Lecture 3, May 11,

2012

Review and Review and Ideas for future Ideas for future

ProjectsProjects

Projects with robots for teens. What we already discussed.

1. Line following robots2. Y shaped lines for robots that drive to selected locations.3. Robots following walls on corridors.4. Algorithms for mazes:

1. Right Wall Following Algorithm (RWFA)2. Left Wall Following Algorithm (LWFA)3. Deterministic Switch from from RWFA and LWFA based on mapping the known part of maze

to memory.4. Variants of searching mazes to find an exit.

5. Deterministic and probabilistic combinational behavior based on input – output matrix and multiplication of matrix by vector.

6. Combinational and State Machine based Braitenberg Vehicles

S1 S2 Q Q+ 0 1

0 0 0 0 0 1

0 0 1 1 1 0

0 1 0

0 1 1

1 0 0

1 0 1

1 1 0

S1 S2 Q Q+ M1 M2

0 0 0 0 0 1

0 0 1 1 1 0

0 1 0 0 1

0 1 1 0 1

1 0 0 0 1

1 0 1 0 1

1 1 0 1 0

S1 S2 Q Q+ M1 M2

0 0 0

1 1 1 1 1 0

1 0 0

1 0 1

1 1 0

Analysis of a Braitenberg robot with Analysis of a Braitenberg robot with memorymemory

J

K

Q

Q

S1

S2

S1

S2

M2

M1

LOGIC

M1

M2

S1 S2 Q J K Q+

0 0 0 0 0 0

0 0 1 0 0 1

0 1 0 0 1 0

0 1 1 0 1 0

1 0 0 0 1 0

1 0 1 0 1 0

1 1 0 1 1 1

0= happy1 =angry

Analysis1. Analyze how this behaves in

room with no light.2. Analyze how this behaves in

room with light on floor, oriented towards robot.

3. Analyze how this behaves in a maze.

4. Draw snaphsots of movie of robot position , orientation and internal state in time

S1

S2

M2

M1

LOGIC

0= happy1 =angry

Maze

exit

Wall is on the left

exit

Robots marks his motion for Left Wall algorithm in blue

Robots maps its position in memory and now is back in the same point

exit

Robots marks his motion for Left Wall algorithm in blue

Robot moves to other wall

exit

Robots marks his motion for Left Wall algorithm in crosses

Robot starts left wall following algorithm (wall

at left)

X X

exit

Robot executes left wall following algorithm (wall

at left)

XX

exit

Robot executes left wall following algorithm (wall

at left)

XXX

exit

Robot executes left wall following algorithm (wall

at left)

XXXX

exit

Robot found the solution to exit by changing the wall in the corridor but still using the left

wall following algorithm (wall at left)

XXXXXX

XX X X

XXXXXXXX X X X X X

XX

Projects with robots for teens Projects with robots for teens

1. Robot finding cans and bringing them to safe place.2. Robot attacking or escaping other robots.3. Robots boxing.4. Robots shooting one another.5. Robots fencing.6. Repeated Prisoner Dilemma for robots.7. Repeated Chicken for robots. 8. Subsumption Architecture9. Maze Searching10. Genetic Algorithm11. Tree search

Advanced Advanced Line Line

FollowingFollowing

SENSOR ARRAY

MINIMUM DISTANCE BETWEEN SENSORS IS 1cm

7 sensors7 sensors

Observe the order of variables from outside to the center

THE PRIORITY ENCODER

7 sensors as inputs

Number of sensor as output

Problem:Problem:Design such priority encoder as a circuit using Kmaps

THE NO SURFACE LOGIC

A

B

C

A

B

C

00

01

A

B

C

01

00

NS signal = no line detected

NS signal = no line detected

INPUTS TO THE MICROCONTROLLER

NS GS A2 A1 A0 STATE IN ACTION

1 X X X X No surface is detected Stop the motors

0 1 X X X No line is detected Execute the no line code (specially designed algorithm)

0 0 0 0 0 A detects the line Sharp turn left

0 0 0 0 1 B detects the line Sharp turn right

0 0 0 1 0 C detects the line Turn left

0 0 0 1 1 D detects the line Turn right

0 0 1 0 0 E detects the line Move left

0 0 1 0 1 F detects the line Move right

0 0 1 1 0 G detects the line Go straight

0 0 1 1 1 Forbidden state Software reset the processor

NS signal = no line detected

How this algorithm based on sensors works?

LINE FIND MODE

Generalizations

• Wall following• Vision based Wall following• Labyrinth problems• Can collecting tasks

FLOW CHART

RESULT AND CONCLUSION

1. The robot follows a line as demonstrated.

2. It effectively overcomes problems such as “barren land syndrome” and line breaks.

3. The hardware and software works as designed.

APPLICATIONS OF LINE APPLICATIONS OF LINE FOLLOWING IDEASFOLLOWING IDEAS

1. Industrial automated equipment carriers2. Automated cars.3. Tour guides in museums and other similar

applications.4. Second wave robotic reconnaissance

operations.

LIMITATIONS1. Choice of line is made in the hardware abstraction and

cannot be changed by software.

2. Calibration is difficult, and it is not easy to set a perfect value.

3. The steering mechanism is not easily implemented in huge vehicles and impossible for non-electric vehicles (petrol powered).

