Abstract: A system and method for tracking the sun with a heliostat mirror is disclosed. The solar tracking system comprises: a camera configured to capture high dynamic range images of the sky, a plurality of cameras configured to capture images of the heliostat mirror, and a tracking controller. The images of the heliostat mirror include reflections of the sky. The tracking controller is configured to generate a circumsolar radiance map characterizing the brightness of at least a portion of the sky with the high dynamic range images.

Abstract: A system and method for tracking the sun with a heliostat mirror is disclosed. The solar tracking system comprises: a camera configured to capture high dynamic range images of the sky, a plurality of cameras configured to capture images of the heliostat mirror, and a tracking controller. The images of the heliostat mirror include reflections of the sky. The tracking controller is configured to generate a circumsolar radiance map characterizing the brightness of at least a portion of the sky with the high dynamic range images.

Abstract: A system and method for localization and calibration of a heliostat is disclosed. The system comprises a controller and a camera configured to acquire images of a plurality of heliostats. The controller and camera are configured to acquire a first image of the plurality of heliostats, move one of the plurality of heliostats, acquire a second image of the plurality of heliostats, generate a difference image by subtracting the second image from the first image, identify the heliostat that was moved based on the difference image, and calibrate the position or orientation of the heliostat based on the difference image. The difference image is generated by pixel-wise subtraction of the second image from the first image. The pixel-wise subtraction exposes the heliostat and enables the calibration of the position and/or orientation of known heliostat positions.

Abstract: A system and method for tracking the sun with a heliostat mirror is disclosed. The solar tracking system comprises: a camera configured to capture high dynamic range images of the sky, a plurality of cameras configured to capture images of the heliostat mirror, and a tracking controller. The images of the heliostat mirror include reflections of the sky. The tracking controller is configured to generate a circumsolar radiance map characterizing the brightness of at least a portion of the sky with the high dynamic range images.

Abstract: Methods, systems, and devices for determining an unsafe region and a safe target in a central receiver solar power plant by projecting the geometry of the central receiver onto a plane image using a perspective transform as seen from the perspective of a heliostat, dilating the geometry of the central receiver in the plane image by a safety margin, and selecting a set of safe target points for the heliostat.

Abstract: A drive assembly for a heliostat and a method of determining the drive's home position are described. The drive assembly comprises at least one mechanical hard stop for impeding the motion of an output gear of at least one gear transmission driven by a motor. Each hard stop may be built into the housing of a gear transmission or may be made integral with an output gear. The method for determining the drive assembly's home position comprises the steps of iteratively actuating an output gear towards, and then away from, a hard stop feature while monitoring the input torque of the driving motor. When the motor input torque is registered to be higher than a predetermined trip torque, the stepper motor is commanded to stop and the home position of the drive assembly is determined.