Remote Kill Switch

[jvriezen]

An even better safety approach is a 'dead man' switch. This requires a person to continuously hold a switch in the pressed position for the robot to operate. Of course you couple this with a policy that you never jerry rig the switch to be held other than by a human watching the robot.

Basically every push lawn mower has one of these on the handle, and every riding lawnmower has a seat switch that does the same thing (at least when the blades are spinning.)

Update: Clarification: I agree, driving in the pits is not appropriate. My suggestion above is more for driving in the shop and could even apply to driving on a practice field, which is more danger prone than a real field. Seems like it would be a good idea to have a driver station setting that allows you to invert the space bar, and require that it be pressed when enabling and result in a kill if released while enabled.

[techhelpbb]

As a person that routinely volunteers as CSA/FTAA please do not make it possible for your robot to drive in the pit.

If you want to put it up on blocks or something that's one thing.
Even better if the venue can help you do that safely with materials.

If you put it on the floor and try to drive I am sorry but I will object to that.
Please use the practice fields to fully test your robot's work envelope.

I am not against additional safety controls like the USB red button which is more recognizable to teams, or even requiring teams to put a label on the space bar in the rules (easy to do and cheap).

However an emergency stop is not replacement for not creating an dire situation in the first place.

[Fields]

Originally Posted by techhelpbb

As a person that routinely volunteers as CSA/FTAA please do not make it possible for your robot to drive in the pit.

If you want to put it up on blocks or something that's one thing.
Even better if the venue can help you do that safely with materials.

If you put it on the floor and try to drive I am sorry but I will object to that.
Please use the practice fields to fully test your robot's work envelope.

I am not against additional safety controls like the USB red button which is more recognizable to teams, or even requiring teams to put a label on the space bar in the rules (easy to do and cheap).

However an emergency stop is not replacement for not creating an dire situation in the first place.

I agree that driving should not happening in the pit. In the other thread someone had talked about testing their actuator and grabbing a tote. In order to get accurate feedback, both items had to be on the same level which worked out to be the floor.

[techhelpbb]

Originally Posted by Fields

I agree that driving should not happening in the pit. In the other thread someone had talked about testing their actuator and grabbing a tote. In order to get accurate feedback, both items had to be on the same level which worked out to be the floor.

Okay but let's consider some issues specific to this year:

A robot outside of transport configuration is probably larger.
The totes are relatively large.

I watched several people put their robot on the floor and test actuators and I am fine with that.

However a large robot, not really designed with crumple zones or padding moving in a room full of tightly packed people?

If you watch the Mount Olive District event I always loaded the Blue Alliance field first. That queue was slow to move. In walking by one of the robots on the field I got shirt caught by a piece of aluminum projecting only because the robot was in a perfectly reasonable configuration for the field.

So realistically speaking, even if the robot is not driving, putting the robot fully expanded on the floor in the pits moving requires a fair deal of consideration to keep people out of the work envelope and the potential drop away of the tote.

I wouldn't object as long as it was clear the area in the work envelope was actively patrolled.

This could be easily addressed by the venue offering a floor level area for testing in addition to the practice field.
For example at Mount Olive High School we certainly have a lot of floor we could offer for temporary use.
If you walked back by our machine shop table there was a large section of the lobby back there empty.

[Ozuru]

Originally Posted by jvriezen

An even better safety approach is a 'dead man' switch. This requires a person to continuously hold a switch in the pressed position for the robot to operate. Of course you couple this with a policy that you never jerry rig the switch to be held other than by a human watching the robot.

Basically every push lawn mower has one of these on the handle, and every riding lawnmower has a seat switch that does the same thing (at least when the blades are spinning.)

Update: Clarification: I agree, driving in the pits is not appropriate. My suggestion above is more for driving in the shop and could even apply to driving on a practice field, which is more danger prone than a real field. Seems like it would be a good idea to have a driver station setting that allows you to invert the space bar, and require that it be pressed when enabling and result in a kill if released while enabled.

I kind of feel that a dead man's switch is kind of extreme for something that already has so many security precautions into place. I wouldn't trust myself with a dead man's switch that would deactivate our robot during the match due to the simple fact that accidents happen and if, for some reason, one would happen during the match, we have the ability to 1) slam the spacebar or 2) press the giant emergency stop button.

[jvriezen]

Originally Posted by Ozuru

I kind of feel that a dead man's switch is kind of extreme for something that already has so many security precautions into place. I wouldn't trust myself with a dead man's switch that would deactivate our robot during the match due to the simple fact that accidents happen and if, for some reason, one would happen during the match, we have the ability to 1) slam the spacebar or 2) press the giant emergency stop button.

The dead man switch would not be needed during a match. In that case you already have three team members at the driver station and refs and FTAs all looking out for your bot, as well as a mostly contained playing field.

The dead man switch approach would be instituted in your shop/practice area at home (based on your perceived need for that level of safety) and could possibly be used at an event practice field where there are lots more people around often without field walls protecting them from bots.

[philso]

A dead man switch would have to be implemented correctly, tested thoroughly and the users trained properly and thoroughly to ensure that it serves it's intended purpose. Otherwise, is a form of false security that creates yet more complexity with little value.

It is a fair bet that FIRST put a lot of time and effort into designing and performing validation testing on the E-Stop function integrated into the FMS.

[MrRoboSteve]

In scenarios where we might need to stop the robot quickly, an operator stays by the driver station is trained to hit the spacebar if things get out of control. Hard to see how a dedicated button improves on that.