This is an old revision of the document!
Notes on robot design - see also lirec notes.
“Robotics is the intelligent connection of perception to action” - Michael Brady
- Perception: Sensors tell a robot about the outside world.
- Action: Actuators allow a robot to change the outside world, to act upon it.
State
State is what the robot collects in order to understand the world.
(not to happy about these definitions…)
Internal state
Directly observable state of the robot. Also it's internal representation of the world - it's internal model.
External state
What's happening in the real world. Can only be known via a robot's sensors.
Observable state
Known at all times, usually internal - eg. battery state.
Partially observable state
Through a sensor, along with noise eg: camera image pixels
Hidden state
What you are actually interested in, in the real world - eg: position of user's head. Can't be directly known, must be indirectly inferred from (maybe multiple) sensors. See sensor fusion.
Deliberative vs Reactive
Think hard - then act!
- Capable of learning and prediction
- Finds strategic solution
but:
- Requires lots of computation - eg. brute force search for potential plan
- Needs a world model
- Slow
Don't think, react!
- Fast
- Powerful, biological parallel
but:
- Minimal state
- No memory
- No internal representation of the world
- Unable to plan ahead
- Unable to learn
Or do both!
- Deliberative system on top
- Reactive underneath
- Hybrid or Behavioural system
Links
Artificial Intelligence versus classical Robotics: http://www.ee.pdx.edu/~mperkows/CLASS_479/hardware/014.Robot-Control-Architectures.ppt
davegriffiths