Fringe projection sensors gain in importance in manufacturing quality control due to their multiple advantages. In order
to adapt the measurement strategy to a specific inspection task, both a suitable sensor and the necessary measurements
have to be chosen, so that the complete workpiece shape is recorded with a tolerance-compatible measurement
uncertainty. Thus a reliable forecast of the measurement uncertainty is crucial for an effective inspection-planning
procedure. There are multiple influences, whose impacts on the measurement result vary dependent on the position of
each measured point. So the local measurement uncertainty at each measured point - here called 'local optical probing
uncertainty' - is individual. Today, this local probing uncertainty cannot be predicted. This paper shows a simulationbased
approach to eliminate this shortfall. Firstly, a definition for local optical probing uncertainty is given. Then the
model for the simulation of fringe projection measurements - including a GUM-compliant forecast for the local probing
uncertainty - is described. This simulation is then implemented into an assistance system that supports the inspection
planner when setting up the measurement strategy. Finally a method for the experimental verification of the local optical
probing uncertainty is introduced and the simulation results are verified.
Multi-component fringe projection sensors allow the fast, holistic, exact, robust, contact free sampling of a workpiece surface. The success of an inspection relies on the skills, diligence and experience of the inspection planner. For setting up an inspection, there is no standardized method established yet. Therefore there is a need for assistance systems to support the operator. A prototype of an such assistance system for multi-component fringe projection sensors is introduced. The assistance system supports the inspection planner in determining the ideal sighting- and positioningstrategy.
As key element, the result of a planned inspection is simulated. First, the optical performance of the designated fringe projection sensor is calculated by use of raytracing software. Then the measurement result and the measurement uncertainty for specific measurement tasks and a chosen measuring pose, is simulated. Fundament for this simulation is a complete mathematical-physical model of the measurement. Building on this and on the knowledge of influences, which were previously inscribed in entry masks, the measurement uncertainty can be estimated and displayed individually for each point of a workpiece surface. Thus the inspection planner can easily evaluate the quality of the planned inspection
setup. Additional optimizing algorithms were implemented. The aim of the multi-criteria optimization is to determine the best configuration for the measurement device and the ideal sighting- and positioning-strategy. As measure of quality serves hereby the reduction of the measurement uncertainty.