INTRODUCTION TO A.I.

Robots

February 2, 2007

7.1	Robots
	What it is (typically)	A phyiscal entity that can move about in a purposeful way
	Autonomy	Robots are not always autonomous, but the popular notion of robots is that they are completely autonomous
	Embodiment	Robots are embodied de facto - typically when we say "robot" we mean "autonomous machine with a physical embodiment"
	Made from artificial materials	Made by humans, as opposed to e.g. cyborgs, who are part human, part machine.
	The concept of "robot"	Typcially is used in a very limited way; "cognitive robotics" is used to indicate "robots with more than just the ability to move".
	The word "robot"	Comes from Karel Capek's play Rossum's Universal Robots; "robot" means "worker" Czech

7.2	Robots: What Are They Good For?
	Tasks	Mobility: Space exploration Boring work in large areas (e.g. cleaning) Dangerous areas (e.g. geological exploration, deep-sea diving) Moving things around Physical manipulation, esp. manufacturing: sorting assemby
	Application areas	Manufacturing Telerobotics, telepresence, virtual reality (with varying degrees of autonomy) Augmentation of human abilities Transportation

7.3	What are Robots Made of?
	Arms	Complexity of arms counted in degrees of freedom (1-dimensional motion ability) - DoFs Unusual to see robots with arms of larger than 6 DoFs, because search space becomes too large Inverse kinematics: mathematics for computing joint angles based on a desired future location of manipulator
	Manipulators	Hands, welders, screwdrivers, etc. [video]
	Legs	Boston Dynamics, U.S. - significant advances in mobility via legs [video] Japanese and Korean projects, incl. Honda, Sony, many universities
	Power	Hydraulic: Only for the largest, strongest (e.g. autonomous backhoe) Pneumatics: requires pressurized air, containers heavy Batteries: Major constraint on mobility and endurance
	Control	Computers small and efficient enough to do plenty of on-board processing Use Wi-Fi for localized robots with more brainpower
	Sensors	Simplest: Sonars, Infrared sensors Medium complexity: Laser range finders Very complex: Cameras, microphones Touch sensors of various sorts Joint position sensing technologies

7.4	Navigation
	Goal of navigation	Find your way from A to B
	Constraints	Obstacles prevent you from going in a straight line
	Planning	Planning algorithms help you navigate around obstacles (planning will be covered in W7)
	Dead-reconing	"Blind" navigation: Using knowledge of starting point, move according to an internal map Problem: drift in sensors and position will accumulate errors in the position and orientation
	Landmark-based navigation	Recognize textures and configurations of objects, walls, etc.
	Reactive navigation	Use external environment to trigger next move(s)
	Map-based navigation	Use an internal map to determine how to get from A to B
	Bounding-box representation	Use bounding boxes around obstacles, to indicate areas safe for travelling Idea from computer graphics (level of detail - LoD) Helps reduce search space by ignoring details of the shape of things
	Challenges	Unreliable sensors (worse the further away objects are) Integrate sensors with a-priori knowledge Build up a usable map of terrain that is being navigated

7.5	Cognition
	"Behavior-based AI"	Term used to describe "reactive" architectures with a tight coupling of sensors and actuators
	Example typical topic	Autonomous vaccum cleaner (i.e. a caricature - but see iRobot's Roomba autonomous vacuum cleaner)
	Behavior-based AI: What it's good for	Robust simple behaviors in complex, realtime environments Insect-like behaviors Reactive planning Instinctive behaviors As a robust basic component in a larger system

	Subsumption control

iRobot Roomba autonomous vacuum cleaner, c.a. y 2002

7.8	Example Robots
	Cog	MIT Main methodology: Subsumption architecture
	RODNEY BROOKS WITH COG
	Attila / Genghis	MIT Main methodology: Competence network; subsumption architecture
	ATTILA - SIX-LEGGED ROBOT AT MIT

	P1 - first Asimo prototype ASIMO - c.a. 2003 ASIMO, HONDA [video]

	TM-SUK female robot 2004

	PINO - open robot platform

	Robots can also swim See also [robotuna]

	Banryu robot guard "dog"



	"Pet" robots are becoming increasingly popular [video]

	Hobby robotics will take off in coming years. Example: Chronio [1] [2] [3] [4] Missing in these robots is a sense of body stance, and they typically have little or no vision. Therefore, their movements are mostly scripted (dead-reconing) movements.

	Humanoid torso powered by pneumatics

	Fact or fiction? [video]