• exoskeletons
• human-robot interaction
• harnesses
• transparency
• kinematic design

Lower Limb Exoskeletons (LLEs) are wearable robotic systems that provide mechanical power to the user. The connections between human and LLE must guarantee the subsistence of the user's natural behavior during the interaction. Hence the robot has to follow the user's motion without exerting undesired forces, i.e. the robot must be transparent. Despite transparency is one of the main goals of LLEs design, only a few works have tackled the general problem of its maximization, and to the author's knowledge none in dynamic settings. Although there exist simulators for human-robot interaction, e.g. AnyBody and OpenSim, their usage expects complex modeling of definite structures.
In this work, Matlab-Simulink is used for implementing a flexible tool for comparing different configurations of a LLE.

The proposed method contemplates simulating the dynamics of the device including its interaction with the human, whose kinematics is imposed as a reference for the LLE to follow. Then an optimization process is performed for minimizing the interaction forces, managing the impedance at the interfaces. Experimental tests are conducted using Wearable Walker and measuring through loadcells the interaction forces compared to those obtained in the simulations. The results have shown that the proposed method provides an estimation of contact forces that is consistent with the preliminary experimental data. Moreover, the conclusions drawn at the design level are in accordance with the literature.