End Effectors, Tracks, Turntables and Work Bases

Over the past 15 years, researchers in architecture and construction have been exploring the possibilities of employing industrial robotic equipment to help create new kinds of architectural forms. There is now a wealth of research in this area that manufacturers can draw on to inform new robotic manufacturing processes, due to the power that they entail in the direct path from digital design to fabrication. For architects, designers and construction managers, this research also points the way to new design possibilities.

In the scope of this training material, examples from current architectural and design research are explored. Recent publications from ROBArch, CuminCAD and prominent universities were analysed to identify key hardware requirements. The key findings of the literature review show that custom end effectors, direct human interaction with technology and vision embedded systems is necessary to correspond to the needs of manufacturing bespoke designs. The results of this research hints that there is a need for a paradigm shift in the way fabrication is thought, as the design methods used in the early exploratory stages directly correlates with the way the industrial robots function and manufacture.

Carving End Effector, image courtesy of UAP
Carving End Effector, image courtesy of UAP

End Effectors

IRAs respond to numerous tasks by utilising different end effectors (EEs) by tools. EEs are gateways to manipulate various materials as well as exploring numerous ways of systems of thinking. The possibility of attaching any kind of a hand tool to an IRA creates immense opportunities and unique ways of exploring material properties and conditions. In that manner, architects have attached; pens, heat guns, extruders, grippers, hot-wire cutters, grinders, drills, chisels, suction heads, welders, etc… as end effectors to the IRAs.

When dealing with custom EEs, the main concerns are to be aware of the tool centre point (TCP) that is the gravitational centre and the payload of the proposed EE. The EEs can be modelled in a 3D modelling software with the tool base at 0, 0, 0 point, where most software use as an import point for the simulation of the kinematics model of the IRA. The weight and the location of the EE, affects the movement of the IRA by means of vibration and locating the workspace and the material that is worked on.

Therefore, they should be calibrated in relation to these parameters. Calibration of an IRA is important to achieve precision and accuracy in the outcomes of the manufactured models. Calibrations are done through 3Points Calibration (XYZ) method or 4 point calibration method.

Sensors

Sensors are the receptors of the IRA. Sensors are used:

  • to contextualize a robot within an environment (Gramazio, Kohler),
  • to use the IRAs in their full capacity,
  • to sense the different material qualities,
  • to create engagement possibilities with the materials,
  • to allow safe human-robot collaboration.

Touch sensors, vision scanners, microphones, force control sensors, motion tracking systems are used to gather information from IRAs surroundings and materials. The gathered information through the sensors are fed into the robot control systems to create feedback loops to allow real-time manipulation of the IRAs movements. Such feedback loops are necessary to have a greater control over the IRA as well as getting accurate or desirable outcomes.

Tracks, Turntables and Work Bases

Most of the IRAs used in architectural manufacturing are 6-axis. In some cases, where more than 6 axis is necessary, the IRA is set up on a moving track or the work table is a turntable. This provides flexibility in the movement of the IRA. In case of the IRA used as a tool in a construction
field, it can be mobile allowing autonomous vehicle properties to be applied. By scanning its surroundings, the IRA can adjust its movements in relation to obstacles, as well as follow directives to complete predefined spatial tasks.