High accuracy robots are valuable tools for many processes in aerospace manufacturing.
FREMONT, CA: Robots have conventionally relied on repeatability. Critical aerospace manufacturing techniques like fastening and drilling were conventionally not held to tight tolerances. The standard is set by the positional need to drill fastener holes, which has been taken as a critical target application for robotics in aerospace manufacturing. Because several factors influence robot accuracy, it is essential to define the accuracy needs for the system. Different levels of accuracy need other solutions; the higher the accuracy required, the more factors must be considered, adding to the cost and complexity. The story of accuracy should be defined in connection to the process demands. Some processes will only need positional accuracy while others need path accuracy, and some applications will require both.
Inconsistent and inaccurately machined replacement parts might conventionally have meant time lost due to trimming or other adjustments. Mitigating fastener tolerances enhances the reproducibility of an assembled component, and it allows for a reduction in structure weight due to reduced fastener size and weight. Avoiding these adjustments by machining precisely formed parts enables predictable and timely replacement, mitigating costs and downtime, and letting for parts to be interchanged repeatedly without interruption in production. The introduction of robotic accuracy into the manufacturing process ensures that this replacement is seamless, does not interrupt the manufacturing process, is cost-effective and highly accurate.
Robot accuracy is enhanced when the work zone is defined as localized as possible. It is essential to define wherein the robot’s work envelope the process will take place. This is called the process work zone. A higher level of accuracy is gained if the process work zone is defined and the calibration is limited to this zone. When defining a process work zone, there are some considerations to follow. First, the process work zone wants to include all processes that need accuracy. Second, make the zone only as large as the process needs. Third, limit robot configuration changes in the process work zone as much as possible. Some other additional applications that have benefited from high accuracy robots are aerospace engine components manufacturing and airframe painting.