Model-augmented methods for estimation of contact pressure distribution

On-line measurement of the contact pressure distribution (CPD) at the tool-workpiece interface during sheet metal stamping is critical to advancing the state-of-art in tool wear and product quality monitoring. Since the number of sensors that can be integrated into a tool structure is limited by concerns of structural integrity and cost, estimation of CPD through a small number of sparsely located sensors has created unique challenges in information acquisition and representation. Specifically, the problem of determining continuous CPD from discrete sensor measurements is under-constrained and thus ill-posed. A mathematical framework is needed for treating such a problem. This paper presents three mathematical approaches Regularization, Kriging, and Spatial Blending to address this problem and discusses their relative merits and limitations.