Deltarobots

Delta robots, also called deltarobots, are a class of parallel robotic manipulators designed for high-speed translational motion with minimal end-effector rotation. They comprise three identical arms connected between a fixed base and a single end-effector plate. Each arm is driven by an actuator at the base and uses a parallelogram linkage to preserve the orientation of the end-effector as its position changes. In typical configurations, the end effector translates in three dimensions while maintaining a roughly constant orientation, making Delta robots well suited for rapid pick-and-place tasks.

Invented by Reymond Clavel in 1985, the Delta robot was developed at EPFL and popularized for industrial use due to its speed, rigidity, and simple kinematics. The architecture results in a light, low-moving-mass end effector, allowing high accelerations and short cycle times. End effectors are commonly grippers, vacuum cups, or simple mechanical fingers.

Control and kinematics: Inverse kinematics—computing actuator positions from a desired end-effector position—is typically solvable in closed form for standard geometries, enabling fast, real-time control. Forward kinematics is more complex but tractable. Modern systems use PLCs or embedded controllers with encoder feedback to maintain accuracy.

Applications: Delta robots are widely employed in packaging, electronics assembly, sorting, food processing, and other high-speed pick-and-place tasks. They are especially valued in operations requiring rapid cycle times and moderate payloads.

Variants and limitations: Different arm lengths, base sizes, and end-effector geometries yield different workspace shapes and reach. While fast and precise within a limited workspace, Delta robots have a more constrained reach and can be sensitive to manufacturing tolerances and gravity effects on heavier payloads.