Browsing by Author "Gouws, Jurgens Erik"

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    Calibration of heliostats using a drone.
    (Stellenbosch : Stellenbosch University, 2018-12) Gouws, Jurgens Erik; Smit, W. J.; Stellenbosch University. Faculty of Engineering. Dept. of Mechanical and Mechatronic Engineering.
    ENGLISH ABSTRACT: The aim of this thesis was to investigate the theoretical feasibility of calibrating heliostats using a drone. Doing so would require the following: (1) First show that it is possible to identify heliostats using a camera. (2) Then prove and test the accuracy of a RTK-GPS. (3) Then assess the target that is used, and prove that it can be identified within the reflection of a heliostat’s concave mirror. The last step is to set up an adjusted calibration equation for the application of using a drone. Due to the number of parameters, a Monte Carlo simulation should be performed using multiple drone inputs to predict the performance of a drone-calibrated heliostat. If the predicted performance of a drone-calibrated heliostat is satisfactory, then it can be claimed that a heliostat could theoretically be calibrated using a drone. A proof of concept established that it is possible to identify the reflection in the heliostat’s concave mirror. It was also shown that it is possible to calculate a weighted average of the reflection, and to identify a feasible point in space for the drone. The RTK-GPS also performed as expected and showed steady results during the tests. Nine parameters were used to describe the mathematical model of the heliostat, and an additional parameter was used to describe the drone offset. The simulation could predict the resulting milliradian error on the target to be less than one milliradian for drone calibration using at least 10 points in space that is further than 32 metres from the pylon. It was concluded that the resulting milliradian error was dependent on the specific noise in the drone position, combined with the drone position chosen, as well as the drone distance from the pylon.