Leg Design and Control of Locomotion

Transkript

1 Bielefeld, 4 June 2004 Leg Design and Control of Locomotion Andre Seyfarth Locomotion Laboratory Jena Locomotion Lab Jena

2 Bewegungswissenschaften in Jena (seit 1995) Sportwissenschaft Biomechanik Prof. Blickhan Biologie: Zoologie Prof. Fischer Medizin: Motorik Prof. Scholle

3 Entstehung des Lauflabors Andre Seyfarth Spowi Jena Hartmut Geyer Spowi Jena 2001/02 Aufenthalt am MIT LegLab, Boston 2002/03 Aufenthalt Unispital Balgrist, Zürich Oktober 2003: Gründung des Labors im Rahmen des Emmy-Noether Programms (DFG) Heidi Knüsel, Bewegungswissenschaften an der ETH Zürich, Diplomarbeit am Lauflabor

4 Mitarbeiter im Labor Andre Seyfarth, Leiter Hartmut Geyer, Modellierung Susanne Lipfert, Laufexperimente Fumiya Iida, Aufbau der Robotik Jürgen Rummel, Laufmaschinen Jan Michel, Objektivierung von Laufleistungen bis März 2004: Heidi Knüsel (ETHZ) Schwungbeinkinematik beim Rennen

5 Ziele des Lauflabors die menschliche Bewegung, insbesondere das Laufen verstehen biologischen, sportlichen sowie medizinischen Kontext herstellen das bestehende Wissen technisch demonstrieren und nutzbar machen

6 Locomotion Experiments Neuromechanical Models Technical Implementation Gait Transitions 3D-instrumented Treadmill Gait specific control templates Legged Systems Gait Orthesis

7 Locomotion Experiments Neuromechanical Models Technical Implementation

8 Central hypothesis To achieve periodic movement patterns, an appropriate design criterion is required. In our approach, system stability is such a criterion.

9 Stability requirements Internal Leg Operation Global

10 Stability requirements Internal Leg Operation Segmentation Control at Joint Level

11 Stability requirements Global Leg Operation Running Walking Gait Transition

12 Overview Part I: Internal Leg Operation Part II: Global Leg Operation Part III: Implications

13 Overview Part I: Internal Leg Operation Part II: Global Leg Operation Part III: Implications

14 Biologically Inspired Approach In many tasks, the leg behavior can be compared to a simple mechanical spring.

15 Control of a segmented leg Idea

16 Control of a segmented leg Idea

17 Control of a segmented leg Idea

18 Control of a segmented leg 3a 3b 3 2 1

19 Control of a segmented leg Solutions + Biarticular Structures (e.g. Muscles) Geometric Constraints (e.g. Heel pad) Seyfarth et al. (2001) Biol. Cybern.

20 Control at Joint Level Where does the muscle activation for periodic movements come from?

21 Control at Joint Level STIM(t) α Positive Force Feedback P(t) Geyer et al. (2003) Proc.Roy.Soc.B.

22 Control at Joint Level

23 Overview Part I: Internal Leg Operation Part II: Global Leg Operation Part III: Implications

24 Control of Pedal Locomotion Axial stance phase REQUIRED swing phase POSSIBLE Rotatory POSSIBLE REQUIRED

25 Running

26 What is a good running strategy?

27 Spring Mass Running fixed angle of attack fixed leg stiffness Seyfarth et al. (2002) J. Biomechanics

28 Spring Mass Running RETRACTION Seyfarth et al. (2003) J. Exp. Biol.

29 Spring Mass Running Seyfarth & Geyer (2002) CLAWAR Meeting, Paris.

30 Gait Transition

31 Gait Transition

32 Gait Transition Question 1: How different are walking and running?

33 Gait Transition Experimental Results

34 Gait Transition Question 2: Why (and when) do we change gait?

35 Gait Transition Max. Speed Inv. Pendulum Kram et al. (1997) J. Exp. Biol. Fr = 4 / π 2 New Theory

36 Gait Transition Experimental Results

37 Gait Transition Question 2: Where does the gait pattern come from?

38 Gait Transition JOGGING ON PLACE WALKING ON PLACE

39 Walking

40 Question: Where does the walking pattern come from?

41 Spring Mass Walking

42 Spring Mass Walking RUNNING stiffness k stiffness 0 stiffness k stiffness 0 WALKING stiffness k stiffness 2k stiffness k stiffness 2k mass m mass m/2 mass m mass m/2

43 Spring Mass Walking

44 Spring Mass Walking Ground Reaction Forces A B C

45 Overview Part I: Internal Leg Operation Part II: Global Leg Operation Part III: Implications

46 Link to Robotics Origin of Movements Neural Program? Mechanical Behavior

47 Link to Robotics Tight-Control Relaxed Control

48 Link to Robotics Hard-Control

49 Link to Robotics Contribution of back movements to locomotion?

50 Link to Robotics Contribution of back movements to locomotion?

51 Link to Rehabilitation Decentralized leg control for locomotion therapy?

52 Link to Rehabilitation PATIENT TRAINER FF: Kinematics FB: Dynamics

53 Link to Rehabilitation

54 Thank you! Hartmut Geyer Heidi Knüsel Fumiya Iida Susanne Lipfert Jürgen Rummel Jan Michel Research Partners Prof. Volker Dietz ParaLab Zurich Prof. Rolf Pfeiffer AI Lab, Zurich Prof. Hugh Herr MIT LegLab, Boston Locomotion Lab Jena University