WM WM trí tuệ nhân tạo cao hoàng trứ chương ter5 1 planning sinhvienzone com

m c o ne Si nh Vi en Zo Planning SinhVienZone.com Chapter https://fb.com/sinhvienzonevn .c o m Overview ne The blocks world C B A D goal Si nh start D en C Vi A Zo B How to achieve the goal from the start? Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 02 April 2010 https://fb.com/sinhvienzonevn .c o m Overview ne • Problem-solving is searching and moving through a Si nh Vi en Zo state space Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 02 April 2010 https://fb.com/sinhvienzonevn .c o m Overview ne • Problem-solving is searching and moving through a Zo state space en • Planning is searching for successful paths through a Si nh Vi state space Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 02 April 2010 https://fb.com/sinhvienzonevn .c o m Overview ne • Planning is the process of computing several steps of Zo a problem-solving procedure before executing them Si nh Vi en • Planning = problem solving in advance Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 02 April 2010 https://fb.com/sinhvienzonevn .c o m Overview ne • Planning is important if solutions cannot be undone Zo • If the universe is not predictable, then a plan can fail Si nh Vi en  dynamic plan revision Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 02 April 2010 https://fb.com/sinhvienzonevn ne c o m The Blocks World C B A D goal Si nh start D en C Vi A Zo B Planning = generating a sequence of actions to achieve the goal from the start Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 02 April 2010 https://fb.com/sinhvienzonevn .c o m The Blocks World ne Actions: en Si nh Vi • STACK(A, B) • PICKUP(A) Zo • UNSTACK(A, B) • PUTDOWN(A) Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 02 April 2010 https://fb.com/sinhvienzonevn .c o m The Blocks World ne Conditions and results: en Zo • ON(A, B) Si nh • CLEAR(A) Vi • ONTABLE(A) • HOLDING(A) • ARMEMPTY Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 02 April 2010 https://fb.com/sinhvienzonevn .c o m The Blocks World ne Specification of actions: Zo • PRECONDITION: list of predicates that must be true en for an operator to be applied Vi • ADD: list of new predicates that an operator causes Si nh to become true • DELETE: list of old predicates that an operator causes to become false • Predicates not in ADD nor DELETE are unaffacted Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 10 02 April 2010 https://fb.com/sinhvienzonevn .c o m The Blocks World ne Specification of actions: Zo STACK(x, y): en P: CLEAR(y)  HOLDING(x) Vi D: CLEAR(y)  HOLDING(x) Si nh A: ARMEMPTY  ON(x, y) UNSTACK(x, y): P: ON(x, y)  CLEAR(x)  ARMEMPTY D: ON(x, y)  ARMEMPTY A: HOLDING(x)  CLEAR(y) Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 11 02 April 2010 https://fb.com/sinhvienzonevn .c o m The Blocks World ne Specification of actions: Zo PICKUP(x): en P: CLEAR(x)  ONTABLE(x)  ARMEMPTY Vi D: ONTABLE(x)  ARMEMPTY Si nh A: HOLDING(x) PUTDOWN(x): P: HOLDING(x) D: HOLDING(x) A: ONTABLE(x)  ARMEMPTY Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 12 02 April 2010 https://fb.com/sinhvienzonevn ne c o m The Blocks World C D en A Zo B Si nh Vi start: ON(B, A)  ONTABLE(A)  ONTABLE(C)  ONTABLE(D)  ARMEMPTY Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com C B A D goal: ON(C, A)  ON(B, D)  ONTABLE(A)  ONTABLE(D)  13 02 April 2010 https://fb.com/sinhvienzonevn .c o m Goal Stack Planning Zo ne Stack Si nh Vi en Goals Operators to satisfy the Goals Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com + Database Current situation Specification of