Distributed NURBS interpolator for high-speed and high precision machining

2012 ◽  
Author(s):  
YanQiang Liu ◽  
Ji Huan ◽  
WenLei Xiao
Keyword(s):  
High Precision ◽  
High Speed ◽  
Precision Machining ◽  
Nurbs Interpolator

High Precision Cutting and High Speed Interrupted Cutting of Hardened Steel With PCBN Tools

1999 ◽  
Author(s):  
Katsuhito Yoshida ◽  
Satoru Kukino ◽  
Takashi Harada ◽  
Tomohiro Fukaya ◽  
Junichi Shiraishi ◽  
...  
Keyword(s):  
High Precision ◽  
High Speed ◽  
New Technologies ◽  
Cubic Boron Nitride ◽  
Cutting Tools ◽  
Hardened Steel ◽  
Precision Machining ◽  
Polycrystalline Cubic Boron Nitride ◽  
Interrupted Cutting ◽  
Pcbn Tools

Abstract PCBN (Polycrystalline Cubic Boron Nitride) cutting tools have become very familiar in the industries for cutting hardened steel parts and the demand for PCBN tools is growing rapidly. One of the reasons for this is the trend of replacing grinding processes with cutting. Although the trend of processing is to use more cutting, there still remains grinding in many processing fields. High precision machining and high speed interrupted machining have been such fields. In this study it has been verified that a novel cutting method can be applied to high precision machining with the smoothness of Rz 0.8 μm and that a new PCBN has sufficient reliability against tool failure in high speed (< 250m/min) interrupted cutting. Thus cutting has become applicable to those machining and the trend of replacement of grinding with cutting will be enhanced. Those new technologies will be introduced in this report.

scholarly journals NURBS Interpolator With Pre-compensation Based on Discrete Inverse Transfer Function for CNC High-precision Machining

2021 ◽  
Author(s):  
Taiyong Wang ◽  
Libo Cao ◽  
Yongbin Zhang ◽  
Jingchuan Dong ◽  
Songhui Jia ◽  
...  
Keyword(s):  
Steady State ◽  
Transfer Function ◽  
High Precision ◽  
Drive System ◽  
Precision Machining ◽  
Contour Error ◽  
Machining Accuracy ◽  
Steady State Response ◽  
Nurbs Interpolator ◽  
State Response

Abstract In the field of CNC machining, high-speed and high-precision machining has been regarded as the key research by many scholars. In conventional methods, high-speed machining and high-precision machining are contradictory. It is inevitable to reduce the feedrate to improve the processing accuracy. In the paper, a pre-compensation based on discrete inverse transfer function (PDIT) theory is proposed. PDIT is able to improve machining accuracy by reducing contour errors without decreasing feedrate. The proposed PDIT theory is divided into three parts, NURBS interpolator, feedrate scheduling, and interpolator with pre-compensation. The NURBS interpolator has greatly advantage to interpolate the parameter curve directly. Therefore, the paper adopts the NURBS interpolator to accomplish interpolation. In the feedrate scheduling, S-type flexible acceleration and deceleration are used for path planning, and the maximum starting feedrate is obtained with the feedrate constraint. In the interpolator with pre-compensation, the NURBS interpolator is pre-compensated by PDIT. For inputs, the response of transfer function reach steady-state response with a little time. Before reaching steady-state response, the unsteady response exists in the transfer function. The unsteady response usually sustains tens of interpolation periods and must be lead contour error in machining. Hence, the PDIT theory is employed to compensate the contour error causing by the unsteady response of transfer function to NURBS interpolator. The drive system is a transfer function, so the unsteady response of drive system cause machining errors before reaching the steady-state response. In the paper, the NURBS interpolator is pre-compensated by PDIT theory before the drive system to reduce contour errors and improve machining accuracy. Finally, the performance of the proposed PDIT is evaluated by simulation experiments. The experimental results illustrate that PDIT theory obviously improve the machining accuracy and reduces the contour error.

scholarly journals Research on Several Tool Chuck Technology in High Speed Milling

2018 ◽  
Vol 207 ◽  
pp. 02007
Author(s):  
Zhenyu Zhao ◽  
Xiaomei Xu ◽  
Yongquan Zhou ◽  
Haibin Xiao
Keyword(s):  
High Precision ◽  
High Speed ◽  
Static Pressure ◽  
Precision Machining ◽  
High Speed Milling ◽  
Existing Problems ◽  
Clamping System

In order to meet the requirements of high-speed precision machining technology, the paper elaborates the tool clamping technology commonly used in high-precision machining, such as the static pressure expansion chuck, CoroGrip chuck, and stress locking chuck and so on. How to correctly select the tool clamping system, the characteristics of the tool clamping system and the existing problems are analyzed.

