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Robots: an educationalrevelation in CS

at a Jesuit College

R. Mark Meyer

Canisius College

Buffalo, NY

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Outline

1. Our grant

2. Our learning goals

3. Our robots

4. Our courses

5. Our languages

6. Our assignments

7. Our experiences and conclusions

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Our grant to put robotics into curriculum

• 2006 We were awarded an in-house 3-year grant to introduce robotics into the curriculum.

• It is called the Peter Canisius Distinguished Teaching Professorship– Deb Burhans (CS and Bioinformatics)– Mark Meyer (CS)– David Sheets (Physics and Pre-engineering)

• Impact plans– Course revision– New courses, some in core curriculum and HONORS programs– Outside speakers– Training events for local high school teachers

• After 1 year, we have met many goals and are on-track• This July we will sponsor a NXT training session for local teachers

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Our Goals (curricular)

• Recruit new CS majors• Retain current CS majors• Make the general studies courses more accessible and fun• Improve early programming skills for CS majors• Introduce AI concepts to juniors/seniors• Learning Goals: the students will know...

1. how to describe and define a robot

2. how to interface robot sensors & motors using Java

3. how to better program traditional loops, decisions, subprograms

4. how to describe some AI challenges and techniques

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Our robots

• Lego Mindstorms RCX (approximately 30)

• Lego Mindstorms NXT (approximately 23)

• Sony AIBO (6) [The cute white “dogs”, no longer made]

• ER-1 (2) [Evolution robotics]

• Create from IRobot (1) [A vacuum-less Roomba for robot experiments] – just got this!

• (Funded by the in-house grant plus a $70,000 NASA grant)

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Our penbot

The Pen bot

a roverbot with

an attached pen

so it can draw,

like turtle

graphics.

(This bot was based on other bots described elsewhere, including the 2005 workshop.)

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Our courses

• CSC 110 – A “CS 0” course

• CSC 109 – Another “CS 0” course that is solely robotics

• EGR 111 – Introduction to engineering (pre-engineers)

• CSC 111 – Our Java-based “CS 1” 1/3 of the labs are robots

• CSC 360 – Intelligent Systems: AI, robotics, knowledge bases

• CSC 391/491 – Seminar, 1 credit hour special projects

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Our Assignments

• Early courses (majors and non-majors)– CSC 109 Build robots for competition using Robolang

– CSC 110 Write programs to draw things

– EGR 111 Write programs using bricxcc

• CS 1 (usually majors)– CSC 111 Use lejos for wide variety of tasks (listed later)

• Junior/Senior courses (majors)– CSC 360 Robot competition, wumpus world, track following

– Seminar Variety of tasks: Sony AIBO, ER-1, etc.

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Our Translator: Robotran V.1

Translator program

Robolang – a simple Python-ish language

Translator to true Lejos

Used as web applet or standalone Java app

Can compile and download

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Robolang Details

• Streamlined syntax for assignments and control structures, especially button handler methods

• Uses Java expression syntax and transparently inserts into the final Lejos code

• Simplified robot commands:– go forward 10 seconds

• Motor.A.start();• Motor.B.start();• try { Thread.sleep(10000); } catch (Exception e) {}

• Simplified function (method) syntax

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Simple Light Follower program

program follow1

constant BLACK = 42

loop

var lightvalue = S3

display lightvalue

if lightvalue < BLACK then

stop

else

go forward

end

end

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Light Hunterprogram follow4global constant BLACK = 42global var turnedLeft = 1loop var lightvalue = S3 display lightvalue if lightvalue < BLACK then do findLight else go forward endend

define huntLeft() returns number turn left sharp 25 degrees var lightvalue = S3 if lightvalue > BLACK then return 1 else turn right sharp 25 degrees return 0 endend

define huntRight() returns number turn right sharp 25 degrees var lightvalue = S3 if lightvalue > BLACK then return 1 else turn left sharp 25 degrees return 0 endend

define findLight var result if turnedLeft = 1 then result = huntLeft() if result = 1 then return end result = huntRight() if result = 1 then turnedLeft = 0 return end end if turnedLeft = 0 then if huntRight() = 1 then return end if huntLeft() = 1 then turnedLeft = 1 return end endend

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Our simulator

• Simulate the penbot, only one at a time, geared towards real assignments

• Don’t get overly caught up with 3d graphics• Provide functionality with both Robolang and Lejos• Make it flexible for future implementation on NXT• Use the lejos compiled code that makes calls to the firmware

ROM• Create our own ROM object with same API and let the compiled

code, running in tinyVM, call it• Then our ROM object sends updates to a graphics simulation

object• Special credit to senior David Puehn for his exceptional

programming and design help on the simulator.

