A Path Planning Method of Robotic Belt Grinding for Workpieces With Complex Surfaces

The problem of the path planning method is regarded as one of the key bottlenecks in the robotic belt grinding system. It has a significant impact on the surface quality of processed workpieces with complex surfaces. To improve the surface quality, a novel path planning method is proposed in this article, which generates the grinding path containing both the grinding position and orientation for an industrial robot. First, the theoretical grinding trajectory is obtained by selecting the key contact points on the 3-D model and calculating the inverse solutions of the B-spline curves. Next, based on the curvature variation rate and curve length criterion, the key contact points are further refined to produce the target points in the sensitive area of the workpiece where surface curvature changes abruptly or surfaces intersect. Finally, the grinding orientation at each target point location is obtained according to the solutions of the surface equation constructed using bicubic B-spline interpolation. To validate the method, a faucet is used for contrast simulation and experiment. The results demonstrate that the proposed method performs better than the section method in terms of both planning efficiency and surface quality. With this method, the surface roughness value
$R_{a}$
of the processed workpiece can be controlled within 0.086
$\mu$
m without the risk of overcut, which is ideal for robotic belt grinding.