ros用python让turtlesim画出一个五角星的轨迹的程序

可以使用以下Python代码来在ROS的turtlesim中画出五角星的轨迹：

#!/usr/bin/env python

import rospy
from geometry_msgs.msg import Twist
from math import pi

def draw_star():
    # 初始化ROS节点
    rospy.init_node('draw_star_node', anonymous=True)
    
    # 创建Publisher发布控制小海龟的命令
    turtle_vel_pub = rospy.Publisher('/turtle1/cmd_vel', Twist, queue_size=10)
    
    # 设置绘制五角星的线速度和角速度
    line_speed = 1
    angle_speed = 1
    
    # 使小海龟逆时针旋转36度
    angular_speed = angle_speed*pi/180
    relative_angle = 36*pi/180
    turn_time = relative_angle/angular_speed
    vel_msg = Twist()
    vel_msg.angular.z = abs(angular_speed)
    t0 = rospy.Time.now().to_sec()
    while (rospy.Time.now().to_sec() - t0) < turn_time:
        turtle_vel_pub.publish(vel_msg)

    # 绘制五角星的每一条边
    vel_msg.linear.x = line_speed
    side_length = 2
    for i in range(5):
        # 使小海龟移动一段距离
        distance = side_length
        time = distance/line_speed
        t0 = rospy.Time.now().to_sec()
        while (rospy.Time.now().to_sec() - t0) < time:
            turtle_vel_pub.publish(vel_msg)
        
        # 使小海龟逆时针旋转72度
        angular_speed = angle_speed*pi/180
        relative_angle = 72*pi/180
        turn_time = relative_angle/angular_speed
        vel_msg.angular.z = abs(angular_speed)
        t0 = rospy.Time.now().to_sec()
        while (rospy.Time.now().to_sec() - t0) < turn_time:
            turtle_vel_pub.publish(vel_msg)

    # 停止海龟
    vel_msg.linear.x = 0
    vel_msg.angular.z = 0
    turtle_vel_pub.publish(vel_msg)
    
    # 关闭ROS节点
    rospy.spin()

if __name__ == '__main__':
    try:
        draw_star()
    except rospy.ROSInterruptException:
        pass

这个程序会使turtlesim画出一个边长为2的五角星。其实现原理是通过通过发布Twist消息来控制小海龟进行顺时针和逆时针旋转、直线移动等操作，从而达到绘制五角星的目的。请注意，为了避免与子弹问题相关的困难，海龟的移动将被禁止（速度将被设置为0），以避免过快运动会扰乱五角星的形状。