Two-arm-system for investigation of two handed manipulation
The development of humanoid robots has made significant progress in the last years. Impressive walking robot systems were developed. The capabilities of these robots to manipulate objects or interact with their surrounding are quite limited.
The objective of our development was to build a manlike upper body with two arms and two hands. The system is used to test programming and control concepts for two-handed mobile manipulation.
The system design uses preliminary works of the institute, namely the DLR light weight robot (LWR) and the DLR hand. The torso based on LWR technology and the newly developed mobile platform enlarge the workspace of the arms and hands in a human like manner, by using coordina¬ted arm and leg movements. The modular design of the LWR and the DLR hands enables the configuration of a human-like left and right arm.
The upper body holds a total of 43 controllable degrees of freedom, equip¬ped with link side torque sensors which enable the impressively sensitive mani¬pulation capabilities.
Modular control- and software¬architecture
From a control point of view, two-handed manipulation can be dealt with in a number of ways. When grasping a big crate, for example, one arm can act as master while the other merely follows the movement. An intuitive approach implemented at the DLR describes the movement of the crate. The arms are connected to the crate using virtual springs.
To be able to test different approaches despite the high complexity of the com¬plete system in a simple and yet flexible manner and to fulfill the high demands on computing power, a new software architecture, the aRD-concept ("agile Robot Development"), was developed at the institute. Using this concept, the classical, predominately monolithic control structure is dissolved into a fine-grained net of communicating modules. The individual modules can be run distributed on multiple processors. Even the execution across computer borders under strict real-time conditions is possible.
The implementation consists of a small collection of libraries and some confi¬guration tools. It allows the integration of a variety of standard tools such as Matlab / Simulink for controller design.
Diameter: approx. 1,7 m
Weight: approx. 45 kg
Payload: approx. 15 kg
Degrees of freedom: 2 x 7 arms
2 x 12 hands
41 x torque (link side)
43 x position (motor / link side)
3DMo - Sensorhead:
Inertial Measurement Unit