Study on Error in Interpolation Algorithm of the-5-DOF-Hybrid Robot

2013 ◽  
Vol 385-386 ◽  
pp. 695-698
Author(s):  
Ji Man Luo ◽  
Ming Shan Zhang ◽  
Yu Zhen An ◽  
Xiao Wei Sun
Keyword(s):  
Degrees Of Freedom ◽  
Convex Surface ◽  
Interpolation Method ◽  
Approximation Error ◽  
Linear Interpolation ◽  
Normal Vector ◽  
Interpolation Algorithm ◽  
Surface Machining ◽  
Set Up ◽  
Circular Interpolation

In order to improve the accuracy of the-5-DOF-hybrid robot motion control, it is necessary to establish a mathematical model of the error in the interpolation process. On the basis of the structure characteristics of five degrees of freedom hybrid robot and the algorithm of linear interpolation and circular interpolation, the error calculation patterns about the concave surface machining and convex surface machining are set up respectively in the paper. Then, examples are analyzed. The results show that the nonlinear error caused by using the straight-line interpolation method is much smaller than the normal vector rotation error and linear approximation error; when conducting surface machining, the error caused by the application of circular interpolation algorithm is less than linear interpolation error. By the comparison of the error analysis of different interpolation method, the control methods for reducing errors are proposed.

scholarly journals Interpolation uncertainty of atmospheric temperature radiosoundings

2020 ◽  
Author(s):  
Alessandro Fassò ◽  
Michael Sommer ◽  
Christoph von Rohden
Keyword(s):  
Missing Data ◽  
Standard Error ◽  
Cross Validation ◽  
Interpolation Method ◽  
Average Length ◽  
Linear Interpolation ◽  
Atmospheric Temperature ◽  
Radiosonde Data ◽  
Published Data ◽  
Set Up

Abstract. This paper is motivated by the fact that, although temperature readings made by Vaisala RS41 radiosondes at GRUAN sites (http://www.gruan.org) are given at 1 s resolution, for various reasons, missing data are spread along the atmospheric profile. Such a problem is quite common in radiosonde data and other profile data. Hence, (linear) interpolation is often used to fill the gaps in published data products. In this perspective, the present paper considers interpolation uncertainty. To do this, a statistical approach is introduced giving some understanding of the consequences of substituting missing data by interpolated ones. In particular, a general frame for the computation of interpolation uncertainty based on a Gaussian process (GP) set-up is developed. Using the GP characteristics, a simple formula for computing the linear interpolation standard error is given. Moreover, the GP interpolation is proposed as it provides an alternative interpolation method with its standard error. For the Vaisala RS41, the two approaches are shown to give similar interpolation performances using an extensive cross-validation approach based on the block-bootstrap technique. Statistical results about interpolation uncertainties at various GRUAN sites and for various missing gap lengths are provided. Since both provide an underestimation of the cross-validation interpolation uncertainty, a bootstrap-based correction formula is proposed. Using the root mean square error, it is found that, for short gaps, with an average length of 5 s, the average uncertainty is smaller than 0.10 K. For larger gaps, it increases up to 0.35 K for an average gap length of 30 s, and up to 0.58 K for a gap of 60 s.

Five-Axis HSM Tool-Path Planning of Integral Impeller

2010 ◽  
Vol 426-427 ◽  
pp. 572-576
Author(s):  
Can Zhao ◽  
Y.Y. Guo ◽  
Guang Bin Bu
Keyword(s):  
High Speed ◽  
Control Algorithm ◽  
Tool Path ◽  
Control Method ◽  
Interpolation Method ◽  
Linear Interpolation ◽  
Normal Vector ◽  
Manufacture Process ◽  
Five Axis ◽  
Uniform Change

There are two key problems in the manufacture process of impeller with HSM(High Speed Machining). One is the collision between tool and blade, the other is gnawed-cutting arisen by non-uniform change of the cutter axis. The control algorithm of collision-free cutter-axis was described and applied in this paper. The cutter-axis vector was optimized by quaternary linear interpolation method to make normal vector of blade changing continuous, so. These methods were synthetically used in the manufacture experiment. And the qualified impeller was produced. It indicated that the tool vector control method was feasible.

