Lecture 3, May 11, 2012

Review and Ideas for future Projects

Projects with robots for teens. What we already discussed. 1.Line following robots 2.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

S1S2QQ S1S2QQ+M1M S1S2QQ+M1M Analysis of a Braitenberg robot with memory J K Q Q S1 S2 S1S2 M2 M1 LOGIC M1 M2 S1S2QJKQ = happy 1 =angry

Analysis 1.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 S1S2 M2 M1 LOGIC 0= happy 1 =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 X

exit Robot executes left wall following algorithm (wall at left) XX

exit Robot executes left wall following algorithm (wall at left) X X X

exit Robot executes left wall following algorithm (wall at left) X X X X

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) X X X X XX X XXX X X XXXX X X XX X XX X X

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 Architecture 9.Maze Searching 10.Genetic Algorithm 11.Tree search

Advanced Line Following

SENSOR ARRAY MINIMUM DISTANCE BETWEEN SENSORS IS 1cm 7 sensors Observe the order of variables from outside to the center

THE PRIORITY ENCODER 7 sensors as inputs Number of sensor as output Problem: Design such priority encoder as a circuit using Kmaps

THE NO SURFACE LOGIC A B C A B C A B C NS signal = no line detected

INPUTS TO THE MICROCONTROLLER NSGSA2A1A0STATE INACTION 1XXXXNo surface is detectedStop the motors 01XXXNo line is detectedExecute the no line code (specially designed algorithm) 00000A detects the lineSharp turn left 00001B detects the lineSharp turn right 00010C detects the lineTurn left 00011D detects the lineTurn right 00100E detects the lineMove left 00101F detects the lineMove right 00110G detects the lineGo straight 00111Forbidden stateSoftware 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 FOLLOWING IDEAS 1.Industrial automated equipment carriers 2.Automated cars. 3.Tour guides in museums and other similar applications. 4.Second wave robotic reconnaissance operations.

LIMITATIONS 1.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 Designs of robots

Robot that delivers stuff to locations A, B, C, D, E, F 1.We will compare robots A, B, C, D, E, F 2.Robot can be prototyped with Lego NXT 3.Then we can add components from Tetrix 4.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 motion 3.Base control How to design mechanically robots that can grab some items and deliver to certain locations?

Robot A 1.Deliver dolls to locations 1.Grabs an item 2.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 D Robot D The same as before, robot delivers dolls to locations

Robot B

Robot delivers dolls to locations, as before

Robot C- to play volleyball 1.Robot plays volleyball

Robot to play hockey

Philosophy How to Design a Robot

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 stages 2.Efficient use of inputs/outputs 3.Low power usage 4.Effective Motor use 5.Sensor placement /use Mechanical 1.– Bearing surfaces 2.– Stiffness 3.– Appropriate constraints on degrees of Freedom 4.– Gearing 5.– Speed 6.– Low mass / moment of inertia

Reliability Electrical 1.Circuit modularity 2.Grounding 3.Shielding Mechanical 1.– Stiffness 2.– Appropriate constraints on degrees 3.of freedom 4.– Simplicity

Ease of Implementation Electrical Electrical 1.Multiple stages 2.Board layout – related ccts on 1 board 3.Circuit modularity 4.Accessibility Mechanical 1. Off-the- shelf parts 2. Simplicity 3. Design for loose tolerances

Grabbing Items Using some intelligence

Tower of Hanoi Problem 1.Write the software for Tower of Hanoi Problem for a robot, with few pegs only. 2.Write the recursive software.

Robot Theatre

Projects from Lego Robots A 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.Smiley face robot chases the moving orange target. 2.The eyebrows and mouth move to show happy and 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 TigerPlace to Help Older Adults Age Safely

Basic Sensors

Detection of Falls See also

PC The robot theatre concept Bluetooth connection Personal computer GPU supercomputer head hands

This generic situation, where the robot’s behavior is conditioned upon the input from the feature detectors connected to the camera, maps to a constraint satisfaction problem as described here.as described here The way this would work is that the human / camera / robot system would generate optimization and satisfiability problems, to determine how the robot’s effectors should fire, and these problems can be remotely solved using Orion. For example, you could acquire a Hansen Robotics Einstein, sit it him on your desk, train a camera on your face, use an anger feature detector that causes the Einstein robot to laugh harder the angrier you get. Hansen Robotics Einstein

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

…BIBLIOGRAPHY Websites 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.