Glossary · Motion control and drives
Interpolation (motion control)
Also known as: Path interpolation
German: Interpolation
In motion control and CNC, interpolation is the calculation of intermediate setpoints for several coordinated axes so that the tool or load follows a defined path, such as a line, an arc or a spline, at the programmed speed.
- Motion control
In one sentence
Interpolation calculates coordinated setpoints for several axes so a tool or load follows a defined path at the programmed speed.
Example
A glue-dispensing robot uses interpolation so the nozzle follows the contour of a housing at constant speed.
How it applies
- Engineering: The interpolator runs in the CNC, robot controller or motion controller and sends setpoints to all involved axes in each cycle. Path accuracy depends on cycle time, look-ahead and axis dynamics.
- Commissioning: Axes in an interpolated group should have matched dynamic behavior; otherwise the path deviates at corners and arcs.
- Operation: Feed rate override changes the speed along the path, not its shape.
- Documentation: Programming manuals should list the supported interpolation types, the syntax, and how speed is defined along the path. Use figures to show paths and blending at corners.
Interpolation vs. point-to-point motion
In point-to-point motion each axis moves to its target independently and the path in between is not defined. Interpolation defines the path itself, which matters for machining, dispensing and collision avoidance.