Research on Surface Machining System for Light Metal Thin-Walled Parts Based on Spherical Coordinate

2010 ◽  
Vol 97-101 ◽  
pp. 1841-1844
Author(s):  
Shi Huan Wang ◽  
Zhi Gang Cai ◽  
Li Fang Lin
Keyword(s):  
Light Metal ◽  
Interpolation Algorithm ◽  
Spherical Coordinate ◽  
Surface Machining ◽  
Spiral Path ◽  
System A ◽  
Machining System ◽  
Thin Walled ◽  
Set Up

Surface machining system based on spherical coordinate is present for the large thin-walled director sphere part turning, to improve the efficiency and quality of part machining. In this system, a thickness surface B-spline model is set up based on spherical coordinates, the space spiral path generation method is planned, row spacing angle is determined by scallop height and blunt radius of cutting tool, and back cutting depth optimization treatment and space spiral interpolation algorithm are present.

Shadow Detecting and Shadow Interpolation Algorithm for InSAS

2012 ◽  
Vol 605-607 ◽  
pp. 2121-2125 ◽  
Author(s):  
Sen Zhang ◽  
Ming Chen ◽  
Jin Song Tang
Keyword(s):  
Real Time ◽  
Interpolation Method ◽  
Linear Interpolation ◽  
Synthetic Aperture ◽  
Interpolation Algorithm ◽  
Synthetic Aperture Sonar ◽  
Shadow Area ◽  
Linear Interpolation Method

The shadow detecting algorithm based on the coherence and the Sigma filter is used to pick up the shadow of interferometric synthetic aperture sonar (InSAS), which can eliminate small separated shadow areas. To solve the problems such as great computer complexity of traditional Shepard interpolation method and large fluctuant of linear interpolation method for the large shadow area, an improved Shepard interpolation method is proposed. Interpolation boundary is picked up by using diffuse search, and interpolation source is adaptively chosen according to the size of shadow area. The method carries out a perfect tradeoff between performance and computer speed. Lake trial dataset is used to validate the performance of proposed method. The results indicate that the proposed method can eliminate the fluctuant from the linear interpolation method and can process in real time in the InSAS system.

Five-Axis Machining Tool Vector Control of Impeller

2009 ◽  
Vol 407-408 ◽  
pp. 264-267 ◽  
Author(s):  
Can Zhao ◽  
Jian Feng Sun ◽  
Guang Bin Bu
Keyword(s):  
Vector Control ◽  
Control Algorithm ◽  
Interpolation Method ◽  
Linear Interpolation ◽  
Normal Vector ◽  
Manufacture Process ◽  
Linear Interpolation Method ◽  
Tip Position ◽  
Five Axis ◽  
Uniform Change

There are two key problems in the manufacture process of impeller, one is the collision of tool and blade, the other is gnawed-cutting arisen by non-uniform change of the cutter axis. UG software was used to solve those problems. Tool tip position was solved by UG. The control algorithm of collision-free cutter-axis was described and applied. The cutter-axis vector was optimized by quaternary linear interpolation method to make normal vector of blade changing continuous, so. These methods were synthetically used in the manufacture experiment. The impeller produced by it was qualified. It indicated that the method of tool vector control was feasible.

Simulation and Implementation of an Improved Inscribed Chord Interpolation Algorithm

2013 ◽  
Vol 756-759 ◽  
pp. 3220-3224
Author(s):  
Hui Zhang ◽  
Qin Ruo Wang
Keyword(s):  
Interpolation Method ◽  
Linear Interpolation ◽  
Comparison Method ◽  
Interpolation Algorithm ◽  
Quadratic Curve ◽  
Operation Process ◽  
Curve Interpolation ◽  
Program Flow ◽  
Simulation Results ◽  
Chord Method

In order to improve the shortcomings of the realization of the traditional quadratic curve interpolation inscribed chord method, this paper proposes an improved internal chord interpolation algorithm. The program flow chart of the algorithm achievement and the interpolation method of circular arc interpolation and linear interpolation of a detailed operation process is given in this paper. Finally through a calculation example the simulation is conducted, and the point by point comparison method were compared. The simulation results show the improvement on the quadratic curve interpolation in the inner string interpolation speed, good flexibility, and it worth popularizing in the interpolation algorithm for real time interpolation.

scholarly journals Interpolation uncertainty of atmospheric temperature profiles

2020 ◽  
Vol 13 (12) ◽  
pp. 6445-6458
Author(s):  
Alessandro Fassò ◽  
Michael Sommer ◽  
Christoph von Rohden
Keyword(s):  
Missing Data ◽  
Standard Error ◽  
Interpolation Method ◽  
Average Length ◽  
Linear Interpolation ◽  
Atmospheric Temperature ◽  
Radiosonde Data ◽  
Published Data ◽  
Future Version ◽  
Set Up

