IUT Microbot Team got the first place among 90
teams, Participated in Class A
Weight : 1950 gr
Total mines found : 15 of 15
Time record for
complete pitch Scanning : 3min & 36sec
Total Score : 2730.1
Looking for Peace and Safety.
International Mine Detector Robots Competition (RoboDeminer Contest 2002) held in AmirKabir University of Technology (Tehran Polytechnic) with
sponsorship of United Nations.
A brief description about the
Deminer robot is as below :
This robot is designed to participate in levels A, B and C of the match.
So it must have the ability that can distinguish both kinds of mines A and B. Therefore, the output of designed sensor system has two different levels for
both kinds of mines.
In the class A of the match, the output of sensor system is used at level1,In the class B of the match ,there is the output of Sensor System at level2,
and in the class C of the match, both levels(1 and 2) are used.
The job of the sensor system which is used for distinguishing mines, relates to
Induction Detection method. The quality and the Care of this method to detect
mines is much better than the other usual methods . (like IB detection or BFO
Pulse induction works by means of a pulse with special frequency which switches
alternatively the coil
Current on and off. At the Negative edge of the pulse ,the input current of
coil is cut. But according to the Lens rule ,a current in the coil,
an extra additional voltage is appeared. but this long extra voltage is not
lasting ,and it will be damped soon.
During this time, the next pulse shouldn't be produced.
By the way, the decreasing steep of the negative
voltage exactly depends on the surrounding around of the coil. It means that the
steep of this curve
at presence of a ferrous material differs with the metal absence. So , with
comparison between these steeps ,it is possible to know that
there would be a metal. Here for showing the steep , in different and exact
times, we take samples from produced voltage on the coil, then extract the
In this way ,it distinct mines. Sensor system block diagram is as below:
Navigation System in this robot depend on Image Processing. By this way ,the
robot situation is extracted using the output of the
camera situated above the pitch, and it is connected to the computer by Grabber
Card. In addition ,to robot situation (Coordination in X-Y
Plane) ,the robot movement speed and the direction is calculated, too.
The software written in Borland Delphi, processes the camera output and
chooses the path and
direction. Then the movement signals for robot is prepared.
These codes are sent to robot In this way : the codes are sent to LPT port of
a 89c51 microcontroller passes the codes to the radio communication channel.
the microcontroller's main tasks are Error checking and parallel to serial
By the way ,the robot will move.
But this movement must be under control, exactly. So PID controller is used
to improve the quality of Navigation. It tries to reduce the Coordination-Error
and Robot's Angle-Error. (according to the differences between chosen direction
, calculated by the computer, and the real motion direction).
Robot's hardware includes the mechanical system and electronic boards. the
mechanical system will
be explained next. Electronic blocks are as below:
-Communication system (Two half-duplex channels which work in multiplexed mode)
-Robot Power supply (A separate battery from out )
The software is written in Delphi and includes 3 main Parts:
1-Image processing section ,in fact ,Plays the role of the robot localization
in the pitch .
Some color markers are on the robot .In this way the robot can be found on the
screen. For finding this special pattern ,Edge Detection and Segmentation
are used. Furthermore , Processing on RGB anf HSV format.
2-Thread of sending and receiving information which connects robot on-line to
computer.It's duty is sending motion orders and receiving special code related to the
3- Result Section and it extracts the mines location exactly , using the matrix
calculations and solving some probabilities
and statistic equations.
While the program is running ,the Receive part (in I/O Thread), fills a
200*200 matrix in memory.
This part of the program divides this large matrix into 400 smaller sub-matrixes,
each of them is
a 10*10 one. After Some possible calculations , a certain number is replaced
instead each sub-matrix. Finally,
we have a pure 20*20 matrix for the map (the matrix's dimensions can easily be
extended), that has the necessary care. At last ,with the usage of this result
it generates a map including the types of distinguished mines, mines
specification, and number of the total mines. And then it will be graphically
This uses two separate DC motors and two suitable Gearboxes. Its motion system
works in Differential Drive mode.
This means that two left and right motors are separately controlled by the
The robot's weight is 1950 gr considering battery packs.
New methods used in our design that increases the robot efficiency:
- The use of Productive methods of localization and Global Positioning in robot
- The independent Image processing to surrounding. (light , distance, pitch
dimensions, motion and color changes)
- Pulse induction Detection for scanning the pitch for mines.