Variable force-stiffness haptic feedback for learning a disturbance rejection task

This paper investigates the use of a variable haptic feedback for training a disturbance rejection task. The haptic feedback was designed as a Force-Stiffness feedback. Throughout the training, Force and Stiffness feedback are decreased to progressively give more control authority to the human operator. The training method was tested in a human-in-the-loop experiment. In the experiment, participants were split into three groups: variable haptic aid (VHA), constant haptic aid (CHA) and no haptic aid (NoHA). The VHA and CHA groups performed a first training phase with variable and constant haptic feedback respectively, followed by an evaluation phase without external aids. The NoHA group performed the entire experiment without external aids. Results showed that in the training phase both VHA and CHA groups performed better than NoHA group. In the evaluation phase though, only the VHA group obtained better performances than the NoHA group. Specifically, participants were able to quickly recover similar performances to those obtained at the end of the training phase. Thus, the variable haptic training proved to be more effective than the constant haptic training and manual control at helping participants learn the task.