Positioning error compensation on two-dimensional manifold for robotic machining

2019 ◽  
Vol 59 ◽  
pp. 394-405 ◽  
Author(s):  
Weidong Zhu ◽  
Guanhua Li ◽  
Huiyue Dong ◽  
Yinglin Ke
2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Guanhua Li ◽  
Wei Dong Zhu ◽  
Huiyue Dong ◽  
Yinglin Ke

Purpose This paper aims to present error compensation based on surface reconstruction to improve the positioning accuracy of industrial robots. Design/methodology/approach In previous research, it has been proved that the positioning error of industrial robots is continuous on the two-dimensional manifold of six-joint space. The point cloud generated by positioning error data can be used to fit the continuous surfaces, which makes it possible to apply surface reconstruction on error compensation. The moving least-squares interpolation and the B-spline method are used for the error surface reconstruction. Findings The results of experiments and simulations validate the effectiveness of error compensation by the moving least-squares interpolation and the B-spline method. Practical implications The proposed methods can control the average of compensated positioning error within 0.2 mm, which meets the requirement of a tolerance (±0.5 mm) for fastener hole drilling in aircraft assembly. Originality/value The error surface reconstruction based on the B-spline method has great superiority because fewer sample points are needed to use this method than others while keeping the compensation accuracy at the same level. The control points of the B-spline error surface can be adjusted with measured data, which can be applied for the error prediction in any temperature field.


2021 ◽  
Vol 183 (2) ◽  
Author(s):  
D. Benedetto ◽  
E. Caglioti ◽  
S. Caracciolo ◽  
M. D’Achille ◽  
G. Sicuro ◽  
...  

AbstractWe consider the assignment problem between two sets of N random points on a smooth, two-dimensional manifold $$\Omega $$ Ω of unit area. It is known that the average cost scales as $$E_{\Omega }(N)\sim {1}/{2\pi }\ln N$$ E Ω ( N ) ∼ 1 / 2 π ln N with a correction that is at most of order $$\sqrt{\ln N\ln \ln N}$$ ln N ln ln N . In this paper, we show that, within the linearization approximation of the field-theoretical formulation of the problem, the first $$\Omega $$ Ω -dependent correction is on the constant term, and can be exactly computed from the spectrum of the Laplace–Beltrami operator on $$\Omega $$ Ω . We perform the explicit calculation of this constant for various families of surfaces, and compare our predictions with extensive numerics.


2021 ◽  
Vol 1920 (1) ◽  
pp. 012088
Author(s):  
Wenjiu Zhu ◽  
Jie Hou ◽  
Zhengqiong Liu ◽  
Zhizhong Ding

2021 ◽  
Vol 92 (8) ◽  
pp. 085107
Author(s):  
Yanchao Chen ◽  
Chunhua Ren ◽  
Hao Liu ◽  
Chenyang Gu

Measurement ◽  
2021 ◽  
pp. 110222
Author(s):  
Jian Wang ◽  
Wenyi Zhao ◽  
Richard Leach ◽  
Long Xu ◽  
Wenlong Lu ◽  
...  

2018 ◽  
Vol 8 (11) ◽  
pp. 2232 ◽  
Author(s):  
Chuanchen Bao ◽  
Qibo Feng ◽  
Jiakun Li

Error measurement of a rotary axis is the key to error compensation and to improving motion accuracy. However, only a few instruments can measure all the motion errors of a rotary axis. In this paper, a device based on laser collimation and laser interferometry was introduced for simultaneous measurement of all six degrees-of-freedom motion errors of a rotary axis. Synchronous rotation of the target and reference rotary axes was achieved by developing a proportional–integral–derivative algorithm. An error model for the measuring device was established using a homogeneous transformation matrix. The influences of installation errors, manufacturing errors, and error crosstalk were studied in detail, and compensation methods for them were proposed. After compensation, the repeatability of axial and radial motion errors was significantly improved. The repeatability values of angular positioning error and of tilt motion error around the y axis and x axis were 28.0″, 2.8″, and 3.9″. The repeatability values of translational motion errors were less than 2.8 μm. The comparison experiments show that the comparison errors of angular positioning error and tilt motion error around the y axis were 2.3″ and 2.9″, respectively. These results demonstrate the effectiveness of our method and the error compensation model.


