Contouring accuracy improvement using natural local approximation for the biaxial system

Contouring error is a key criterion in high-speed and high-precision multi-axes manufacturing. However, it´s hard to find the analytical expression of the real contouring error for any free-form contour and most of existing researches focused on the estimation methods. In order to achieve high contouring accuracy, we design a decoupled controller based on the contouring error information by applying natural local approximation method, which is suitable for not only 2-dimensional planar contours but also 3-dimensional spatial ones. Experiments demonstrated the advantage of our proposed method with tangent line approximation method and circular approximation method.