ROS CPP: 乌龟三角形编队控制 - 等边三角形编队实现

以下是一个可能的实现：

#include <ros/ros.h>
#include <geometry_msgs/Twist.h>
#include <turtlesim/Pose.h>
#include <cmath>

class TurtleController {
public:
  TurtleController(const std::string& name, double x, double y, double theta)
    : name_(name), x_(x), y_(y), theta_(theta), vx_(0), vy_(0), vtheta_(0)
  {
    ros::NodeHandle nh;
    pose_sub_ = nh.subscribe(name_ + "/pose", 1, &TurtleController::poseCallback, this);
    twist_pub_ = nh.advertise<geometry_msgs::Twist>(name_ + "/cmd_vel", 1);
  }

  void move(double vx, double vy, double vtheta) {
    vx_ = vx;
    vy_ = vy;
    vtheta_ = vtheta;
  }

  void poseCallback(const turtlesim::PoseConstPtr& pose) {
    x_ = pose->x;
    y_ = pose->y;
    theta_ = pose->theta;
  }

  void update() {
    geometry_msgs::Twist twist;
    twist.linear.x = vx_;
    twist.linear.y = vy_;
    twist.linear.z = 0;
    twist.angular.x = 0;
    twist.angular.y = 0;
    twist.angular.z = vtheta_;
    twist_pub_.publish(twist);
  }

  double getX() const { return x_; }
  double getY() const { return y_; }
  double getTheta() const { return theta_; }

private:
  std::string name_;
  double x_;
  double y_;
  double theta_;
  double vx_;
  double vy_;
  double vtheta_;
  ros::Subscriber pose_sub_;
  ros::Publisher twist_pub_;
};

int main(int argc, char** argv) {
  ros::init(argc, argv, "turtle_triangle");
  ros::NodeHandle nh;

  TurtleController turtle_a("turtle_a", 1.0, 1.0, 0.0);
  TurtleController turtle_b("turtle_b", 1.0 + std::cos(M_PI / 3), 1.0 + std::sin(M_PI / 3), -2 * M_PI / 3);
  TurtleController turtle_c("turtle_c", 1.0 + std::cos(M_PI / 3), 1.0 - std::sin(M_PI / 3), 2 * M_PI / 3);

  ros::Rate rate(10);
  while (ros::ok()) {
    double ax = turtle_a.getX();
    double ay = turtle_a.getY();
    double bx = turtle_b.getX();
    double by = turtle_b.getY();
    double cx = turtle_c.getX();
    double cy = turtle_c.getY();

    double ab = std::sqrt(std::pow(bx - ax, 2) + std::pow(by - ay, 2));
    double ac = std::sqrt(std::pow(cx - ax, 2) + std::pow(cy - ay, 2));
    double bc = std::sqrt(std::pow(cx - bx, 2) + std::pow(cy - by, 2));

    double target_ab = 1.0;
    double target_ac = 1.0;
    double target_bc = 1.0;

    double error_ab = target_ab - ab;
    double error_ac = target_ac - ac;
    double error_bc = target_bc - bc;

    double k = 1.0;

    double vx_a = k * error_ab * std::cos(turtle_a.getTheta()) + k * error_ac * std::cos(turtle_a.getTheta() + 2 * M_PI / 3);
    double vy_a = k * error_ab * std::sin(turtle_a.getTheta()) + k * error_ac * std::sin(turtle_a.getTheta() + 2 * M_PI / 3);
    double vtheta_a = 0;

    double vx_b = k * error_bc * std::cos(turtle_b.getTheta()) + k * error_ab * std::cos(turtle_b.getTheta() + 2 * M_PI / 3);
    double vy_b = k * error_bc * std::sin(turtle_b.getTheta()) + k * error_ab * std::sin(turtle_b.getTheta() + 2 * M_PI / 3);
    double vtheta_b = 0;

    double vx_c = k * error_ac * std::cos(turtle_c.getTheta()) + k * error_bc * std::cos(turtle_c.getTheta() + 2 * M_PI / 3);
    double vy_c = k * error_ac * std::sin(turtle_c.getTheta()) + k * error_bc * std::sin(turtle_c.getTheta() + 2 * M_PI / 3);
    double vtheta_c = 0;

    turtle_a.move(vx_a, vy_a, vtheta_a);
    turtle_b.move(vx_b, vy_b, vtheta_b);
    turtle_c.move(vx_c, vy_c, vtheta_c);

    turtle_a.update();
    turtle_b.update();
    turtle_c.update();

    ros::spinOnce();
    rate.sleep();
  }

  return 0;
}

在这个实现中，我们定义了一个TurtleController类来管理每只乌龟的状态和行为。该类包含了一个ROS订阅器来接收乌龟的位姿信息，以及一个ROS发布器来发送速度控制信息。在主函数中，我们创建了三只乌龟A、B、C，并使用三角函数计算它们的初始位置和方向。然后，我们进入一个循环，在每个循环中计算当前三只乌龟与目标等边三角形的距离误差，并根据误差计算每只乌龟的速度。最后，我们将速度信息发布到ROS话题中，并等待下一个循环。注意，为了使三只乌龟始终保持等边三角形的编队，我们在计算速度时使用了两个相位差为120度的正弦函数和余弦函数。