self.theta = atan2(abs(self.turtlerandom_pose_y - self.turtle1_pose_y),
                               abs(self.turtlerandom_pose_x - self.turtle1_pose_x))

            turtle_velocity_param = Twist()

            turtle_velocity_param.linear.x =  self.distance * cos(self.theta) * 0.05
            turtle_velocity_param.linear.y =  self.distance * sin(self.theta) * 0.05
            turtle_velocity_param.linear.z = 0.0

            turtle_velocity_param.angular.x = 0.0
            turtle_velocity_param.angular.y = 0.0
            turtle_velocity_param.angular.z = 0.0

            self.publish_velocity_create.publish(turtle_velocity_param)

使用该代码的目的，是让乌龟2跟随乌龟1，当乌龟1静止时，乌龟2应该直线跟随，但是该代码是以弧形路径去跟随，旋转到目标乌龟，此旋转是路径，就像螺旋线