Switched control algorithms to robot-human bilateral interaction without contact

This paper presents a switched control strategy to interpret and design a human-robot bilateral interaction when a human follows a non-holonomic mobile robot at a desired distance while the robot is already following a known path. Furthermore, it proposes and experimentally validates a model that mathematically describes the human behavior when performing the task of tracking a mobile robot. This model is useful for the purposes of control system design and its associated stability analysis. Switched systems are proposed to model the complete behavior. The switching strategy is based on the human-robot relative position and on the human intention to follow the robot. Control errors are defined in terms of human to robot and robot to path instantaneous distances. Human variables of interest are obtained by a leg detection algorithm. Stability of the individual controllers using Lyapunov theory is provided and the algorithms for the switching controllers are described in detail. Real human-robot interaction experiments show the performance of the proposed controllers.