A Real Time Error Compensation Method for CNC Machine Tools Based on Redevelopment of Human-Machine-Interface

2014 ◽  
Vol 556-562 ◽  
pp. 2519-2522
Author(s):  
Hong Xing Lu ◽  
Jian Guo Yang ◽  
Si Tong Xiang

This paper proposes a new real time error compensation implementation method for CNC machine tools. The proposed method reduces the complexity of compensation system significantly, which takes full advantage of numerical control system. The Compensation Control software is developed based on original Human-Machine-Interface software of Siemens 840D numerical control system. Meanwhile, the compensation controller shares the CPU of with the Man-Machine-Communication module. Due to it hardly needs any external devices except some necessary sensors, the proposed compensation strategy greatly reduces the cost of building a compensation system and the stability of compensation system is enhanced accordingly. Experiments have been conducted and the results show that the proposed method can improve the accuracy of machine tools dramatically.

2012 ◽  
Vol 220-223 ◽  
pp. 1107-1110
Author(s):  
Zhong Wei Ren ◽  
Ming Song ◽  
Lin Yang ◽  
Yu Kun He

An open numerical control system was built based on DMC movement controller. The system was simple and practical for most common CNC machine tools transform. The open numerical control system was introduced, the hardware connection and user interface program were designed combined with CA6140 lathe. The constructed CNC system has general functions of CNC system, the jog and interpolated motion can be realized, and this open control system can reach the requirements of customer. The experiments indicate that the open numerical control system can be applied to other machine tools, it has certain efficiency and usability.


2013 ◽  
Vol 415 ◽  
pp. 188-191 ◽  
Author(s):  
Si Tong Xiang ◽  
Mu Wen Shen ◽  
Jian Guo Yang

A distributed numerical control (DNC) strategy for error compensation on Fanuc and Siemens CNC machine tools is proposed. A DNC network is built in multi-Fanuc CNC machine tools and the error compensation of all the machine tools is realized simultaneously. A human machine interface (HMI) is developed for Siemens 840D CNC machine tools, error components are decoupled in the X, Y and Z directions and they are compensated by 840Ds own function of thermal error compensation. Experimental verification is conducted and it proves that the proposed DNC strategy for error compensation is an effective and precision manner to improve the accuracy of machine tools.


Machines ◽  
2021 ◽  
Vol 9 (9) ◽  
pp. 180
Author(s):  
Cheng-Hsien Kuo ◽  
Po-Cheng Chen

For machining parts with complex shapes, consisting of computer numerical control (CNC) machine tools, different CNC machine tools will be used according to the machining method. If the workpiece is removed for off-machine measurement after machining, when the size is incorrect, it will need to be returned to the CNC machine tool for secondary machining. In this case, the workpiece surface quality and machining accuracy will be affected, which is very time-consuming. On-machine measurement and complex machine center is a key to solve this problem. In the recent researches that the touch probe was integrated on three or five axis machine for error compensation and shape construction based on on-machine measurement, but turning-milling machine was rare. In addition, the most types of parts were thin-walled parts or thin web parts. In this study, a contact measurement system is integrated into a CNC combined turning-milling machine for on-machine measuring. Macro-programming is used to design the machining path of A6061-T6 aluminum alloy hexagonal punch, and the action of probe measurement is added to the machining path. As the measured data exceed the tolerance range, the calculated data are fed back to the controller for machining improvement by compensation. The finished hexagonal punch is measured in a 3D coordinate measuring machine and the error is compared. The experimental results show that the contact probe needs to be corrected before machining, and the size of the corrected workpiece can reach the tolerance range of ±0.01 mm. The size error of rough machining is larger than that of fined machining, and the size error of rough machining will increase with the length of the workpiece.


Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2913
Author(s):  
Rafał Gołębski ◽  
Piotr Boral

Classic methods of machining cylindrical gears, such as hobbing or circumferential chiseling, require the use of expensive special machine tools and dedicated tools, which makes production unprofitable, especially in small and medium series. Today, special attention is paid to the technology of making gears using universal CNC (computer numerical control) machine tools with standard cheap tools. On the basis of the presented mathematical model, a software was developed to generate a code that controls a machine tool for machining cylindrical gears with straight and modified tooth line using the multipass method. Made of steel 16MnCr5, gear wheels with a straight tooth line and with a longitudinally modified convex-convex tooth line were machined on a five-axis CNC milling machine DMG MORI CMX50U, using solid carbide milling cutters (cylindrical and ball end) for processing. The manufactured gears were inspected on a ZEISS coordinate measuring machine, using the software Gear Pro Involute. The conformity of the outline, the tooth line, and the gear pitch were assessed. The side surfaces of the teeth after machining according to the planned strategy were also assessed; the tests were carried out using the optical microscope Alicona Infinite Focus G5 and the contact profilographometer Taylor Hobson, Talysurf 120. The presented method is able to provide a very good quality of machined gears in relation to competing methods. The great advantage of this method is the use of a tool that is not geometrically related to the shape of the machined gear profile, which allows the production of cylindrical gears with a tooth and profile line other than the standard.


Author(s):  
Qin Hu ◽  
Youping Chen ◽  
Jixiang Yang ◽  
Dailin Zhang

Linear motion commands of multi-axis computer numerical control (CNC) machine tools need to be smoothed at the transition corners, because the velocity discontinuities at corners can result in fluctuations on machine tool motions and lead to poor surface quality. However, no research has been reported on local corner smoothing algorithm for four-axis CNC machine tools with two rotary axes by considering their special kinematic characteristics. To this end, this paper proposes an analytical C3 continuous local corner smoothing algorithm for four-axis CNC machines with two rotary axes. After coordinates transformation, the tool tip positions and tool orientations are smoothed by locally inserting specially designed three-dimensional (3D) quintic B-splines and one-dimensional (1D) quintic B-splines into the corners between linear motion segments, respectively. The smoothing algorithm guarantees C3 continuity of the tool tip position and C3 continuous synchronization of the tool orientation related to the tool tip position, through analytically evaluating control points of the inserted microsplines. The maximum error tolerances of the tool tip position and tool orientation are mathematically constrained. Experiments on an in-house developed four-axis machine verify the efficacy of the proposed algorithm, where maximal errors caused by the local corner smoothing algorithm are constrained, the synchronization of the tool orientation and the tool tip position are achieved, and the proposed C3 continuous corner smoothing algorithm has lower jerk and jounce but higher tracking and contour accuracy than C2 continuous algorithm.


2019 ◽  
Vol 9 (13) ◽  
pp. 2701 ◽  
Author(s):  
Li ◽  
Yang ◽  
Gao ◽  
Su ◽  
Wei ◽  
...  

Error compensation technology offers a significant means for improving the geometric accuracy of CNC machine tools (MTs) as well as extending their service life. Measurement and identification are important prerequisites for error compensation. In this study, a measurement system, mainly composed of a self-developed micro-angle sensor and an L-shape standard piece, is proposed. Meanwhile, a stepwise identification method, based on an integrated error model, is established. In one measurement, four degrees-of-freedom errors, including two-dimensional displacement and two-dimensional angle of a linear guideway, can be obtained. Furthermore, in accordance with the stepwise identification method, the L-shape standard piece is placed in three different planes, so that the measurement and identification of all 21 geometric errors can be implemented. An experiment is carried out on a coordinate measuring machine (CMM) to verify the system. The residual error of the angle error, translation error and squareness error are 1.5″, 2 μm and 3.37″, respectively, and these are compared to the values detected by a Renishaw laser interferometer.


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.


2012 ◽  
Vol 488-489 ◽  
pp. 1697-1701
Author(s):  
Rui Wu ◽  
Yuan Kui Xu

With the continuous progress of science and technology, manufacturing has been a huge space for development. Nowadays numerical control system is widely used in manufacturing. Numerical control system is actually manufacturing control system. By actual information required, with decoded by computer, after information processing It will the process control operations of machine tools to process out the right components. With more complexity of manufacturing, we have higher requirements to pretreatment data of numerical control system. This paper will focus on numerical control algorithm and hardware system to study.


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