IMU-based Joint Trajectories and Gait Contact Event Detection: A Vicon-Referenced Analysis

Soft exoskeletons, also known as exosuits, provide lightweight and ergonomic gait assistance for mobility-impaired individuals, leveraging textile architectures for better compatibility and comfort compared to rigid exoskeletons. Precise lowerlimb kinematics are required for gait phase recognition and adaptive torque delivery aligned with biomechanical needs. To achieve this, it is necessary to estimate lower-limb joint angles and to validate these estimates against a reference system to ensure accurate alignment between the measured kinematics and the user's actual movement.In this work, we present a preliminary validation of a custom IMU-based angular-pattern estimator, comparing its segments (thigh, shank and foot) angles estimation against those obtained from a Vicon optical motion-capture system through a custom Bodybuilder model to establish reliability for real-time control. In addition, a first implementation of gait-event detection id introduced for the purpose of gait-phase analysis.