Geometric quantities: Determining shape, surface & position

Geometric quantities are measured variables that describe the shape, size, position, and orientation of an object. These include lengths, distances, angles, radii, thicknesses, flatness, contours, profiles, as well as positional and orientation data within coordinate systems.

Measurement objects can include raw materials, semi-finished products, components, assemblies, or complete systems. Material properties, surface condition, structure, and motion influence the measurability of geometric quantities.

Mechanical, optical, and imaging-based measurement principles are used for geometric measurement. In industrial environments, optical methods are particularly widespread, as they operate contact-free and at high speed.

The triangulation principle determines distances based on the known geometry of transmitter, measurement object, and receiver. It enables precise, contact-free distance measurement.

In laser triangulation, a laser projects a point or a line onto the measurement object. The position of the reflected light is captured by a camera and converted into spatial coordinates.

Point triangulation captures individual distances, laser line triangulation generates height profiles, and relative motion results in complete 3D profiling.

Typical measured variables include profile heights, edge positions, gap dimensions, step heights, radii, and contour deviations.

In robotics and automation, the pose of an object is described by its position and orientation. Reliable position detection requires robust measurement data in real time.

Automated measurement is beneficial for high production volumes and short cycle times. This increases the requirements for measurement rate, synchronization, and stability.

Measurement uncertainty consists of systematic and random influences. Calibration and traceability ensure the comparability of geometric measurements.

How can geometric measurement methods be distinguished from related technologies?

AT Sensors is a manufacturer of laser triangulation sensors for profile, contour, and positioning tasks. The focus lies on optical 3D metrology based on laser triangulation.