29-10-2012, 12:04 PM
A Novel, New Design for a Dual Magnetorheological Fluid/Wrap Spring Brake
A Novel, New Design.ppt (Size: 5.53 MB / Downloads: 66)
Functional Electrode Stimulation (FES)
Stimulation of muscle groups
Enables paraplegics to walk
Stabilizing device required
Internal and external
Controlled Brake Orthosis
Designed by Michael Goldfarb at MIT
Provide rigid support during stance and leg trajectory control during FES-gait
decrease muscle fatigue and improve trajectory over conventional FES-aided gait in paraplegics
Brake Mechanism Issues
Braking issues on current CBO
Transmission Gear
Increases Complexity
Increases Cost
Power Consumption
Dual Brake
Dual Brake – Generation 1 (2001 Merz Thesis)
Combine controllability of a magnetic particle brake with the high torque capacity of a wrap spring brake
Still required a transmission ratio
Brake footprint was very large
Conclusions
Passive Torque
Redesign seals – eliminate O-rings
Axial Distance
Reduce rotor thickness or number of wrap spring turns
Power
Further optimize winding design
Weight
Increase amp-turns or use stronger ferromagnetic materials