Reintroduce the man in factories
The word “cobot” (contraction of collaborative robot) was introduced to describe a class of robots dedicated to objects handling in cooperation with human operators and with capabilities to set up virtual surfaces which can be used to constrain and guide motion.
The Cobomanip was designed to assist the operator during handling operation and not to replace any operator during the execution of a process. It is therefore not designed as a standard robot driven in position control mode but as a force generator. In the entire workspace it will assist or oppose to
the movements of the operator according to the task definition and the requested assistances. One may therefore consider two distinct operating modes:
- Movements in free space: the Cobomanip is a perfect balance with
3 or 4 dofs. It behaves like if the load is handled in a zero-gravity area.
- Constrained movements: motors (one for each dof) apply counteracting torques to limit the manipulator movements into specific directions.
- All the frictions are compensated with motors situated in the frame
of the cobot.
During tasks execution, operators often have to deal with secondary tasks such as: finding the path toward the real working place, avoiding obstacles, keeping orientation of a tool in a specific direction. One alternative to keep the attention of the operator focused on the main task is to offer assistances during the task execution. Assistances may be: passive (mechanical guides mounted on the handled component, tool or on its housing) or active.
One of the most useful assistance is to constrain the movement of the operator within a specific part of the workspace. Concepts for such constraints applied to teleoperation tasks are proposed in two distinct types:
- The operator can not enter a specific area of the workspace.
The movement is possible until a boundary is reached.
- Assistance to guide the operator. Movements of the operator
are limited to those allowed by a mechanism attached to the robot.