Robot Localisation Flashcards
What is a pose
Combination of position and orientation (i,j,t)
What is the problem of robot localisation?
Ensuring the degrees of belief about its location give it as much information as possible
The collections of positions form a…
partition
How can we work out L_(i,j)?
(sum t)L_(i,j,t)
How can we work out L_t?
(sum i) (sum j) L_(i,j,t)
How do we encode the robot’s state of mind?
Probability distribution
What algorithms do we need to devise for assigning the relevant degrees of belief?
Assigning initial degrees of belief
Updating belief based upon sensor information
Updating belief in response to its action
How do we assign initial degrees of belief?
Assign all non-occupied poses an equal probability
How do we update the degrees of belief based on sensor information?
p(l_(i,j,t) | o) = p(o | l_(i,j,t))p(l_(i,j,t)) / sum i’,j’,t’ p(o | l_(i’,j’,t’))p(l_(i’,j’,t’))
What sensors does our robot have?
left, right, forward
What does it mean to say a reading is noisy for us?
if the true reading is k, the sensor will return an integer between 0 and 2k, normally distributed with mean k and standard deviation k/3
How do we update the degrees of belief in response to an action?
p(l’(i,j,t) | a_h) = sum i’,j’,t’ p(l’(i,j,t) | l_(i’,j’,t’) and a)p(l_(i’,j’t’))
we get here from:
what we want- p(l’(i,j,t) | a and l(i’,j’,t’))
p(l’(i,j,t) | a_h) = sum i’,j’,t’ p(l’(i,j,t) | l_(i’,j’,t’) and a) p(l_(i’,j’,t’) | a_h)
we know- p(l_(i’,j’,t’) | a_h) = p(l_(i’,j’,t’))