2019 ◽  
Vol 9 (13) ◽  
pp. 2701 ◽  
Author(s):  
Li ◽  
Yang ◽  
Gao ◽  
Su ◽  
Wei ◽  
...  

Error compensation technology offers a significant means for improving the geometric accuracy of CNC machine tools (MTs) as well as extending their service life. Measurement and identification are important prerequisites for error compensation. In this study, a measurement system, mainly composed of a self-developed micro-angle sensor and an L-shape standard piece, is proposed. Meanwhile, a stepwise identification method, based on an integrated error model, is established. In one measurement, four degrees-of-freedom errors, including two-dimensional displacement and two-dimensional angle of a linear guideway, can be obtained. Furthermore, in accordance with the stepwise identification method, the L-shape standard piece is placed in three different planes, so that the measurement and identification of all 21 geometric errors can be implemented. An experiment is carried out on a coordinate measuring machine (CMM) to verify the system. The residual error of the angle error, translation error and squareness error are 1.5″, 2 μm and 3.37″, respectively, and these are compared to the values detected by a Renishaw laser interferometer.


Sensors ◽  
2020 ◽  
Vol 20 (8) ◽  
pp. 2428 ◽  
Author(s):  
Qian Deng ◽  
Shuliang Zou ◽  
Hongbin Chen ◽  
Weixiong Duan

Attachment changing in demolition robots has a high docking accuracy requirement, so it is hard for operators to control this process remotely through the perspective of a camera. To solve this problem, this study investigated positioning error and proposed a method of error compensation to achieve a highly precise attachment changing process. This study established a link parameter model for the demolition robot, measured the error in the attachment changing, introduced a reference coordinate system to solve the coordinate transformation from the dock spot of the robot’s quick-hitch equipment to the dock spot of the attachment, and realized error compensation. Through calculation and experimentation, it was shown that the error compensation method proposed in this study reduced the level of error in attachment changing from the centimeter to millimeter scale, thereby meeting the accuracy requirements for attachment changing. This method can be applied to the remote-controlled attachment changing process of demolition robots, which provides the basis for the subsequent automatic changing of attachments. This has the potential to be applied in nuclear facility decommissioning and dismantling, as well as other radioactive environments.


Sensors ◽  
2020 ◽  
Vol 20 (1) ◽  
pp. 294
Author(s):  
Bo Shi ◽  
Fan Zhang ◽  
Fanlin Yang ◽  
Yanquan Lyu ◽  
Shun Zhang ◽  
...  

Global navigation satellite system (GNSS)/inertial navigation system (INS) navigation technology is one of the core technologies in a mobile measurement system and can provide real-time geo-referenced information. However, in the environment measurements, buildings cover up the GNSS signal, causing satellite signals to experience loss-of-lock. At this time errors of INS independent navigation accumulate rapidly, so it cannot meet the needs of the mobile measurement system. In this paper, a positioning error compensation method based on plane control is proposed by analyzing the error characteristics of position and orientation caused by satellite signal loss-of-lock in the urban environment. This method control uses planar features and the laser point cloud positioning equation to establish an adjustment model that ignores the influence of the attitude error and finds the positioning error at the middle point of the GNSS signal loss-of-lock time period, and then compensates for the error at other points by using the characteristics of the positioning error. The experimental results show that the accuracy of the compensated laser point cloud has been significantly improved, and the feasibility of the method is verified. Meanwhile, the method can rely on the existing building plane so the method is adaptable and easy to implement.


2012 ◽  
Vol 472-475 ◽  
pp. 3029-3034
Author(s):  
Peng Li ◽  
Ying Hu ◽  
Zi Ma

Related to the machining precision, especially for the middle and low end machining center, the positioning error is often considered as a major factor, which can be traditionally decreased by the pitch compensation function integrated in the CNC system. However, the function is just founded on that all of positioning errors remain constant in the machining process, and it is difficulty to meet the compensation needs in different machining condition. At the same time, it involves a mass of parameters that need professional manual correction. Therefore, the software error compensation method is put forward. Firstly, based on cubic spline interpolation, the error compensation model is designed through the processing of positioning error which is collected by the laser interferometer. Secondly, with the characteristics of G codes, the database is established for error compensation, which can effectively correct different machining G codes with enough error information. Finally, by the experiment and accuracy evaluation, results show that after the positioning error of machining center is compensated by the presented scheme, its precision is improved obviously.


Sign in / Sign up

Export Citation Format

Share Document