1. Asguard: A Hybrid Legged-Wheel Security and SAR- Robot Using Bio-Inspired Locomotion for Rough Terrain DFKI- Labor Bremen & Universität Bremen Forschungsgruppe Robotik Director: Prof. Dr. Frank Kirchner www.dfki.de/robotics robotics@dfki.de

2. 2 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich Overview Motivation for Legged-Wheel Locomotion The Physical Robot Asguard CPG-based Locomotion Control Adaptive Proprioceptive Control Results

3. 3 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich Motivation for Legged-Wheel Locomotion Wheels are most suitable for high velocities Legs are suitable to overcome obstacles and climb stairs Many robotic applications in security and SAR fields need both Combining the advantages of wheeled and legged locomotion in one system ARAMIES Walking Robot Asguard Hybrid Legged-Wheel Robot

4. 4 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich The Physical Robot Asguard (I) Five compliant legs are mounted around an axis shaft Elastic foot tips reduce shock for high velocities Elastic spinal column (passive) for ground adaptation Asguard compliant leg Shock absorbing foot tip Schematic of stair climbing

5. 5 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich The Physical Robot Asguard (II) LiPoly Battery 30V/10Ah PC 104 Onboard Computer Modular Camera Section (Zoom / IR) Custom FPGA Sensor/Motor Board 4x Faulhaber 24V DC 83W Weight: 11.5 kg 95 cm 50 cm

6. 6 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich CPG Based Locomotion Control (I) Central Pattern Generators in biological systems are self- sustaining neural circuits which produce rhythmic oscillations. These patterns can be found in biological systems (from insects to humans), where rhythmic actuation is required (e.g. walking, chewing). Eight legged scorpion robotHadrurus arizonensis

7. 7 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich CPG Based Locomotion Control (II)

8. 8 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich Adaptive Proprioceptive Control (I) Key idea and innovation for compliant legs:  No fixed motion pattern for different types of terrain  Adjustment of CPG internal control loop  Use of „adaptive spring“, based on proprioceptive data (energy distribution for each leg) Adaptive control based on proprioceptive data

9. 9 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich Adaptive Proprioceptive Control (II) Online adaptation of internal position controller by adjusting the proportional factor in correlation with the current discrepancy

10. 10 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich Fig. 1: Front LeftFig. 2: Front Right Fig. 3: Rear LeftFig. 4: Rear Right Results (I): Phase Sync Without Adaptive Control

11. 11 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich Results (II): Phase Sync With Adaptive Control Fig. 1: Front LeftFig. 2: Front Right Fig. 3: Rear LeftFig. 4: Rear Right

12. 12 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich Results (III): Demonstration of Mobility

13. 13 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich Outlook Investigation about different gaits in terms of efficiency/speed Research about adaptive gait transitions Next prototype (waterproof) already under development Increase autonomy in terms of navigation under Asguards odometry constraints

14. 14 / 14 ASGUARD: A Hybrid Legged-Wheel Security and SAR-Robot Using Bio-Inspired Locomotion for Rough Terrain Dipl. Inf. Markus Eich Questions?/Comments? Thank you for your attention