Discussion of “A Review of Intent Detection, Arbitration, and Communication Aspects of Shared Control for Physical Human–Robot Interaction” (Losey, D. P., McDonald, C. G., Battaglia, E., and O'Malley, M. K., 2018, ASME Appl. Mech. Rev., 70(1), p. 010804)

A unifying description of the shared control architecture within the field of physical human–robot interaction (pHRI) facilitates the education of those being introduced to the field and the framing of new contributions to it. The authors' review of shared control within pHRI proposes such a unifying framework composed of three pillars. First, intent detection addresses the robot's interpretation of human goals, representing one-way communication. Second, arbitration manages the respective roles of the human and robot in the shared control. Third, feedback is the mechanism by which the robot returns information to the human, representing one-way communication in the opposite direction. Interpreting existing contributions through the lens of this framework brings out the importance of mechanical design, modeling, and state-based control.