![Page 1: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/1.jpg)
Towards Proactive Replanningfor Multi-Robot Teams
Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for SpaceOctober 23, 2006 Trestle
ProjectRobotics Institute
Carnegie Mellon University
![Page 2: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/2.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 2
Motivation
•Human workers:• Predict likely outcomes• Move between teamsmid-task
•Can multi-robotteams do thesame?
![Page 3: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/3.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 3
What is Proactive Replanning?
• Predict problems and opportunities
•Replan before they manifest
![Page 4: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/4.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 4
Idea
• Iterative repair planner•Add Proactive Replanning
• Duration Prediction• Live Task Modification
•Replan and modify active teams to:
• Forestall problems• Grasp opportunities
![Page 5: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/5.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 5
Results Preview
• Stochastic domain•Metric is schedule makespan•Makespan reductions of 11-32%
![Page 6: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/6.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 6
Approach Overview
•Domain•Architecture•Duration Prediction• Live Task Modification
![Page 7: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/7.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 7
Domain
•Multi-agent, multi-team assembly•Goal: Minimize schedule length
![Page 9: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/9.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 9
Architecture
Planner (ASPEN):• Centralized• Repairs & optimizes schedule• Dispatches tasks• Duration Prediction & Live Task Modification
Executive:• Manages execution of tasks• Monitors resource usage• Transmits state to planner
Behavioral:• Interfaces with hardware• Transmits state to executive• Behavioral and hardware
both simulated
![Page 10: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/10.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 10
Planner
•ASPEN: Iterative repair and optimization•Duration Prediction within constraint network• Live Task Modification during repair and optimization
![Page 12: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/12.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 12
Planner: Optimization
•Metric: schedule length•Use idle agents to:
• Start tasks on the “critical path”• Speed up executing tasks on the critical path
![Page 14: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/14.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 14
Duration Prediction: How?
• Predict remaining duration at each timestep•Replan in response•Challenge:
• Accurate predictions within resource bounds
•Current approach:• Offline simulation + lookup table
![Page 16: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/16.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 16
Live Task Modification: How?
•As part of schedule repair or optimization
• Heuristically select a new team• Subject to constraints• Currently assume instant transfers
![Page 17: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/17.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 17
Live Task Modification: How?
•Challenge: search large space of teams and agents
![Page 18: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/18.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 18
Experimental Results
• Scenario•Conditions•Data
![Page 20: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/20.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 20
Experimental Approach
• 50 simulated assemblies per condition• 4 conditions
![Page 21: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/21.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 21
Baseline Condition
•ASPEN•No Proactive Replanning• Each time step:
• Right-shift• Left-shift• Optimize• Repair
![Page 22: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/22.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 22
Experimental Conditions
•Baseline, plus:• Prediction, or:• Live Modification, or:• Combined
![Page 24: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/24.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 24
Results Details
50 runsper conditionmean (std dev)
Baseline(ASPEN)
Prediction Modification Combination
Schedule length (s)
1176.90 (343.58)
1050.14 (273.32)
820.84 (123.55)
802.76 (141.53)
Reduction in length
---- (----) 10.8% 30.3% 31.8%
Repair episodes
30.04 (36.60)
123.28 (23.06)
15.78 (8.00)
97.38 (23.86)
Useful team modifications
35.26 (6.15)
35.14 (5.46)
51.64 (6.19)
48.58 (7.58)
![Page 25: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/25.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 25
Future Work
• Function approximation and Duration Prediction•Durative agent transfers•Risk management
![Page 26: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/26.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 26
Summary
• Initial implementation of Proactive Replanning•Results are promising:
• Makespan reductions of up to 32%• Further work is underway
![Page 27: Towards Proactive Replanning for Multi-Robot Teams Brennan Sellner and Reid Simmons 5th International Workshop on Planning and Scheduling for Space October](https://reader036.vdocuments.mx/reader036/viewer/2022062309/56649f4d5503460f94c6da2a/html5/thumbnails/27.jpg)
IWPSS 2006 - Brennan Sellner [email protected] Slide 27
Thanks!
The executive's first name was Tanner,
A shy, but proactive, replanner Who solved every trouble With a change, on the double,Which finished the job in fine manner.