Generally speaking, there are three types of interactions between humans and robots: coexistence, cooperation and collaboration (ISO/ TS 15066-2016). In coexistence interactions, a robot and an operator function at different times in separated workspaces. In this case, a protective barrier surrounds the robot, which is locked including access doors. This barrier limits human access while the robot is in operation mode. Consequently, an operator must stop the robot operation for maintaining the robot and other locked equipment. This form of interaction is the predominant mode of operation for industrial robots in manufacturing at the moment. In cooperative interactions, operator and robot work towards a shared goal in the same workspace, but task execution is realised at different times. As human and robot share the same workspace, operations require adequate safety measures in place, for example, progressive padding, pressure mats and laser-based safety curtains. In collaborative interactions, an operator and a robot perform shared tasks within the same workspace and at the same time. Considering an operator and a robot work in such vicinity, the three factors, that is, force, speed and path of the robot must be controlled.

Collaborative interactions are an evolution in the field of robotics and represents one of the primary areas of focus for the DigiTOP project.