TAILIEUCHUNG - Influence of acceleration on the CMMS accuracy in fast measuring
This paper presents a theoretic and practical approach to confirm the dynamic errors induced by acceleration on CMMs during fast measuring. To simplify, a physical model, a mathematical model of the bridge component and the prismatic joint that move along X axis of a bridge CMM are presented. | Science & Technology Development, Vol 15, 2012 INFLUENCE OF ACCELERATION ON THE CMMS ACCURACY IN FAST MEASURING Thai Thi Thu Ha, Pham Hong Thanh University of Technology, VNU-HCM (Manuscript Received on April 5th, 2012, Manuscript Revised November 20rd, 2012) ABSTRACT: This paper presents a theoretic and practical approach to confirm the dynamic errors induced by acceleration on CMMs during fast measuring. To simplify, a physical model, a mathematical model of the bridge component and the prismatic joint that move along X axis of a bridge CMM are presented. The research points out that there is sure to be the dynamic errors when there is acceleration. This has been demonstrated by the simulation of the errors on the tip probe by Matlab sofware and the experimental results are obtained. The dynamic errors will decrease the accuracy of CMMs so it is necessary to make out a compensation software to keep up the the accuracy of the measuring results. Keywords: Fast measuring, Fast probing, CMMs, Accuracy, Velocity, Acceleration, Dynamic error. 1. INTRODUCTION Today, CMMs have been developed in the trend that they’re kept up their accuracy during fast measuring [2], [4], [12]. When CMMs are measuring at high speed, there are some kinetic elements, which cause the dynamic errors and reduce the accuracy of CMMs. They are the approach distance to the surface, the speed of the approach to the surface, t/he acceleration of Y X the approach to the surface and the direction of the approach to the surface [5]. Therefore, it is Z necessary to research the influence of these kinetic elements on the accuracy of CMMs and suggest some methods or some directions of Figure 1. The whole of structure of a moving solution to make sure the demand CMM’s bridge CMM accuracy in fast probing. 2. STRUCTURE BRIDGE CMM [14] Trang 60 OF Structure elements serve as the backbone THE MOVING of CMM. The machine base, table to support the part to be measured, machine .
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