Replacing the Office Intern: An Autonomous Coffee Run with a Mobile Manipulator
Tony Pratkanis, Adam Leeper, and Ken Salisbury
Introduction
- Purely autonomous purchase of a coffee
- No training of coffee shop staff
- Completely unmodified environment
- Willow Garage PR2 robot
- Limited robot modification: cup holder
- 2835 second (47.25 minute) run time
Multi-Map Navigation
- Allows navigation across multiple 2D-maps
- Connected by "transition" events
- Useful for multi-story buildings
- Break down large maps to reduce memory use
- Avoid excessively long SLAM sessions
- http://www.ros.org/wiki/multi_map_navigation
Transparent Spring Loaded Doors
- Doors too heavy for the robot's arm
- Elaborate 'dance' with base to open doors
- Transparent doors cannot be detected easily
- 2D-Computer vision based approaches fail
- Use laser scanners to find the glass 'hole'
- Haptic detection of the door handles
Elevator Operation
- Modification of elevators politically difficult
- Extreme certification costs + chicken/egg problem
- Inside of elevators extremely reflective
- 2D-computer vision detection of call buttons
- Use elevator walls to position robot to buttons
- Accelerometer determination of which floor to exit
Object Transfer
- Need to pass objects to and from people
- People have a natural way to pass objects
- Use accelerometers, camera, and arm deflection
- Use physical cues and text-to-speech sounds
- Robot receives objects by gesture
- If any criteria met, then robot will grasp object
- If object not present, then the robot will retry
- Give objects by waiting for the human to pull
Conclusions & Future Work
- Lessons Learned
- Robotics software engineering not solved
- Robots need extensive holders
- PR2 is inherently slower than humans
- Future Work
- Next generation BLAST executive
- Speeding up the robot