Screenshot of new Robotran and Simulator

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Activities & Assignments (CSC 111)

1. Robot acts like a sentry (back and forth)

2. Robot avoids obstacles by randomly turning after bumps

3. Robot randomly moves around (Brownian motion)

4. Robot responds to input through the buttons

5. Robot plays music

6. Robot senses light values and displays numbers on LCD

7. Robot goes forward only when flashlight is turned on

8. Robot turns to find light if low light level is sensed

9. Robot uses more elaborate schemes to find light source

10.Robot remembers direction of last successful turn to find light

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Activities and Assignments (CSC 111)

11.Robot is taught a path which it can then replay (uses arrays)

12.Robot receives input from bumps and button presses, including binary or unary numbers

13.Robot draws a letter based on input number

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Activities and Assignments (upper level)

These are used in the robot competition, which can be entered by

anyone in any class, from beginning to junior/senior level.

1. Robot follows a line on the floor, part of drag race competition

2. Robot tries to stay within a sumo ring while pushing another robot outside the ring

3. Robot navigates a maze (needs to remember path & obstacles)

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Activities and Assignments (CSC 360)

• LEGO Mindstorms competition last 2 years

• “In 360 we only used the Aibos this year (2007.) Students learned how to control them using Pyro and completed basic labs on movement and vision. Then they worked on the wumpus world challenge with the low level operations using Pyro and high level KR&R using SNePS with the architecture that connects SNePS to Pyro that Alistair and I created.” (Deb Burhans)

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Strategies for Worthwhile assignments

(This applies only to CSC 111 assignments.)• Don’t try to accomplish too much in one program! … keep the

time-frame in mind and how much out-of-lab time they can have.• Reinforce structured programming (use given methods and

construct new ones; emphasize problem decomposition).• Require use of appropriate data structures (usu. Arrays).• Get them thinking about AI issues, especially flexible problem-

solving strategies and multiple alternatives.• Progress from simple to several more complex versions of same

problem, e.g. the light follower.• Use the button press model to reinforce listeners and handlers

which are used in other aspects of Java (like GUIs).

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Our experiences and conclusions• Surveys show a strong positive attitude on part of students• The comments are lavish with praise, but a few thought the

robots were too primitive• CS 1 students say the robots motivate them to stay in CS• More CS 0 students are going on to CS 1 for the fun of it,

especially the CSC 109 students• No significant change in CS 1 final grades or other indicators of

acquisition of programming skills• Students in 110 and 109 liked Robolang better than Lejos when

they got into 111• In our robot competition, groups used brixcc, Lejos and

Robolang and did comparably using any language

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Our experiences and conclusions (2)• We need a lot of help in the labs (so we hire student helpers)• Grading is a pain (can’t download and test every single

program)• Robot labs take a lot more time for students to complete; can’t

do as much• We need to staff after-hours lab time• So far, no theft and almost no breakage!• Students respond much more positively when each has their

own robot to program; group exercises in 110 (made necessary by large number of students) were less gratifying

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Our future plans

• Finish the Robotran simulator

• Port it to the NXT

• HONORS science elective on robotics in Spring 2008– D. Burhans will teach

– LEGO robot programming will be used for concrete activities

– Readings, movies, discussions and papers will accompany

• Continue fulfilling broader goals of the Peter Canisius DT professorship

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Our Contact Information

• cs.canisius.edu/~robotics– SOFTWARE tab on left: Several versions of robotran

– COURSES tab: the CSC 111 assignments and Robolang programs

• email addresses:– meyer@canisius.edu

– burhans@canisius.edu

– sheets@canisius.edu