距离传感器

距离传感器测量它前方第一个物体的距离，单位为米，最远 0.8 m。入门机器人有三个距离传感器：leftDist、frontDist 和 rightDist，分别朝向左方、前方和右方。

读取传感器

Python

from controller import Robot

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

frontDist = robot.getDevice("frontDist")  # Get the sensor by name
frontDist.enable(timeStep)                 # Enable it

while robot.step(timeStep) != -1:
    print("Front:", round(frontDist.getValue(), 3), "m")

C/C++

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

using namespace webots;
using namespace std;

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

  DistanceSensor *frontDist = robot->getDistanceSensor("frontDist"); // Get the sensor by name
  frontDist->enable(timeStep);                                        // Enable it

  while (robot->step(timeStep) != -1)
    cout << "Front: " << frontDist->getValue() << " m" << endl;

  delete robot;
  return 0;
}

寻找墙壁

一个地块宽 12 cm，所以当机器人位于地块中央时，它侧面的墙大约在 5 cm 之外。下面的程序会检查三个传感器，并打印出哪些传感器看到了墙：

Python

from controller import Robot

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

# Keep the sensors in a dictionary, to use them by name
sensors = {}
for name in ["leftDist", "frontDist", "rightDist"]:
    sensors[name] = robot.getDevice(name)
    sensors[name].enable(timeStep)

WALL = 0.07  # Closer than 7 cm counts as a wall next to the robot

while robot.step(timeStep) != -1:
    walls = [name for name, sensor in sensors.items() if sensor.getValue() < WALL]
    print("Walls:", walls)

C/C++

#include <iostream>
#include <string>
#include <vector>
#include <webots/Robot.hpp>
#include <webots/DistanceSensor.hpp>

using namespace webots;
using namespace std;

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

  vector<string> names = {"leftDist", "frontDist", "rightDist"};
  vector<DistanceSensor *> sensors;
  for (const string &name : names) {
    sensors.push_back(robot->getDistanceSensor(name));
    sensors.back()->enable(timeStep);
  }

  const double WALL = 0.07; // Closer than 7 cm counts as a wall next to the robot

  while (robot->step(timeStep) != -1) {
    cout << "Walls:";
    for (size_t i = 0; i < sensors.size(); i++)
      if (sensors[i]->getValue() < WALL)
        cout << " " << names[i];
    cout << endl;
  }

  delete robot;
  return 0;
}

传感器是从它们在机器人上的位置开始测量的，而不是从机器人的中心。把机器人放在墙边打印这些数值，然后选出你自己的阈值。