Solar Concentrator Surface Measurement Using Reflected Patterns

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current methods for measuring solar thermal concentrators are either insufficiently precise, time-consuming, or limited to small areas, making it difficult to accurately assess the quality and efficiency of large mirror surfaces in solar thermal power plants.

Innovation Solution

A method that uses reflected patterns to determine surface normals and gradients on the concentrator surfaces, allowing for two-dimensional evaluation and high-resolution measurements of local gradients with minimal time and material expenditure, using a simple target like a printed plate and computer image evaluation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Area of stationary object

If a large-area target is attached to the concentrator for measurement, then measurement coverage is improved, but cost and device complexity increase significantly

Engineering Contradiction:
Improvemeasurement coverage areaVSAvoidtarget attachment complexity
Core Design Contradiction:
Area of stationary objectVSDevice complexity

Solution Approach 1:

The patent uses a simple printed plate with pattern as a target instead of a complex large-area target. The pattern on the plate is reflected by the concentrator surface and captured by a camera, creating an optical copy that enables measurement without requiring physical attachment of complex measurement equipment to the concentrator surface.

Inventive Principle:
Principle #26Copying

Solution Approach 2:

The measurement target is implemented as a simple printed plate that can be easily manufactured and replaced. This disposable-like approach eliminates the need for expensive, complex, and durable target attachments, significantly reducing measurement system cost while maintaining measurement capability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Measurement precision

If traditional measurement methods are used for large concentrator areas, then measurement completeness is improved, but measurement time increases significantly

Engineering Contradiction:
Improvemeasurement completenessVSAvoidmeasurement time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent captures the entire concentrator surface reflection in a single two-dimensional camera image, transitioning from sequential point-by-point or line-by-line measurement to simultaneous area-wide measurement. This dimensional approach allows complete coverage of large concentrator surfaces without time-consuming sequential scanning.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The measurement system is pre-configured with a camera positioned at the focal point and a patterned plate at a known distance. This preliminary setup enables direct calculation of surface normals and gradients from the captured image without requiring time-consuming iterative measurements or adjustments during the actual measurement process.

Inventive Principle:
Principle #10Preliminary action

3Ease of operation

If qualitative image comparison is used for mirror adjustment, then ease of operation is improved, but quantitative measurement capability deteriorates

Engineering Contradiction:
Improveadjustment simplicityVSAvoidquantitative measurement capability
Core Design Contradiction:
Ease of operationVSMeasurement precision

Solution Approach 1:

The patent transforms the measurement from qualitative image comparison to quantitative parameter extraction by calculating surface normals and gradients from the reflected pattern geometry. The known pattern dimensions and camera position enable mathematical computation of precise surface parameters, providing both ease of operation through automated calculation and high measurement precision through quantitative data.

Inventive Principle:
Principle #35Parameter changes

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enables accurate, fast, and economical measurement of large concentrator areas, providing quantitative data on slope errors and tilting, which can be used for precise adjustment and optimization of solar thermal power plants.

Implementation Method 1

a camera (22) which is arranged behind the target (20) in such a way that the image of the target reflected by the concentrator (10) falls onto the camera

Methodology Applied
Scientific EffectReflection: Reflection

Data Source

PatentEP1717568B1Method for measuring a solar thermal concentrator
Publication Date: 2012.07.25 DEUTSCHES ZENTRUM FÜR LUFT UND RAUMFAHRT E V
  • EP1717568B1 patent drawingFigure 1~2
  • EP1717568B1 patent drawingFigure 3~6
  • EP1717568B1 patent drawingFigure 7~9

AI summary

The method involves allocation of the structure visible in the image with the coordinates of the target (20) in the source image. Calculating the determination of the normal surface for the reflection plane at different positions of the concentrator (10) from the clear allocation of the mapped structures. Comparisons of the upward gradients of the normal surface with the target gradient of an ideal form of the concentrator.