## 3 Main Assistive Scenarios  
Cobots can assist an industrial worker in many ways and in many types of tasks. Based on the literature, we define the main scenarios that cover large part of these tasks [41] as follows:  
* Standard **pick and place** (known locations): There may be several different tasks, and their names and locations should be clearly defined for the human and cobot. The cobot trajectory of a given pick and place is relatively easy to compute. As an input for computing the trajectory, it only needs the coordinates in the space of the origin (pick), the destination (place), and the cobot's end effector (the edge of the cobot's arm). The end effector must be properly quipped for the \"grasp\" at the pick location and the \"release\" at the place location. * **Fetch** distinct **tool/part/material**: Visual search may be needed for identifying the object and corresponding grasping strategy. On the other hand, the destination location must be either predetermined or determined based on the type of tool/part and the context (such as the operation stage or the worker's location). Besides the need to identify the origin and destination coordinates, the trajectory computation carries a striking resemblance to the pick and place task. * **Return tool/part/material**: A predetermined pickup place typically facilitates finding and picking the tool/part/material. Returning the tool to its dedicated storage location may be easy if there is only one possible location for this tool/part. However, having several identical tools may require a visual search for an empty placing location. Additionally, tool placement may require some manipulation and an aligning strategy. * **Dispose of defective tool/part/material**: The cobot must identify the defective tool/part/material and plan a trajectory for grasping it. Then, it should identify the closest or correct dispose location, and plan a trajectory to reach it. * **Turn Object**: \"Turn object\" requires specifying the object, its location, the turn direction, and the turn extent in part of a circle (e.g., half, third...tenth of a circle) or degrees. For example, \"Turn the left box clockwise three-quarters a of a circle\" or \"Turn the left box clockwise 270 degrees\". * **Clear away:** This task is required in cases where the cobot is in the path of the main activity or the human worker, and should move away to clear the path. This command must be accompanied by a direction of movement. For example, \"Clear away left\" turns the whole robot arm left. * **Move and align**: The input to this task must include a specification of the object to move/align and the destination of the object movement. The end effector camera should identify the object and the area up to the destination, and plan the trajectory for the move. * **Drill**: This task must be accompanied by the drill coordinates and orientation, and the specification of drill bit type and drilling speed and depth. The cobot end effector must first be equipped with a drill with the right drill bit. Then, the trajectory to the drilling location is computed. Upon arrival of the drill to its location and orientation a drilling operation starts. Finally, the drill returns to its intial position. * **Screw**: The screw location must be defined (or pre-defined). The \"Screw\" task assumes that a screw is already in place waiting to be screwed. So, a pick and place of a screw usually precedes this task. To execute this task, first the cobot must locate and fetch a screwdriver. Then, it has to move and align the screwdriver with the screw, and then rotate in the clockwise direction for tightening the screw and counterclockwise for releasing it. * **Solder/glue-point**: the Location must be pre-defined. * **Inspect**: The robot has to bring the camera to a given location. Typically, the camera is an integral part of the cobot, located near its end effector. Either the coordinates or the object to be inspected must be specified.