The proximity of the human and the cobot necessitates designing-in safety. The virtual caster mode is invoked when the cobot is away from all defined constraint surfaces. In this mode, the cobot permits any motion that the operator attempts to impart by servo-controlling the wheels such that user forces perpendicular to the wheel's rolling direction are nulled. Virtual wall mode is invoked when the user brings the cobot into contact with the constraint surface. The cobot wheels are controlled to roll tangential to the constraint surface.
Control switches back to the caster mode when contact is lost with the constraint surface.
The principal goals are to understand how human operators relate to and interact with cobots and to identify assembly line specific issues that will direct future efforts in cobotics. Our work is also innovative from an organizational perspective. Rather than the traditional technology push scenario, where the goal is to transfer university solutions to industry, this work has been driven by problems identified on the assembly line by the end user. Close interactions among the line workers, plant personnel, management, and research engineers has guided the invention and evolution of cobots. The benefits of this collaboration are many.