Observer Based Method for Joint Torque Estimation in Active Orthoses

This contribution presents a new approach of estimating the joint torques for an active orthosis. The new approach combines inverse dynamics and measured ground reaction forces. The joint torques can easily be computed from the ground reaction forces, but the measurement is usually flawed. An obsererver is employed to estimate the disturbance of the measurements and restore the original joint torques.A model of the human lower extremity is presented and additional seat forces are introduced to model the seat. Simulation results on the Sit-to-Stand movement illustrate the effectivity of the new approach.