So You Think You Can Program an Elevator

Re:So You Think You Can Program an Elevator by hvidgaard on Wednesday January 13, 2016 @02:27AM (#10892823)

There is nothing that dictates that you use a stack when designing a FSM. I'm not going to argue that a BT wouldn't be a good solution, I'm sure it can be used to make a reasonable one.

In any case, a well designed FSM would get you a long way. Since the input (pressed buttons) is finite, you can cover every single case and weight according to importance of floor and wait time.

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Re:So You Think You Can Program an Elevator by seivan on Wednesday January 13, 2016 @03:58AM (#10893110)

I was actually promoting a stack as that would make things easier, but it's still tacked on a solution that isn't as good.

A well designed FSM doesn't necessarily mean an easily read FSM.

I always try to draw states and transitions on paper, and I end up making a mess. That could be a flaw on my side. But I won't be making the same mess with BT.

I don't see how a FSM could avoid having transitions back and forth.

  * Elevator is on level 3
  * A person in the elevator wants to go to level 4
  * A person waiting for down on level 5
  * A person in the elevator wants to go to level 2
  * A person waiting for down on level 2

FSM would need to track current floor and direction. Would need guards/predicates on transitions for inputs Could just be me, but I wouldn't be able to draw a pretty picture with those.

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