Robô SCARA | Como construir seu próprio robô baseado em Arduino

Visão geral

Modelo 3D do robô SCARA

Impressão 3D das peças do robô

Montando o robô

• 4x haste de haste lisa – 10mm 400mm……… Amazon / Banggood / AliExpress
• 1x Parafuso de avanço – 8mm 400mm  ………………… Amazon / Banggood / AliExpress
• 4x rolamentos lineares 10mm ……………………..……. Amazônia / Banggood / AliExpress
• 1x rolamento de esferas axiais 40x60x13mm   …..… Amazon / AliExpress
• 2x rolamento de esferas axiais 35x52x12mm   …..… Amazon / AliExpress
• 5x rolamento de esferas radial 8x22x7mm ……………. Amazônia / Banggood / AliExpress
• Vários comprimentos de parafusos e porcas M3, M4 e M5

Diagrama de circuito do robô SCARA

• Motor de passo – NEMA 17……………… 
• Driver de passo A4988…………………..… 
• Arduino CNC Shield ………………………. Amazônia / Banggood / AliExpress
• Arduino Uno…………………………………..… 
• Servomotor MG996R………………….….
• Interruptor de limite ……………………………………. Amazônia / Banggood / AliExpress
• Fonte de alimentação CC ……………………………. Amazônia  / Banggood / AliExpress

Finalizando a montagem

Como funciona o robô SCARA

Programação do robô SCARA – Arduino e código de processamento

// FORWARD KINEMATICS
void forwardKinematics() {
  float theta1F = theta1 * PI / 180;   // degrees to radians
  float theta2F = theta2 * PI / 180;
  xP = round(L1 * cos(theta1F) + L2 * cos(theta1F + theta2F));
  yP = round(L1 * sin(theta1F) + L2 * sin(theta1F + theta2F));
}Code language: Arduino (arduino)

/ INVERSE KINEMATICS
void inverseKinematics(float x, float y) {
  theta2 = acos((sq(x) + sq(y) - sq(L1) - sq(L2)) / (2 * L1 * L2));
  if (x < 0 & y < 0) {
    theta2 = (-1) * theta2;
  }
  
  theta1 = atan(x / y) - atan((L2 * sin(theta2)) / (L1 + L2 * cos(theta2)));
  
  theta2 = (-1) * theta2 * 180 / PI;
  theta1 = theta1 * 180 / PI;

 // Angles adjustment depending in which quadrant the final tool coordinate x,y is
  if (x >= 0 & y >= 0) {       // 1st quadrant
    theta1 = 90 - theta1;
  }
  if (x < 0 & y > 0) {       // 2nd quadrant
    theta1 = 90 - theta1;
  }
  if (x < 0 & y < 0) {       // 3d quadrant
    theta1 = 270 - theta1;
    phi = 270 - theta1 - theta2;
    phi = (-1) * phi;
  }
  if (x > 0 & y < 0) {       // 4th quadrant
    theta1 = -90 - theta1;
  }
  if (x < 0 & y == 0) {
    theta1 = 270 + theta1;
  }
  
  // Calculate "phi" angle so gripper is parallel to the X axis
  phi = 90 + theta1 + theta2;
  phi = (-1) * phi;

  // Angle adjustment depending in which quadrant the final tool coordinate x,y is
  if (x < 0 & y < 0) {       // 3d quadrant
    phi = 270 - theta1 - theta2;
  }
  if (abs(phi) > 165) {
    phi = 180 + phi;
  }

  theta1=round(theta1);
  theta2=round(theta2);
  phi=round(phi);
  
  cp5.getController("j1Slider").setValue(theta1);
  cp5.getController("j2Slider").setValue(theta2);
  cp5.getController("j3Slider").setValue(phi);
  cp5.getController("zSlider").setValue(zP);
}Code language: Arduino (arduino)

if (gripperValuePrevious != gripperValue) {
    if (activeIK == false) {     // Check whether the inverseKinematics mode is active, Executre Forward kinematics only if inverseKinematics mode is off or false
      gripperAdd = round(cp5.getController("gripperValue").getValue());
      gripperValue=gripperAdd+50;
      updateData();
      println(data);
      myPort.write(data);
    }
  }Code language: Arduino (arduino)

public void updateData() {
  data = str(saveStatus)
    +","+str(runStatus)
    +","+str(round(cp5.getController("j1Slider").getValue())) 
    +","+str(round(cp5.getController("j2Slider").getValue()))
    +","+str(round(cp5.getController("j3Slider").getValue()))
    +","+str(round(cp5.getController("zSlider").getValue()))
    +","+str(gripperValue)
    +","+str(speedSlider)
    +","+str(accelerationSlider);
}Code language: Arduino (arduino)

if (Serial.available()) {
    content = Serial.readString(); // Read the incomding data from Processing
    // Extract the data from the string and put into separate integer variables (data[] array)
    for (int i = 0; i < 10; i++) {
      int index = content.indexOf(","); // locate the first ","
      data[i] = atol(content.substring(0, index).c_str()); //Extract the number from start to the ","
      content = content.substring(index + 1); //Remove the number from the string
    }
    /*
     data[0] - SAVE button status
     data[1] - RUN button status
     data[2] - Joint 1 angle
     data[3] - Joint 2 angle
     data[4] - Joint 3 angle
     data[5] - Z position
     data[6] - Gripper value
     data[7] - Speed value
     data[8] - Acceleration value
    */Code language: Arduino (arduino)

// If SAVE button is pressed, store the data into the appropriate arrays
    if (data[0] == 1) {
      theta1Array[positionsCounter] = data[2] * theta1AngleToSteps; //store the values in steps = angles * angleToSteps variable
      theta2Array[positionsCounter] = data[3] * theta2AngleToSteps;
      phiArray[positionsCounter] = data[4] * phiAngleToSteps;
      zArray[positionsCounter] = data[5] * zDistanceToSteps;
      gripperArray[positionsCounter] = data[6];
      positionsCounter++;
    }Code language: Arduino (arduino)

stepper1.moveTo(stepper1Position);
  stepper2.moveTo(stepper2Position);
  stepper3.moveTo(stepper3Position);
  stepper4.moveTo(stepper4Position);

  while (stepper1.currentPosition() != stepper1Position || stepper2.currentPosition() != stepper2Position || stepper3.currentPosition() != stepper3Position || stepper4.currentPosition() != stepper4Position) {
    stepper1.run();
    stepper2.run();
    stepper3.run();
    stepper4.run();
  }Code language: Arduino (arduino)

Wrap up