Enrico C. Quintana

Exploring diagnostic capabilities for application to new photovoltaic technologies

Explosive growth in photovoltaic markets has fueled new creative approaches that promise to cut costs and improve reliability of system components. However, market demands require rapid development of these new and innovative technologies in order to compete with more established products and capture market share. Oftentimes diagnostics that assist in R&D do not exist or have not been applied due to the innovative nature of the proposed products. Some diagnostics such as IR imaging, electroluminescence, light IV, dark IV, x-rays, and ultrasound have been employed in the past and continue to serve in development of new products, however, innovative products with new materials, unique geometries, and previously unused manufacturing processes require additional or improved test capabilities. This fast-track product development cycle requires diagnostic capabilities to provide the information that confirms the integrity of manufacturing techniques and provides the feedback that can spawn confidence in process control, reliability and performance. This paper explores the use of digital radiography and computed tomography (CT) with other diagnostics to support photovoltaic R&D and manufacturing applications.

Using Sampling Moiré to Extract Displacement Information from X-Ray Images of Molten Salt Batteries

Full-field axial deformation within molten-salt batteries was measured using x-ray imaging with a sampling moire technique. This method worked for in situ testing of the batteries because of the inherent grid pattern of the battery layers when imaged with x-rays. High-speed x-ray imaging acquired movies of the layer deformation during battery activation. Numerical validation of the technique, as implemented in this paper, was done using synthetic and numerically shifted images. Typical results of a battery are shown for one test. Ongoing work on validation and more test results are in progress.

Stereo X-Ray System Calibration for Three-Dimensional Measurements.

Advances in multiple view computer vision techniques have made it possible to make highly accurate three-dimensional (3D) measurements using calibrated stereo image systems. Recent experiments conducted at Sandia National Laboratories have demonstrated the feasibility of applying these techniques on an X-Ray system. Acquiring measurements from stereo image systems, be it visible or x-ray, require the estimation of the system’s intrinsic and extrinsic parameters via a calibration process. There are several calibration methods depending on the system’s configuration and its intended use. In most cases, one or more image pairs of a calibration artifact such as a 3D object of known dimension or a 2D target board are processed to estimate the system’s calibration parameters. For this paper, methods based on both types of calibration artifacts will be discussed along with experimental results.