The recently developed machine hammer peening process is used at the die shop of the Mercedes-Benz plant in Sindelfingen in order to replace manual surface finish of deep drawing dies. The goal of the process is surface roughness reduction after milling to ensure the tribological properties, which are necessary for the sheet metal forming process. Using machine hammer peening it is also possible to create defined surface structures that may be employed to influence local friction conditions and therewith overcome current limitations of the forming process. To take advantage of the surface structuring capabilities it is necessary to understand how to create defined surface structures using machine hammer peening and how the created structures affect friction and material flow behavior. In this work an approach is presented to describe the interaction of milling and machine hammer peening parameters on the created topography by wave theory. Especially the influence of tool path parameters of milling and consecutive machine hammer peening is investigated. The results, which are calculated using wave theory, are verified by FEM simulations and real experiments. In addition, suitable process parameters for machine hammer peening are derived from the obtained results, as they are used at the Mercedes-Benz die shop today.

Machine hammer peening (MHP) is a mechanical surface treatment that employs a tungsten carbide tool to hammer the surface of a work piece. It was the goal of this study to find relations between the process parameters and the surface smoothing effect of MHP by finite element simulations. Impact experiments have been conducted in order to find suitable loaddeformation-relations for a selection of work piece materials and to validate the model. A finite element model has been established with good agreement to the experimental results. Simulations have been conducted to investigate the influence of main process parameters on the surface roughness reduction. Additional simulations were performed and a way of creating uniform smooth surfaces with respect to small duration of surface treatment is presented.

This paper describes a novel method to improve the accuracy of industrial robot by calibration technique. Robot calibration is broadly classified into model-based and modeless techniques. In this paper, a modeless technique capable of interpolating the deviation along the Z-axis is defined which doesn’t consider any kinematic model, instead adapts interpolation method to compensate errors. The robot’s deviation is measured with a laser tracker and the deviation controlling parameters are calculated. The controlling parameters interpolate the deviation and with an online compensation program this deviation is compensated in real time scenario. This modeless technique is experimentally tested and it demonstrates a substantial improvement in the accuracy of the robot.

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