Delta Pick-and-Place Robot

Overview

The delta robot is a parallel-kinematic manipulator built for high-speed pick-and-place: sorting, packing, and feeding small parts moving on a conveyor. Three arms hang from an overhead platform at 120° spacing, and because the heavy servo motors stay fixed on the frame, only the light arms and end plate move. That low moving mass is what lets a delta reach accelerations many times gravity and sustain well over a hundred picks per minute. A central fourth axis adds tool rotation, and an overhead vision system locates parts on the belt so the robot can track and grip them on the fly.

How it works

Each of the three Drive Actuator units mounts on the Fixed Base Plate and pairs an AC servo with a low-backlash planetary gearbox, an absolute encoder, and a holding brake. Each actuator swings a rigid Upper Arm Link, which connects through a Lower Arm Parallelogram parallelogram of carbon-fibre rods on spherical ball joints to the moving end plate. The parallelogram geometry keeps the Traveling Platform level at all times, so the controller only has to solve for position. The Fourth Axis Drive runs a telescoping spline shaft down the center to spin the tool independently of the arms.

The Vacuum Gripper is a vacuum gripper with a Venturi ejector, fast solenoid valve, suction cups, and a vacuum sensor that confirms each grip. Part positions come from the Vision System, which combines an overhead camera, ring light, and a conveyor encoder so the robot can track moving parts. All four axes are commanded by the Controller Cabinet cabinet, which houses the motion CPU, servo drives, power supply, and a dual-channel safety module. The whole robot hangs over the line on the Mounting Gantry.