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Intelligent Patrolling. Sarit Kraus Department of Computer Science Bar-Ilan University Collaborators: Noa Agmon, Gal Kaminka, Efrat Sless. Physical Security with Bounded Resources. - PowerPoint PPT Presentation
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Intelligent Patrolling Intelligent Patrolling
Sarit KrausDepartment of Computer Science
Bar-Ilan University
Collaborators: Noa Agmon, Gal Kaminka, Efrat Sless
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Physical Security with Physical Security with
Bounded ResourcesBounded Resources• Limited security resources prevent full security
coverage at all times; allows adversaries to observe and exploit patterns in selective patrolling or monitoring.
• Randomized patrolling or monitoring is necessary.
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Randomized CheckpointsRandomized Checkpoints
Multi-Robot Adversarial Multi-Robot Adversarial PatrolPatrol
• Motivation:
• High security facilities
• Large military bases
• Neighborhood watch
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Protecting a Parade: Protecting a Parade: route is announcedroute is announced
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Protecting a Moving Protecting a Moving Target: randomizing the Target: randomizing the
routeroute
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Why Do We Need Why Do We Need Automated Methods Automated Methods
for Randomizationfor Randomization??• People are not good at randomization
• The randomized strategy should depend on:o the adversary and the defenders’ utilitieso the environment parameters
o the defender’s resources.
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Multi-Robot Multi-Robot Adversarial Patrol: Adversarial Patrol: The EnvironmentThe Environment
• PerimeteroDivided into segmentsoUniform time-distanceoRobot travels through one segment per time
unit
• Adversaryo Tries to penetrate through the perimetero Takes t>0 time units to penetrate
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Robotic ModelRobotic Model• k homogenous robots
• Robotic movement model:o Robots’ movement is directedo Turning around “costs” τ time units
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Algorithm FrameworkAlgorithm Framework• Patrol algorithm:
o Continue straight with probability po Turn around with probability 1-p
• PPD: Probability of Penetration Detection
• p depends on the distance between robots and on the penetration time.
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Robot MovementRobot Movement
• Optimal: Robots are uniformly placed around the perimeter
• Coordinatedo If decide to turn around they do it simultaneouslyo Preserve uniform distance
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• Optimal: Robots are uniformly placed around the perimeter
• Coordinated
– If decide to turn around they do it simultaneously
– Preserve uniform distance
Robot MovementRobot Movement
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• Optimal: Robots are uniformly placed around the perimeter
• Coordinated
– If decide to turn around they do it simultaneously
– Preserve uniform distance
Robot MovementRobot Movement
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• Optimal: Robots are uniformly placed around the perimeter
• Coordinated
– If decide to turn around they do it simultaneously
– Preserve uniform distance
Robot MovementRobot Movement
Handling EventsHandling EventsWhat if a robot needs to inspect the penetration?
•Once a penetration is detected, one robot is extracted from the team to inspect it
•Coordinated attacks are beneficial to the adversary
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What Happens If What Happens If Penetration DetectedPenetration Detected??
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What Happens If Penetration What Happens If Penetration
DetectedDetected??• Robot that detected the penetration will inspect it
• Other k-1 robots will spread uniformly o To achieve optimal behavior for k-1 robots
Phase 1: k robots (before event), steady statePhase 2: ReorganizationPhase 3: k-1 robots (after event), steady state
Optimal patrol known
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Naïve ApproachNaïve Approach• Deterministic:
Each robot goes straight to its final position
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Randomized Randomized ReorganizationReorganization
• Challenges: o each robot needs to move differentlyo How much time to spend on the reorganization?
• We randomized over possible paths
• Finding the strategy is complex, in theory, but we used heuristics to find it in reasonable time
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Physical Security with Physical Security with
Bounded Resources: SummaryBounded Resources: Summary• Randomized patrolling or monitoring is necessary.
• Automated randomization is important
• Interesting problems? [email protected]