Robotics gives superhuman strength to shipbuilders

Daewoo Shipbuilding and Marine Engineering (DSME) has developed wearable robotic RoboShipbuilder suits for workers at its South Korean yards. The shipbuilder wants to take vessel production to the next level by outfitting staff with robotic exoskeletons that give them superhuman strength for heavy equipment handling.

Prototypes of these robotic suits are being tested at DSME’s facility in Okpo-dong, on Geoje Island. If the trials are successful, the exoskeletons could be used more widely in the company’s shipyards in the near future. The early feedback from workers using the suits during the trials is positive, but there is still more research to be done.

The exoskeletons are made of lightweight aluminium alloy and steel and are engineered to follow the wearer’s movements. They weigh 28kg and are designed to fit workers between 160cm and 185cm tall. There are pads at the feet and padded straps that go across the thigh, waist and chest to connect the user to the suit. This enables the user to have control of the robotic suit and the ability to move heavy loads around.

The first generation of RoboShipbuilder suits has a three-hour battery life before needing to be recharged. They use a mixture of hydraulics and electric servomotors to carry the load. A system consisting of hydraulic joints and small electric motors runs along the outside of the leg linking to a backpack, which powers and controls the robotic suit. Other devices within the exoskeleton include high-precision actuators, gears and motors.

European Automation supplies these devices, as well as the controls, actuators and the power systems for the robotic systems on the suits. The UK-based company also supplies selective compliance-articulated arms, with six axes of movement for other robotic applications, such as in the manufacturing of electronic systems.

Devices designed for individual tasks can be attached to the backpack. One such contraption arches over a worker’s head to act like a small crane. Other devices help workers manipulate heavy components precisely into position for difficult welding tasks. The robotic suit takes the majority of the weight, so the worker is effectively handling light objects.

During the trials, DSME discovered that its shipyard workers are capable of lifting up to 30kg using the prototype robotic suits. The manufacturer predicts that this can be more than doubled.

The lead engineer in DSME’s research and development division, Gilwhoan Chu, said a trial had received positive worker feedback as they found it enabled heavy lifting while relieving stress and strain. Workers said they needed to move more quickly and cope with heavier loads. DSME is working on increasing the load capacity to 100kg, which is roughly the weight of a standard 2m steel support beam.

Other companies are developing robotic suits. Raytheon has developed a second generation of its Sarcos exoskeleton (XOS 2) for the US Defense Advanced Research Projects Agency. This suit is capable of lifting up to 90kg, but it is tethered, weighs more than 50kg and requires a hydraulic power source.

The XOS 2 is powered by an internal combustion hydraulic engine and has an electrical system. There are various sensors equipped throughout the suit that specify the position and the force required during lifts. Raytheon has incorporated computer processors at every joint of the exoskeleton and sensors send signals to these processors through an Ethernet network. This further prompts the actuators to deliver about 200kg/cm2 of force by using pressurised hydraulic systems. A fully operating tethered version is expected to enter into military service by 2015.

Raytheon is focusing its research on developing a logistics support variant, which would enable the continuous lifting of heavier objects by military personnel to reduce orthopaedic injuries. It could also be used for more strategic missions. The design would need to be an untethered version with a fuel-carrying backpack and customised hydraulic servos to provide endurance of around eight hours. The suit could be ready for service by 2020.

Lockheed Martin has also developed an exoskeleton design for industrial and military use. The HULC suit for heavy loads is untethered and is hydraulic-powered. It has an onboard microcomputer that ensures the exoskeleton moves in parallel with the individual inside. The suit is modular, allowing for major components to be swapped when required, while its power-saving design allows the user to operate on battery power for extended missions.

The Massachusetts Institute of Technology (MIT) is also developing and testing robotic systems under its supernumerary robotic limbs project. MIT intends to produce designs for auxiliary systems that act as a second set of hands for workers. A prototype presented earlier this year weighs only 4.5kg and may be worn as a backpack-like harness, which has straps over the shoulders and around the waist. MEC

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