Cartesian mechanisms have long been the mainstay of pick-and-place operations. They are simple to design and easy to program. Using linear actuators to move in X, Y and Z enables engineers to map end-effector coordinates directly to actuator positions. The velocity and acceleration of each axis are easy to calculate, and single-feedback control loops can be used on each axis.
However, Cartesian mechanisms are not without limitations. For one, they require a lot of space. And since two or three actuators are stacked one atop the other, when one motor is moving, the other motors are dead weight. Add the weight of the power and control cables—not to mention the payload—and that’s a lot of mass to move around.