scholarly journals Vision Servo Motion Control and Error Analysis of a CoplanarXXYStage for Image Alignment Motion

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Hau-Wei Lee ◽  
Chien-Hung Liu
Keyword(s):  
Motion Control ◽  
Degrees Of Freedom ◽  
Servo Control ◽  
Image Alignment ◽  
Work Piece ◽  
Alignment Algorithm ◽  
Alignment System ◽  
Vision Servo ◽  
Smart Mobile ◽  
Touch Panels

In recent years, as there is demand for smart mobile phones with touch panels, the alignment/compensation system of alignment stage with vision servo control has also increased. Due to the fact that the traditional stacked-typeXYθstage has cumulative errors of assembly and it is heavy, it has been gradually replaced by the coplanar stage characterized by three actuators on the same plane with three degrees of freedom. The simplest image alignment mode uses two cameras as the equipments for feedback control, and the work piece is placed on the working stage. The work piece is usually engraved/marked. After the cameras capture images and when the position of the mark in the camera is obtained by image processing, the mark can be moved to the designated position in the camera by moving the stage and using alignment algorithm. This study used a coplanarXXYstage with 1 μm positioning resolution. Due to the fact that the resolution of the camera is about 3.75 μm per pixel, thus a subpixel technology is used, and the linear and angular alignment repeatability of the alignment system can achieve 1 μm and 5 arcsec, respectively. The visual servo motion control for alignment motion is completed within 1 second using the coplanarXXYstage.

Study on Track Control to the Multiple Degrees of Freedom Mechanical Arm of the Sampling Machine for Coal at Railway Carriage

2012 ◽  
Vol 542-543 ◽  
pp. 963-967
Author(s):  
Zhi Xue Tong ◽  
Li Chen Shi ◽  
Jing Yang ◽  
Li Gang Zhang
Keyword(s):  
Motion Control ◽  
Intelligent Control ◽  
Hydraulic System ◽  
Degrees Of Freedom ◽  
Optimization Method ◽  
Hydraulic Press ◽  
Servo Control ◽  
Multiple Degrees Of Freedom ◽  
Servo Control System ◽  
Set Up

The multiple degrees of freedom mechanical arm of sampling machine for coal at railway carriage is driven by hydraulic press. It is a kind of joint. During working, the sampling head not only keeps in its poses, but also moves along a straight path. The mechanical arm’s motion is resolved into three independent motion systems, foundation rotation, straight motion of 3 degrees of freedom kinematics chain, and servo control system of the sampling head. A group of motion equations is set up. According to the reversion theory and optimization method, the motion control model is built up in order to reappear the motion track. The method is efficient to solve the motion control problem. And the result of driving curve is more suitable for the hydraulic system. This method is useful for motion intelligent control of different kinds of joint manipulator.

scholarly journals Development of a High Precision Edge Alignment System for Touch-Panel Glass Substrates

2014 ◽  
Vol 6 ◽  
pp. 904061 ◽  
Author(s):  
Hau-Wei Lee ◽  
Chien Hung Liu ◽  
Jenq-Shyong Chen
Keyword(s):  
Edge Detection ◽  
High Precision ◽  
Glass Substrate ◽  
Detection Method ◽  
Work Piece ◽  
Glass Substrates ◽  
Alignment System ◽  
Edge Detection Method ◽  
Touch Panels ◽  
Panel Glass

There are two kinds of alignment systems, marked and unmarked. The glass substrate for touch panels is categorized as an unmarked work piece. Vision based glass substrate alignment (GSA) relies on the edge of the glass. Traditional GSA systems compensate first for angular and then for linear error. This reduces alignment accuracy and increases alignment time and edge detection usually takes longer than 10 ms. This study proposes an effortless edge detection method. This method is very simple and can significantly reduce the time taken to detect the edge to about 6 ms using a 1.3 megapixel image. In this study, a floating center idea is used to control the glass substrate on a high precision coplanar XXY alignment stage. According to the method, users can set the rotation center anywhere as long as it is on the working ( xy) plane. Tolerance prognosis is also considered in this study to help the operator decide if the substrate is usable or should be rejected. The experimental results show alignment repeatability of the x, y, and θ axes to be 1 μm, 1 μm, and 5 arcsec, respectively.

Micro-vision servo control of a multi-axis alignment system for optical fiber assembly

2017 ◽  
Vol 27 (4) ◽  
pp. 045010 ◽  
Author(s):  
Weihai Chen ◽  
Fei Yu ◽  
Jianliang Qu ◽  
Wenjie Chen ◽  
Jianbin Zhang
Keyword(s):  
Optical Fiber ◽  
Servo Control ◽  
Fiber Assembly ◽  
Alignment System ◽  
Axis Alignment ◽  
Vision Servo

Optimization in Trajectory Planning of Multi-Jointed Fingers in Dextrous Hand Designs

1991 ◽  
Author(s):  
A. Meghdari ◽  
H. Sayyaadi
Keyword(s):  
Dynamic Programming ◽  
Motion Control ◽  
Trajectory Planning ◽  
Degrees Of Freedom ◽  
Optimization Technique ◽  
Dynamic Programming Algorithm ◽  
Programming Algorithm ◽  
Kinematics And Dynamics ◽  
Feasible Solutions ◽  
Dextrous Hand

Abstract An optimization technique based on the well known Dynamic Programming Algorithm is applied to the motion control trajectories and path planning of multi-jointed fingers in dextrous hand designs. A three fingered hand with each finger containing four degrees of freedom is considered for analysis. After generating the kinematics and dynamics equations of such a hand, optimum values of the joints torques and velocities are computed such that the finger-tips of the hand are moved through their prescribed trajectories with the least time or/and energy to reach the object being grasped. Finally, optimal as well as feasible solutions for the multi-jointed fingers are identified and the results are presented.

