Predictive Measurement Method for Time Grating Displacement Sensor

2008 ◽  
Vol 381-382 ◽  
pp. 403-406 ◽  
Author(s):  
Xiao Kang Liu ◽  
Ye Tai Fei ◽  
D. Peng ◽  
X. Wang
Keyword(s):  
Prediction Error ◽  
Measurement Method ◽  
Servo Control ◽  
Displacement Sensor ◽  
Rotary Table ◽  
Positioning Accuracy ◽  
Measuring Period ◽  
Position Feedback ◽  
Predicted Values ◽  
Measuring Space

Time grating displacement sensor is briefly introduced for measuring space with time. The measured values of time grating will not update during the measuring period. To use the sensor as position feedback component for CNC rotary table positioning servo control, this paper firstly introduces prediction conception to measurement field, and predictive measurement method is firstly proposed. Predicted values are derived form past measured values and the prediction error is corrected in real time using the new measured values. The positioning accuracy of the CNC rotary table is improved greatly. Experiment results conform the validity of the proposed method.

Position Predictive Measurement Method for Time Grating CNC Rotary Table

2010 ◽  
Vol 139-141 ◽  
pp. 1587-1590
Author(s):  
Xiao Kang Liu ◽  
Ji Sen Yang ◽  
Zhong Hua Gao ◽  
Dong Lin Peng
Keyword(s):  
Time Domain ◽  
Prediction Error ◽  
Measurement Method ◽  
Prediction Method ◽  
Experimental System ◽  
Estimation Algorithm ◽  
Rotary Table ◽  
Space Domain ◽  
Time Space ◽  
Domain Information

Time grating sensor transforms space domain information to time domain and measures spatial displacement with time. To develop high precision time grating CNC rotary table and reduce the dynamic position feedback error of the table, circular position predictive measurement method is proposed for transforming time domain information back to the space domain based on time-space transformation technology. Predicted values are obtained by modeling the measured values with time series theory, and the last prediction error is corrected in real time using the current measured values. Modeling method and parameter estimation algorithm are presented. To confirm the validity of the position prediction method, an experimental system is designed. The dynamic prediction error of the rotary table circular position is 2, and precise predicting is achieved.

On Improving the Performances of Hydraulic Incremental Positioning Units with Mechanical Position Feedback

2012 ◽  
Vol 463-464 ◽  
pp. 1277-1280 ◽  
Author(s):  
Constantin Bucşan ◽  
Mihai Avram
Keyword(s):  
Real Time ◽  
Correction Method ◽  
Practical Application ◽  
Positioning Accuracy ◽  
Positioning Systems ◽  
Sensing System ◽  
Position Feedback ◽  
Time Determination ◽  
Interesting Solution

This paper presents a method for increasing the speed and the positioning accuracy of the positioning systems with mechanical position feedback. The method consists in using a position transducer for real time determination of the position of the load and correcting this position using an adequate algorithm. It is preferable not to modify the construction of the positioning unit, allowing the user to decide when to use this correction method according to the practical application. An interesting solution to this problem is to use an external space-position finding sensing system, as presented in the paper.

Probabilistic Interval Prediction of Wind Power

2015 ◽  
Vol 740 ◽  
pp. 429-432
Author(s):  
Mao Yang ◽  
Gang Du ◽  
Li Sun
Keyword(s):  
Wind Power ◽  
Prediction Error ◽  
Rapid Development ◽  
Wind Generation ◽  
Power Prediction ◽  
System Operation ◽  
Probabilistic Distribution ◽  
Wind Power Prediction ◽  
Predicted Values ◽  
Point Forecast

As wind power generation rapid development in china, wind power prediction is the key to the system operate safely. Given significant uncertainties involved in wind generation, probabilistic interval forecasting provides a unique solution to estimate and quantify the potential impacts and risks facing system operation with wind penetration beforehand. this paper based on the point forecast, calculate wind power prediction error, formulate the distribution of prediction error, you can get the historical probabilistic distribution of prediction error, use the distribution of error to build the risk assessment of wind power after prediction, give the fluctuate range of predicted values. Probabilistic interval forecasting can obtain the probably of power system operation safely and reliability assessment criterion.

scholarly journals High Performance Rotary Table for Machine Tool Applications

2009 ◽  
Vol 3 (3) ◽  
pp. 343-347 ◽  
Author(s):  
K. M. Muditha Dassanayake ◽  
◽  
Masaomi Tsutsumi ◽  
Keyword(s):  
Machine Tool ◽  
Frequency Response ◽  
High Performance ◽  
Worm Gear ◽  
Rotary Table ◽  
Positioning Accuracy ◽  
Roller Drive ◽  
Gear Mechanism ◽  
Accuracy And Repeatability

