1. Leg ideas Sprawlita Rhex Rolling Contact 4 bar Flex Chain Pantograph 2R serial chain

2. 4 Bar Leg Design Advantages: 1 DOF Variety of paths Disadvantages: Several links Limited design space (path, velocity, force profiles) Design Possibilities Straight line motion Curved arc Faster swing phase than stance phase Ankle orientation Attachment/Detachment motions

3. Matlab tool to generate a variety of Designs Press to Play MovieMovie

4. Working Model 2D to Simulate Designs Calculate Velocites, Forces, etc. Simulate Multiple Legs Quick & Dirty Locomotion Tests

5. Potential Leg Designs in WM

6. Some Movies

7. A Quick Prototype Click for Movie

8. Pantograph Leg Design A B C

9. Advantages Arbitrary Path/Speed within Working Area Simple Control/Design: – dX Leg = a*dS Actuator1 – dY Leg = b*dS Actuator2 Disadvantages 2DOF (more complex) Requires Moving Linkage Singularity Positions Exist Foot Angle Constrained by Geometry and Trajectory

10. Sample Leg Trajectories Circle Ellipse Flat Ellipse Rectangle

11. Movie: Moving Leg

12. Walking Movie

13. Questions we would like to start to answer: What foot trajectory is appropriate for climbing? What attachment/detachment motions are necessary for: clawed feet? feet with dry adhesives? To what degree and where do we want compliance in the leg design?