Question L3-C4

The question is about the disadvantages of having an active sensor, in this case a triangulation camera with a laser projection, in a situation with a high density of robot. The question is: "In a plan of a factory where mobile robots freely circulate in areas that are shared with humans, the paths of the robots among themselves, and with human, will cross very often as their density will be high. To ensure security, one colleague suggests to have on each robot a
detector of collision, generating a stop of the robot, based on an active sensor that can be seen by the humans, in opposition to ultrasound or infrared sensors. This sensor is built using a human-safe red laser line projector directed to the ground in front of the robot, without any modulation, and a camera looking to the same area from another angle and equipped with a red filter adjusted to the laser red (see figure 9.1). This would allow humans to see the zone of detection. What do you think about this idea?". On the right of the text, Fig 9.1 illustrated the principle of camera triangulation with a laser line projection.
Four possible answers are proposed:

Answer A: "It’s a good idea, because of the nice interaction with humans."
This answer is wrong. It's true that the interaction with humans is nice, but this line with no modulation will be detected by other robots and will disturb their measure. It's very bad for a safety sensor.
In the explanation of the students we would like to see that they understand that the proposed solution is generating a lot of interferences among robots and that this is a priority in respect to the interaction with humans.

Answer B: "It’s a good idea, because it’s reliable for any obstacle on the ground."
This answer is wrong. It's true that the sensor is reliable in respect to the shape of the obstacles, but this line with no modulation will be detected by other robots and will disturb their measure. It's very bad for a safety sensor.
In the explanation of the students we would like to see that they understand that the proposed solution is generating a lot of interferences among robots and that this is a priority in respect to the good detection of obstacles in an ideal (one robot) situation.

Answer C: "It’s NOT a good idea, because it’s generating interference between robots."
This answer is correct. This line with no modulation will be detected by other robots and will disturb their measure. It's very bad for a safety sensor.
In the explanation of the students we would like to see that they understand that the proposed solution is generating a lot of interferences among robots.

Answer D: "It’s NOT a good idea, because the laser can potentially impact some production processes."
This answer is wrong. It's true that the laser could impact some processes, in case there are some that are sensible to the laser, but this line with no modulation will be detected by other robots and will disturb their measure. This is much worse, especially for a safety sensor.
In the explanation of the students we would like to see that they understand that the proposed solution is generating a lot of interferences among robots and that this is a priority in respect to the potential impact on a production process.