1. Institut für Regelungs- und Automatisierungstechnik 1 Michael Hofbaur Modular Machines Modular Machines - reconfigurable mobile robots for research and education Michael Hofbaur Institut für Regelungs- und Automatisierungstechnik Technische Universität Graz

2. Institut für Regelungs- und Automatisierungstechnik 2 Michael Hofbaur Modular Machines Motivation Robot drives with diverse wheel-geometry and drive-functionality Teaching Hands-on experience with diverse drives Verify and understand robot kinematics Research Investment costs / re-usable hardware Novel, but still generic drive concepts Industrial Application Easy configuration Fault tolerance

3. Institut für Regelungs- und Automatisierungstechnik 3 Michael Hofbaur Modular Machines Motivation Robot drives with diverse wheel-geometry and drive-functionality

4. Institut für Regelungs- und Automatisierungstechnik 4 Michael Hofbaur Modular Machines Motivation Robot drives with diverse wheel-geometry and drive-functionality

5. Institut für Regelungs- und Automatisierungstechnik 5 Michael Hofbaur Modular Machines Motivation Robot drives with diverse wheel-geometry and drive-functionality

6. Institut für Regelungs- und Automatisierungstechnik 6 Michael Hofbaur Modular Machines Modular Mobile Robot Goal: quickly build/configure diverse wheeled robot drives Innovative Design: –6-edge honey-comb prism –Module-in-Module design

7. Institut für Regelungs- und Automatisierungstechnik 7 Michael Hofbaur Modular Machines Application: Teaching & Research Toolbox for diverse robots/applications cost-effective starter-kit expandable re-usable versatile configurations for research & education new perspectives & coole ideas

8. Institut für Regelungs- und Automatisierungstechnik 8 Michael Hofbaur Modular Machines Robot Control How do we operate / control robots with diverse wheel configurations and geometries? Keyword: kinematics / inverse kinematics Drive CommandWheel Setpoints

9. Institut für Regelungs- und Automatisierungstechnik 9 Michael Hofbaur Modular Machines Robot Control How do we operate / control robots with diverse wheel configurations and geometries? Keyword: kinematics / inverse kinematics Drive CommandWheel Setpoints VIDEO wheel_view_of_gamepad_drive_short.avi

10. Institut für Regelungs- und Automatisierungstechnik 10 Michael Hofbaur Modular Machines Model-programmed Robot Drive Control instead of using the (manually) derived inverse-kinematics for a drive we: specify a model that captures the drives geometry and functionality analyze the kinematics and deduce the inverse-kinematics on-line during operation of the robot

11. Institut für Regelungs- und Automatisierungstechnik 11 Michael Hofbaur Modular Machines Model-programmed Robot Drive Control instead of using the (manually) derived inverse-kinematics for a drive we: specify a model that captures the drives geometry and functionality analyze the kinematics and deduce the inverse-kinematics on-line during operation of the robot Complete Architecture Kinematics Reasoning Monitoring & Diagnosis Coordinated Control Model / autom. Modelling

12. Institut für Regelungs- und Automatisierungstechnik 12 Michael Hofbaur Modular Machines Model-programmed Robot Drive Control instead of using the (manually) derived inverse-kinematics for a drive we: specify a model that captures the drives geometry and functionality analyze the kinematics and deduce the inverse-kinematics on-line during operation of the robot Complete Architecture Kinematics Reasoning Monitoring & Diagnosis Coordinated Control Model / autom. Modelling

13. Institut für Regelungs- und Automatisierungstechnik 13 Michael Hofbaur Modular Machines Model-programmed Robot Drive Control MODEL: specifies the drives geometry and functionality

14. Institut für Regelungs- und Automatisierungstechnik 14 Michael Hofbaur Modular Machines Kinematics Analysis Wheel geometry & functionality constrains the possible movements of the robot: it defines its Kinematics Example 1: omnidirectional 3-wheel robot admissible & controllable movements B

15. Institut für Regelungs- und Automatisierungstechnik 15 Michael Hofbaur Modular Machines Kinematics Analysis Example 2: differential-drive robot with steered front wheel admissible & controllable movements B Wheel geometry & functionality constrains the possible movements of the robot: it defines its Kinematics

