William Regli Geometric and Intelligent Computing Laboratory Department of Computer Science

1. Special Topics in Computer ScienceComputational Modeling for Snake-Based RobotsIntroductionWeek 1, Lecture 1 William Regli Geometric and Intelligent Computing Laboratory Department of Computer Science Drexel University http://gicl.cs.drexel.edu

2. Team 1 • Lead Institution: Drexel University • PI William Regli, co-PI Michael Piasecki • University of Maryland @ College Park • SK Gupta • University of North Carolina @ Chapel Hill • Ming Lin and Dinesh Manocha • University of Wisconsin @ Madison • Nicola Ferrier, Vadim Shapiro, Krishnan Suresh

3. W. Regli CS, ECE and Mech E 1997 NSF CAREER M. Piasecki Civil SK Gupta Mech E PECASE, CAREER, and ONR YIP M. Lin CS CAREER D. Manocha CS PYI, ONR YIP, Sloan Fellow N. Ferrier Mech E NSF CAREER V. Shapiro Mech E, Math & CS NSF CAREER K. Suresh Mech E About the Team

4. Goals and Objectives • Build and play with robots • Course is fundamentally about modeling • Mathematically model robot kinematics and dynamics • Geometrically model robot design • Virtually simulate robot behavior and performance • Document experiences in GICL Wiki for • Use by future generations of students • Development of outreach materials (I.e. K-12) • Development of demonstration materials • Illustrate comprehensive, multidisciplinary, engineering modeling

5. Course Outcomes • The goal of this class is to build comprehensive engineering models of biologically-inspired robotic systems. Students completing this class will • be able to identify problems resulting from the interdisciplinary interactions in bio-inspired robots; • perform system engineering to design, test and build bio-bots; • be able to apply informatics principles to bio-bot design and testing; • gain experience using a variety of pedagogically appropriate hardware (i.e. Lego Mindstorms, Roombas, etc) and software tools (see above) for robot design/analysis.

6. Hardware Available • Lego MindStorms Robot Kits, V1 • Note: I will buy V2 or other modules as needed • IRobot Roomba • Sony Aibo • ERS 7M3 • HP iPAQs • 3800 and 5400 series

7. Lego Mindstorms Kits • 12+ 1st generation kits • Motors, sensors, handyboards, etc • Many examples on the web of bio-lego designs http://www.bea.hi-ho.ne.jp/meeco/index_e.html

8. iRobot Roomba • Basic vacuum cleaner robot, but • Has USB port • Hacker guides • http://www.roombareview.com/hack/ • Issues: • Not particularly bio-inspired

9. Sony Aibo • Sadly, discontinued • Happily, we have 2 • Fully programmable • Quadruped motion • Internal wifi, cameras, etc • Lots of tools on the internet for hacking Aibos

10. Also available: HP iPaqs • More interesting behaviors might require more computational power • Several late-model HP iPaqs can be made available to the class

11. Given the hardware, What do we mean by modeling?

12. What do we mean by modeling? • There are several kinds we care about in this class • System modeling • Software, hardware, power, sensors and their interactions • CAD/3D/Assembly Modeling • Geometry, topology, constraints, joints and features • Functional Modeling • Intended use (or function) for the device (note, device may have other unintended functions or uses) • Behavioral Modeling • System inputs/outputs, motion characteristic, etc that achieve the function • Physics-based modeling • Statics, kinematics, dynamics and laws of physics • Information Modeling • Data, relationships, semantics (meaning)

13. Basic Engineering for CS Students • Statics: The branch of physics concerned with the analysis of loads (force, moment, torque) on a physical systems in static equilibrium, that is, in a state where the relative positions of subsystems do not vary over time, or where components and structures are at rest under the action of external forces of equilibrium. • Kinematics: The branch of mechanics (physics) concerned with the motions of objects without being concerned with the forces that cause the motion. • Inverse Kinematics: The process of determining the parameters of a jointed flexible object in order to achieve a desired pose. • Dynamics: The branch of classical mechanics (physics) that is concerned with the effects of forces on the motion of objects.

14. Physics-Based Modeling • The creation of computational representations and models whose behaviors are governed by the laws of the physical world • In the context of bio-inspired robots: create an virtual environment for creation, testing and simulation of virtual robot design

15. An example of a multi-disciplinary engineering model

16. Designing a “Windshield Wiper” • From D. Macaulay, “How Things Work” • What are the models? • Functional • Behavioral

17. Models (1) • Functional model • The function of a windshield wiper is to remove dirt from the surface of a car’s windshield • Behavioral model • Input: motor rapidly rotating around the z axis • Output: oscillation in the yz plane with low frequency

18. Models (2) • CAD Models • 3D models with joints and constraints • Typically consist of • Part models • Assembly model(s) • Formats can be 3D solid or 3D wireframe 3 Lego models of a wiper assembly

19. Models (3): Information

20. Models (3): Information • Information modeling representations • XML, OWL, FOL, UML… • Information modeling tools • Protégé, Ontobuilder, Rational, etc • Information modeling tasks • Knowledge engineering, ontology building, creating a knowledge base, functional modeling, etc.

