An intelligent approach to non-constant feed rate determination for high-performance 2D CNC milling

Author(s):  
Zezhong C. Chen ◽  
Zhibin Miao
1993 ◽  
Vol 58 (7) ◽  
pp. 1476-1484
Author(s):  
Václav Dušek ◽  
František Skopal

For a chemical reactor with constant volume feed rate equations have been derived which describe the time dependences of concentration of the reaction components, and their approximation has been suggested. The applicability of the approximation has been verified on a model redox system Ce(IV)/V(IV) in sulfuric acid medium.


Aviation ◽  
2021 ◽  
Vol 25 (4) ◽  
pp. 268-277
Author(s):  
Volodymyr Dzyura ◽  
Pavlo Maruschak ◽  
Stoyan Slavov ◽  
Diyan Dimitrov ◽  
Dimka Vasileva

The basic regularities in the influence of processing parameters on the geometrical characteristics of the partially regular microreliefs, formed on the rotary body face surface, are established. Combinations of partially regular microreliefs are formed by using a contemporary CNC milling machine, and an advanced programing method, based on previously developed mathematical models. Full factorial experimental design is carried out, which consist of three factors, varied on three levels. Regression stochastic models in coded and natural form, which give the relations between the width of the grooves and the deforming force, feed rate and the pitch of the axial grooves, are derived as a result. Response surfaces and contour plots are built in order to facilitate the results analysis. Based on the dependencies of the derived regression stochastic models, it is found that the greatest impact on the width of the grooves has the magnitude of the deforming force,followed by the feed rate. Also, it is found that the axial pitch between adjacent toolpaths has the least impact on the width of the grooves. As a result of the full-factorial experiment, the average geometric parameters of the microrelief grooves were obtained on their basis. When used, these values will provide for the required value of the relative burnishing area of the surface with regular microreliefs, and, accordingly, the specified operational properties.


Author(s):  
Adel Sedaghati ◽  
Hamed Bouzary

In this paper, the effect of water cooling on mechanical properties and microstructure of AA5086 aluminum joints during friction stir welding is investigated. For doing so, the mechanical and microstructural behavior of samples welded both in air and in water was analyzed. Tests were performed involving both butt and lap welds and the results were compared. The effect of rotational speed at constant feed rate of 50 mm/min and changing rotational speed ranging from 250 to 1250 r/min was investigated. The results showed a significant change in the tensile behavior of the butt-welded specimens due to water cooling. In addition, welding was performed at constant spindle speed of 800 r/min and various traverse speeds (25 mm/min to 80 mm/min) to determine the effect of feed rate. The strength increases at first, but then decreases dramatically along with the feed rate which is due to the occurrence of a groove defect. Results showed some generally positive impacts of water cooling which are discussed in terms of tensile results, hardness distributions and microstructure analysis.


2020 ◽  
Vol 2 (2) ◽  
pp. 49-60
Author(s):  
Farizi Rachman Farizi Rachman ◽  
Bayu Wiro K ◽  
Tri Andi Setiawan ◽  
Pradita Nurkholies

Industri manufaktur di Indonesia semakin meningkat seiring dengan tingkat kebutuhan manusia yang beraneka ragam dan memicu berkembangnya teknologi, salah satunya industri proses permesinan atau machining. Kualitas produk yang baik dapat dilihat dari tingkat kekasaran permukaannya karena kekasaran permukaan dapat mempengaruhi performa yang berkaitan dengan aspek fungsional dari produk. Pada penelitian ini telah dilakukan optimasi setting parameter CNC milling terhadap kekasaran permukaan pada material S50C dengan end mill HSS diameter 8 mm. Material S50C banyak digunakan dalam manufaktur mesin seperti mekanis base plate, roda gigi, standart punch head dan komponen mesin lainnya. Penelitian ini menggunakan metode Taguchi. Parameter yang digunakan yaitu spindle speed, Feed rate dan depth of cut dengan cairan pendingin sebagai variabel konstan. Parameter optimum untuk mendapatkan nillai kekasaran yang rendah yaitu spindle speed 1100 rpm, feed rate 46 mm/min dan depth of cut 0.5 mm. Dengan taraf signifikansi 0.1 menunjukkan bahwa spindle speed berpengaruh secara signifikan dengan kontribusi 38.42% diikuti feed rate dengan kontribusi 34.16%.


