Research on the influence of design tolerances on the pointing error of the fulcrum of the reflective surface of a heliostat

In this study, we delve into the impact of fabrication and assembly discrepancies in heliostat support structures on the alignment inaccuracies of solar reflective surfaces. Our approach involves the application of a three-dimensional error propagation calculation methodology. We have formulated a mathematical model that correlates the dimensional and angular tolerances of the heliostat bracket structure with the pivot's pointing error. Through experimental validation, we have compared the theoretical pointing error associated with a given design tolerance to the empirical data collected from a 4m² heliostat. This comparison has enabled us to elucidate the pattern of influence that different angular and dimensional tolerances exert on the mirror pointing error of the heliostat bracket structure. Our findings reveal that the bracket structure's pointing error of a heliostat tends to escalate with an increase in design tolerance across various angular and dimensional tolerances. However, it is noteworthy that the rate of this escalation diminishes progressively. This insight is pivotal for optimizing the design and assembly processes to minimize alignment errors in solar reflective systems.