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Subject: 
Re: Robot Ant and Data logging
Newsgroups: 
lugnet.robotics.rcx.robolab
Date: 
Thu, 4 Apr 2002 19:38:45 GMT
Viewed: 
6174 times
  
In lugnet.robotics.rcx.robolab, Mike Reddy writes:
HI,

I am building a robot ant and using a light sensor to detect lines to
follow. However, the algorithm I am using must not be deterministic; i.e. I
need to do a sensor sweep and build a graph of the relative light levels at
the left, front and right of the ant, then to use a weighted probability to
choose the direction - very like real ants with pheremone trails. Is it
possible to do a data log for the light sensor, then have the robot itself
do the calculation to determine the direction, rather than uploading and
post processing with Investigator? I am using a mac and robolab 2.5.

Ideally, I want the robot movement to be autonomous, as I will be using the
IR channel for other communications with different ants, food, nest etc.

Thanks

Hi Mike,

Unfortunately there is no possibility under Robolab 2.5 that the RCX might
itself access the data collected in the log. Robolab 2.5 is based on
LEGO-firmware 2.0, which has many new features, but not this one.

If you want to do your analysis in real time without IR-communication to the
PC, you must deal with the RCX limits, which are:

32 global variables and 16 local variables per task (maximum 10 tasks).

You could for instance use a classical data-reduction technic, which is the
least square polynomial. (We explained the technic at
http://www.convict.lu/Jeunes\Math\least_squares_polynomial.htm .)

You could collect the data in function of the angle of the sweeping
light-sensor - I suppose you use some kind of angle-measurement to know
where the sensor points to -, then compute the different sums. I think a
second degree polynomial function would do the job.

Of course this is again tricky in Robolab with the integer-number limits,
but not impossible.

After all, that kind of problem invites you to change to leJOS!

Claude



Message is in Reply To:
  Robot Ant and Data logging
 
HI, I am building a robot ant and using a light sensor to detect lines to follow. However, the algorithm I am using must not be deterministic; i.e. I need to do a sensor sweep and build a graph of the relative light levels at the left, front and (...) (23 years ago, 4-Apr-02, to lugnet.robotics.rcx.robolab)

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