21. Physics-based Models • Kinematics (i.e. Animation) • Just move the parts based on joints & constraints • Dynamics • Incorporate forces, motor torques, power consumption, friction, etc • Other issues: • collision detection algorithms that check for intersection, calculate trajectories, impact times and impact points in a physical simulation

22. End Result of this Class • 10-to-12 comprehensive engineering models of bio-inspired robot designs • Individuals, teams (1-to-2 people) • All documentation in the Wiki • “README.TXT”-like instructions so as to make work reproducible • Your audience: Projects could be accessible to K-12 students or Frosh design

23. Grading • Three duties: • 15%, Weekly scribe: everyone will get a turn scribing notes and discussion from each week’s class into the Wiki. The more details the better (i.e. scribe is encouraged to ‘back-fill’ discussion with links and references and to-do items). • 35% Weekly progress: each person/group will set up a project space in the Wiki to document complete design and modeling project • Instructor will use the ‘discussion’ mechanism to post feedback and monitor progress; students welcome to comment on the work of other students; vandalism harshly punished • 50% Final project: due on or before finals week. Includes walking robot, mathematical and physical models, and Wiki pages.

24. Bio-Inspired Robot Locomotion: Topics • Explain motivation for bio-inspiration in mobile robot design • What ideas can nature offer engineers? • Can bio-inspired designs outperform traditional technology? • Identify important design parameters in nature • How can we quantify and evaluate nature? • How can we measure maneuverability and the ability to navigate various terrain? • Show successful implementation of bio-inspiration in mobile robot design • How is the source for bio-inspiration chosen? • How is the bio-inspiration implemented into the design? • What advantages does the bio-inspired robot offer over the traditional robot alternatives?

25. Cockroach Stick Insect Spider Scorpion Crab Lobster Some Concepts from Nature  

26. Some Concepts from Nature  • Dog • Gorilla • Human  • Snake • Gecko • Dinosaur

27. Example: Snake Robot Applications • Search and Rescue • Urban environments • Natural environments • Planetary surface exploration • Minimally invasive surgery / examination • Pipe inspection / cable routing

28. Example: Snake Robot Applications Snakes are also being used as inspiration for stationary robots that are capable of complex manipulations. • Bridge inspection • Disarming bombs • Construction/repair in space http://voronoi.sbp.ri.cmu.edu/serpentine/serpentine.html

29. Design Problem • Design requirements • Small body diameter • Small area required for locomotion • High maneuverability • Ability to navigate obstacles • Locomotion through various environments • Dirt • Rocks • Water • Obstacles • Application: Search and rescue • Motivation • Hazardous environments • Further collapse • Fire and toxic gases • Narrow spaces • Obstacles may be densely packed • People, devices, or conventional robots may not fit

30. Conventional Robots • Require large cross sectional areas for passage due to wheels or legs • Cannot navigate through narrow spaces • Have limited maneuverability • Limited by terrain and obstacle height

31. Where do we start? • Projects should focus on robot locomotion and gait • Wheels are not allowed • Identify bio-mimetic behaviors • i.e. 4 legs, make a mathematical model of movement for each leg, how many joints does each leg need, etc • Build some bots • Legos are probably easiest to start with • Iterate between working in the physical world and enhancing the virtual world • Objective: create as complete and high-fidelity model as possible! • When in the virtual world, you’ll need to learn about and teach yourself a number of tools • CAD/CAE, 3D, etc.

32. Project Examples • 1-to-10 legged robot • Turtle, ant, spider, etc. • “Snake” that lifts its head • i.e. climb up a stair step • Jumping robot • How high can you jump? How far (Frog)? • Tumbling robot • i.e. Star Wars • Whatever your imagination can think up!

33. Software to Investigate • Anything is fair game! Part of this classes’ goals is to explore what works best in the classroom • Software is needed for • Design • Modeling • Simulation

34. Modeling Software • CAD Systems • Pro/ENGINEER • SDRC/UG I-DEAS • AutoCAD, MicroStation, SolidWorks • Lower level • Models: OpenCascade, ACIS, Parasolid • Rendering: OpenGL, DirectX

35. Simulation Software • OpenSource • Open Dynamics Engine • Open Source dynamics & collision detection • Game engines • Havoc • CAD • Pro/MECHANICA, Adams, … • Other • Matlab, maple

36. Initial Data • Lego Models • http://gicl.cs.drexel.edu/repository/datasets

37. Discussion Topics • Engineering Datatypes • 2D/3D, standards, proprietary • How to represent an assembly • Role of the Wiki • Expectations of the scribe • Help spend money!

38. Other Events This Term • Two talks sponsored by GRASP Lab • Fridays at 11am • THIS FRIDAY: Daniella Rus, MIT • Oct 13: Dinesh Manocha, UNC

39. END

40. Issues in Physics-Based Modeling of Bio-Robots • One needs to algorithmically and

41. Engineering Design