inspection planning for sensor coverage of 3d marine structures brendan englot and franz hover...

Inspection Planning for Sensor Coverage of 3d Marine Structures

Brendan Englot and Franz Hover

Presented by Arvind Pereira for the CS599 Class on Sequential Decision Making in Robotics

Objective

• Algorithm to achieve complete sensor coverage of complex 3-d structures when surveyed by an autonomous agent with multiple degrees of freedom

• Motivating application is ship-hull inspection using bathymetric sonar

• Plans on a closed triangular mesh model of the structure being inspected

Related Work

• Art Gallery Problem – Minimum # of guards who can together observe the entire gallery

• Car painting/Building inspection – Specific geometry of structure being covered

• Challenging issues in Computational Geometry for complex 3-d models in the absence of a priori knowledge

Related Work

• Sampling-based planning for similar problems employed the “art gallery” approach i.e. choosing a set of configurations which offer complete coverage and finding a feasible tour among these nodes

• Postman Framework – information efficient approach to solve deterministically-designed inspections for point robots in a 2-d workspace when robot has a small FOV relative to the size of the workspace

Sensor Footprint of a bathymetric sweep

Graph Construction Algorithm

Find Neighbors

Add Missing View to Graph

Add To Graph

Connect Subtours

Path-Finding AlgorithmIncidence Matrix

for flows

Constraint Matrix ensuring that all

nodes are inspected by a chosen path

Constraint that enforces the

initial node is on the graph

Structure Models

Dense Graphs for Examples

Paths Found

Subtour Connection

Algorithm Performance

Conclusion

• Algorithm ensures coverage planning over arbitrary discrete 3D structures using an information-efficient postman formulation

• Need to be more efficient in the search for feasible views

• Want to optimally manage the division between graph construction and path-finding