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I need some help and don't know more where look :/

e14 Contributor

Hello Guys,

 

First I isn't be a good writer on English Language but a will try my best for you help me.

 

I'm using a QTR-8A on a Robot but a I need do this with him...

Following a Line and Line Breaks...

 

This is my program for follow line:

 

<code>

#include <DualVNH5019MotorShield.h>

#include <QTRSensors.h>

 

 

DualVNH5019MotorShield md; //declaracao dos pinos dos motores

QTRSensorsAnalog qtr((unsigned char[]) {0, 1, 2, 3, 4, 5, 6, 7}, 8); // declaracao sensores analogicos

 

 

unsigned int sensors[8]; //diz quantos sensores tem utilizados

 

 

const float KP = 0.1; // potencial

const float KD = 5.0; // derivado

 

 

int last_error = 0; // erro

 

 

const int M1 = 200; // velocidade 1

const int M2 = 200; // velocidade 2

 

 

void setup() {

  md.init();

  md.setSpeeds(200, -200);

  for (int i = 0; i < 250; i++) {

    qtr.calibrate();

    delay(20); // rotina de calibracao 1

  }

  md.setSpeeds(-200, 200);

  for (int i = 0; i < 250; i++) {

    qtr.calibrate();

    delay(20); // rotina de calibracao 2

  }

}

 

 

void loop() {

  int position = qtr.readLine(sensors);

  int error = position - 1000;

  int motor_speed = (int)(KP * error + KD * (error - last_error));

 

  last_error = error;

  int m1_speed = M1 + motor_speed;

  int m2_speed = M2 - motor_speed;

  m1_speed = constrain(m1_speed, 0, 400);

  m2_speed = constrain(m2_speed, 0, 400);

  md.setSpeeds(m1_speed, m2_speed);

}

</code>

 

But I don't know how I do for him pass the Break Line !.

Help me guys please !

  • 0

    Olá Luis Henrique,

     

    I suppose you mean dashed line when say break, am I rigth?

    If yes, and you have your robot working following a normail line. What you can do is,  when no line is read you go straight (same speed on both motor) for a very short time (ms) and read the sensor again, because of the robot is going straight and the width of the sensor is bigger than the width of the lines, probably you will have no problem, despite of this, just make 3 or 4 tempts in order not make the robot go out of the route.other optionis when the robot cannot sense the lines, go straight until it senses a line again, and you can use a timer for do it just for a while, in order not to take the robot out of the route.

     

    Hope it helps, let me know your progress on it.

     

    Regards,

    Miguel

  • 0

          From
    http://www.pololu.com/docs/0J19/all


    void     loop()
    {
      unsigned int sensors[3];
      // get calibrated sensor values returned in the sensors array, along with the line position
      // position will range from 0 to 2000, with 1000 corresponding to the line over the middle sensor
      int position = qtr.readLine(sensors);

      // if all three sensors see very low reflectance, take some appropriate action for this situation
      if (sensors[0] > 750 && sensors[1] > 750 && sensors[2] > 750)
      {
        // do something.  Maybe this means we're at the edge of a course or about to fall off a table,
        // in which case, we might want to stop moving, back up, and turn around.
        return;
      }

      // compute our "error" from the line position.  We will make it so that the error is zero when
      // the middle sensor is over the line, because this is our goal.  Error will range from
      // -1000 to +1000.  If we have sensor 0 on the left and sensor 2 on the right,  a reading of -1000
      // means that we see the line on the left and a reading of +1000 means we see the line on
      // the right.
      int error = position - 1000;

      int leftMotorSpeed = 100;
      int rightMotorSpeed = 100

    --
    William Alan Thomas Bottger
    "Meaning, Reduction, Recursion"
    Mathgomery, AL

    Play along with me at the
    Rebel Matrix Math challenge
    http://mathcontest.olemiss.edu/
       .
        .
    On the other hand ===>>

      // if all three sensors see very HIGH reflectance, take some appropriate action for this situation

      if (sensors[0] < 100 && sensors[1]  < 100 && sensors[2]< 100)

      {

        // do something.  Maybe this means the robot has found a break in the line

        // in which case, we might want to move straight ahead for a reasonable distance, before travelling along a curved (know circlular arc of fixed radius) path to the unknown line or the original line and having measured the distance traveled know the difference.

        return;

      }