Table of Contents

Background Information

What is a Robot?

A robot is simply a machine that seems to exhibit "intelligent behaviour" by performing an action cued by an external stimulus or cued by an internally programmed instruction.

Simple robotic devices can perform jobs based on a set of one or more simple instructions which are input, stored, and followed. A modern pop-up toaster would have seemed extremely "smart" to our ancestors. It seems to "know" how to make perfect toast without human intervention.

Complex and more intelligent robots are programmed to assess external conditions and can modify the event sequence according to whatever external conditions they find. The autopilots found in modern aircraft (and the space shuttle orbiter) are considered extremely intelligent robotic devices.

The Three Primary Categories of Robots and Robotic Devices

1. Directly controlled robotic devices.

   These are the most common type of robots, many of which we come in contact with in our everyday lives. These directly controlled robotic devices are also known as programmable devices since their apparent intelligence is acquired from specific instructions that we program into them. Examples of directly controlled robotic devices include microwave ovens, VCRs, and desktop computers.

2. Semi-autonomous robotic devices.

   These are directly or remotely controlled devices that can make simple decisions. For example, semi-autonomous robotic devices can detect when a problem occurs and then take appropriate action to remedy the problem. Even "smarter"
   semi-autonomous robots can anticipate that a problem is likely to occur (based on its detection and evaluation of current conditions) and then take appropriate action to prevent the problem.

   The sophisticated Canadarm2 is an excellent example of this type of robot. It is sufficiently intelligent that it is capable of avoiding potentially catastrophic actions such as a collision with itself. This sense of "robot-self-protection" allows it to protect itself against accidental operator error.

3. Fully autonomous robotic devices (true robots).

   These robots are capable of assessing all external conditions and formulating appropriate action(s). So far, no robot has been created (except in science fiction) which is fully autonomous in all activities; however, some robots have been designed to exhibit autonomous behaviour in selected tasks.

Activity: "Seeing" Without Eyes

Background

Most robots and robotic devices have no "eyes", and yet many of these robots are able to navigate from one place to another with considerable skill. Without vision, how is this possible?

The answer lies in the robot's ability to translate numbers into a specific location in space. By providing the robot with a set of numbers, called coordinates, the robot will then convert these numbers into specific actions allowing it to move from one position to the next according to the coordinates that it is given.

 

The following activities explore the properties of three-dimensional coordinate space from a robot's point of view.

To do this we will need to build a very simple three-dimensional space-coordinate probe.

Three-Dimensional Space-Coordinate Probe

Equipment

1. 3 pieces of doweling about 1 metre long

2. One small cube of wood about 2 to 3 centimetres on each side.

3. Drill and bit (bigger in diameter than the doweling)

4. Coloured markers

5. Safely goggles ( 1 pair per student)

Assembly

1. Begin with a small cube of soft wood, (such as pine), about 2 to 3 cm on each side.

2. Drill a hole through each face of the cube so that the holes are non-intersecting.

   The holes must be large enough so that a piece of doweling can easily pass through each hole as shown in the photo.

   This cube is called the coordinate marker since its location will be used to define the three coordinates which describe its position (in space).

   

3. The coordinate marker is used with the 3 long dowels.

   Each dowel is to be passed through one of the holes in the cube face.

   The dowels define the direction of each coordinate axis, x, y, and z respectively.

   

4. Mark each dowel, x, y, and z, with a different coloured marker in 10 cm increments.

   

Procedure

1. Engage students in a discussion of what they know about robots - their purpose and how they function. During the course of the discussion help students to recognize the difference between the appearance and function of robots portrayed in science fiction and those used in real-life applications.

   Explain that in this activity they will simulate a robot's ability to move by translating numbers into a specific location in space.

2. Clear a large area on the classroom floor.

3. Ask for a student volunteer "robot". Tell the "robot" that it cannot see, hear, move or think on its own. It can only perform the instructions it has been given.

4. Define a task for the student "robot", e.g. proceed to a chair and pick up a book.

5. Ask students to define the instructions to give the "robot" in order to accomplish the task, e.g. proceed 5 steps forward; turn to the right; proceed two steps forward; lift arm halfway; grasp book etc. Record instructions on the board.

6. Repeat the procedure with different "robot" volunteers using the same instructions each time. Discuss with the students the effectiveness of the instructions with different "robots". Students will notice that different "robots" had different step sizes and made turns of varying degrees. Lead students to the conclusion that standard and precise measurements are needed in order for robots to perform tasks.

7. Explain the function of the prepared coordinate marker, inserting only one piece of dowel at a time. Ask a pair of students to each grasp one end of a piece of dowel in the position of the x axis. Show students that the coordinate marker can move left and right along the x axis. Choose one student to move the marker and ask other students in turn to give instructions for moving the marker. Since students at this age have had limited experience using coordinate systems, e.g. in maps and grids or in simple games such as battleship, in this initial stage, allow students to give instructions in general terms, such as move the marker 4 steps along the blue rod, (i.e. rod with the blue markings).

   

   

   

8. In similar fashion introduce the y axis. Have students give instructions for moving the marker left and right; up and down.

   

   

   

9. Finally introduce the z axis. Have students give instructions for moving the marker left and right; up and down; and forwards and backwards.

   

   

   

10. Explain to students that the rods represent different axis which are identified by x, y, and z and that the steps marked by the three different coloured markings are 10 cm apart. Explain that the origin is identified as (0,0,0) and demonstrate the correct format for identifying the origin on the board.

    

11. Point out a spot on each axis and ask students to accurately describe the location e.g. (70,0,0) or (0,80,0) or (0,0,60).

    

    

    

12. Allow students opportunities for exploration taking turns:

    • holding the ends of the axis,

    • manoeuvring the coordinate marker to locations within (and above) the work space,

    • describing the coordinates of the marker,

    • recording the coordinates on the board.

    

Extension: Finding the Shortest Path

A Robot's Obstacle Course

Background

In the activity that follows, the robot would use the least amount of energy by following the shortest path. This is not always the case. The shortest path is not necessarily the one that requires the least energy. Consider a path from point A to point B which are on opposite sides of a very tall hill. The shorter route involves climbing a hill between the two points. The longer route involves walking around the hill. Discuss with students the energy expenditure for each route.

Procedure

1. Define a start and finish point within the workspace.

2. Place an obstacle in the workspace.

3. Ask students to plan the shortest path between the start and finish points in the workspace while having to navigate around the obstruction.

4. Ask students to record the path, i.e. the series of waypoints used to guide the robot.[A complex journey along a curved path can be simplified by breaking it into a series of straight-line segments each pointing in a different direction. The point at which one segment of the journey ends and a new segment begins is called a waypoint.]

5. Debrief the activity asking students to evaluate whether or not they chose the shortest path between the start and finish points. The group shown in the pictures below decided that they had used more energy than was required because waypoint 1 was further along the y axis than needed in order to clear the obstacle.