There exists a demand in the aerospace industry for highly configurable and flexible automated riveting cells to manufacture small to medium sized panels of complex geometries. To meet this demand Electroimpact has developed a manufacturing system consisting of a stationary Electro-squeeze C-frame riveter, coupled with a robot part positioner to present the component to the process head tool point.
The C-frame can install a wide range of aerospace rivets and perform specialist functions including backside countersinking operations, giving potential for double flush fastening. The geometric limitations and high implementation costs of large cartesian based positioning barges or fixed jig tooling and moving gantry riveters are avoided when exchanged for a robot part positioner. To achieve the high levels of accuracy and repeatability required within the industry the robot part positioner is a KUKA KR1000L750 upgraded with EI proprietary Accurate Robot Technology (+/- 0.25 mm large volume global accuracy).
Critical to the success of the system is high speed and seamless communication between the robot and C-frame, it is the details of this that will be explored within the paper. In summary this is achieved by deploying a Siemens 840D CNC as the singular central controller handling the robot motion control, riveting process and cell safety features. With twenty-seven individual servo driven axis’ working in harmony to perform the core manufacturing functions the single 840D controller allows for a more efficient and simplistic control architecture when compared to the typical methodology of integrating a separate motion controller. A critical capability enabled by this approach is the ability to position components normal to the fastening axis via live sensor feedback at the tool point in real time. In circumstances where the system is reliant on the integration of a separate motion controller this type of closed loop feedback simply would not be possible.