从娱乐角度上看已经能够实现地图切换和车辆的控制，但是，仿真环境的车辆在很多方面会与实际车辆不同，传感器的配置就属于这样的不同。
通过carla_ros_bridge_with_example_ego_vehicle.launch创建的Model3车辆模型，默认配置有激光雷达、摄像头、imu、gnss等。
这些传感器信息存放在carla_spawn_objects/config/obects.json
激光雷达默认安装在车顶，位于模型几何中心的。注意，Carla中传感器的安装位置都是相对于这个原点！
{"type": "sensor.lidar.ray_cast","id": "lidar","spawn_point": {"x": 0.0, "y": 0.0, "z": 2.4, "roll": 0.0, "pitch": 0.0, "yaw": 0.0},"range": 50,"channels": 32,"points_per_second": 320000,"upper_fov": 2.0,"lower_fov": -26.8,"rotation_frequency": 20,"noise_stddev": 0.0}
所以，sensor.lidar.ray_cast的安装位置x=0,y=0。我们也可以根据需要增加激光雷达传感器。
{"type": "sensor.lidar.ray_cast","id": "lidar_left","spawn_point": {"x": 2.469, "y": -1.025, "z": 0.8, "roll": 0.0, "pitch": 0.0, "yaw": 0.0},"range": 50,"channels": 32,"points_per_second": 320000,"upper_fov": 23.8,"lower_fov": -2.0,"rotation_frequency": 20,"noise_stddev": 0.0},{"type": "sensor.lidar.ray_cast","id": "lidar_right","spawn_point": {"x": 2.469, "y":1.025, "z": 0.8, "roll": 0.0, "pitch": 0.0, "yaw": 0.0},"range": 50,"channels": 32,"points_per_second": 320000,"upper_fov": 23.8,"lower_fov": -2.0,"rotation_frequency": 20,"noise_stddev": 0.0},
设置好安装位置的xyz参数，还有雷达的线数、fov等参数
新增加的传感器大概就在途中黑色圆圈中。
这个为确认是一个大坑，前面也介绍了车辆传感器的安装原点是车辆的几何中心！
{"type": "sensor.other.gnss","id": "gnss","spawn_point": {"x": 1.0, "y": 0.0, "z": 2.0},"noise_alt_stddev": 0.0, "noise_lat_stddev": 0.0, "noise_lon_stddev": 0.0,"noise_alt_bias": 0.0, "noise_lat_bias": 0.0, "noise_lon_bias": 0.0},{"type": "sensor.other.imu","id": "imu","spawn_point": {"x": 2.0, "y": 0.0, "z": 2.0, "roll": 0.0, "pitch": 0.0, "yaw": 0.0},"noise_accel_stddev_x": 0.0, "noise_accel_stddev_y": 0.0, "noise_accel_stddev_z": 0.0,"noise_gyro_stddev_x": 0.0, "noise_gyro_stddev_y": 0.0, "noise_gyro_stddev_z": 0.0,"noise_gyro_bias_x": 0.0, "noise_gyro_bias_y": 0.0, "noise_gyro_bias_z": 0.0},
这是默认的gnss和imu传感器的安装位置，并且还能支持噪声模拟……但是，是车上这个位置都是被映射到车辆后轴中心点！
{"type": "sensor.other.gnss","id": "gnss","spawn_point": {"x": -1.369, "y": 0.0, "z": 2.0},"noise_alt_stddev": 0.0, "noise_lat_stddev": 0.0, "noise_lon_stddev": 0.0,"noise_alt_bias": 0.0, "noise_lat_bias": 0.0, "noise_lon_bias": 0.0},{"type": "sensor.other.imu","id": "imu","spawn_point": {"x": -1.369, "y": 0.0, "z": 2.0, "roll": 0.0, "pitch": 0.0, "yaw": 0.0},"noise_accel_stddev_x": 0.0, "noise_accel_stddev_y": 0.0, "noise_accel_stddev_z": 0.0,"noise_gyro_stddev_x": 0.0, "noise_gyro_stddev_y": 0.0, "noise_gyro_stddev_z": 0.0,"noise_gyro_bias_x": 0.0, "noise_gyro_bias_y": 0.0, "noise_gyro_bias_z": 0.0},
如果不将传感器的位置映射到车辆后轴中心，当自动驾驶程序运行起来，Carla中的ego的轨迹跟踪效果就变差了！
欢迎关注
古德曼那汽车工业