Abstract. This paper is motivated by the fact that, although temperature readings made by Vaisala RS41 radiosondes at GRUAN sites (https://www.gruan.org/, last access: 30 November 2020) are given at 1 s resolution, for various reasons, missing data are spread along the atmospheric profile. Such a problem is quite common with radiosonde data and other profile data. Hence, (linear) interpolation is often used to fill the gaps in published data products. From this perspective, the present paper considers interpolation uncertainty, using a statistical approach to understand the consequences of substituting missing data with interpolated data. In particular, a general framework for the computation of interpolation uncertainty based on a Gaussian process (GP) set-up is developed. Using the GP characteristics, a simple formula for computing the linear interpolation standard error is given. Moreover, the GP interpolation is proposed as it provides an alternative interpolation method with its standard error. For the Vaisala RS41, the two approaches are shown to provide similar interpolation performances using an extensive cross-validation approach based on the block-bootstrap technique. Statistical results about interpolation uncertainty at various GRUAN sites and for various missing gap lengths are provided. Since both approaches result in an underestimation of the interpolation uncertainty, a bootstrap-based correction formula is proposed. Using the root mean square error, it is found that, for short gaps, with an average length of 5 s, the average uncertainty is less than 0.10 K. For larger gaps, it increases up to 0.35 K for an average gap length of 30 s and up to 0.58 K for a gap of 60 s. It is concluded that this approach could be implemented in a future version of the GRUAN data processing.

Ball-Based Surface Machining System Used in Non-Contour Control

2012 ◽  
Vol 229-231 ◽  
pp. 2239-2242
Author(s):  
Shi Huan Wang ◽  
Lin Sen Zhu
Keyword(s):  
Interpolation Algorithm ◽  
Spherical Coordinate ◽  
Surface Machining ◽  
B Spline ◽  
Spiral Path ◽  
System A ◽  
Contour Control ◽  
Machining System ◽  
Set Up

Surface machining system based on spherical coordinate, which is used in non-contour control, is present for the thin-walled director sphere part turning, to improve the efficiency and quality of part machining. In this system, a thickness surface B-spline model is set up based on spherical coordinate, the space spiral path generation method is planned. To meet the requirement of surface quality, row spacing angle is determined by scallop height and blunt radius of cutting tool, and angle B-spline model for back cutting depth is given. Moreover, space spiral interpolation algorithm is present in CNC.

scholarly journals Analysis of Contact Part of Error Tooth Surface and Dynamic Performance Prediction for Involute Gear

2017 ◽  
Vol 2017 ◽  
pp. 1-11
Author(s):  
Xinrong Liu ◽  
Zhonghou Wang
Keyword(s):  
Interpolation Method ◽  
Dynamic Performance ◽  
Linear Interpolation ◽  
Transmission Error ◽  
Discrete Data ◽  
Tooth Surface ◽  
Interpolation Algorithm ◽  
Involute Gear ◽  
Data Points ◽  
Contact Part

Aiming at the problem of constructing digital model of involute gear with error, the method of linear interpolation combined with area weight interpolation is proposed. Based on the non-feature discrete data block technique, the true tooth surface discrete data obtained by the coordinate measuring instrument is divided into blocks, and then the interpolation method is used to interpolate the nonmeasurement area to construct the real tooth surface with errors. The contact part and dynamic performance of the gear are predicted by using the constructed error tooth surface. The contact error of the tooth surface and the transmission error of the gear are verified by the test, and the reliability of the judgment result is judged by measuring the vibration in the direction of the gear meshing line. Compared with the example, this method not only reduces the computational complexity of the interpolation algorithm, but also improves the accuracy of the tooth interpolation data points and the smoothness of the error tooth surface.

Research and Simulation of an Efficient Circular Interpolation Algorithm

2012 ◽  
Vol 542-543 ◽  
pp. 1204-1208 ◽  
Author(s):  
Xiao Ling Yan ◽  
Wang Long Wang ◽  
Nan Xue
Keyword(s):  
Feed Rate ◽  
High Efficiency ◽  
Interpolation Method ◽  
High Accuracy ◽  
Interpolation Algorithm ◽  
Machining Errors ◽  
Circular Interpolation ◽  
Program Show

During the process of conventional DDA circular interpolation, the synthesis feed rate fluctuations often, the machining errors are large also. A new efficient arc interpolation method is proposed in this paper, which uses the principle of DDA circular interpolation, it’s function is optimized and improved, Radius is used as the basis of interpolation feed, the left normalized data and pre-loaded are used also. The simulation result of VB program show that efficient circular interpolation method not only has high efficiency,but also has high accuracy.

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