SherpaTT


SherpaTT
SherpaTT (current state as of June 2016) (Photo: Florian Cordes, DFKI GmbH)

Technical Details

Size: Variable, smallest foot print: 1m x 1m. Biggest foot print: 2.4m x 2.4m. Height ranges from 0.8m to 1.8m
Weight: 150 kg
Power supply: LiPo primary battery: 44,4 V; 10 Ah & LiPosecondary battery: 44,4 V; 10 Ah (autonomous hot switching)
Speed: 0.7 m/s (max) 0.1 m/s (nominal)
Actuation/ Engine:
4-wheel drive with active ground adaption, alternatively short traverses of walking motion
Sensors:
- Lidar: Velodyne HDL-32E
- Laser range finder: Hokuyo UST-20LX
- Camera: Basler Ace (2048 x 2048px, 25 fps)
- IMU: Xsens MTi-300 AHRS
- Force-Torque sensor FT-DELTA 160 at each wheel
Communication:
- Mobile access point: 2.4 GHz, 802.11n,
- Remote control: Bluetooth
- Remote stop: 868 MHz Xbee-Pro
On-Board Computer:
IntelCore i7-4785T, 2.2GHz
Structure and Mechanisms:
- 6 DoF Manipulator
- 4x 5DoF Suspension Units

Organisational Details

Sponsor: German Aerospace Center e.V.
Federal Ministry of Economics and Technology
Grant number: Grant no. 50 RA 1301
Team: Team V - Behavior Control & Simulation
Application Field: Space Robotics
SAR- & Security Robotics
Underwater Robotics
Related Projects: SIROM
Standard Interface for Robotic Manipulation of Payloads in Future Space Missions (11.2016- 01.2019)
FT-Utah
Field Trials Utah with the TransTerrA System (06.2016- 03.2017)
TransTerrA
Semi-autonomous cooperative exploration of planetary surfaces including the installation of a logistic chain as well as consideration of the terrestrial applicability of individual aspects (05.2013- 12.2017)
Related Robots: Sherpa
Expandable Rover for Planetary Applications
Coyote III

System description

SherpaTT in the artifical crater environment of DFKI RIC (Photo: Florian Cordes, DFKI GmbH)
SherpaTT, equipped with final hull oft he central body and flexible wheels in the artifical crater environment of DFKI RIC (Photo: Florian Cordes, DFKI GmbH)
CAD-Rendering of the underwater version SherpaUW (Rendering: David Grünwald, DFKI-GmbH)
SherpaTT is a hybrid walking and driving rover with an active suspension system developed for high mobility in irregular terrain. The internal power supply (2x 10,000m Ah@44.4 V), a lidar sensor, a camera and the manipulator arm allow the cinduction of autonomous exploration activities.

The rover is equipped with six standardized electro-mechanical interfaces, one of them being the manipulators hand interface. Due to the electro-mechanical itnerfaces, the robot can be equipped and reconfigured with modular payload items to match the current task. One example being the usage of modular sampling devices, that can be sealed and handed over to the robotic team mate Coyote III.

SherpaTT’s overall weight is about 150 kg. Due to self-locking gears in the four suspension units, the rover is able to cope with high additional payload weights without increasing energy consumption to maintain the current robot’s body pose.

SherpaTT is developed within the scope of the project TransTerrA which aims to implement a logistics chain, based on a heterogeneous team of mobile and stationary robotic devices. SherpaTT has the role of an exploration and sample collecting rover in the heterogeneous robotic team. Collected samples are handed over to the Shuttle rover (Coyote III) for transport to the landing site and eventually sample return to earth.

SherpaTT represents an enhanced design of the Sherpa rover, which was originally developed within the RIMRES project. The design considerations and development concept of SherpaTT is derived from the lessons learned of Sherpa.  By introducing a knee joint within the suspension units (“legs” of the system, a three dimensional workspace is created. Furthermore two of the joints in the original design were used very rarely. Hence, a reduction from six degrees of freedom (DoF) in the original design to five  DoF in the new design along with a significant increase of the workspace of each suspension unit was possible.

Besides the primary scenario with respect to extraterrestrial exploration, SherpaTT demonstrates its application to terrestrial scenarios as well, such as search and rescue and /or security. The water proof design of the suspension units allows to exchange the central body of the robot to create SherpaUW which is aspired to be applied in deep sea exploration scenarios.

Videos

Field Trials Utah: Roboter-Team simuliert Marsmission in Utah

Eine karge, felsige Wüstenlandschaft und keine Menschenseele weit und breit – um den unwirtlichen Bedingungen auf dem Roten Planeten möglichst nahe zu kommen, testeten Wissenschaftler des Robotics Innovation Center des Deutschen Forschungszentrums für Künstliche Intelligenz (DFKI) vom 24. Oktober bis 18. November 2016 die Kooperation verschiedener Robotersysteme in der Halbwüste des amerikanischen Bundesstaates Utah.

SherpaTT in Außentests

SherpaTT zeigt seine Fähigkeit mittels aktiven Fahrwerk auch große Unebenheiten ausgleichen zu können.

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© DFKI GmbH
last updated 05.10.2017
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