Over the last two decades, the foundations for physical human–robot interaction (pHRI) have evolved from successful developments in mechatronics, control, and planning, leading toward safer lightweight robot designs and interaction control schemes that advance beyond the current capacities of existing high-payload and highprecision position-controlled industrial robots. Based on their ability to sense physical interaction, render compliant behavior along the robot structure, plan motions that respect human preferences, and generate interaction plans for collaboration and coaction with humans, these novel robots have opened up novel and unforeseen application domains, and have advanced the field of human safety in robotics.
This chapter gives an overview on the state of the art in pHRI as of the date of publication. First, the advances in human safety are outlined, addressing topics in human injury analysis in robotics and safety standards for pHRI. Then, the foundations of human-friendly robot design, including the development of lightweight and intrinsically flexible force/torque-controlled machines together with the required perception abilities for interaction are introduced. Subsequently, motionplanning techniques for human environments, including the domains of biomechanically safe, risk-metric-based, human-aware planning are covered. Finally, the rather recent problem of interaction planning is summarized, including the issues of collaborative action planning, the definition of the interaction planning problem, and an introduction to robot reflexes and reactive control architecture for pHRI.
A control strategy for human-friendly robots
Author Jochen Heinzmann, Jon Kieffer, Alexander Zelinsky
Video ID : 611
The video shows the basic behavior of the system: A zero-gravity simulation with a Barrett Whole Arm Manipulator (WAM), a lightweight, 7-DOF robot driven by cable drives. The zero-G module applies the appropriate motor torques to counteract the gravity effects. The psychological impression is that the robot is completely passive although considerable forces are required for the gravity compensation. The robot is slowed down by friction only. In the second part of the video, the gravity constant is increased by 60%. This causes the robot to float up into a vertical configuration, as if the robot would be mounted upside down.
(Video Proceedings of the Int. Conf. Robot. Autom. (ICRA), 1999)