Mobile Robotics:2. Robotics Fundamentals

Dr. B

rian Mac N

amee (w

ww

.comp.dit.ie/bm

acnamee)

2of25

2of26 Acknowledgments

These notes are based (heavily) on those provided by the authors to accompany “Introduction to Autonomous Mobile Robots” by Roland Siegwart and Illah R. Nourbakhsh

More information about the book is available at:http://autonomousmobilerobots.epfl.ch/

The book can be bought at:The MIT Press and Amazon.com

3of25

3of26 ContentsToday we’ll look in more detail at what we mean when we talk about robots

– Definition– Taxonomy– Applications– Advantages & disadvantages– Components– Autonomous robot control

4of25

4of26 What Is A Robot?The term robot was first introduced by the Czech playwright Karel Čapek in his 1921 play Rossum’s Universal Robots (the word robota being the Czech word for worker)

We will use the following definition:

Karel Čapek was one of the most influential Czech writers of the 20th century. At one

time the Gestapo had ranked him as "public enemy number 2" in

Czechoslovakia!

“a robot is an artificial physical agent that performs tasks by

manipulating the physical world”

5of25

5of26 Robot TaxonomyThe Japanese Industrial Robot Association gives the following classification of robots:

– Class 1: Manual Handling Device– Class 2: Fixed Sequence Robot– Class 3: Variable Sequence Robot– Class 4: Playback Robot– Class 5: Numerical Control Robot– Class 6: Intelligent Robot

6of25

6of26 Robot TaxonomyWe are primarily interested in intelligent robots and can break these down simply as follows:

– Manipulator robots– Mobile robots– Humanoid robots

7of25

7of26 Manipulator RobotsPhysically anchored to their workplace

Manipulator motion usually involves an entire chain of controllable joints, enabling such robots to place their effectors in any position within the workplace

Manipulators are by far the most common type of industrial robots - a 2 billion dollar industry!

8of25

8of26 Mobile RobotsWe can divide mobile robots into the following categories:

– Wheeled robots– Legged robots– Aerial robots (UAVs)– Others

9of25

9of26 Wheeled Robots

For more on the DARPA Grand Challenge go to:www.darpa.mil/grandchallenge/index.asp

10of25

10of26 Legged Robots

For more on Boston Dynamics go to: www.bostondynamics.com

11of25

11of26 Aerial Robots

More information on these projects can be found at:lis.epfl.ch/index.html?content=research/projects/BioinspiredFlyingRobots/index.php

12of25

12of26 Aerial Robots

More information on these projects can be found at:lis.epfl.ch/index.html?content=research/projects/BioinspiredFlyingRobots/index.php

13of25

13of26 Other Mobile Robots

A video of a slightly scary robotic amphibious snakehttp://www.techeblog.com/index.php/tech-gadget/acm-r5-amphibious-snake-like-robot

14of25

14of26 Humanoid RobotsHybrid robot: a mobile robot equipped with manipulators

Hybrids can apply their effectors further a-field then anchored manipulators

However, their task is made harder because they don’t have the rigidity that the anchor provides

15of25

15of26 ASIMO

ASIMO slalom video available at:world.honda.com/HDTV/ASIMO/New-ASIMO-slaloming/index.html

Loads of ASIMO videos are available from HONDA at:world.honda.com/HDTV/ASIMO/

16of25

16of26 Robot ApplicationsIndoor Structured Environments

– Transportation– Customer support in museums, shops, etc.– Cleaning large buildings– Building surveillance– Research– Entertainment

17of25

17of26 Robot Applications (cont…)Outdoor Unstructured Environments

– Space– Mining– Sewage tubes– Forest– Agriculture

– Construction– Fire fighting– Military– Underwater– Aerial

18of25

18of26 AdvantagesThe major advantages of robots are:

– Decreased labor costs– Increased precision and productivity– Increased flexibility compared with specialised

machines– Robots can perform dull, repetitive jobs– Robots can operate in hazardous environments

19of25

19of26 ComponentsThe major components of a mobile robot are:

– Power supply– Sensors– Control– Actuators

Actuators

Power

Sensors

Control

Environment

20of25

20of26 Components (cont…)Power Supply: the power plant and associated power transmission system, such as a battery with associated equipment, or a power supply unit which converts electricity from the mains to appropriate power requirements

Sensors: Including lasers, cameras, sonar and microphones, sensors enable robots to collect information about their own state and the state of their environment

21of25

21of26 Components (cont…)Actuators: devices which transduce power into kinetic energy or movement

Types of actuators include: – Electric motors– Pneumatic actuation (using compressed gas) – Hydraulic actuation (using pressurized fluids)– Robotic end effectors (e.g. grippers)

Control Subsystem: responsible for evaluating the information collected and processed by sensors and for planning actions

22of25

22of26 Robot Control MechanismsRobots may be controlled:

– Directly by a human, such as remotely-controlled bomb-disposal robots, robotic arms, or shuttles

– Autonomously according to their own decision making ability, provided by artificial intelligence

Many robots fall in-between these extremes, being controlled by pre-programmed computers

23of25

23of26 Mobile Robot Control

Tele-operated– Pioneer, robot that

was designed to explore the Sarcophagus at Chernobyl

24of25

24of26 Mobile Robot Control (cont…)Autonoumous

– EPFL Guide Robot

We are primarily interested in autonomous robots

25of25

25of26 Autonomous Robot Control

ActuatorsSensors

Control

Deliberative Behaviour

Reactive Behaviour

Environment

26of25

26of26 SummaryToday we:

– Defined what we mean by a robot– Investigated some of the areas in which robots

are used– Defined the key components of a robot– Started to think about robot control mechanisms

Next time we start the real work

27of25

27of26 Questions

?