ROS2机器人turtlesim绘制圆形轨迹的Python代码

以下是绘制圆形轨迹的Python代码：

import rclpy
from rclpy.node import Node
from geometry_msgs.msg import Twist
from turtlesim.msg import Pose

class TurtleSimCircle(Node):

    def __init__(self):
        super().__init__('turtle_sim_circle')
        self.publisher_ = self.create_publisher(Twist, 'turtle1/cmd_vel', 10)
        self.subscription = self.create_subscription(Pose, 'turtle1/pose', self.listener_callback, 10)
        self.subscription  # prevent unused variable warning

    def listener_callback(self, msg):
        if msg.theta > :
            angular_speed = -.5
        else:
            angular_speed = .5
        linear_speed = 2
        twist = Twist()
        twist.linear.x = linear_speed
        twist.angular.z = angular_speed
        self.publisher_.publish(twist)

def main(args=None):
    rclpy.init(args=args)

    turtle_sim_circle = TurtleSimCircle()

    rclpy.spin(turtle_sim_circle)

    turtle_sim_circle.destroy_node()
    rclpy.shutdown()

if __name__ == '__main__':
    main()

这段代码可以让ROS2机器人turtlesim绘制圆形轨迹。