Quality standards are very high in carriage manufacturing, due to the fact, that the visual quality impression is highly
relevant for the purchase decision for the customer. In carriage parts even very small dents can be visible on the
varnished and polished surface by observing reflections. The industrial demands are to detect these form errors on the
unvarnished part. In order to meet the requirements, a stripe projection system for automatic recognition of waviness
and form errors is introduced<sup>1</sup>. It bases on a modified stripe projection method using a high resolution line scan camera.
Particular emphasis is put on achieving a short measuring time and a high resolution in depth, aiming at a reliable
automatic recognition of dents and waviness of 10 μm on large curved surfaces of approximately 1 m width. The
resulting point cloud needs to be filtered in order to detect dents. Therefore a spatial filtering technique is used. This
works well on smoothly curved surfaces, if frequency parameters are well defined. On more complex parts like
mudguards the method is restricted by the fact that frequencies near the define dent frequencies occur within the surface
as well. To allow analysis of complex parts, the system is currently extended by including 3D CAD models into the
process of inspection. For smoothly curved surfaces, the measuring speed of the prototype is mainly limited by the
amount of light produced by the stripe projector. For complex surfaces the measuring speed is limited by the time
consuming matching process. Currently, the development focuses on the improvement of the measuring speed.
Hip and knee prostheses are complex products with high quality standards. The aim is to reproduce the behavior of a natural joint. This can be achieved by using a hard and a soft component. The research project "Optical Geometry Acquisition of Medical Implants and Prostheses", short "OptiGIP", explores methods for an automated quality assurance included in the production chain of these components. The approach is divided in two sections, a three dimensional and a two dimensional measurement technique. First a stripe projection method is used to produce a three dimensional model of the component. This model can be used to verify the geometry of the component. Furthermore it enables a new examination method, the Model-Based RSA, which is used to explore the effect of loosening. A late loosening of the components within the bones is the most important quality criterion for a successful implantation. The second part of described measurement method aims at a reduction of an early loosening of the prosthesis. Even very small scratches on the prosthesis's surface can have an impact on an early loosening because of friction between the soft and hard surface. Scratches produce bigger particles of the soft component than an undamaged surface would do. Recent research activities show that these bigger particles have an influence on an early loosening mechanism. The two-dimensional measurement checks the quality of the surface of the hard component of the implant. The approach is to use an extended dark field method. The prosthesis is illuminated from various angles producing a sequence of images. These images are filtered to distinguish between reflections from scratches and direct reflections. A combination of the filtered images shows the scratches.