Small pick and place robotics have broad application in manufacturing automation. The functionality of moving a part or a product from one location to another is very basic stuff. In the process of movement the object being transported many need to assume a new position before it arrives at the destination. The movement of these objects in an automated production environment can be the job of pick and place robotics. There are some variations in the capabilities of different types of these robotics. These differences are caused by the methods that are used to make motion with these devices.
Some pick and place robotics use air cylinders to power their movements from one place to another. The device can have one or more air cylinders that are used to power movements. A cylinder may be set up to move along the horizontal plane, and another can be set up to move along the vertical plane. There may even be another air cylinder set up to make the object being moved to turn on an axis, flip over, or rotate to a given angle. A negative characteristic of the air cylinder based pick and place is the fact that movements are often herky-jerky, not moving the object in a smooth fashion, but kind of lunging it from place to place. This erratic movement makes for inaccuracies in placement when taking an object to a specific location in an automation cycle. This can cause a problem in the cycle of automation, if the movement is too erratic. The jerking can make the acceleration and deceleration of the robot difficult to control. If the inaccuracy of placement and the erratic movement is not a problem then the air cylinder powered pick and place robotic could be effective.
Pick and place robotics can also be powered by cams. A cam has peaks and valleys cut into its edge. As the cam is turned on a shaft the peaks and valleys define the movement of the pick and place robotic. The cam makes for a very precise movement to a location without deviation. Accuracy of placement is a strength of a cam driven pick and place robotic. It is also easy for the velocity and displacement of the cam-driven pick and place robotic to be adjusted. The cam, however, has only one set of motions that it can perform. If the peaks and valleys need to be changed then a new cam will have to be created in order to change the movement locations. Cam-driven robotic devices are quieter during operation than the air cylinder types.
There are electromechanical pick and place robotics that use both the air cylinder and the cam to drive robotic movements and are powered by electric motors. Air cylinders are st up to control vertical and horizontal movements, while cams are used to control the acceleration and deceleration of the movements and allow the movements to change direction. This hybrid can be actuated sooner that the non-hybrid models which cuts down on the cycle time. Adding electromechanical functionality to this device gives it much more manageable abilities. These devices are much more flexible in doing tasks. It is possible to adjust the length of stroke with an electrical powered robotic so that it can stop at any point in its travel length. It is not forced to stop only at the end of its travel, it can stop at any place along the route.
Air cylinder devices do not handle the need to stop at multiple locations very well. Neither are they able to handle the acceleration and deceleration that is sometimes required in an automation cycle. The motor powered robotic models are much more energy-efficient the air cylinder types. The electric driven may cost more initially, but are more efficient to operate. The cost of air cylinders over a long period of time make that method more expensive. The efficiency level of an electromechanical robotic is 80 percent, while the air-based model is only 60 percent efficient.
The ability to program the movements of the electric model makes this device the most useful of the two. The lower cost of electrics and drives and stability and flexibility of operation has made the hybrid the best choice for most automation applications. Control of some models of the electric type are simplified by the advanced controls and the capabilities that are already built into the controller. Some devices have the calculations already done and ready for the robot to access. There is no need to have to teach the robot every point because it already knows some of them. Some have a linear motor for movement in the vertical and horizontal planes. Electric is the best way to go for pick and place robotics.
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