Interpolation in robot programming

Definition: interpolation is the calculation of intermediate positions between a start point and an end point taught in the program, so that the robot moves along a defined path instead of jumping between points.

The controller generates these intermediate points at a fixed update interval (a few milliseconds) and sends them as set-points to the joint servos.

Why it is needed

• Only a few key points are taught; the path between them must be generated.
• It controls path shape, speed and acceleration.
• It makes the motion smooth and prevents jerks that could damage the mechanism or the workpiece.

Effect of the method chosen

The interpolation type decides the tool path: joint interpolation is fastest but the path curves, linear interpolation keeps the tool on a straight line, and circular interpolation follows an arc.

Exam tip

Define it in one sentence and name the three main types, which Q4(b) expands.