Research on Workpiece Machining Precision PID Control Model in Closed-Loop Manufacturing Systems

2009 ◽  
Vol 16-19 ◽  
pp. 1174-1178 ◽  
Author(s):  
Jun Lu ◽  
Yu Mei Huang ◽  
Yang Liu ◽  
Wen Wen Li ◽  
Hua Zhong
Keyword(s):  
Experimental Method ◽  
Pid Control ◽  
Error Compensation ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Closed Loop ◽  
Control Model ◽  
Cnc Machining ◽  
Machining Error ◽  
Machining Precision

In this article, a new concept named ‘Closed-loop Manufacturing System’ (CLMS) is introduced. The Workpiece Machining Precision PID Control Model (WMPPCM) is proposed and described. PID error compensation model expressions are structured. The experimental method of WMPPCM is established. In the experiment, WMPPCM could be utilized to estimate the trend of machining error so as to conduct the adjustment before production. The experiment has verified the feasibility and validity of WMPPCM. The experiments have also proved that WMPPCM can decrease machining error more effectively then traditional CNC machining method.

Study on Workpiece Machining Precision PID Control Model in Closed-Loop Manufacturing Systems

2009 ◽  
Vol 419-420 ◽  
pp. 469-472 ◽  
Author(s):  
Jun Lu ◽  
Yu Mei Huang ◽  
Wen Wen Li ◽  
Yang Liu ◽  
Hua Zhong
Keyword(s):  
Pid Control ◽  
Error Compensation ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Closed Loop ◽  
Theoretical Foundation ◽  
Control Model ◽  
Machining Precision ◽  
Processing Error

In this paper, a new concept named “Closed-loop Manufacturing System” (CLMS) is proposed. The Workpiece Machining Precision PID Control Model (WMPPCM) is outlined firstly, in which PID model expressions are structured and the role of proportion, integration, differential adjustment are analyzed. Then, the experimental method of WMPPCM is established to verify the feasibility and validity of this model. In the experiment, WMPPCM could be utilized to estimate the trend of processing error so as to conduct the adjustment before production. It is also proved that WMPPCM in CLMS has a significant effect on error compensation, which builds up the theoretical foundation for paper research on CLMS in terms of WMPPCM.

Research on PID Control Model for Error Compensation in Milling Thin-Wall Parts

2011 ◽  
Vol 127 ◽  
pp. 522-526
Author(s):  
Lei Zhu ◽  
Jun Lu ◽  
Yan Liu
Keyword(s):  
Pid Control ◽  
Error Compensation ◽  
Control Model ◽  
Thin Wall ◽  
Cnc Milling ◽  
Machining Error ◽  
Proportional Integral ◽  
Improving Accuracy

Accuracy of machined components is one of the most critical considerations for any manufacturer. To improve the accuracy by diminishing errors in CNC milling thin-wall parts, this article analyzes sources of errors and provides PID control model to error compensation, namely acquiring offset value by calculating the coefficients of proportional, integral and differential and corresponding errors, and then adjusts codes of next processes. The effectiveness of PID control model in improving accuracy is testified by experiments contrasting with groups of non-compensation and completely-compensation. The experiments have proved that PID control model of CNC milling thin-wall parts can predict machining error trends and have advance regulation.

Kinematic and Dynamic Analysis for Closed-Loop Flexible Manufacturing Systems Using Nonlinear Recursive Method

2006 ◽  
Vol 505-507 ◽  
pp. 1015-1020
Author(s):  
Yunn Lin Hwang ◽  
Shen Jenn Huang
Keyword(s):  
Dynamic Analysis ◽  
Flexible Manufacturing ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Closed Loop ◽  
Recursive Method ◽  
Coupled Equations ◽  
Joint Reaction Forces ◽  
Reaction Forces ◽  
Joint Reaction

In this paper, a nonlinear recursive method for the dynamic and kinematic analysis of a closed-loop flexible manufacturing system is presented. The kinematic and dynamic models are developed using absolute reference, joint relative, and elastic coordinates as well as joint reaction forces. This recursive method leads to a system of loosely coupled equations of motion. In a closed-loop manufacturing system, cuts are made at selected secondary joints in order to form spanning tree structures. Compatibility conditions and reaction force relationships at the secondary joints are adjoined to the equations of open-loop manufacturing systems in order to form closed-loop kinematic and dynamic equations. Using the sparse matrix structure of these equations and the fact that the joint reaction forces associated with elastic degrees of freedom do not represent independent variables, a method for decoupling the joint and elastic accelerations is developed. Unlike existing recursive formulations, this method does not require inverse or factorization of large nonlinear matrices. The application of nonlinear recursive method in kinematic and dynamic analysis of closed-loop manufacturing systems is also discussed in this paper. The use of the numerical algorithm developed in this investigation is illustrated by a closed-loop flexible four-bar mechanism.

Modelling and Design of Closed-Loop Manufacturing Systems

2013 ◽  
Vol 378 ◽  
pp. 367-374 ◽  
Author(s):  
Andrey A. Kutin ◽  
Mikhail Turkin
Keyword(s):  
Analytical Method ◽  
Flexible Manufacturing ◽  
Manufacturing Systems ◽  
Manufacturing System ◽  
Flexible Manufacturing System ◽  
Closed Loop ◽  
Production Systems ◽  
Finite Buffers ◽  
Unreliable Machines

This paper introduces an analytical method for evaluating the performance of closed loop manufacturing systems with unreliable machines and finite buffers. The method involves transforming an arbitrary loop into one without thresholds and then evaluating the transformed loop using a new set of decomposition equations. It is more accurate than existing methods and is effective for a wider range of cases. The convergence reliability, and speed of the method are also discussed. In addition, observations are made on the behavior of closed loop production systems under various conditions. Finally, the method is used in a case study to design a flexible manufacturing system for production of aerospace parts.

