______ robots can work from an overhead grid. Also known as gantry robots, this type of robot is an accurate, quick solution for material handling applications.

• A. polar
• B. cartesian
• C. articulated
• D. cylindrical

Answer: (B)

Movement in three straight, perpendicular directions defines a Cartesian robot, and gantry systems are a classic overhead implementation of that idea. In a gantry setup, X and Y travel is provided by carriages sliding along overhead beams, while the vertical Z motion comes from a separate actuator. This arrangement gives very stiff, straight-line motion with high repeatability, which is ideal for fast material handling tasks like picking, placing, and moving parts across a production line. The heavy frame carries most of the load, keeping the end-effector mass low and reducing backlash, so commands translate into precise, rapid positioning. Other robot types rely on rotary joints or curved paths—polar uses rotation around a point, cylindrical combines linear and rotational motion around an axis, and articulated involves multiple rotary joints, which makes straight, large-area linear travel less efficient and more complex. That combination of straight-line accuracy, large usable work area, and strong rigidity is why this overhead-grid, Cartesian gantry approach is the best fit.