Design of Plane Magnetic Field Image Drawing System Based on PLC Motion Control

2014 ◽  
Vol 525 ◽  
pp. 282-286
Author(s):  
Jia Xin You ◽  
Hui Min Liang ◽  
Kun Zhang ◽  
Guo Fu Zhai
Keyword(s):  
Magnetic Field ◽  
Permanent Magnet ◽  
Motion Control ◽  
Fem Simulation ◽  
Servo Control ◽  
Programmable Logic ◽  
Magnetic Powder ◽  
Fem Model ◽  
Drawing System ◽  
The Magnetic Field

The image of magnetic field is traditionally obtained by spreading magnetic powder manually or by sparse arrays of magnetic needles, obtaining the images of the magnetic field in different permanent magnet shapes and do repeated tests on the permanent magnet are in need. Based on programmable logic controller (PLC) motion control, the servo control and mechanical system have been built, the control strategy is discussed and the software is programmed. 2D FEM model of a test permanent magnet bar is built. Compared with the FEM simulation results, the system has achieved the goal that spreading magnetic powder quickly and evenly in the appointed area.

Quasi-human biped walking

Robotica ◽  
2005 ◽  
Vol 24 (2) ◽  
pp. 257-268 ◽  
Author(s):  
Hun-ok Lim ◽  
Sang-ho Hyon ◽  
Samuel A. Setiawan ◽  
Atsuo Takanishi
Keyword(s):  
Motion Control ◽  
Continuous Time ◽  
Degrees Of Freedom ◽  
Biped Robot ◽  
Humanoid Robots ◽  
Compensation Method ◽  
Biped Walking ◽  
Working Space ◽  
Physical Construction

Our goal is to develop biped humanoid robots capable of working stably in a human living and working space, with a focus on their physical construction and motion control. At the first stage, we have developed a human-like biped robot, WABIAN (WAseda BIped humANoid), which has a thirty-five mechanical degrees of freedom. Its height is 1.66 [m] and its weight 107.4 [kg]. In this paper, a moment compensation method is described for stability, which is based on the motion of its head, legs and arms. Also, a follow walking method is proposed which is based on a pattern switching technique. By a combination of both methods, the biped robot is able to perform dynamic stamping, walking forward and backward in a continuous time while someone is pushing or pulling its hand in such a way. Using WABIAN, human-fellow walking experiments are conducted, and the effectiveness of the methods are verified.

Impact Control of Flexible Robots Using Sliding Mode Technique

1993 ◽  
Author(s):  
Eming Chen
Keyword(s):  
Motion Control ◽  
Dynamic Models ◽  
Sliding Mode ◽  
Contact Process ◽  
Control Technique ◽  
Work Piece ◽  
System Control ◽  
State Variables ◽  
Flexible Robot ◽  
Nonlinear System Control

Abstract In the flexible robot force control situations, if there exists a discontinuity between the robot tip sensor and the work-piece, the robot contact process becomes a nonlinear system control problem. The control tasks require the robot hand to switch from free motion control to contact motion control. The inevitable high impact force tends to let the system become unstable. The purpose of this paper is to investigate the control of the manipulator during this process. In this paper, dynamic models of the flexible link manipulator in both non-contacted and contacted modes are first derived. Due to the fact that the arm vibration shape functions are changed between the two modes, a transform matrix will be used to transform the controlled state variables, such as generalized position and velocity. A nonlinear sliding mode control technique has been implemented in an attempt to extinguish the chatter phenomenon and settle quickly to the desired setpoint.

Development of an eccentric cam-based active pre-alignment system for the compact linear collider main beam quadrupole magnet

2010 ◽  
Vol 1 (MEDSI-6) ◽  
Author(s):  
F. Lackner ◽  
K. Artoos ◽  
C. Collette ◽  
H. M. Durand ◽  
C. Hauviller ◽  
...  
Keyword(s):  
Degrees Of Freedom ◽  
Linear Collider ◽  
Contact Region ◽  
Main Beam ◽  
Particle Accelerators ◽  
Quadrupole Magnet ◽  
Electron Positron ◽  
Alignment System ◽  
New Energy ◽  
Mechanically Stabilized

Compact linear collider (CLIC) is a study for a future electron–positron collider that would allow physicists to explore a new energy region beyond the capabilities of today's particle accelerators. The demanding transverse and vertical beam sizes and emittance specifications are resulting in stringent alignment and a nanometre stability requirement. In the current feasibility study, the main beam quadrupole magnets have to be actively pre-aligned with a precision of 1 µm in five degrees of freedom before being mechanically stabilized to the nanometre scale above 1 Hz. This contribution describes the approach of performing this active pre-alignment based on an eccentric cam system. In order to limit the amplification of the vibration sources at resonant frequencies, a sufficiently high eigenfrequency is required. Therefore, the contact region between cam and support was optimized for adequate stiffness based on the Hertzian theory. Furthermore, practical tests performed on a single-degree-of-freedom mockup will show the limitation factors and further improvements required for successful integration in a full-scale quadrupole mockup presently under design.

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