Adaptive control of a biped robot mobilized by linear actuators considering articular restrictions

This study is summarising the design of an output hybrid feedback controller for biped robots where the motion range for each joint is being considered. The design considers the hybrid nature of biped device when it is developing an entire gait cycle including the interaction with the environment touching the support floor. A simplified hybrid model is proposed to represent the dynamics of the robotic device in a realistic form. The proposed biped device is driven using linear actuators with a motion transfer system. A hybrid formulation for the control with adaptive state dependent gains regulates the articulations motion considering the limits of actuator motion. The dynamics of the adaptive gains is obtained with the application of a control barrier-like Lyapunov function for hybrid systems. The explicit structure of these gains are derived in a formal way. A set of numerical simulations is used to demonstrate the applicability of the developed controller analysing the tracking of bio-inspired reference trajectories obtained from reported biomechanical information. The numerical simulations used a virtual model of a biped robotic device where the interaction with the environment was considered for analysing the effect of hybrid evolution.