4. Few curves are not made efficiently, and must be avoided.

…LIMITATIONS

1. Lack of a four wheel drive, makes it not suitable for a rough terrain.

2. Use of IR even though solves a lot of problems pertaining to interference, makes it hard to debug a faulty sensor.

3. Lack of speed control makes the robot unstable at times.

FUTURE SCOPE

1. Software control of the line type (dark or light) to make automatic detection possible.

2. “Obstacle detecting sensors” to avoid physical obstacles and continue on the line.

3. Distance sensing and position logging & transmission.

Mechanical Mechanical Designs of Designs of

robotsrobots

Robot that delivers stuff to Robot that delivers stuff to locationslocations

1. We will compare robots A, B, C, D, E, FA, B, C, D, E, F2. Robot can be prototyped with Lego NXT3. Then we can add components from Tetrix4. It is often faster, cheaper and better to design the robot

from wood, plastic and metal by yourself and only use gears and motors with encoders from Tetrix.

5. We use this approach in our theatre.6. Needs:

1. Doll grabbing (lifting)2. Linear motion3. Base control

How to design How to design mechanically mechanically robots that can robots that can grab some items grab some items and deliver to and deliver to certain locations?certain locations?

Robot ARobot A1. Deliver dolls to locations

1. Grabs an item2. Releases the item

2. Can be used to deliver little robot actors to locations in robot theatre

3. Uses line following

Robot takes some object (a doll) in place X and delivers it to the location in place Y

Robot DRobot D• The same as before, robot delivers dolls to

locations

Robot B

Robot BRobot B• Robot delivers dolls to locations, as before

Robot C- to play volleyballRobot C- to play volleyball

1. Robot plays volleyball

Robot to play hockeyRobot to play hockey

Robot to play hockeyRobot to play hockey

Robot to play hockeyRobot to play hockey

Robot to play hockeyRobot to play hockey

Robot to play hockeyRobot to play hockey

Philosophy How Philosophy How to Design a to Design a

RobotRobot

General Design Considerations

• Effectiveness– Does the robot do what you want it to?– Speed & accuracy

• Reliability– How often will it work?

• Ease of Implementation– Balance complex, effective solutions with simple to build

solutions– Faster implementation means that you have more time

allowed for debugging, • and probably, it means less debugging

Effectiveness• Electrical

1. Multiple stages2. Efficient use of

inputs/outputs3. Low power usage4. Effective Motor

use5. Sensor

placement /use

Mechanical1. – Bearing surfaces2. – Stiffness3. – Appropriate constraints on

degrees of Freedom4. – Gearing5. – Speed6. – Low mass / moment of inertia

Reliability

• Electrical1. Circuit

modularity2. Grounding3. Shielding

MechanicalMechanical1. – Stiffness2. –

Appropriate constraints on degrees

3. of freedom4. – Simplicity

Ease of Implementation

• ElectricalElectrical1. Multiple stages2. Board layout –

related ccts on 1 board

3. Circuit modularity4. Accessibility

MechanicaMechanicall

1. Off-the-shelf parts

2. Simplicity

3. Design for loose tolerances

Grabbing Items Grabbing Items Using some Using some intelligenceintelligence

Tower of Hanoi ProblemTower of Hanoi Problem1. Write the software for Tower of Hanoi

Problem for a robot, with few pegs only.2. Write the recursive software.

Robot Robot TheatreTheatre

Projects from Lego RobotsProjects from Lego RobotsA piano-playing robotA piano-playing robot

The piano-playing robot positions itself correctly in front of the piano (using a camera following a color target) and then plays with its two-fingered hand.

Projects from Lego Robots

1.1. Smiley face Smiley face robot chases robot chases the moving the moving orange orange target. target.

2.2. The eyebrows The eyebrows and mouth and mouth move to show move to show happy and happy and sad.sad.

1. Smiley face also has a small camera that tracks colors so it can follow the orange target.

2. The mouth and eyebrows move using servo motors.

Robots for Autism Therapy

Teleoperated bear developed at MU

Yale University

University of Hertfordshire UK

University of Sherbrooke

Sensors for TigerPlaceto Help Older Adults Age Safely

Basic Sensors

Detection of Falls

See also http://eldertech.missouri.edu

PC

The robot theatre concept

Bluetooth connection

Personal computer

GPU supercomputer

headhands

BIBLIOGRAPHY

• Programming and Customizing the PIC microcontroller by Myke Predko

• PICmicro Mid-Range MCU Family Reference Manual by MICROCHIP

• PIC Robotics, A beginner’s guide to robotics projects using the PICmicro by John Iovine

…BIBLIOGRAPHYWebsites referred…

• The Seattle Robotics Society Encoder library of robotics articles

• Dallas Personal Robotics Group. Most of these tutorials and articles were referred.

• Go Robotics.NET, this page has many useful links to robotics articles.

…BIBLIOGRAPHY

• Carnegie Mellon Robotics Club. This is the links page with lots of useful resources

• This page is called the “Micro-mouse Handbook” and an excellent tutorial for small scale robotics.

• This is the main website of microchip. Thousands of application notes, tutorials & manuals can be found here.