Karel the Robot

KarelJRobot.jar WorldBuilder.bat test.kwld KarelMain.java Template.java Template.java superRobot.java WorldBuilder Directions Java Installation Instructions First download the SDK(Standard Development Kit)and install it. Second download the docs and install them. Download JCreator Third download jcreator (LE is free, PRO is $35) and install it.

Karel's World

• Karel: a robot living in a great, flat plane with standard north/south/east/west directions.
• Streets and Avenues
  • Karel's world is crisscrossed with streets (east/west) and avenues (north/south); a street corner, or intersection, is formed wherever a street and avenue intersect
  • One or more robots can occupy any corner facing any one of the four directions.
  • Will usually refer to just one robot: Karel
    • This robot is named Karel after the Czechoslovakian dramatist Karel Capek.
    • Capek wrote the play R. U. R. (Rossum's Universal Robots) which made the word robot popular.
    • The word robot is derived from a Czech word that translates into "forced labor."
  • Streets and avenues are numbered
    • origin is at 1st Street and 1st Avenue, (1,1)
    • positions can be absolute or relative
    • will sometimes view world as North=up, South=down, West=left, East=right
  • Walls:
    • Intersections are sometimes separated by walls.
    • Walls are made of solid neutronium, making them impenetrable to robots.
    • We will build worlds by using WorldBuilder.
    • The world is bounded by infinitely long walls to the West and South so robots don't fall off.
    • Walls can be used to represent hurdles, mountains, fences, etc., that robots have to navigate around.
  • Beepers:
    • Small, plastic cones at intersections that emit a quiet beeping noise.
    • We place beepers in the world (and remove them) by clicking on the centers of intersections.
    • Robots have a bag they can place beepers into and an arm to pick them up and put them down.
    • There can be more than one beeper on an intersection.
    • Robots can move past beepers easily.
    • Primary tasks for robots: drop, pick up, and generally move beepers around.

Robot Capabilities

• Robots can move forward, turn in place.
• Robots have a TV camera pointing straight ahead that can be used to detect if a wall is blocking the way.
• Robots can hear beepers that are on the same intersection as the robot.
• Robots can tell which direction they are facing.
• Robots have a mechanical arm that can be used to drop and pick up one beeper at a time.
• Robots have a bag to hold beepers; this bag is soundproof so any beepers in it don't confuse the sensors.
• Robots can turn themselves off.

Programming Karel

• The Karel Java programming language is made up of instructions that only robots understand.
  • This is not English; the language has its own syntax and meaning.
• Purpose of programs: solve a task; something we want Karel to do.
  • E.g. move to corner of 4th street and 9th avenue, escape from jail/maze, find a beeper and put it somewhere
  • situation: exact description of Karel's world: wall placement, beeper placement, Karel's position, direction Karel is facing
  • Tasks are usually defined by an initial situation and a final situation.

Simple Instructions

• move(): move forward 1 block
  • Attempting to move into a wall will force Karel to shut off.
• turnLeft(): turn 90 degrees to the left
  • No error shutoff can occur.
  • There is no turnright instruction! How can we make Karel turn right?
• pickBeeper(): pick up a beeper from the current corner and put it in the beeper bag
  • Only one beeper is picked up at a time with this instruction.
  • Trying to pick up a beeper when there's none available causes an error shutoff.
• putBeeper(): take a beeper out of the bag and drop it on the current corner.
  • Again, only one beeper is dropped.
  • Trying to drop a beeper when the bag is empty causes an error shutoff.
• Commands are case sensitive: "dropbeeper" is not the same as "DROPBEEPER".
• turnOff(): Must be used at the end of a program

The Karel World with walls and beepers.