Perhaps the most important long-term trend has been the increased advances in robot intelligence. Since their initial inception, robots have had some level of intelligence in making decisions about part availability, checking if a feature is present, detecting error conditions, or related issues. In most cases, this intelligence was based on a specific sensor detecting a specific condition.
For example, a photo eye is used to detect that a part is present, and in the correct orientation through the presence or absence of a pin, detent or other feature. This photo eye is then wired to a PLC or directly to the robot controller. At the appropriate time in the robot program the robot checks this photo eye to confirm that the part is in position and in the correct orientation before picking it up or performing some other operation.
Using a photo eye or similar sensor for this example is a simple and reliable approach, and is probably the right choice in this instance. However, opportunities for automation are not always this simple. Multiple part styles may need to be handled. The means of differentiating parts may be more complex.
Parts or the manufacturing process may not lend itself to simple conveyors. For example, parts located in bins, with layers separated by a slip sheet are commonly used for metal parts. Parts may have complex geometries, making them more difficult to locate without the additional cost for fixtures to locate the parts.
Two Dimensional Vision Location
Adding the means necessary to deal with these types of complexities has been a major barrier to the increased use of robotics in some industries. Recently this has begun to change. The technology that has had the most significant short -term impact has been two dimensional vision systems. For info on vision, see the Automated Imaging Association .
2D vision systems consist of standard industrial cameras used to take images that are processed by the robot to make decisions on how parts should be handled. Industrial vision systems have been available for some time, but they have reached the price-performance-reliability point that allows them to be used for applications that were not feasible just a few years ago.
A good example is using a vision system in conjunction with a robot to locate parts stacked in bins separated by standard slip sheets. This is a common means of transporting parts from plant to plant or even to transport parts within a plant. Without the use of a vision system, manufacturers must use relatively expensive formed plastic dunnage or some other means of accurately locating parts within a bin This type of formed plastic dunnage that can be stacked within a bin is relatively expensive with the mold alone costing $60,000 to $100,000 to design and manufacture.
