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RE2 Robotics Inc. today said that the U.S. Patent and Trademark Office has issued Patent No. 10,704,665 for the invention of a “Fluid Rotary Joint and Method of Using the Same.” The Pittsburgh-based company said the new fluid rotary joint is capable of precise positioning while being driven by both fluids and gasses, including water, hydraulic fluid, and air. RE2 said the patent adds to its intellectual property and confirms its expertise in mobile manipulation and underwater robotics.

RE2 Robotics said it develops intelligent mobile manipulation systems that operate in a variety of complex indoor and outdoor environments. They include robotic arms, intuitive controllers, and advanced autonomy software. The company said its mission is to develop systems that empower humans to do their jobs faster and safer in the aviation, defense, energy, and medical industries.

New joint includes strain-wave gear, fluidic actuators

The invention, which was developed during the design of an inflatable underwater manipulator for explosive ordnance disposal (EOD) applications, can be used in robotic arms to provide precise rotational positioning for dexterous manipulation. It combines a strain-wave gear and fluidic actuators in a compact, precise rotary joint.

The strain-wave gear uses materials with tunable load transmission characteristics for the flex spline, rather than expensive toothed interfaces. The fluidic actuators generate the waves that drive the flex spline, and the tunable nature of the flex spline materials enables different modes of behavior. This allows the joint output to be driven in a clockwise or counter-clockwise direction, to freely rotate, or to act as a torque-limiting device by having limited contact with the circular spline.

“By locating this type of actuator at the end of a robotic manipulator, arm mass, inertia, and electromagnetic signature are reduced,” stated Dr. Andrew Mor, principal research scientist and part of the team that invented the joint. “The actuation of the joint is remote, so we are able to reduce mass at the joint level.”

“In addition, since the joint is inherently torque-limited, it can be tuned and utilized in locations where safety could be an issue, such as with underwater oil and gas inspections or when naval divers are inspecting and neutralizing water-borne explosive devices,” he said.

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RE2 claims leadership in mobile manipulation

RE2 Robotics has 3D-printed face shields and grown 50% during the COVID-19 pandemic, and it announced a facility expansion in September. Last month, the U.S. Army awarded the company a contract for the Autonomous Casualty Extraction program, which also uses mobile manipulation.

“The issuance of this patent further solidifies RE2’s position as a world-class intelligent mobile manipulation provider,” said Jorgen Pedersen, president and CEO of the company. “It also reinforces the brilliance and dedication of our engineers and scientists, who are encouraged to design creative solutions to solve our customers’ most challenging manipulation problems.”