Author(s):  
Rau´l M. del Toro ◽  
Michael C. Schmittdiel ◽  
Rodolfo E. Haber-Guerra ◽  
Rodolfo Haber-Haber

A simple, fast, network-based experimental procedure for identifying the dynamics of the high-performance drilling (HPD) process is proposed and successfully applied. This identification technique utilizes a single-input (feed rate), single-output (resultant force) system with a dual step input function. The model contains the delays of both the network architecture (a PROFIBUS type network) and the dead time related with the plant dynamic itself. Classical identification techniques are used to obtain first order, second order, and third order models on the basis of the recorded input/output data. The developed models relate the dynamic behavior of resultant force versus commanded feed rate in HPD. Model validation is performed through error-based performance indices and correlation analyses. Experimental verification is performed using two different work piece materials. The models match perfectly with real-time force behavior in drilling operations and are easily integrated with many control strategies. Furthermore, these results demonstrate that the HPD process is somewhat non-linear with a remarkable difference in gain due to work piece material; however, the dynamic behavior does not change significantly.


Author(s):  
Mohammed Abdel-Nasser ◽  
Omar Salah

Robotics technology is used widely in minimally invasive surgery (MIS) which provides high performance and accuracy. The most famous robot arm mechanisms, which are used in MIS, are tendon-driven mechanism (TDM), and concentric tube mechanism (CTM). Unfortunately, these mechanisms until now have some limitations, i.e. making friction with the tissue during extracting and retracting and strain limits, for TDM and CTM respectively. A new hybrid concentric tube-tendon driven mechanism (HCTDM) is proposed to overcome these limitations. HCTDM enables the end-effector to get close to and get away from the surgical area during the operation without harming the tissue and with more flexibility. In addition to that, the workspace increases as a result of this combination, too. This benefit serves MIS, especially endoscopic surgeries (ESs). We did an analytical study of this idea and got the forward kinematics. In the inverse kinematics, an intelligent approach which is called an adaptive neuro-fuzzy inference system (ANFIS) is used because the closed-form solution is more complicated for such these mechanisms. Finally, HCTDM is analyzed and evaluated by using a computer simulation. The simulation results show that the workspace becomes wider and has more dexterity than use TDM or CTM individually. Furthermore, various trajectories are used to test the mechanism and the kinematic analysis, which show the mechanism can follow and track the trajectories with maximum mean error 1.279, 0.7027, and [Formula: see text] for X, Y, and Z axes respectively.


Author(s):  
Hanmant V. Shete ◽  
Madhav S. Sohani

Machining with pressurized coolant is nowadays widely accepted technique in the manufacturing industry, especially in high performance machining conditions. The data on the effects of variation of high coolant pressure in drilling operation is limited. This paper presents the effect of high coolant pressures along with spindle speed, feed rate and peck depth on hole diameter accuracy. Experiments were performed on EN9 steel with TiAIN coated through coolant drill on CNC vertical machining center. Taguchi technique was employed for design of experiments and analysis of results. Results showed that the higher values of optimal coolant pressure and spindle speed were demanded for drilling at bottom of hole as compared to that for drilling at top of hole. The optimal values of feed rate and peck depth were same for both the cases of drilling at top and bottom of hole. Use of high coolant pressure in drilling permits higher peck depth for better hole diameter control which results in reduced cycle time and hence production cost.


2016 ◽  
Vol 36 (3) ◽  
pp. 89 ◽  
Author(s):  
Orquídea Sánchez López ◽  
Armando Rosas González ◽  
Ignacio Hernández Castillo

The aim of this research is to analyze the influence of cutting speed, feed rate and cutting depth on the surface finish of grade GSP-70 graphite specimens for use in electrical discharge machining (EDM) for material removal by means of Computer Numerical Control (CNC) milling with low-speed machining (LSM). A two-level factorial design for each of the three established factors was used for the statistical analysis. The analysis of variance (ANOVA) indicates that cutting speed and feed rate are the two most significant factors with regard to the roughness obtained with grade GSP-70 graphite by means of CNC milling. A second order regression analysis was also conducted to estimate the roughness average (Ra) in terms of the cutting speed, feed rate and cutting depth. Finally, the comparison between predicted roughness by means of a second order regression model and the roughness obtained by machined specimens considering the combinations of low and high levels of roughness is also presented.


Author(s):  
Rodolfo E. Haber-Guerra ◽  
Rodolfo Haber-Haber ◽  
Diego Martín Andrés ◽  
Angel Alique Palomar

