Robot Fabrication MURI Fabrication High-Level Control MURI Low-Level Fabrication Robust biomimetic structures and systems Built-in tailored compliance and damping

Shape Deposition Manufacturing Add and Remove material – relatively arbitrary geometries Mill accuracy for external and internal surfaces Part Support Deposit (part) Shape

SDM Process Can also embed components Pressure Transducer

SDM Process Can spatially vary material properties – within and between layers Embed Shape

SDM Process Material Properties and Database cdr.stanford.edu /biomimetics/sdm.html Material Considerations Machinability Minimal shrinkage Bonds to self Low viscosity Low curing temperature Strength/stiffness

State of the Art – Sept. 1999 Manufacturing Embedded components Leaf-spring Piston Pressure Sensor Fitting Inlet Valve Exhaust Valve 10 cm Embedded components Multiple-materials

State of the Art - Sept. 1999 Robot prototypes – Old Sprawl Passive compliant hips Walks well No control of direction or amount of compliance Ad hoc construction – No SDM

Goal for Aug. 2000 – SDM Robot Compliant hip Feedforward Alternating tripod Stable running Obstacle traversal

SDM Robots 1st SDM leg Limited control of amount and direction of compliance Imbedded connectors and piston Reproducible, but non-functional design

SDM Robots 1DOF leg One primary direction of compliance Works very well, robust Currently investigating the effect of varying compliance

SDM Robots 2 DOF legs Linear and Rotational DOFs Can independently control direction and amount of compliance

Spatial 4-bar Mechanism

SDM Process Planning

Current Work Modular Compliance Can manually swap flex segments 10 different levels Is being used to test the effects of varying the stiffness of the leg

Current Work Modular Bodies Can manually swap Servo Motors and Valves Embedded electronic backbone Robust packaging

Future Work Foot Design Design feet for optimal ground contact Embed contact/force sensors into legs Feed back for adaptation Jorge failed feet