The high performance rotary tables are immense necessary part for the multi-axis machines. These rotary tables are yet in the developing stage. In this report, a rotary table driven by roller drive is introduced and the characteristics of that are discussed by comparing them with the characteristics of rotary table driven by worm gear mechanism. As the characteristics, the positioning accuracy and repeatability, frequency response, rotational fluctuations and influence of unbalance mass on motion are measured. According to the measured results, it can be said that the rotary table driven by roller drive shows high performances and therefore it can be said that this type of rotary tables are well suited for machine tool applications.

scholarly journals Measurement method of repeated positioning accuracy of pinhole runnerbased on combination of laser and CCD

2021 ◽  
Vol 42 (5) ◽  
pp. 919-925
Author(s):  
LIANG Weiyu ◽  
◽  
◽  
YE Chao ◽  
HU Qiu ◽  
...  
Keyword(s):  
Measurement Method ◽  
Positioning Accuracy

Design and Characterization of Precise Laser-Based Autofocusing Microscope with Reduced Geometrical Fluctuations

2013 ◽  
Vol 284-287 ◽  
pp. 672-676
Author(s):  
Chien Sheng Liu ◽  
Yang Cheng Lin ◽  
Pin Hao Hu
Keyword(s):  
Experimental Results ◽  
Feedback Signal ◽  
Positioning Accuracy ◽  
Geometrical Center ◽  
Ccd Sensor ◽  
Position Feedback ◽  
Better Than

The present study proposes a laser-based microscope system in which a precise autofocusing capability is achieved using a position feedback signal based on the distance L between the geometrical center (Xc, Yc) of the image captured by the CCD sensor and the centroid (xcentroid, ycentroid) of the image. The experimental results show that the proposed system has a positioning accuracy of 2.2 μm given a working range of ±200 μm. The autofocusing performance of the proposed system is thus better than that of a conventional centroid-based system, which typically achieves a positioning accuracy of around 5.2 μm.

Process Feedback Control of Non-Circular Turning for Camshaft Machining

1999 ◽  
Author(s):  
Zongxuan Sun ◽  
Tsu-Chin Tsao
Keyword(s):  
Feedback Control ◽  
Servo Control ◽  
Displacement Sensor ◽  
Turning Process ◽  
Spindle Rotation ◽  
Control Scheme ◽  
Precise Tool ◽  
Cam Profile ◽  
Process Feedback ◽  
Profile Errors

Abstract This paper presents a process feedback control scheme for cam profile generation by non-circular turning process. While precise tool slide motion can be generated based on real-time servo feedback control, it does not necessarily ensure accurate machined cam profiles. The effects of tool/workpiece geometry, tool wears, machine deformations, and spindle runout error can not be measured by the tool slide displacement sensor and hence are not compensated for by the servo control. A process feedback controller is designed to compensate for the repeatable profile errors from one machining cycle to another. Utilizing the fact that the desired cam profile is periodic over one spindle rotation, process feedback control is analyzed and designed in the frequency domain. Implementation of the process feedback control on a steel camshaft turning demonstrates improvement of the maximum cam profile errors from 80 microns to within 20 microns in five iterations.

Proposal of an Improved Contactless Measurement Method Using an Advanced LED Displacement Sensor for Vibration Stress of Piping Systems

2021 ◽  
Author(s):  
Akira Maekawa ◽  
Takashi Tsuji ◽  
Tsuneo Takahashi
Keyword(s):  
Mode Shape ◽  
Measurement Method ◽  
Previous Method ◽  
Measuring System ◽  
Displacement Sensor ◽  
Contactless Measurement ◽  
Piping System ◽  
Bending Mode ◽  
Piping Systems ◽  
Vibration Stress

Abstract The present paper proposes an improved contactless measurement method for vibration stress of piping systems, by which the measurement time is shorter and the measuring works are more simple. The proposed method includes two processes, in which the bending mode shape of piping vibration is identified by a transmission-type light emitting diode (LED) displacement sensor and the vibration stress is calculated based on beam theory using the approximated curve of the bending mode shape. The proposed method uses one advanced LED displacement sensor to measure the vibration stress though multiple conventional LED sensors must be used in the previous method developed by the authors. Therefore, the measuring system could be reduced in size and a light-weight and portable measurement instrument was developed. The measurement accuracy and reliability of the new method were validated by the vibration experiment using a mock-up piping system.

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