Particles Filter, MCL & Augmented MCL

Chee Yu

111 )(),|()|()( tttttttt dxxBelxuxPxzPxBel

Bayes Filter

111 )(),|()|()( tttttttt dxxBelxuxPxzPxBel

Particles Filter

Samplings of previous belief

111 )(),|()|()( tttttttt dxxBelxuxPxzPxBel

Particles Filter (Continued)

111 )(),|()|()( tttttttt dxxBelxuxPxzPxBel

Particles Filter (End)

Monte Carlo Localization (Table 8.2)

Generating w

Monte Carlo Localization (Table 8.2)

1. Algorithm systematic_resampling(S,n):

2.

3. For Generate cdf4. 5. Initialize threshold

6. For Draw samples …7. While ( ) Skip until next threshold reached8. 9. Insert10. Increment threshold

11. Return S’

Resampling Algorithm

11,' wcS

ni 2i

ii wcc 1

1],,0[~ 11 inUu

nj 1

11

nuu jj

ij cu

1,'' nxSS i

1ii

Also called stochastic universal sampling

Resampling

Problems

• Chee could not recover if he was kidnapped by his roommate.

• What can we do?

Problems

• What if we throw in random variables?

• Yeah! But when and how many?

• Look at the average weight? No…

• Then, what?

Augmented MCL (Table 8.3)

Augmented MCL (Continued)

Augmented MCL (Continued)

Augmented MCL (Ended)

Augmented MCL (Ended)

Suggestions• Use creative ways to learn .• Finish the project . on understanding instead of

random try, Google search and friends.• When facing problems try to find out what you

don’t understand.• Do not ask Dr. Sridharan too specific information

about homework in order to just finish the assignment without understanding the material.

• Able to finish the homework after being given lot of hints does not means you understand.

• You should be able to applied what you learned to a new problem.