Kinematics and Simulation for a High-Precision Parallel Kinematic Platform

2006 ◽  
Vol 315-316 ◽  
pp. 834-837
Author(s):  
Ying Hu ◽  
Hong Hu ◽  
B. Li
Keyword(s):  
High Precision ◽  
Inverse Kinematics ◽  
High Speed ◽  
Virtual Prototype ◽  
Precision Machining ◽  
Kinematic Simulation ◽  
Calibration Algorithm ◽  
Parallel Kinematic ◽  
Simulation Results

To meet the high speed and high precision requirements of machining freeform workpieces, a 4-DOF parallel kinematic platform with the configuration of 4 actuated legs plus a passive leg is proposed in this paper. Inverse kinematics and the calibration algorithm are developed, and virtual prototype modeling and kinematic simulation using MSC/ADAMS are carried out. The simulation results exhibit that the proposed structure is capable of implementing the high-precision machining requirements of freeform parts.

130 Servo Technology for High Speed and High Precision Machining

2001 ◽  
Vol 2001.3 (0) ◽  
pp. 179-180
Author(s):  
Hideaki INOUE ◽  
Yasusuke IWASHITA
Keyword(s):  
High Precision ◽  
High Speed ◽  
Precision Machining

An Optimization Model of High-Speed and High-Precision Machining Based on Model Predictive Control

2018 ◽  
Author(s):  
Jing Zhang ◽  
Jiexiong Ding ◽  
Qingzhao Li ◽  
Qicheng Ding ◽  
Zhong Jiang ◽  
...  
Keyword(s):  
Model Predictive Control ◽  
High Precision ◽  
Predictive Control ◽  
Feed Rate ◽  
Optimization Model ◽  
High Speed ◽  
Machining Process ◽  
Precision Machining ◽  
Contouring Error

In the multi-axis high-speed and high-precision machining process, the contouring error and the feed rate of tool tip and affect the quality of machined workpiece and the processing efficiency, respectively. The faster feed motion will result in greater tracking error of each axis. The contouring error which directly affects the quality of machined part is caused by the tracking errors of the axes. Obviously, it is difficult to improve the contouring accuracy and increase the feed rate simultaneously. To this end, a novel optimization model is developed here based on the model predictive control method. First, the feed servo model of translational and rotary axes are established, and the contouring error model is afterwards constructed. Subsequently, the optimization algorithm is derived to achieve the high processing speed, and input constraints are addressed to avoid violation of the performance limitation of the drivers. In addition, contouring error constraint, which is obtained by calculating the contouring error of the processed path, is addressed to high contour accuracy. Finally, a simulation is conducted to verify the effectiveness and superiority of the proposed method.

scholarly journals Variable step control to improve scanning speed of gene sequencing stage

2021 ◽  
pp. 002029402110022
Author(s):  
Xiaohua Zhou ◽  
Jianbin Zheng ◽  
Xiaoming Wang ◽  
Wenda Niu ◽  
Tongjian Guo
Keyword(s):  
Motion Control ◽  
High Precision ◽  
High Speed ◽  
Stable State ◽  
Gene Sequencing ◽  
Scanning Speed ◽  
Settling Time ◽  
Step Motion ◽  
Variable Step ◽  
Step Control

High-speed scanning is a huge challenge to the motion control of step-scanning gene sequencing stage. The stage should achieve high-precision position stability with minimal settling time for each step. The existing step-scanning scheme usually bases on fixed-step motion control, which has limited means to reduce the time cost of approaching the desired position and keeping high-precision position stability. In this work, we focus on shortening the settling time of stepping motion and propose a novel variable step control method to increase the scanning speed of gene sequencing stage. Specifically, the variable step control stabilizes the stage at any position in a steady-state interval rather than the desired position on each step, so that reduces the settling time. The resulting step-length error is compensated in the next acceleration and deceleration process of stepping to avoid the accumulation of errors. We explicitly described the working process of the step-scanning gene sequencer and designed the PID control structure used in the variable step control for the gene sequencing stage. The simulation was performed to check the performance and stability of the variable step control. Under the conditions of the variable step control where the IMA6000 gene sequencer prototype was evaluated extensively. The experimental results show that the real gene sequencer can step 1.54 mm in 50 ms period, and maintain a high-precision stable state less than 30 nm standard deviation in the following 10 ms period. The proposed method performs well on the gene sequencing stage.

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