The high-performance drilling (HPD) process has a significant impact on production in many industries, such as the automotive, die/mold and aerospace industries. However, cutting conditions for drilling are generally chosen from a machining-data handbook, requiring operator experience and skill. In order to improve drilling efficiency while preserving tool life, the current study focuses on the design and implementation of a simple, optimal fuzzy-control system for drilling force. The main topic of this study is the design and implementation of a networked fuzzy controller. The control system consists of a two-input (force error and change of error), single-output (feed-rate increment) fuzzy controller with nine control rules, the sup-product compositional operator for the compositional rule of inference, and the center of area as the defuzzification method. The control algorithm is connected to the process through a multipoint interface (MPI) bus, a proprietary programming, and communication interface for peer-to-peer networking that resembles the PROFIBUS protocol. The output (i.e., feed-rate) signal is transmitted through the MPI; therefore, network-induced delay is unavoidable. The optimal tuning of the fuzzy controller using a maximum known delay is based on the integral time absolute error (ITAE) criterion. The goal is to obtain the optimal tuning parameters for the input scaling factors while minimizing the ITAE performance index. In this study, a step in the force reference signal is considered a disturbance, and the goal is to assess how well the system follows set-point changes using the ITAE criterion. The optimization is performed using the Nelder–Mead simplex (direct search) method. The main advantage of the approach presented herein is the design of a simple fuzzy controller using a known maximum allowable delay to deal with uncertainties and nonlinearities in the drilling process and delays in the network-based application. The results demonstrate that the proposed control strategy provides an excellent transient response without overshoot and a slightly higher drilling time than the CNC working alone (uncontrolled). A major issue in high performance drilling is the increase in cutting force and torque that occurs as the drill depth increases. Therefore, the fuzzy-control system reduces the influence of these factors, thus eliminating the risk of rapid drill wear and catastrophic drill breakage.


2020 ◽  
Vol 1 (2) ◽  
pp. 62-71
Author(s):  
Festo Andre Hardinsi ◽  
Oyong Novareza ◽  
Achmad As’ad Sonief

Abstrak Objektif. Getaran yang sering terjadi pada pengerjaan proses produksi menggunakan permesinan CNC milling merupakan hal yang sangat penting untuk diperhitungkan. Getaran ini dapat menyebabkan perubahan dimensi dan mempengaruhi tingkat kualitas benda kerja yang dihasilkan, sehingga efek getaran chatter atau self-excited vibration  pada proses pengerjaan produksi menjadi masalah utama dalam proses permesinan milling. Nilai getaran chatter ditentukan menggunakan grafik SLD secara ekperimental untuk mengetahui batas antara chatter free dan chatter occurs. Material and Metode. Material yang digunakan dalam penelitian ini adalah Stanless steel 304, dengan menggunakan sensor MPU 6050 yang terhubung pada mikrokontroler Arduino Uno menggunakan software LabVIEW 2019 student edition yang digunakan untuk mengidentifikasi nilai acceleration getaran chatter. Besar nilai acceleration diukur menggunakan FFT menggunakan software DIAdem 2019 student. Metode yang digunakan dalam penelitian ini adalah dalam bentuk eksperimental, dengan geometri pahat Variabel Helix Angle (VHA) 2 variasi sudut yaitu 40/42 (Derajat), Spindel Speed sebesar 2000,2500,3000 (RPM) , Axial Depth Of Cut sebesar 0.5, 1.0, 1.5 (mm), dan Feed Rate sebesar 100, 125 dan 150 (mm/s). Hasil. Hasil pada Grafik Stability Lobe Diagram yang didapatkan pada proses permesinan slot milling menggunakan pahat variable helix angle 40/42 derajat dengan feed rate 150 mm/mnt memiliki  chatter free yang lebih tinggi dibandingkan dengan feed rate 100 dan 125 mm/mnt. Kesimpulan.  Dari hasil yang didapatkan bahwa semakin tinggi nilai feed rate maka nilai acceleration getaran chatter semakin rendah. Untuk pengembangan dalam penelitian selanjutkan maka perlu dilakukan pemilihan parameter geometri pahat dengan variasi 3 sudut mata pahat untuk mengetahui nilai getaran chatter yang signifikan. Abstrack Objective.Vibration that often occurs in the production process using CNC milling is very important to be taken into account. This is vibration can cause dimensional changes and affect the level of quality of the workpiece produced. Therefore, effect of chatter vibration or self-excited vibration on production process becomes a major problem in the milling machining process. Chatter vibration values ​​can be determined using experimental SLD for determine boundary between free chatter and chatter occur. Materials and Methods .The material used in this study is stanless steel 304, using the MPU 6050 sensor connected to Arduino Uno mikrokontroler using LabVIEW 2019 student edition software that is used to identify chatter vibration acceleration. Acceleration is measured using FFT using  2019 student DIAdem software. The method used is experimental, geometry Variable Helix Angle 2 angular 40/42 (Degrees), Spindel Speed ​​of 2000,2500,3000 (RPM), Axial Depth Of Cut of 0.5, 1.0, 1.5 (mm), and Feed Rate of 100, 125 and 150 (mm / s). Results. Results in the Graph Lobe Stability Diagram obtained in  slot milling machining process using a variable helix angle of 40/42 degrees with  feed rate of 150 mm / min have higher chatter free compared to feed rates of 100 and 125 mm / min. Conclusion. The results show that  higher the value of  feed rate, chatter vibration acceleration value is lower. For further development in research, it is necessary to select  tool geometry parameters with variations of 3 tool eye angle to determine  chatter vibration significant


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