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Sensors and measurement systems have a key position in the production process in industrial 4.0. To optimize the quality of the production of workpieces that have complex surfaces, such as molds, dies, turbine blades, and others, it is necessary to develop machine tool metrology and machining strategies. So far, dynamic contouring especially trajectory has not been considered important, because they are still considered related to the feed motion. In this paper, an investigation of the trajectory errors of the servo feed drive system of the machine tool is carried out using an artifact and an optical scanning measurement system using a laser displacement sensor. The artifact is mounted on a machine tools table to realize the trajectory errors investigation of the feed motion. The laser displacement sensor can scan the surface of an artifact with sub-micron motion accuracy. To evaluate the measurement accuracy of servo feed motion, experiments to investigate trajectory errors were conducted, and the measurement system of the precision artifact is carried out by using the laser displacement sensor. [ABSTRACT FROM AUTHOR]

Milling is one type of cutting process that is most often used in the manufacturing industry. Flank wear is a wear phenomenon on the cutter that usually occurs in milling. This wear can affect the accuracy of the product and the quality of the cutting finish surface and can cause damage to the cutting tool. This paper will discuss how to improve the accuracy of cutting tool wear predictions based on vibration signals obtained from the machining process. The signals from the milling process are decomposed by Variational Mode Decomposition (VMD) method before being applied to the machine learning algorithm. As a comparison level of accuracy, the root mean square error (RMSE) parameter is used to determine the error between the actual value and the predicted value of the trained model. The results of the experiments show that using the VMD decomposition feature can improve the performance of the Support Vector Machine (SVM) algorithm in predicting tool wear when compared to those using the time and frequency domain features or those using only the time domain features [ABSTRACT FROM AUTHOR]

Boring bars are widely used in deep-hole machining. Vibration often occurs in the boring process due to the low stiffness of the long cantilever boring bar. Shape and material selection are decisive factors for increasing rigidity in boring bars. The vibrations produced in a boring tool in internal turning deteriorate the machined surface quality and reduce the tool life, which results in massive noise during the machining. This paper has investigated the effect of material selection on building a passive constrained boring bar with a hybrid geometric-material layer to chatter mitigation. Initially, the dynamic models of the conventional are thoroughly studied using Euler-Bernoulli beam theory (EBT) and validated with finite element modeling (FEM). Use the obtained data to create a boring bar model and conduct field tests. The frequency response functions (FRFs) obtained from simulation tests estimate the modal parameters (Natural Frequency). The semi-analytical stability lobe diagrams (SLDs) are plotted with the conventional and model boring bar for the boring system. The resulting natural frequency is 226 Hz with a deflection value of 1.662 mm at a load of 1,350 N in a radial direction. The natural frequency is not as significant as an increase compared to combining two different materials. [ABSTRACT FROM AUTHOR]

Geothermal turbine blade can be made by machining process using a 5-Axis Turn-Mill CNC Machine and the raw material is generally SUS 410 stainless steel which tend to be a difficult to cut material. This paper presented the vibration response in Turn-Milling of SUS 410 with different rough milling strategy to investigate the characteristics of these strategies. Initially, the modal parameters were measured by hammering test. Then, the turn-milling tests were conducted for a long cylindrical workpiece with a flat end mill using raster and vortex strategy extracted from PowerMill software. In this machining process, the axial depth changes gradually as the tool moves along the cutting path. Acceleration signals of machining were obtained by a three-axis accelerometer and analyzed by Fast-Fourier Transform (FFT). The results showed that vortex strategy has a significant lower vibration amplitude than raster's at every radial and axial depth of cut, there is no chatter detected in vortex's frequency domain, while in raster's there is chatter near its natural frequency. [ABSTRACT FROM AUTHOR]

Signal characterization using the capacitive measurement method is studied on the effect of frother dosage in the two-phase column flotation process. The aim of the study is to characterize the signal on the effect of frother dosage. A laboratory flotation column with 0.05 m diameter and 1.25 m height is used for the experiment. Frother of methyl isobutyl carbinol (MIBC) with the concentration of 1-50 ppm is used as a frother and the air injection from 1 to 5 liter per minute (l/m) is given to each frother dosage. All experiments use distilled water to maintain the purity of water since its purity affects the electrical properties. The results show that the capacitive signals as a function of time with and without the frother are different, in which the fluctuation of the process without frother is higher and it appears more frequent than with the frother, especially the difference is clearly seen at the air injection of 2.5 l/m. Furthermore, the capacitive signal decreases as the frother dosage increases. This occurs because the more frother dosage tends to produce more bubble which can decrease the capacitive signal. Based on this result, the effect of frother dosage can be characterized using the capacitive measurement method. Therefore, it has a potency to be developed as the process control and monitoring technology in the field of the flotation process. [ABSTRACT FROM AUTHOR]

A preliminary study of column flotation monitoring process using electrical capacitance volume tomography (ECVT) was conducted. ECVT was one of the monitoring systems which based on the capacitance measurement. It was used to understand the phenomenon that occurs inside the column in a three-dimensional (3-D) image. A linear back projection (LBP) algorithm technique was used to reconstruct the 3-D ECVT images from all measurement data obtained in this study. As a preliminary study, the effect of gas injection in the two-phase (liquid and gas) system was conducted. This study is conducted to assess the possibility of ECVT system in the monitoring of column flotation process. The experiments were conducted by using column flotation with 5 cm diameter and 150 cm height in which a sparger was installed at the bottom of column to inject air inside the column. 32-CH rectangular ECVT sensor was installed at 13 cm above the sparger and placed around the column. The gas injection variations used were 2-7 l/min with interval 1 l/min and all experiments were conducted at room temperature. Based on the signal and image analysis, the signals and 3-D ECVT images showed differences when the gas injection was varied. An increase in gas injection will decrease the fluctuation of signal intensity which correlates to the 3-D ECVT images. Average signals obtained by ECVT when given gas injection variations were in the range of 440.09 to 453.62 mV from high to low gas injection. Based on these results, ECVT has a prospect as an imaging tool to monitor the column flotation process. And also, hopefully, based on the analysis of 3-D images generated by ECVT system, the metallurgical performance would be analyzed in the further researches. [ABSTRACT FROM AUTHOR]