Light - Weight Robots

DLR Light-Weight Robot 1 (1995)


Light-Weight Robot (LWR) I

The researchers at the Institute for Robotics and Mechatronics have developed the first robotic system which flew in space. During the ROTEX-mission (1993) they demonstrated in an impressive manner that it was possible to control a space robotic system from earth. They delay time of up to 3s was “compensated” with on-board autonomy. The autonomy was achieved by a multi-sensor grippe, the so-called ROTEX-gripper. The robot, which was developed by Dornier, was not able to move its own weight on earth.

For training the astronauts a light, flexible robot was needed. That was the point of time when the idea was born to develop the first light-weight robot.

Although the development was pushed by space robotic requirements, the light-weight robot had its breakthrough with terrestrial applications.

There are several aspects all DLR-light-weight robots have in common:

The kinematics is similar to the human arm, each joint is equipped with a torque sensor, the complete electronics is integrated in the arm, and the weight was reduced wherever it was possible.
LWR I was the platform with which we gained a lot of experience and know-how. The huge step we made with the second generation would not have been possible without LWR I.


Total Weight 14,5 kg
Max. Payload 7 kg
Max. Joint Speed 120 °/s
Axes 7 (R-P-R-P-R-P-R)
Total Length 1338 mm
Motors Stepping Motor Escap
Gears DLR Planetary Gear
Sensors (each joint) 1 Incremental Position Sensor, 1 Torque Sensor
Brakes Self-locking Gear
Power Supply 50V 20 kHz AC-Bus
Control Position-, Torque-, Impedance Control

Control Cycles: Current 40 kHz, Joint 2 kHz, Cartesian 1 kHz
Integrated Electronics, external Cabling, Communications by optical SERCOS-Bus



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