Motion Planning for Tower Crane Operation

Motivation

Tower crane impacts the schedule greatly Safety of tower crane operation is critical

Major Challenges Schedule

Predict? Guess?

Special Projects Complex projects Fast-track projects Critical working space constrains

Tower Crane Operation

Secure structure element to hook

Move piece from original location to final position

Holding time Repositioning of crane to next piece

T1T1 T2T2 T3T3 T4T4

The Crane

Configure Space vs World Space

{H}

{B}

Θ1

Θ4

d2

d3

1000

100

0

0

),,,(3

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4321 d

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zy

xα

β

γ

Planning Algorithm (RRT)

While (MaxStep is not reached)While (MaxStep is not reached)1. Expand Tree_1 (init) & Tree_2 (goal)1. Expand Tree_1 (init) & Tree_2 (goal)2. Connect check2. Connect check if connected, then Generate a Path if connected, then Generate a Path else goto 1. else goto 1.

Expand:Expand:1. Create a random node 1. Create a random node 2. find nearest node2. find nearest node3. try to add nearest node to tree3. try to add nearest node to tree4. try to add the random node the tree4. try to add the random node the tree

Connect:Connect:1. Can the new added nodes See any of the 1. Can the new added nodes See any of the nodes from another tree? (collision detection nodes from another tree? (collision detection as a straight line)as a straight line)InitInit

GoalGoal