Computer-aided inspection (CAI) is the use of software tools to assess manufactured objects. It is closely related to computer-aided design (CAD) and

computer-aided manufacturing Computer-aided manufacturing (CAM) also known as computer-aided modeling or computer-aided machining is the use of software to control machine tools in the manufacturing of work pieces. This is not the only definition for CAM, but it is the most ...

(CAM). Its primary purpose is to allow engineers to more quickly and precisely assess the physical properties of manufactured objects. These properties can include

dimensions In physics and mathematics, the dimension of a mathematical space (or object) is informally defined as the minimum number of coordinates needed to specify any point within it. Thus, a line has a dimension of one (1D) because only one coord ...

, material consistency, roughness and

roundness Roundness is the measure of how closely the shape of an object approaches that of a mathematically perfect circle. Roundness applies in two dimensions, such as the cross sectional circles along a cylindrical object such as a shaft or a cylindr ...

Uses

CAI has applications in industries ranging from

food production The food industry is a complex, global network of diverse businesses that supplies most of the food consumed by the world's population. The food industry today has become highly diversified, with manufacturing ranging from small, traditional, ...

aerospace Aerospace is a term used to collectively refer to the atmosphere and outer space. Aerospace activity is very diverse, with a multitude of commercial, industrial and military applications. Aerospace engineering consists of aeronautics and astrona ...

, commonly being used in the quality assurance step of the manufacturing process. It involves comparing manufactured objects with a CAD model,

technical drawing Technical drawing, drafting or drawing, is the act and Academic discipline, discipline of composing Plan (drawing), drawings that Visual communication, visually communicate how something functions or is constructed. Technical drawing is essent ...

data sheet A datasheet, data sheet, or spec sheet is a document that summarizes the performance and other characteristics of a product, machine, component (e.g., an electronic component), material, subsystem (e.g., a power supply), or software in sufficie ...

to ensure that the finished product is within

specification A specification often refers to a set of documented requirements to be satisfied by a material, design, product, or service. A specification is often a type of technical standard. There are different types of technical or engineering specificat ...

and meets design intent.

Technologies

CAI machines can use a variety of technologies depending on the material of the product to be inspected, the properties to be measured, and the precision required.

Digital Cameras

Digital cameras A digital camera is a camera that captures photographs in digital memory. Most cameras produced today are digital, largely replacing those that capture images on photographic film. Digital cameras are now widely incorporated into mobile device ...

are frequently used in situations where the shape or colour of an object needs to be analysed. Using

machine vision Machine vision (MV) is the technology and methods used to provide imaging-based automatic inspection and analysis for such applications as automatic inspection, process control, and robot guidance, usually in industry. Machine vision refers to m ...

, the CAI program can make decisions about objects by comparing them to a master photo or data array.

Laser Scanning

Laser scanning Laser scanning is the controlled deflection of laser beams, visible or invisible. Scanned laser beams are used in some 3-D printers, in rapid prototyping, in machines for material processing, in laser engraving machines, in ophthalmological ...

CAI machines use

point clouds Point or points may refer to: Places * Point, Lewis, a peninsula in the Outer Hebrides, Scotland * Point, Texas, a city in Rains County, Texas, United States * Point, the NE tip and a ferry terminal of Lismore, Inner Hebrides, Scotland * Poin ...

to generate a 3D model which is compared to the required specification. Laser scanners are generally used to check the external geometry of parts with low reflectivity and translucence.

Structured Light Scanning

Structured light scanners use projected light patterns and digital cameras to analyse the

geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...

of an object. As with laser scanning, objects with high reflectivity and translucence can cause problems but temporary coatings can be applied to prevent this.

CT Scanning

Industrial CT scanners use

X-rays X-rays (or rarely, ''X-radiation'') are a form of high-energy electromagnetic radiation. In many languages, it is referred to as Röntgen radiation, after the German scientist Wilhelm Conrad Röntgen, who discovered it in 1895 and named it ' ...

to image an object from many angles, building up a 3D image to compare to a specification. CT scans can be used to analyse the internal geometry of parts because the X-rays penetrate the object being scanned. Higher resolution CT scans can also check for cavities, cracks, and other undesirable features inside parts.

References

Computer-aided design Metrology {{engineering-stub