Hip Exoskeleton Thighbar with Extra DOF for Misalignment Compensation

I designed a lightweight thighbar that wraps around the wearer's leg and connects the hip exoskeleton to the thigh. A passive prismatic rail lets the interface move up and down during gait, adding one translational degree of freedom so the device can absorb alignment changes instead of pushing them into the wearer.

Design requirements

• Wrap securely and comfortably around the thigh.
• Allow controlled up-and-down motion during gait without binding.
• Add misalignment compensation without another actuator, keeping added weight minimal.

Why the extra DOF is needed

The wearer's hip and the exoskeleton shift relative to each other during gait. A rigid thighbar resists that mismatch, while the added vertical degree of freedom lets the interface follow the leg.

What I designed

The assembly combines a wraparound thigh interface, a guided linear rail, and a motor-side support structure. The rail carries the assembly vertically while constraining unwanted motion in the other directions, preserving a stable mechanical connection throughout the gait cycle.

Design outcome

The final thighbar combines the thigh wrap, slider, and exoskeleton connection in a compact, serviceable mechanism. It adds passive gait-driven motion without the mass and complexity of another actuator.