Error Compensation Algorithms for Sculptured Surface Production

1994 ◽  
Vol 116 (2) ◽  
pp. 144-152 ◽  
Author(s):  
W. R. Dinauer ◽  
N. A. Duffie ◽  
M. L. Philpott
Keyword(s):  
Error Analysis ◽  
Error Compensation ◽  
Closed Loop ◽  
Production Control ◽  
Open Loop ◽  
Cnc Machining ◽  
Surface Finishing ◽  
Sculptured Surface ◽  
Control Surfaces ◽  
Surface Production

Four algorithms for removing shape and waviness errors in sculptured surface production processes are described in the paper. One of the algorithms employs an open-loop strategy without inspection, error analysis, and error compensation. The other three algorithms employ closed-loop inspection error analysis and error compensation strategies to manipulate control surfaces used in sculptured surface production. Coordinate measurements made on the surface being produced are compared with a designed surface and the results are used to modify related control surfaces that are used to guide processing equipment. Two of the closed-loop algorithms also use intermediate planned surfaces to improve error compensation and production control. Experiments are described in the paper in which the algorithms were tested on an experimental surface finishing system that included an optical probe, grinding spindle, and computer control system integrated with a CNC machining center. The results obtained using open-loop and closed-loop algorithms are compared, and it is shown that surface inspection, surface error analysis, surface compensation, and surface grinding can be iteratively applied to converge rough-machined test surfaces to their designed shape. The closed-loop algorithms are shown to be capable of compensating for disturbances in the finishing process that went undetected when the open-loop algorithm was used. The closed-loop algorithms have significant potential for application in automated finishing systems for molds and dies.

Application of Tool Compensation in CNC Machining

2014 ◽  
Vol 800-801 ◽  
pp. 435-439 ◽  
Author(s):  
Lian Jun Zhang ◽  
Chun Li He ◽  
Guang Jun Chen
Keyword(s):  
Dynamic Parameter ◽  
Cnc Machining ◽  
Machining Process ◽  
Maximum Probability ◽  
Machining Error ◽  
Process Step ◽  
Machining Precision ◽  
Minimum Probability ◽  
Radius Compensation ◽  
Tool Compensation

Tool compensation determines the machining precision and quality . There are tool length compensation,tool radius compensation and corner radius compensation in CNC system .The parameters of these compensation are all static.The purpose of this study was that the machining precision and quality were improved by changing the parameters of tool compensation,based upon changing the static parameters into the dynamic parameters of tool compensation.The three tool compensations were introduced and discussed about these being used in machining process and the function in processing.The concept of dynamic tool compensation was proposed in this paper. The method was used that the dynamic parameter substituted the static parameter in the processing by calculating . The process machining crafts information was included in tool compensation in every process step. The computer program was finished about how to calculate the dynamic parameter. The results indicate that high-precision machining is within the range of the maximum probability and the large machining error is within the range of the minimum probability by useing this method. Further more, the end qualified product is more than before.Process indicators and tool compensation merged is a breakthrough research by probability calculating for impoving the machining precision.We confirmed that the proposed method could be l used widely.

The Reserch on PID Control Modle of the Components Working Accuracy for Slender Shaft on the NC Lathe

2011 ◽  
Vol 403-408 ◽  
pp. 727-731
Author(s):  
Yu Kun Wang ◽  
Jun Lu ◽  
Hong San Xi
Keyword(s):  
Pid Control ◽  
Error Compensation ◽  
Closed Loop ◽  
Black Box ◽  
Programming System ◽  
Automatic Programming ◽  
Control Points ◽  
Manufacture System ◽  
Processing Error ◽  
System Deviation

In this article, a PID control modle of working accuracy is constructed to control the processing process，regarding the closed loop manufacture system as a black box and the processing error as system deviation. A slender shaft with a surface is turned,the control points of the error compensation can be abtained by a probe.Based on the CAM technology，an automatic programming system is developmented to control the processing process.Through a set of comparative experiments,the detaction and the analysis of datas confirmed the validity of the PID control modle,validated the accuracy of the slender shaft can be improved by the PID control modle.

Integrating CAD/CAPP/CAM/CNC with Inspections

2009 ◽  
pp. 297-310
Author(s):  
Xun Xu
Keyword(s):  
Conceptual Framework ◽  
Manufacturing System ◽  
Closed Loop ◽  
Research Work ◽  
Past Research ◽  
Cnc Machining ◽  
Machining Process ◽  
Tight Control ◽  
Good Data ◽  
The Past

A logical step after CNC machining is inspection. With inspections, Closed-Loop Machining (CLM) can be realized to maximize the efficiency of a machining process by maintaining a tight control in a manufacturing system. CLM is normally regarded as the highest level of CNC automation. CLM however, requires a tight integration between CAD, CAPP, CAM, and CNC, in particular CAM and CNC and inspections. The questions that are to be answered are (a) what type of inspections is fit for CLM and (b) is there a good data model that one can use to bring machining and inspections together? This chapter tries to provide some possible solutions to these questions. Prior to this, a brief review of the past research work is given. Toward the end of the chapter, a conceptual framework for integrating machining with inspections is presented.

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