Carnegie Mellon University

ARMOR 1 Mat Sinking System

NREC is engineering an automated robotic system for the US Army Corp of Engineers to perform “revetment” operations. Revetment refers to structures that stabilize a river by restoring its banks, particularly where down-cutting currents are strongest. The system is called “ARMOR ONE.”

Once deployed on the Mississippi river, ARMOR ONE will replace the Corp’s old Mat Sinking Unit, originally built in 1948. The ARMOR ONE system will not only dramatically increase the speed of revetment operations but will also improve the safety and working conditions of the employees who perform this vital work.
The current process is hazardous, manually-intensive, and tedious. It includes cranes that are manually operated to grab rows of concrete pads from the supply barge and place them on the manufacturing barge. A group of workers just under the cranes help position the pads correctly with crowbars. Another group of workers operate tying devices that attach the pads to the steel wires to create a mattress of connected concrete pads. This process puts the workers at a risk for injuries.

When completed, ARMOR ONE will include six, independent, robotic cranes. These cranes will pick up the large concrete squares from the supply barge and place them on the “mat deck” of ARMOR ONE’S manufacturing barge. There, the individual squares will be tied together into one 140 ft wide (and up to 900 ft long) flexible “mat” by an automated tie system (also engineered by NREC). The completed mat will be launched from the barge and will be submerged along the banks of the Mississippi River, while more mats are continuously being assembled on the deck.
Several important aspects of the system are:

  1. Coordinated motions of multiple arms, working together on a shared space, while also being cognizant of human workers in the vicinity.
  2. Fail-over capability, such that if one arm becomes inoperable, it can quickly and easily be disengaged and another arm can do the work of both.
  3. Fully automated tying of the mats providing increased worker safety by reducing the number of workers required to be present on the mat deck area.
  4. Automated mat cut-off operations eliminating the need for potentially hazardous manual operations
The ARMOR ONE system is scheduled to be deployed and begin operations on the Mississippi in 2023.