## 8 Outlook and Future Work  
This paper presented a comprehensive range of future research prospects, which can be broadly categorized into three distinct clusters. The first over-arching cluster involves the **evaluation of cognitive assistance applications** with a moving head; a special focus can be applied to its existing workflow integration as well as further research regarding worker acceptance. Another focus within this cluster can be applied to the scaling of the assistance system with multiple moving heads, sharing the dynamics of a common workspace as well as other assistance systems in an effort to avoid occlusion by objects, tools and workers. Different shapes for the Gobo wheels can be explored to enrich the light spot with simple information.  
The second cluster entails improvements to the **iterative algorithm**. Several approaches are possible, including the use of other non-linear solvers for the derived equations, or the merging of two iteration steps to solve the aforementioned discrepancy between the steps. While [PERSON]'s method is simple to implement, it requires a reasonably good estimation of the result to avoid local minima. A logical next step is therefore evaluating different iteration algorithms for improved performance and robustness. Weighing factors could also be introduced to tune the results in the case of the heterogeneous distribution of angle ranges on the reference points as well as potential methods to reduce the amount of reference points if they offer little to no additional accuracy for the end result, thus simultaneously increasing performance. Manual plausibility checks in the case of multiple solutions due to Euler's angles could also be introduced. To mitigate this problem, especially within applications where assumptions made about the coordinate system do not hold, the use of quaternions instead of Euler's angles can be examined. An additional focus can rest on quality measures of the calculated result in order to improve the validity assessment, and potentially, the feedback of metrics into the algorithm.  
The third and final cluster expresses the **characterization of the moving head** itself. One aspect of this characterization entreats further research into the mechanical accuracy of each mechanical and optical axis with the methods described in this paper. Using a laser tracker, it is possible to determine pose accuracy and repeatability. With a mathematical description of the mechanical zoom, in conjunction with the focus and either custom Gobo wheels or a separate iris, a variable and controllable spot size at the workpiece is achievable. The custom Gobo wheels can be used for a precompensation of the aforementioned spot distortion, which leads to vast uncertainty. For this precompensation, a mathematical description of this distortion in combination with different workpiece surfaces is necessary.  
The presented features and capabilities of a moving head spot, in conjunction with further research, situates the moving head as a viable low-cost alternative to established light projection systems, incentivizing its deployment in the production environments of large scale products.  
J.K.: Conceptualization, methodology, software, validation, supervision, project administration, writing--original draft preparation, writing--review and editing; C.B.: conceptualization, methodology, software, validation, formal analysis, investigation, writing--original draft preparation, writing--review and editing; T.S.: funding acquisition, writing--review and editing. All authors have read and agreed to the published version of the manuscript.  
This research was funded by the German Federal Ministry for Economic Affairs and Climate Action (BMWK) (Program LuFo VI-I; Project \"digitaleQM\"). Publishing fees supported by Funding Programme Open Access Publishing of Hamburg University of Technology (TUHH).  
Not applicable.  
Data Availability Statement: Data are available in the Appendix C.