pressure profile during voiding. In this study, ...the authors propose noninvasive estimation of this pressure profile. In four soft tissue mimicking models of the urethra with increasing degree of obstruction, the authors measured deformation of the wall during flow, using ultrasound imaging. Combined with estimates of the model compliance, the authors were able to estimate the pressure profile.
Methods:
First, the compliances (Young's moduli) of the four models were derived by applying static luminal pressure and measuring the resulting strain of the tissue using an ultrasound imaging system. Next, continuous flow was applied to the models and the strain in the urethral wall was measured similarly. The luminal pressure profile was estimated from the strain (measured under continuous flow conditions) and the derived compliance (measured under static pressure conditions). The estimated pressures up‐ and downstream of the obstruction were compared with the corresponding measured pressures. In the obstructed region, the strain gradient was estimated using linear regression.
Results:
The luminal pressure values estimated from the ultrasound data up‐ and downstream of the obstruction were not significantly different from the corresponding measured pressures. The general pressure profile showed a decrease along the length of the obstruction followed by a small increase after the obstruction. The strain gradient in the obstructed region reflected the decrease in urethral pressure and increased with flow rate and degree of obstruction.
Conclusions:
The results from this model study illustrate the feasibility of noninvasive estimation of the urethral pressure profile using ultrasound. This offers the prospect of a noninvasive, ultrasound based diagnostic tool for assessment of bladder outlet obstruction in men with lower urinary tract symptoms.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Although micrometer is a representative length measuring instrument, it is usually difficult for beginners to read the measuring value correctly because of its unique scale marking system. Therefore, ...the emphasis in the educational practice and training program of mastering micrometer was mainly put on how to read its scale. However, with the popularization of micrometers with digital displays, the scale reading becomes much less important. On the other hand, our comparison of measuring operations between skilled workers and beginners showed that the situation of contact between the micrometer′s spindle and the measured object seems more important than the scale reading itself. Particularly, the measuring force applied when the micrometer comes in contact with the measured object should always be constant, and the control of the measuring force has become an important skill for mastering the use of the micrometer. In this study, first an apparatus to measure the measuring force of the micrometer was developed. Then, the force applied by workers under different skilled levels was investigated by using this apparatus. Furthermore, related educational practice was conducted and the result showed that the developed apparatus was quite effective in measuring skill training.
In this study, a resonance based touch trigger probe that detects a contact with lower measuring force is developed. The touch trigger probe is consisted of 2 parallel thin cross-shaped leaf springs ...and a piezoelectric actuator. The fundamental concepts and analysis by FEM are described. From the analysis, when the probe vibrates at the frequency of the 5th natural mode, the probe is considered to oscillate like an inverted pendulum with the center of oscillation being near the tip of the stylus. If a contact has been made when the probe is in the condition of natural vibration, the waveform is changed. Thus a contact can be detected by catching the change of waveform. A prototype is constructed and tested. According to the results of experiments, the measuring force is smaller than 50μN, and the repeatability could be smaller than 500 nm. Meanwhile, because the trajectory of the tip of the stylus remains still unknown, further analytic investigation is needed and it will lead to the optimum design.
Development of Pneumatic Ball Probe (2nd Report) KUO, Chih-Che; TAKAMASU, Kiyoshi; HIRAKI, Masahiko ...
Journal of the Japan Society for Precision Engineering,
2000, Volume:
66, Issue:
4
Journal Article
Open access
In this paper, a novel touch trigger probe which has a totally different construction concept, namely, a pneumatic ball probe has been developed. This touch trigger type pneumatic ball probe consists ...of a small probe ball, a thin pipe, a pneumatic trigger sensor and a vacuum pump. The fundamental concepts and theoretical analysis of the pneumatic ball probe are described. A prototype of the probe is made and tested. From the experimental tests, the measuring force is reduced to a great extent by using this structure of separating the probe ball from the stylus. The fundamental analysis and the experiment show that it is possible to measure the distance between two walls such as a groove or a drilled hole without restriction of material for two dimension measurement. Using this pneumatic ball probe, it is found that the width between gauge blocks could be measured within a standard deviation of 1.1 μm as well as it is influenced by the vacuum of probe and the inclination of the measurement.
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