A cartesian robot, also known as a cartesian coordinate robot, is a common type of industrial robot. It has three "arms" that each function along linear axes of control. Each of these axes is at a right angle to the other two. A common application for the cartesian robot is a computer numerical control (CNC) machine, and it can have a multitude of uses, especially as either a milling or drawing machine.
The basic form of a cartesian robot consists of three "arms." Each arm can move only along a two dimensional axis — it can only move backward or forwards or, if the arm is vertical, up or down. Each arm is at a right angle to the other two, though, which allows the robot to utilize the motions of all three arms to reach various points in a three-dimensional space. These arms can vary tremendously in size, depending on the purpose of the robot. In some particularly large designs, the horizontal arm will have support on both ends. This is called a gantry robot.
The primary advantage that the cartesian robot has over other types of industrial robots is that all three of its axes of control are linear rather than rotational. Having a linear axis of control is an advantage because it greatly simplifies the robot's arm solution. In order to program a robot for a specific task, the programmer must be able to program the robot to move along its axes of control to reach the various desired positions. Determining this arm solution requires calculations to determine the desired positions relative to the robot's axes of control. Linear calculations are far easier to calculate, because the programmer can perform these calculations in a closed form using basic trigonometric principles.
As a result of the cartesian robot's ability to reach different points in a three-dimensional space with relative ease, its most common application is as a CNC machine. CNC machines use computer programs to extract the necessary commands to cause the robot to function in the desired manner and then to load these commands into the robot. They enable the robot to move very precisely and thus make cartesian robots suitable for different drawing and drafting functions. When a cartesian robot is used in this manner, a tool can be lowered onto or raised off of a surface while moving along the X and Y planes to create a specific design.
