Robotics: A General Overview - IITK - Indian Institute of

Robotics: A General Overview


Bhaskar [email protected]

http://home.iitk.ac.in/˜ dasgupta

Indian Institute of Technology

Kanpur, India

July 28, 2008

Bhaskar Dasgupta, IIT Kanpur, India.


Topics to Discuss

Background

Recent Trends

The Dream



Background

Conception of a Robot

I Karel Capek: Rossum’sUniversal Robots (1921)

I Isaac Asimov: ThreeLaws of Robotics (1942)

I Science Fiction andCinema

I A NaturalTerminology

I Performancebenchmarks

I The Myth of“Frankenstein”

Definition: Reprogrammable

multifunctional manipulator Bhaskar Dasgupta, IIT Kanpur, India.


Background

Conception of a Robot

I Karel Capek: Rossum’sUniversal Robots (1921)

I Isaac Asimov: ThreeLaws of Robotics (1942)

I Science Fiction andCinema

I A NaturalTerminology

I Performancebenchmarks

I The Myth of“Frankenstein”

Definition: Reprogrammable

multifunctional manipulator Bhaskar Dasgupta, IIT Kanpur, India.


Background

Historical Perspective

1905: Factory automation

1945: Telemanipulation

1948: Servocontrolled telemanipulator

1952: NC Machines

1954: Programmable Robot design

1961: First robot installed

1970’s : Robotics as a discipline



Background

Historical Perspective

1905: Factory automation

1945: Telemanipulation

1948: Servocontrolled telemanipulator

1952: NC Machines

1954: Programmable Robot design

1961: First robot installed

1970’s : Robotics as a discipline

Trend of jargon:

Cybernetics −→ Robotics −→ Mechatronics



Background

Robotic Systems

I Components of a Robot: Manipulator (arm), controller(brain), sensors (eyes, ears, skin), actuators (muscles)

I Siblings and cousins of Robots: Hard automation,Telemanipulators, NC machaines, AGVs, Walking machines,multifunction toys etc

Robots are characterized by

generality and autonomy.



Background

Robotic Systems

I Components of a Robot: Manipulator (arm), controller(brain), sensors (eyes, ears, skin), actuators (muscles)

I Siblings and cousins of Robots: Hard automation,Telemanipulators, NC machaines, AGVs, Walking machines,multifunction toys etc

Robots are characterized by

generality and autonomy.

Robotic Applications

Industrial: welding, spray-painting, material handling, assembly,inspection, mining etc

Strategic: nuclear, space, underwater, demining, reconnaissanceand surveillance etc

Services: surgery, prostheses, entertainment etc



Recent Trends

Redundant RobotsMore degrees of freedom than required

I For example, a 6-dof planar robot

Allows

I Enhanced dexterity

I Obstacles avoidance

I Singularity avoidance

I Task optimization



Recent Trends



Allows




I Task optimization

Can the robot reach point A with three links?



Recent Trends



Allows




I Task optimization

Can the robot reach point A with three links?

With 10 links?Bhaskar Dasgupta, IIT Kanpur, India.


Recent Trends

Rigid-link robot manipulators

I Rigid in what sense?I Why rigid?

I Ease of modellingI Positioning precision

Task ↔ Joint Motion ↔ Actuation

I The price?I Bulky structureI High-power actuators



Recent Trends

Flexible robots

I Flexible and light

I Smaller actuators

I Less energy consumption

I Manouverability

Challenges of flexible robots

I Modelling: incorporating flexibility in dynamic formulationTask ⇐==⇒ Actuation

I Analysis

I Vibration control

I Implementation



Recent Trends

Drawbacks of Serial-chain Structure

I Low load-carrying capacity

I Low stiffness: Vibration at high speeds

I Positioning precision low



Recent Trends

Drawbacks of Serial-chain Structure

I Low load-carrying capacity

I Low stiffness: Vibration at high speeds

I Positioning precision low

Look up the real world for the way out.



Recent Trends



Recent Trends

Parallel Manipulators

Motivations

I High load-carrying capacity

I Good dynamic performance

I Precise positioning

Challenges

I Restricted workspace

I Singularities

I Complicated kinematics and dynamics



Recent Trends

Modular robots

I Self-assembly of constituent parts

I Greater versatility

I Convenient transport

Micromanipulators

I Miniaturized robots in microscopic spaces

Biomechanics and Bio-medical Engineering

I Artificial body parts

I Rehabilitation



Recent Trends

Walking Machines

Advantages over tracked/wheeled vehicles

I Greater mobility

I Fuel efficiency

I Terrain independence

Typical instances: vehicles with 2-6 legs



Recent Trends

Three legs are needed for static stability.



Recent Trends

Three legs are needed for static stability.

Humanoid Robots: Biped locomotion is a control challenge.



Recent Trends

Dynamic model-based control

Figure: Traditional servo-control

Figure: Model-based or computed torque control

F.F.G. : feedforward gain, F.B.C. : feedback compensation



Recent Trends

Dynamic model-based control

Figure: Traditional servo-control

Figure: Model-based or computed torque control

F.F.G. : feedforward gain, F.B.C. : feedback compensationAdaptive control

I Learning the dynamic modelBhaskar Dasgupta, IIT Kanpur, India.


Recent Trends

TeleroboticsI Distant applicationsI Hazardous applications



Recent Trends


Force ControlI Where maintaining prescribed forces are importantI While handling delicate objects



Recent Trends


Force ControlI Where maintaining prescribed forces are importantI While handling delicate objects

ComplianceI Where positioning accuracy is not reliable



Recent Trends

IntelligenceQuestion: What is intelligence?



Recent Trends

IntelligenceQuestion: What is intelligence?

Do you expect a robot to comprehend and operate as a child can?Bhaskar Dasgupta, IIT Kanpur, India.


Recent Trends

The apparent intelligence in robots

I Obstacle avoidance and path planning

I Application of expert systems

I Application of neural networks



Recent Trends





Aid to intelligence: sight, sound, touch



Recent Trends





Aid to intelligence: sight, sound, touch

Three-fold task of robotic (artificial) intelligence

I Model construction of external world

I Integration of sensory data

I Consequent reasoning and decision-making

Vision

I Extraction, characterization and interpretation of informationfrom 2-d images of a 3-d world



The Dream

The perfect robot

I equipped with high-performance sensors and vision,

I capable of working in unstructured environments,

I able to handle rapid and unexpected changes in scenario,

I withI fault-tolerance and decision-making capability,I adaptability to environment,I stopped only by the threshold of physical impossibility of the

commanded task — with diagnostics.



Thank you.

Queries?


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