Researching a Online Method of Measuring Three-Dimensional Deformation for Large Overhead Crossbeam

Aiming at the difficulty of online measurement for three-dimensional deformation of large overhead crossbeam in gantry CNC machining centre, this paper proposes a measuring method based on multi-points attitude of crossbeam-body. Real-time measuring the attitudes of some equidistant points on crossbeam-body, dealing with the measurement information by adopt shockproof filtering, wavelet denoising and smoothing. Then infer the formulas to calculate deformation of each point along different directions ofx-axis,y-axis,z-axis. The experiment uses triaxial acceleration sensor modules to measure crossbeam attitude. Experimental results show that the minimum deformational angle can be measured low to 0.06°. And if the spacing between sensor modules has mm level accuracy, the precision of calculation about deformation can reach up to 10-3mm level. In addition, this method is strongly suitable for on-site environment, and it can lay a foundation for further researching about prediction and compensation in the CNC processing.