Positioning Calibration of a Parallel Mechanism Worktable with 6-DOF

Abstract:

In this study, a small 6-DOF (degree of freedom) parallel mechanism worktable for machine tool was developed. There are many factors that affect the positioning precision and the accuracy of the machine tool. The uncertainty in position is mainly due to the structural rigidity, the geometric error of the parts and the assembly errors. It is very difficult to estimate the assembly errors and the link parameter of each part. Moreover, it is necessary to make clear the relation of cross talk between each axis for parallel mechanism. In this research, a method to compensate the movement error of worktable based on the measurement result was proposed and discussed. First, in order to measure the positioning accuracy of the worktable a measuring method by using 3-dimensional coordinate measuring machine (CMM) was proposed. After the evaluation, the positioning accuracy of the parallel mechanism worktable, the error of each configuration parameter can be obtained. By the correction of the inverse kinematic program, the improvement of the positioning accuracy of the worktable was confirmed. After calibrating several times, the positioning error became stable within a constant range. It is confirmed that this method to obtain the parameter error is effective, and it is possible to improve the positioning accuracy.

• Periodical: Key Engineering Materials (Volume 625)
• Pages: 392-397
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.625.392
• Online since: August 2014
• Authors: Yuan Rui Zhang*, Shigenobu Nagase, Jiang Zhu, Tomohisa Tanaka, Yoshio Saito
• Keywords: 6-DOF Parallel Mechanism, Calibration, Error Compensation, Inverse Kinematics, Positioning Accuracy, Precision, Worktable

References

[1] OTA Hiromichi，SHIBUKAWA Tetsuro, TOOYAMA Taizo, Study of kinematic calibration method for parallel mechanism (1st Report): Kinematic calibration using inverse kinematics，Journal of JSPE, 66. 2（2000）950.

DOI: 10.2493/jjspe.66.950

[2] OTA Hiromichi，SHIBUKAWA Tetsuro, TOOYAMA Taizo, UCHIYAMA Masaru, Study of kinematic calibration method for parallel mechanism (2nd Report), Kinematic calibration using forward kinematics，Journal of JSPE，66. 10(2000)1568.

DOI: 10.2493/jjspe.66.1568

[3] OTA Hiromichi，OTHUBO KAzuyosi , UCHIYAMA Masaru, TOOYAMA Taizo, SHIBUKAWA Tetsuro, Study of kinematic calibration method for parallel mechanism (3rd Report) : Gravity compensation and kinematic calibration considering gravity，Journal of JSPE，67，7(2001).

DOI: 10.2493/jjspe.67.1114

[4] TAKEDA Yukio, SHEN Gang, FUNABASHI Hiroaki, Kinematic calibration of in parallel actuated mechanisms using Fourier series: 1st Report, Calibration method and selection method of the set of measurement paths：Bulletin of JSME68 (673), 2002, pp.2762-2769.

DOI: 10.1299/kikaic.68.2762

[5] M Komori, J Zhu, T Tanaka, Y Saito, Development of Work Table System with 6-DOF parallel mechanism for Machine Tools, 3rd International Conference of Asian Society for Precision Engineering and Nanotechnology, Nov. 2009, 2A1-4.

[6] Tomohisa TANAKA, Masahiro Komori, JIANG ZHU, YOSHIO SAITO. Development of flexible worktable for end milling based on parallel mechanism, Key Engineering Materials, Trans Tech Publications, Vol. 447-448, pp.826-830, Jul. (2010).

DOI: 10.4028/www.scientific.net/kem.447-448.826

[7] Yuanrui Zhang, Jiang Zhu, Tomohisa Tanaka, Yoshio Saito, Measurement of movement error and its compensation for 6-DOF parallel mechanism worktable, Key Engineering Materials (Emerging Technology in Precision Engineering XIV), Vol. 523-524, 2012, pp.463-468.

DOI: 10.4028/www.scientific.net/kem.523-524.463