Robots with a human touch
The German Aerospace Center's (DLR) Institute of Robotics and Mechatronics in Oberpfaffenhofen develops some of the world's most advanced robotic systems. A primary focus is on telerobotics and haptic feedback, which allow human operators to control a robot from a distance and "feel" what the robot touches. This technology was tested in space as early as 2005 with the ROKVISS experiment, a robotic arm mounted on the exterior of the International Space Station (ISS). For over five years, operators at the DLR facility in Weilheim controlled the 50-centimeter arm, performing delicate tasks to test the reliability of lightweight robotic joints in the harsh space environment, where temperatures ranged from -20 to +60 degrees Celsius.
This research into remote operation continues with humanoid robots like Rollin' Justin. This 200 kg wheeled robot has two compliant, lightweight arms, four-fingered hands, and a head with stereo cameras for 3D vision. Its upper body has 43 controllable degrees of freedom, and its joints are equipped with torque sensors that allow it to perform sensitive manipulation tasks, such as catching a thrown ball or preparing coffee without spilling. Astronauts aboard the ISS, like Frank Rubio, have remotely controlled Rollin' Justin as it navigates a simulated Martian landscape at the Oberpfaffenhofen facility, practicing the setup of a planetary base.
From space stations to operating rooms
The technology pioneered for space has direct applications on Earth, particularly in medicine. The MIRO robot, a compact and lightweight arm weighing just 10 kg, is designed for surgical applications. Its dimensions are similar to a human arm, allowing it to assist surgeons directly at the operating table. The MiroSurge system uses multiple MIRO arms to guide surgical instruments and a stereoscopic camera for minimally invasive procedures. The system provides force feedback, enabling the surgeon, who operates from a console, to feel the resistance of tissues as if they were performing the procedure by hand. Technological principles from the MiroSurge system are now incorporated in the commercially available Hugo™ RAS (robotic-assisted surgery) system.
To develop and refine these remote control systems, the institute created the Haptic User Gerät (HUG), a bimanual device composed of two lightweight robot arms mounted behind a user. This setup provides realistic force feedback to the operator's hands, making it a versatile tool for training astronauts, simulating virtual assembly tasks, and even for rehabilitation. The system's control loop runs at a rate of 1 kHz, enabling highly responsive and stable interaction with virtual or remote environments.