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Robocup Rescue 2003 Robocup Rescue 2002 Deminer Robocont Intelligent Mouse Router, Maze solver & Finder
 
RoboDeminer

    IUT Microbot Team got the first place among 90 teams, Participated in Class A

  Specifications :

  
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.

The First International Mine Detector Robots Competition (RoboDeminer Contest 2002) held in AmirKabir University of Technology (Tehran Polytechnic) with the sponsorship of United Nations.

      A brief description about the Deminer robot is as below :

Detector:

     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 Pulse 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 detection)
      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 voltage diagram. In this way ,it distinct mines. Sensor system block diagram is as below:

Navigation:

      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 computer then a 89c51 microcontroller passes the codes to the radio communication channel. the microcontroller's main tasks are Error checking and parallel to serial conversion.
      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).

Hardware:

      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)
      -Microcontroller
      -motor Drive-
      -Robot Power supply (A separate battery from out )
      -sensor system.

Software:

      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 found mine.

      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, that 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 matrix, it generates a map including the types of distinguished mines, mines specification, and number of the total mines. And then it will be graphically printed.

 

Mechanical structure:

      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 motor driver. The robot's weight is 1950 gr considering battery packs.

Invention:

      New methods used in our design that increases the robot efficiency:
      - The use of Productive methods of localization and Global Positioning in robot navigation.
      - The independent Image processing to surrounding. (light , distance, pitch dimensions, motion and color changes)
      - Pulse induction Detection for scanning the pitch for mines.