Making Robot




Making Robot

With regard to designing and building a robot as 'an object to think with', I had 'hatched' a plan! Imagine an injured bird finding a way into a shed or garage looking for refuge and feeling frightened in the strange environment. What would it do? After a short brainstorming session with the children, we agreed that the bird would most likely move from the open space to be near a wall. We took this a step further and decided that the bird would feel even safer if it got itself into a corner of the shed.

... And SMART BIRD was hatched.


Smart Bird Hatching!

construct one

A group of children started construction in another room.

We designed the SMART BIRD robot with one sensor (a touch sensor) to allow it to stop on contact with an obstacle - in this case the wall - before continuing its programmed manoeuvre. The touch sensor is employed twice in the program to assist SMART BIRD in finding a safe corner.



construct two

SMART BIRD robot is basic in design. There is a simple chassis on which the RCX and the two motors sit and two medium-sized rear wheels which are appropriate for completing the programmed tasks. SMART BIRD also has a small rounded lego piece which allows the RCX unit to move smoothly over most surfaces. The touch sensor which, when looked at from the front, successfully mimics SMART BIRD'S head including eyes and beak, is placed so as to jut out past the RCX's front surface in order to make first contact with the obstacle. Two short wings were added primarily for aesthetic purposes. They were kept short so as not to hinder the turning movements.


construct three

Would our bird move?

We built and programmed SMART BIRD using a Lego Mindstorms kit with a few extra bricks from my son's toybox! The SMART BIRD program contains one long stack of commands condensed by the use of 2 'MY BLOCKS' , TURN and TURN 2, for the two turning movements.


smart bird front

Et voilà!


smart bird side

Our bird was ready to fly...

...or crawl quietly into a corner.



Smart Bird in Action!

move one

The first portion of the stack commands SMART BIRD to move forward slowly until it reaches the wall in front of it. The touch sensor is the first piece to make contact and is thus activated causing SMART BIRD to stop.


move two


move three

The next sequence of command blocks makes SMART BIRD reverse slightly. The correct balance between motor power and wait time helps to execute this task effectively.

move four

The next section of the command chain (in a My Block called TURN) makes SMART BIRD execute a 90 degree right turn.


move five

The next section of the program is a repeat of the initial forward, stop and reverse requests executed at the beginning of the program.


move six

SMART BIRD'S next turn is effected using a 'My Block' called TURN 2. This time a right turn of approx 135 degrees is required so that SMART BIRD can end up by reversing exactly into the corner. This is achieved by increasing the value on the 'Wait for' small block from the 1.1 seconds used in the 90 degree turn to 1.4 secs for a 135 degree turn.


move seven

The final section of this command stack effects a short reversing movement by SMART BIRD before he comes to a standstill.



The Program

program one

As the program was rather long, I've exploded it into five chunks to enable viewing on one screen. The course of the program is marked out by the white arrows.



program two

Here's the complete program stack minimised.


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