The Error Analysis and Compensation of Two-Dimensional Precision Positioning Platform

2012 ◽  
Vol 268-270 ◽  
pp. 1380-1384
Author(s):  
Mu Cheng Zhu ◽  
Xian Peng Luo ◽  
Ya Ping Wang
Keyword(s):  
Error Compensation ◽  
Compensation Effect ◽  
Closed Loop ◽  
Two Dimensional ◽  
Location Error ◽  
Precision Positioning ◽  
Positioning Accuracy ◽  
Loop Control ◽  
Dimensional Precision ◽  
Motion Control Card

Through measuring and analyzing the location error of two-dimensional precision positioning system based on the motion control card, and according to the deficiency of the first error compensation, a strategy that enhance addition based on first error compensation was put forward. That using closed loop control to compensate and correct the location error makes the positioning accuracy improved obviously, and achieves an ideal compensation effect. Under the loading conditions, X axial positioning accuracy reached 11μm, Y axial positioning accuracy reached 10μm.

Research on Error Compensation by Semi-Closed Loop Control for a 3-UPS Parallel Machine Tool

2012 ◽  
Vol 461 ◽  
pp. 272-276
Author(s):  
Jian Ye Guo ◽  
Jia Shun Shi ◽  
Liang Zhao
Keyword(s):  
Machine Tool ◽  
Error Compensation ◽  
Closed Loop ◽  
Parallel Machine ◽  
Control Mode ◽  
Closed Loop Control ◽  
Kinematics Analysis ◽  
Compensation Strategy ◽  
Loop Control ◽  
Parallel Machine Tool

This paper took a 3-UPS Parallel Machine Tool (PMT) as the object of research; it mainly introduced the process of establishing the compensation strategy for this PMT. Firstly the kinematics equations on driving chain and constraint chain was established on the basis of kinematics analysis. Then according to the structural characteristics and the results of kinematics analysis, the error compensation strategy of feedback correction type with the semi-closed loop control mode was used in the error compensation for this PMT by the method of installing respectively the encoders on the each joint of parallelogram mechanism, namely the compensation way of “parallel driving and series feedback” was adopted. Finally this paper has also deduced the theoretical model of error compensation. The research results in this paper provided a theoretical basis for realizing error compensation of this PMT, and had important practical significance for improving machining precision of PMT

scholarly journals Modelling and Experiment Based on a Navigation System for a Cranio-Maxillofacial Surgical Robot

2018 ◽  
Vol 2018 ◽  
pp. 1-14 ◽  
Author(s):  
Xingguang Duan ◽  
Liang Gao ◽  
Yonggui Wang ◽  
Jianxi Li ◽  
Haoyuan Li ◽  
...  
Keyword(s):  
Skull Base ◽  
Closed Loop ◽  
Control Method ◽  
Maxillofacial Surgery ◽  
Surgical Robot ◽  
Closed Loop Control ◽  
Robot System ◽  
Positioning Accuracy ◽  
Loop Control ◽  
Model Experiments

In view of the characteristics of high risk and high accuracy in cranio-maxillofacial surgery, we present a novel surgical robot system that can be used in a variety of surgeries. The surgical robot system can assist surgeons in completing biopsy of skull base lesions, radiofrequency thermocoagulation of the trigeminal ganglion, and radioactive particle implantation of skull base malignant tumors. This paper focuses on modelling and experimental analyses of the robot system based on navigation technology. Firstly, the transformation relationship between the subsystems is realized based on the quaternion and the iterative closest point registration algorithm. The hand-eye coordination model based on optical navigation is established to control the end effector of the robot moving to the target position along the planning path. The closed-loop control method, “kinematics + optics” hybrid motion control method, is presented to improve the positioning accuracy of the system. Secondly, the accuracy of the system model was tested by model experiments. And the feasibility of the closed-loop control method was verified by comparing the positioning accuracy before and after the application of the method. Finally, the skull model experiments were performed to evaluate the function of the surgical robot system. The results validate its feasibility and are consistent with the preoperative surgical planning.

Wavelet Analysis for Assessment of Localized Spectral Variations in Surface Topographic Data

1995 ◽  
Author(s):  
Vivek G. Badami ◽  
Susan S. Hefner ◽  
Stuart T. Smith
Keyword(s):  
Wavelet Analysis ◽  
Closed Loop ◽  
Atomic Force Microscope Image ◽  
Open Loop ◽  
Closed Loop Control ◽  
Sample Length ◽  
Two Dimensional ◽  
Loop Control ◽  
Atomic Force ◽  
Scanning Mechanism

Abstract In this paper, a two dimensional wavelet analysis using Daubechies D14 wavelets has been used to decompose an Atomic Force Microscope image of the surface of a two dimensional calibration grid. Operating the microscope in open loop mode results in image distortions due to nonlinearities of the scanning mechanism which are subsequently reduced under closed loop control. Such distortions in the image are not readily apparent even using Fourier transform techniques and may be overlooked in a routine calibration. Through an appropriate choice of sample length so that the periodicity of the grid is coincident with the bandpass cut-off of the wavelet transform, it is shown in this paper that distortions can be clearly identified in individual levels of the wavelet reconstruction.

Dynamic and Control Modeling and Simulation of High Speed Precision Positioning XY Table

2011 ◽  
Vol 467-469 ◽  
pp. 978-983
Author(s):  
Zhi Peng Ma ◽  
Xing Yu Zhao ◽  
Fu Jun Wang ◽  
Da Wei Zhang
Keyword(s):  
Control Strategy ◽  
High Speed ◽  
Closed Loop ◽  
Dynamic Performance ◽  
Matching Law ◽  
Closed Loop Control ◽  
Precision Positioning ◽  
Loop Control ◽  
Decoupling Mechanism ◽  
And Control

To study the dynamic performance and control strategy of a kind of high speed precision positioning XY table with a new kind of decoupling mechanism, the electromechanical co-simulation model with three closed-loop control system using proportional–integral–derivative controller (PID controller) is constructed. By use of finite element analysis (FEA) and co-simulation method, the preloaded spring as the key component in the decoupling mechanism is optimized. The matching law of the spring stiffness and preload is presented. The decoupling mechanism influence on the dynamic performance of the XY table during the movement is fully discussed. Based on the electromechanical model, a three closed-loop control scheme with disturbance observer and feed-forward controller is proposed. Co-simulation results demonstrate the validity of the control strategy.

Emissivity Independent Process Control in a Short Wavelength ARC Lamp RTP Chamber

1996 ◽  
Vol 429 ◽  
Author(s):  
Marcel E. Lefrançois ◽  
David M. Camm ◽  
Brendon J. Hickson
Keyword(s):  
Short Wavelength ◽  
Closed Loop ◽  
Ccd Camera ◽  
Closed Loop Control ◽  
Temperature Profiles ◽  
Two Dimensional ◽  
Reflectivity Measurement ◽  
Loop Control ◽  
Patterned Wafers ◽  
Independent Process

AbstractTwo dimensional temperature measurements of patterned wafers are presented. The measurements are made using a commercially available CCD camera operating at λ=900nm, yielding a spatial resolution of 1 pixel per mm2 and a relative accuracy of ±0.25 °C. The emissivity is determined using a reflectivity measurement made possible by the unique properties of a short wavelength arc lamp RTP chamber. The use of this measurement system for closed loop control is discussed and the application to maintaining accurate time temperature profiles independent of emissivity is described.

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