If you can't understand LaserRangeFinder come in(Just to newer,Thanks to Paul)

• General discussion

• Many people use Microsoft Robotic Studio just to understand how robots works,or how to make a program to control a robot in the attracted simulation environment.Sometimes they don’t have a “real” robot,I am one of them.

So it may be hard to understand how the robot works,especially sensors on robot(like contact or LRF sensor).I post my question on this form,many warm-heart and kind people helped me(like Paul,thanks you a lot).Now I think I have understood how LRF works,so I share it to many green-hand hope it helps :-D

In the LRF sensor.it return a value of an int-type array named DistanceMeasurements.If you don’t do any change to it,it updatas 5 time per second.The index of it from 0 to n (n = DistanceMeasurements.Length).0 Means the most right side. n means the most left side.it clearly that n/2 means the forward of the bot.To present clearly,I “draw” the following picture:

-90 to -22.5 degrees - referred to as "Right"

-22.5 to 22.5 degrees - referred to as "Center" (a 45 degree arc centered on the direction the robot is facing)

22.5 to 90 degrees - referred to as "Left"

Code Snippet
Centre
_,,.-/-.,,,
,-'`     |     `'-,
_,'         |         ``.          .
`.    ,-            |            ',      .`
', /              |              \   .`
.',              |PI/2           .-`
/   `.            |             .`  \
/      `.          |           .`     \   Right
Left     /         `.        |         .`        ,
|           `.      |       .`          |
|              `.    |     .`             |
|                `.  |   .`               |
|                   `.| .`                  |
PI-----------------------------\`---------------------------- 0

DistanceMeasurements:
n------------------------------n/2---------------------------0

So in the program,we define these variables:

Offset,Limit : The right and left range of once check.

Increment : It’s easy to understand,like “delta”.

Best : Now smallest num found in once scan.

Name : Partition different type of scan.

In the program robot compare 3 different variables : Left,Right,Centre,if a obstacle in the forward of this robot,he should turn to left or right side(lie on their values).

Hope it helps

Tan Wangda.

Sunday, June 10, 2007 12:36 AM