Future Aerospace Assembly using HMI and Robotic Riveting (or Fastening)
HMI is Human Machine Interface and in the context of Robotic Riveting refers to the Riveting Team....the Riveter and the Bucker (the upper sidebar shows a classic Riveting Operation).
HMI remotely supervises the Robotic Riveting (or Fastening) operation via a computer screen on which a laser scan of the component being assembled by a team of robot pairs is overlaid on a CAD master image such that any deviation caused by preload or out-of-sequence processing is revealed by a change in colour of the overlay alerting the human supervisor to potential non conformance. (the middle sidebar shows the intent)
(Essentially at the programming stage any possibility of deviation would be anticipated and the robots which are all interconnected would be adjusted to rivet or fasten in a sequence which would avoid that kind of problem)...however unintended consequences would require correction by the HMI team.
The experience, know how and tribal knowledge of the HMI team allows for the adjustment of the riveting preload condition by remotely changing the sequence of events to relieve the preload and return the component to the design intent.
Previously a laser scan of the first article production component would have provided an “as built” database with point cloud clusters at significant locations which can be used as in process assembly check points by Quality Assurance as the build progresses.
By monitoring events as they happen and using machine vision to sample and time stamp for conformance such items as cracked rivets or improperly seated fasteners will be highlighted to the HMI team and problem and suspect areas marked for later identification.
In the classical riveting operation carried out by the two person team fatigue begins to set in towards the end of the working day because of the noise and repetitive muscle strain.
In contrast the robots are not aware of such things except that wear and tear on the end effectors may require the HMI team to progressively monitor the indicators built into the robots and their decisions to adjust or change the conditions maintains continuity in the process.
LIDAR software can be used to program the robot riveting sequence by importing the 3D CAD master data and have the robots simulate the sequence by establishing master start and end points with the linear pitches as an array along the rivet line adjusting for curvature as the array progressively drives the robots along the x,y,and z co-ordinates. Any canted components with angled pitches would be treated as special cases again under the control and supervision of the HMI team.
The lower side bar shows the background documentation used to elaborate on the projected system.
Non conformance records will show a history of problem locations and where robots enter these areas a flashing screen and audible warning alerts HMI supervision to enhance vigilance, and the use of virtual imaging headgear linked to machine vision allows supervision to zero in on locations requiring detailed observation.