PICK AND PLACE
Pick-and-place applications comprise both primary handling—putting individual pieces of product into a tray or carton—and case packing. Advances in materials of construction, controlling software and hardware, vision systems and other aspects have made robots, of various types, an increasingly viable option for pick-and-place. The type of robot most appropriate for a given pick-and-place application depends on the speed required, the size of the payload and other factors. For most applications, only one type of robot will be appropriate. But there are many borderline applications where more than one type could be used, and the end user (or his/her system integrator) must prioritize the factors.
Another development is refinements to motion control software and hardware. Motion control is the essence of robotics. It’s needed to find objects, to guide the robot arm in picking them up and releasing them, and to coordinate with equipment upstream and down.
In the past, operating a robot would have required integration between the robot’s motion controller and the programmable logic controllers (PLCs) that coordinate the robot’s actions with the rest of the line. But the trend has been to combine those functions, as much as possible, into common controllers. This eliminates software coding that would otherwise have been required to coordinate the separate controllers.
Several kinds of robots can be used for upstream pick-and-place:
- Delta-style robots that operate from overhead with three or four long, thin arms that meet at the effector head;
- SCARA (selective compliant articulated robot arm) models, which are fixed-base robots with three vertical-axis (horizontal-motion) rotary arms; and
- Multi-axis articulated robots, which can have up to six axes, with joints that can rotate in any direction.
As with most aspects of packaging, end users want pick-and-place to run as fast as possible. But some applications have practical limitations. Fragile products like baked goods have to be handled gently, which means slowing down.
Pick-and-place applications are fertile ground for robotic equipment. As technology and other developments make such equipment increasingly viable, end users who pick the right machines will find themselves in a good place.