<机器人技术创新与实践>课程-Webots自主研习

在进行本课程之前需要先完成：

• 课程说明
• Gazebo仿真篇

Webots是一款功能强大的跨平台机器人仿真软件，在启动并进入镜像之后，单击右侧第二个甲壳虫图标。

下面简要介绍一下该机器人软件的功能。

1. 上方：菜单栏
2. 左侧：场景物品属性
3. 右侧：代码框
4. 下方：调试控制台
5. 中部：三维仿真全景+工具栏

代码可以编译和调试，需要安装对应包，make等。支持Python、C++和Java等。

具备完整稳定的ROS1和ROS2接口。

案例非常豐富。

飛行器系列：

外星探测车系列：

#include <stdio.h>
#include <webots/keyboard.h>
#include <webots/motor.h>
#include <webots/robot.h>

#define TIME_STEP 64
#define VELOCITY 0.6

enum {
  back_left_bogie,
  front_left_bogie,
  front_left_arm,
  back_left_arm,
  front_left_wheel,
  middle_left_wheel,
  back_left_wheel,
  back_right_bogie,
  front_right_bogie,
  front_right_arm,
  back_right_arm,
  front_right_wheel,
  middle_right_wheel,
  back_right_wheel,
  JOINTS_MAX
};

WbDeviceTag joints[JOINTS_MAX];

void move_4_wheels(double v) {
  wb_motor_set_velocity(joints[front_left_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[middle_left_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[back_left_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[front_right_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[middle_right_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[back_right_wheel], v * VELOCITY);

  wb_motor_set_available_torque(joints[middle_right_wheel], 0.0);
  wb_motor_set_available_torque(joints[middle_left_wheel], 0.0);
}

void move_6_wheels(double v) {
  wb_motor_set_available_torque(joints[middle_right_wheel], 2.0);
  wb_motor_set_available_torque(joints[middle_left_wheel], 2.0);

  wb_motor_set_velocity(joints[front_left_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[middle_left_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[back_left_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[front_right_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[middle_right_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[back_right_wheel], v * VELOCITY);
}

void turn_wheels_right() {
  wb_motor_set_position(joints[front_left_arm], 0.4);
  wb_motor_set_position(joints[front_right_arm], 0.227);
  wb_motor_set_position(joints[back_right_arm], -0.227);
  wb_motor_set_position(joints[back_left_arm], -0.4);
}

void turn_wheels_left() {
  wb_motor_set_position(joints[front_left_arm], -0.227);
  wb_motor_set_position(joints[front_right_arm], -0.4);
  wb_motor_set_position(joints[back_right_arm], 0.4);
  wb_motor_set_position(joints[back_left_arm], 0.227);
}

void wheels_straight() {
  wb_motor_set_position(joints[front_left_arm], 0.0);
  wb_motor_set_position(joints[front_right_arm], 0.0);
  wb_motor_set_position(joints[back_right_arm], 0.0);
  wb_motor_set_position(joints[back_left_arm], 0.0);
}

void turn_around(double v) {
  wb_motor_set_position(joints[front_left_arm], -0.87);
  wb_motor_set_position(joints[front_right_arm], 0.87);
  wb_motor_set_position(joints[back_right_arm], -0.87);
  wb_motor_set_position(joints[back_left_arm], 0.87);

  wb_motor_set_velocity(joints[front_left_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[middle_left_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[back_left_wheel], v * VELOCITY);
  wb_motor_set_velocity(joints[front_right_wheel], -v * VELOCITY);
  wb_motor_set_velocity(joints[middle_right_wheel], -v * VELOCITY);
  wb_motor_set_velocity(joints[back_right_wheel], -v * VELOCITY);

  wb_motor_set_available_torque(joints[middle_right_wheel], 0.0);
  wb_motor_set_available_torque(joints[middle_left_wheel], 0.0);
}

int main() {
  // Required to initialize Webots
  wb_robot_init();

  joints[back_left_bogie] = wb_robot_get_device("BackLeftBogie");
  joints[front_left_bogie] = wb_robot_get_device("FrontLeftBogie");
  joints[front_left_arm] = wb_robot_get_device("FrontLeftArm");
  joints[back_left_arm] = wb_robot_get_device("BackLeftArm");
  joints[front_left_wheel] = wb_robot_get_device("FrontLeftWheel");
  joints[middle_left_wheel] = wb_robot_get_device("MiddleLeftWheel");
  joints[back_left_wheel] = wb_robot_get_device("BackLeftWheel");
  joints[back_right_bogie] = wb_robot_get_device("BackRightBogie");
  joints[front_right_bogie] = wb_robot_get_device("FrontRightBogie");
  joints[front_right_arm] = wb_robot_get_device("FrontRightArm");
  joints[back_right_arm] = wb_robot_get_device("BackRightArm");
  joints[front_right_wheel] = wb_robot_get_device("FrontRightWheel");
  joints[middle_right_wheel] = wb_robot_get_device("MiddleRightWheel");
  joints[back_right_wheel] = wb_robot_get_device("BackRightWheel");

  wb_motor_set_position(joints[front_left_wheel], INFINITY);
  wb_motor_set_position(joints[middle_left_wheel], INFINITY);
  wb_motor_set_position(joints[back_left_wheel], INFINITY);
  wb_motor_set_position(joints[front_right_wheel], INFINITY);
  wb_motor_set_position(joints[middle_right_wheel], INFINITY);
  wb_motor_set_position(joints[back_right_wheel], INFINITY);

  printf("Select the 3D window and use the keyboard to drive this robot:\n");
  printf("\n");
  printf("Q: forwards-left;  W: forwards;  E: forwards-right\n");
  printf("S: spin counter-clockwise\n");
  printf("Y: backwards-left; X: backwards; C: backwards-right\n");
  wb_keyboard_enable(TIME_STEP);

  // start moving
  move_6_wheels(1.0);

  while (wb_robot_step(TIME_STEP) != -1) {
    int key = wb_keyboard_get_key();
    switch (key) {
      case 'W':
        // forwards
        wheels_straight();
        move_6_wheels(1.0);
        break;
      case 'X':
        // backwards
        wheels_straight();
        move_6_wheels(-1.0);
        break;
      case 'Q':
        // forwards left
        turn_wheels_left();
        move_4_wheels(1.0);
        break;
      case 'E':
        // forwards right
        turn_wheels_right();
        move_4_wheels(1.0);
        break;
      case 'Y':
        // backwards left
        turn_wheels_left();
        move_4_wheels(-1.0);
        break;
      case 'C':
        // backwards right
        turn_wheels_right();
        move_4_wheels(-1.0);
        break;
      case 'S':
        // spin counter-clockwise
        turn_around(1.0);
        break;
    }
  }

  wb_robot_cleanup();

  return 0;
}

INFO: sojourner: Starting controller: /home/zhangrelay/webots/projects/robots/nasa/controllers/sojourner/sojourner

Select the 3D window and use the keyboard to drive this robot:

Q: forwards-left; W: forwards; E: forwards-right

S: spin counter-clockwise

Y: backwards-left; X: backwards; C: backwards-right

对应代码：

  printf("Select the 3D window and use the keyboard to drive this robot:\n");
  printf("\n");
  printf("Q: forwards-left;  W: forwards;  E: forwards-right\n");
  printf("S: spin counter-clockwise\n");
  printf("Y: backwards-left; X: backwards; C: backwards-right\n");

多多尝试案例，并读懂代码，其他内容后续补充。