Operators/Actions 14 02 April 2010 https://fb.com/sinhvienzonevn .c o m Goal Stack Planning Zo ne Push the original goal to the stack Repeat until the stack is empty: – If stack top is a compound goal, push its unsatisfied en subgoals to the stack Vi – If stack top is a single unsatisfied goal, replace it by an Si nh operator that makes it satisfied and push the operator’s precondition to the stack – If stack top is an operator, pop it from the stack, execute it and change the database by the operation’s affects – If stack top is a satisfied goal, pop it from the stack Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 15 02 April 2010 https://fb.com/sinhvienzonevn ne c o m Goal Stack Planning C D en A Zo B Si nh Vi start: ON(B, A)  ONTABLE(A)  ONTABLE(C)  ONTABLE(D)  ARMEMPTY Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com C B A D goal: ON(C, A)  ON(B, D)  ONTABLE(A)  ONTABLE(D)  16 02 April 2010 https://fb.com/sinhvienzonevn Stack Database ON(B, A) OTACD ARMEMPTY Vi en Zo ne ON(C, A) ON(B, D) ON(C, A)  ON(B, D)  OTAD c o m Goal Stack Planning Si nh CLEAR(A) HOLDING(C) CLEAR(A)  HOLDING(C) STACK(C, A) ON(B, D)  ON(C, A)  ON(B, D)  OTAD Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com ON(B, A) OTACD ARMEMPTY 17 02 April 2010 https://fb.com/sinhvienzonevn m Goal Stack Planning ne Zo en Si nh Vi UNSTACK(B, A) STACK(B, D) PICKUP(C) STACK(C, A) c o Plan Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 18 02 April 2010 https://fb.com/sinhvienzonevn ne c o m Goal Stack Planning B en A Zo C Si nh Vi start: ON(C, A)  ONTABLE(A)  ONTABLE(B)  ARMEMPTY A B C goal: ON(A, B)  ON(B, C) Sussman Anomaly (1975) Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 19 02 April 2010 https://fb.com/sinhvienzonevn m Goal Stack Planning ne Zo Vi en UNSTACK(C, A) PUTDOWN(C) PICKUP(A) STACK(A, B) UNSTACK(A, B) PUTDOWN(A) PICKUP(B) STACK(B, C) PICKUP(A) STACK(A, B) Si nh 10 .c o Plan Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 20 02 April 2010 https://fb.com/sinhvienzonevn m Goal Stack Planning ne Zo Vi en UNSTACK(C, A) PUTDOWN(C) PICKUP(A) STACK(A, B) UNSTACK(A, B) PUTDOWN(A) PICKUP(B) STACK(B, C) PICKUP(A) STACK(A, B) Si nh 10 .c o Plan Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 21 02 April 2010 https://fb.com/sinhvienzonevn .c o m Questions ne • Why stacks used? Zo • Why a compound goal retained in the stack with its en subgoals? Si nh Vi • Does the order of subgoals in the stack matter? Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 22 02 April 2010 https://fb.com/sinhvienzonevn .c o m Linear vs Non-Linear Planning ne • Goal Stack planning is linear: satisfies subgoals Zo sequentially, one after another en • Non-linear planning: consider interaction among Si nh Vi subgoals Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 23 02 April 2010 https://fb.com/sinhvienzonevn Si nh Vi en Zo ne Reading Non-linear planning c o m Homework Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 24 02 April 2010 https://fb.com/sinhvienzonevn ... them Si nh Vi en • Planning = problem solving in advance Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 02 April 2 010 https://fb.com/sinhvienzonevn .c o m Overview ne • Planning is important... CLEAR(x)  ARMEMPTY D: ON(x, y)  ARMEMPTY A: HOLDING(x)  CLEAR(y) Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com 11 02 April 2 010 https://fb.com/sinhvienzonevn .c o m The Blocks World ne Specification... ARMEMPTY Cao Hoang Tru CSE Faculty - HCMUT SinhVienZone.com C B A D goal: ON(C, A)  ON(B, D)  ONTABLE(A)  ONTABLE(D)  13 02 April 2 010 https://fb.com/sinhvienzonevn .c o m Goal Stack Planning