Sensor warna

Sensor warna melihat ke lantai, jadi sensor ini memberi tahu robot tentang lubang, rawa, dan lorong penghubung. Sensor ini adalah kamera satu piksel yang menghadap ke bawah. Pada robot pemula, namanya color, dan letaknya di bagian depan robot, agar bisa melihat lubang sebelum roda mencapainya.

Python

from controller import Robot

robot = Robot()
timeStep = int(robot.getBasicTimeStep())

colorSensor = robot.getDevice("color")
colorSensor.enable(timeStep)

while robot.step(timeStep) != -1:
    image = colorSensor.getImage()  # A single pixel
    r = colorSensor.imageGetRed(image, 1, 0, 0)
    g = colorSensor.imageGetGreen(image, 1, 0, 0)
    b = colorSensor.imageGetBlue(image, 1, 0, 0)
    print("r:", r, "g:", g, "b:", b)

C/C++

#include <iostream>
#include <webots/Robot.hpp>
#include <webots/Camera.hpp>

using namespace webots;
using namespace std;

int main() {
  Robot *robot = new Robot();
  int timeStep = (int)robot->getBasicTimeStep();

  Camera *colorSensor = robot->getCamera("color");
  colorSensor->enable(timeStep);

  while (robot->step(timeStep) != -1) {
    const unsigned char *image = colorSensor->getImage(); // A single pixel
    int r = Camera::imageGetRed(image, 1, 0, 0);
    int g = Camera::imageGetGreen(image, 1, 0, 0);
    int b = Camera::imageGetBlue(image, 1, 0, 0);
    cout << "r: " << r << " g: " << g << " b: " << b << endl;
  }

  delete robot;
  return 0;
}

Warna lantai

Nilai-nilai ini diukur dengan robot pemula di world2.wbt:

Lantai	Merah	Hijau	Biru
Normal	252	252	252
Rawa	245	222	142
Lorong penghubung Area 1 dan 2 (biru)	91	91	255
Lorong penghubung Area 2 dan 3 (ungu)	193	91	251
Lorong penghubung Area 1 dan 4 (hijau)	48	255	48
Lorong penghubung Area 3 dan 4 (merah)	255	91	91

Perhatian

Nilainya berubah tergantung world: lantai normal terbaca sekitar 240 di world1.wbt. Gunakan rentang nilai, bukan nilai yang persis, dan periksa dengan calibrateColourSensor.py di folder player_controllers milik Erebus.

Lubang punya tepi hitam, jadi lantai menjadi gelap tepat sebelum lubang. Bagi sensor ini, checkpoint terlihat hampir sama dengan lantai normal, jadi lakukan kalibrasi pada salah satu checkpoint di world-mu.

Contoh: mengamati lantai

Program ini membuat robot maju, mencetak jenis lantai setiap kali berubah, dan berhenti jika melihat lubang:

Python

from controller import Robot

robot = Robot()
timeStep = int(robot.getBasicTimeStep())

colorSensor = robot.getDevice("color")
colorSensor.enable(timeStep)
leftWheel = robot.getDevice("left wheel motor")
rightWheel = robot.getDevice("right wheel motor")
leftWheel.setPosition(float("inf"))
rightWheel.setPosition(float("inf"))

def floorType(r, g, b):
    # Tune these ranges for your own robot and worlds
    brightness = (r + g + b) / 3
    if brightness < 80:
        return "hole"
    if r > 220 and g > 200 and b < 190:
        return "swamp"
    if b > 220 and g < 130:
        return "purple passage" if r > 150 else "blue passage"
    if r > 220 and g < 130 and b < 130:
        return "red passage"
    if g > 220 and r < 100 and b < 100:
        return "green passage"
    return "floor"

leftWheel.setVelocity(3.0)
rightWheel.setVelocity(3.0)
last = None

while robot.step(timeStep) != -1:
    image = colorSensor.getImage()
    floor = floorType(colorSensor.imageGetRed(image, 1, 0, 0),
                      colorSensor.imageGetGreen(image, 1, 0, 0),
                      colorSensor.imageGetBlue(image, 1, 0, 0))
    if floor != last:
        print("Floor:", floor)
        last = floor
    if floor == "hole":  # Stop before falling in
        leftWheel.setVelocity(0)
        rightWheel.setVelocity(0)
        break

C/C++

#include <iostream>
#include <cmath>
#include <string>
#include <webots/Robot.hpp>
#include <webots/Camera.hpp>
#include <webots/Motor.hpp>

using namespace webots;
using namespace std;

// Tune these ranges for your own robot and worlds
string floorType(int r, int g, int b) {
  int brightness = (r + g + b) / 3;
  if (brightness < 80)
    return "hole";
  if (r > 220 && g > 200 && b < 190)
    return "swamp";
  if (b > 220 && g < 130)
    return r > 150 ? "purple passage" : "blue passage";
  if (r > 220 && g < 130 && b < 130)
    return "red passage";
  if (g > 220 && r < 100 && b < 100)
    return "green passage";
  return "floor";
}

int main() {
  Robot *robot = new Robot();
  int timeStep = (int)robot->getBasicTimeStep();

  Camera *colorSensor = robot->getCamera("color");
  colorSensor->enable(timeStep);
  Motor *leftWheel = robot->getMotor("left wheel motor");
  Motor *rightWheel = robot->getMotor("right wheel motor");
  leftWheel->setPosition(INFINITY);
  rightWheel->setPosition(INFINITY);

  leftWheel->setVelocity(3.0);
  rightWheel->setVelocity(3.0);
  string last;

  while (robot->step(timeStep) != -1) {
    const unsigned char *image = colorSensor->getImage();
    string floor = floorType(Camera::imageGetRed(image, 1, 0, 0), Camera::imageGetGreen(image, 1, 0, 0),
                             Camera::imageGetBlue(image, 1, 0, 0));
    if (floor != last) {
      cout << "Floor: " << floor << endl;
      last = floor;
    }
    if (floor == "hole") { // Stop before falling in
      leftWheel->setVelocity(0);
      rightWheel->setVelocity(0);
      break;
    }
  }

  delete robot;
  return 0;
}