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Re: What gear ratio are people actually running on hip/knee actuators?
Posted: Wed Mar 19, 2025 4:56 am
by zoeanderson
@yuki71 Just to be precise about one thing:
Series elastic actuators add a spring element in series with the drivetrain, which gives cheap, precise torque sensing (measure spring deflection) and passive shock absorption, at the cost of reduced control bandwidth and added complexity.
Re: What gear ratio are people actually running on hip/knee actuators?
Posted: Sun Mar 30, 2025 10:50 pm
by kwilliams
@zoeanderson Can I ask a dumb follow-up -
Motor cogging torque (the 'notchy' feel from magnet-to-slot interactions) shows up as small periodic torque ripple that can translate into visible joint jitter at low speeds - it's usually mitigated with skewed magnets, better current control, or software compensation tables.