16. Institut für Regelungs- und Automatisierungstechnik 16 Michael Hofbaur Modular Machines Kinematics Analysis Wheel geometry & functionality constrains the possible movements of the robot: it defines its Kinematics Example 2: differential-drive robot with steered front wheel admissible & controllable movements B

17. Institut für Regelungs- und Automatisierungstechnik 17 Michael Hofbaur Modular Machines Kinematics Analysis Wheel geometry & functionality constrains the possible movements of the robot: it defines its Kinematics Example 2: differential-drive robot with steered front wheel admissible & controllable movements B

18. Institut für Regelungs- und Automatisierungstechnik 18 Michael Hofbaur Modular Machines Kinematics Analysis Wheel geometry & functionality constrains the possible movements of the robot: it defines its Kinematics Example 3: robot with two standard wheels and a steered front wheel admissible & controllable movements B

19. Institut für Regelungs- und Automatisierungstechnik 19 Michael Hofbaur Modular Machines Kinematics Reasoning Unit on-line kinematics solver that computes B and allows: variable robot geometry –geometry & number of wheels can change during operation variable drive functionality –operational- and fault modes self-awareness –drive explicitely knows the space of possible movements for the drive ( B ) –validate a drive command from higher level control –reconfiguration

20. Institut für Regelungs- und Automatisierungstechnik 20 Michael Hofbaur Modular Machines Kinematics Reasoning Unit on-line solver for robot kinematics: assumption: drive with unsteered wheels rolling constraint for wheel i : sliding constraint for wheel i :

21. Institut für Regelungs- und Automatisierungstechnik 21 Michael Hofbaur Modular Machines Kinematics Reasoning Unit Combination of the constraints for all wheels: on-line solver for robot kinematics: assumption: drive with unsteered wheels

22. Institut für Regelungs- und Automatisierungstechnik 22 Michael Hofbaur Modular Machines admissible movements: controllable movements: admissible & controllable movements: Kinematics Reasoning Unit on-line solver for robot kinematics: assumption: drive with unsteered wheels Combination of the constraints for all wheels:

23. Institut für Regelungs- und Automatisierungstechnik 23 Michael Hofbaur Modular Machines admissible movements: controllable movements: admissible & controllable movements: Kinematics Reasoning Unit on-line solver for robot kinematics: assumption: drive with unsteered wheels Combination of the constraints for all wheels: How can we apply this line of reasoning to steered wheels, faults, etc.

24. Institut für Regelungs- und Automatisierungstechnik 24 Michael Hofbaur Modular Machines admissible movements: controllable movements: admissible & controllable movements: Kinematics Reasoning Unit Qualitative rolling & sliding constraints for steered wheels

25. Institut für Regelungs- und Automatisierungstechnik 25 Michael Hofbaur Modular Machines Kinematics Reasoning Unit Qualitative rolling & sliding constraints for mecanum wheels admissible movements: controllable movements: admissible & controllable movements:

26. Institut für Regelungs- und Automatisierungstechnik 26 Michael Hofbaur Modular Machines (Re)Configuration & Control Example: Eye-Catcher Task desired behaviour Fault-szenario (blocked steering in one wheel) with reconfiguration VIDEO eye-catcher_wo_fault.avi VIDEO eye-cather_w_cool_reconf.avi

27. Institut für Regelungs- und Automatisierungstechnik 27 Michael Hofbaur Modular Machines Virtual rekonfiguration of the drive geometry Coordinated control of Multi-Robot Systems Basis for control is a model of the drive geometry that can change during operation of the robot (Re)Configuration & Control VIDEO drivemovie1.avi

28. Institut für Regelungs- und Automatisierungstechnik 28 Michael Hofbaur Modular Machines Drive modules as wheel-units for an automated guided vehicle: flexible – easy configuration of mechanics & control costs - standard-units robust - modules replaceable new perspectives –multi-robot transport –direkt objekt transport Application: Automated Guided Vehicles

29. Institut für Regelungs- und Automatisierungstechnik 29 Michael Hofbaur Modular Machines Modular Machines - Summary Hardware Patent-pending modular robot design to realize wheeled robots with diverse drive geometries Module-in-module design – extend your robots with additional modules to meet demanding research requirements Multi-robot (re)configuration Software / Control Model-programmed self-configuring kinematics control Real-time kinematics analysis Health monitoring/diagnosis for fault tolerant operation