17. Markov Assumption for Motion Model: Quiz

Markov Assumption for Motion Model Quiz

What do you think about these two assumptions:

(a) Since we (hypothetically) know in which state the system is at time step t-1, the past observations z1:t1 z_{1:t-1} and controls u1:t1 u_{1:t-1} would not provide us additional information to estimate the posterior for xt x_t , because they were already used to estimate xt1 x_{t-1} . This means, we can simplify p(xtxt1,z1:t1,u1:t,m) p(x_t|x_{t-1}, z_{1:t-1}, u_{1:t},m) to p(xtxt1,ut,m) p(x_t|x_{t-1}, u_t, m) .

(b) Since ut u_t is “in the future” with reference to xt1,ut x_{t-1}, u_t does not tell us much about xt1 x_{t-1} . This means the term p(xt1z1:t1,u1:t,m) p(x_{t-1}|z_{1:t-1}, u_{1:t}, m) can be simplified to p(xt1z1:t1,u1:t1,m) p(x_{t-1}|z_{1:t-1}, u_{1:t-1}, m) .

Markov Assumptions for Motion

What do you think about the two assumptions?

SOLUTION: Both assumptions are meaningful