1️⃣Camera Sensor

import cv2
import rospy
import numpy as np

from sensor_msgs.msg import Image
from cv_bridge import CvBridge

bridge = CvBridge()
cv_image = np.empty(shape=[0])

def img_callback(self, data):
		global cv_image
		cv_image = bridge.imgmsg_to_cv2(data, "bgr8")

rospy.Subscriber("/usb_cam/image_raw/", Image, img_callback)
<launch>
	<include file="$(find usb_cam)/launch/xycar_cam.launch" />
</launch>
<launch>
	<include file="$(find usb_cam)/launch/xycar_cam.launch" />
		<param name="/usb_cam/exposure" value="30" /> #노출값 조정 부분
</launch>

2️⃣Lidar Sensor

rospy.Subscriber("/scan", LaserScan, lidar_callback, queue_size=1)

def lidar_callback():
<launch>
  <include file="$(find xycar_lidar)/launch/xycar_lidar.launch" />
</launch>

3️⃣Ultrasonic Sensor