Which term describes the two-dimensional movement of a robot arm in a plane?

The term that describes the two-dimensional movement of a robot arm in a plane is Cartesian coordinates. This coordinate system uses two axes, typically referred to as the X and Y axes, to denote positions in a two-dimensional space. In this system, any point in the plane can be defined by an ordered pair of values corresponding to its positions along these axes.

In the context of robotic movement, when a robot arm operates within a flat plane, it effectively translates and rotates based on these Cartesian coordinates, allowing it to reach various points efficiently. The simplicity of the Cartesian system makes it particularly suitable for programming robotic movements, with clear and direct mapping to the arm's actuators and joints.

Other coordinate systems, such as polar, cylindrical, and spherical, involve different representations that incorporate radial distances or angles, which are more complex and not typically used for straightforward two-dimensional movement tasks. Thus, for describing a robot arm's operation strictly within a two-dimensional plane, Cartesian coordinates is the most appropriate and efficient choice.