Compensation strategy to minimize over-cut effects in robotic belt grinding with passive-compliant tools

At the beginning of the robotic belt grinding path, passive-compliant tools can generate an over-cut effect. The transient state from the first contact point between tool and workpiece to the grinding steady state can generate an excess of material removal at the workpiece border. If successive grinding passes are made, this effect will accumulate, increasing the shape deviation at the workpiece border. Therefore, the purpose of this research is to analyze this phenomenon and develop an easy-to-implement compensation strategy to avoid removing an excess of material at the beginning of grinding paths. Specifically, a geometric model of the contact has been developed that, together with the material removal model, allows to reproduce the cut-in effect for a robot-operated passive-compliant tool case. In turn, the compensation strategy that has been designed, avoids removing an excessive amount of material by means of a cut-in path that adjusts the feed velocity to the instantaneous contact force. This path is based on the tool geometry and grinding process parameters. In order to validate the proposed strategy, several experiments have been performed for different process conditions. Results show how the proposed solution significantly reduces the over-cut effect providing a homogeneous material removal since the beginning of the grinding.