Methodology for obtaining C3 continuity on tool trajectory featuring acceleration and jerk constraint on computer numerical control machine

Author(s):  
J R Rivera-Guillen ◽  
R J Romero-Troncoso ◽  
R A Osornio-Rios ◽  
A Domínguez-González

High-quality material manufacture requires the improvement of the computer numerical control (CNC) machine performance. Such task can be achieved by considering the tool trajectory, in which it is important to minimize the acceleration and jerk levels. Previous research works are focused on providing smooth movements at most with C2 continuous trajectories, and the results of using C3 continuity in the trajectory are not evaluated. The contribution of this study is the design of a methodology for obtaining C3 tool trajectories while acceleration and jerk levels are constrained through adaptive feed-rate. C3 and C2 trajectories are executed in a CNC machine. Speed, acceleration, and jerk are monitored in order to validate the proposed methodology and to analyse and quantify the differences between using C2 and using C3 trajectories.

2013 ◽  
Vol 446-447 ◽  
pp. 645-649
Author(s):  
Jie Yu ◽  
Wu Sheng Tang ◽  
Ting Ting Wang ◽  
Qiao Chan Li ◽  
Zhan Guo Li

Reliability is most important to the CNC machine tools and reliability estimation is a very important part of the reliability which has magnificence to allocate resources and put forward scientific policy. Reliability evaluation of computer numerical control machine tools can use all sorts of effective information to decrease the size of test samples and save the development costs and shorten the production cycle. The paper put forward to use D-S evidence theory and the information of experts system to decrease the uncertainty of the reliability evaluation of computer numerical control machine tools. The results show that the method can effectively decrease the uncertainty of the reliability evaluation of computer numerical control machine tools.


Author(s):  
Shao-Hsien Chen ◽  
Zih-Jing Haung

Nowadays, the feeding systems of computer numerical control machine tools are lubricated by periodic oil supply or fixed stroke, the lubrication is insufficient in the case of high load and high-speed movement, and the lubrication is excessive during finishing and low feed rate. This study discusses the optimum lubrication timing of the feeding system. When the feeding system is moving, the servomotor torque value and current, accuracy, and oil film thickness are measured by sensors. Moreover, the lubrication characteristic model is validated and built by using the sensor values, and the optimal lubrication state estimation is obtained by using the back-propagation neural model. Then analyzed and feedback to the machine tool controller, to intelligent the lubrication system. According to the test, when the feed rate is increased by 5 m/min, the friction coefficient increases with rate, increasing the output of the frictional value of the work table by 6.90%. When the load is increased by 175 kg, the friction coefficient decreases with load, reducing the frictional value output of table movement by 6.71%. In the relationship between oil film thickness and current, the accuracy difference between the prediction and actual test results is less than 10%; in the case of the same accuracy, the oil supply frequency is reduced by 80%, and environmentally friendly machine tool has been achieved.


2013 ◽  
Vol 274 ◽  
pp. 7-10 ◽  
Author(s):  
Xiao Meng Lu

Based on the study of ergonomics, this paper summarizes morphological characteristics of computer numerical control machine tool modeling, and according to the work functions and operation characteristics, it gives an analysis of the principles and requirements of computer numerical control machine tool modeling design and ergonomics, which will help broaden our thoughts in designing more vivid, lively and rapid new computer numerical control machine tool modeling.


2013 ◽  
Vol 561 ◽  
pp. 626-629
Author(s):  
Shang Jun Guan ◽  
Ke Yang

Our self-developed a combining CNC machine tool of turning and grinding uses modular structure,easy to operate and easy to service,so it has been widely applied. For the most part, there will be alarms when the combining CNC machine tool of turning and grinding has faults, but sometimes there may be no alarm. This paper briefly presents the no alarm faults examples and its resolutions for a combining CNC (Computer Numerical Control) machine tool of turning and grinding, which provides an important basis for technicians to operate and maintain the Combining CNC machine tool of turning and grinding.


2011 ◽  
Vol 105-107 ◽  
pp. 2217-2220
Author(s):  
Mu Lan Wang ◽  
Jian Min Zuo ◽  
Kun Liu ◽  
Xing Hua Zhu

In order to meet the development demands for high-speed and high-precision of Computer Numerical Control (CNC) machine tools, the equipped CNC systems begin to employ the technical route of software hardening. Making full use of the advanced performance of Large Scale Integrated Circuits (LSIC), this paper puts forward using Field Programmable Gates Array (FPGA) for the functional modules of CNC system, which is called Intelligent Software Hardening Chip (ISHC). The CNC system architecture with high performance is constructed based on the open system thought and ISHCs. The corresponding programs can be designed with Very high speed integrate circuit Hardware Description Language (VHDL) and downloaded into the FPGA. These hardening modules, including the arithmetic module, contour interpolation module, position control module and so on, demonstrate that the proposed schemes are reasonable and feasibility.


Author(s):  
Yan Ran ◽  
Teng Zhang ◽  
Zongyi Mu ◽  
Genbao Zhang ◽  
Hongwei Wang ◽  
...  

Since computer numerical control machine tool is composed of multiple meta-action units to achieve one specific function, including the meta-action units' own quality, it still needs to control the coupling relationships among different meta-action units' quality characteristics to guarantee the whole machine's quality. In this article, a method of quality characteristic decoupling planning based on meta-action unit for computer numerical control machine tool was proposed. Firstly, the coupling constraint models based on meta-action unit were established. Secondly, the comprehensive coupling strengths of meta-action units were calculated and introduced into the design structure matrices. Thirdly, multidisciplinary design optimization method was adopted to obtain the optimized control sequence of different meta-action units' quality characteristics. What is more, automatic pallet changer rotary motion of computer numerical control machine tool was taken as an example to illustrate the rightness and effectiveness of this method.


2015 ◽  
Vol 809-810 ◽  
pp. 1504-1509 ◽  
Author(s):  
Ana Lacramioara Ungureanu ◽  
Gheorghe Stan ◽  
Paul Alin Butunoi

In this paper are proposed two new approaches to maintenance strategies for Computer Numerical Control (CNC) machine tools. The analysis is done for different families of CNC machine tools from S.C. Elmet Bacau, a company specialized in aviation. In maintenance actions applied to CNC machine tools is very important to know the evolution of defects and critical state of electrical and mechanical components. The results of this analysis concludes that maintenance actions can be judged by the developing time period diagram, between failure appearance and interruptions in operation. It is also analyzed the financial impact, revealed from known maintenance strategies adopted on CNC machine tools, resulting in a positive approach of condition based maintenance.


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