ethz-asl/kalibr is a toolbox that solves the following calibration problems:
Multiple camera calibration: intrinsic and extrinsic calibration of a camera-systems with non-globally shared overlapping fields of viewCamera-IMU calibration: spatial and temporal calibration of an IMU w.r.t a camera-systemRolling Shutter Camera calibration: full intrinsic calibration (projection, distortion and shutter parameters) of rolling shutter cameras本文以 单目+IMU 和 双目+IMU 为例，讲解使用 Kalibr工具 标定 Camera-IMU，其中使用的摄像头分别为 Realsense ZR300 和 MYNT-EYE S系列摄像头。
注意：本文用于学习kalibr标定过程，文中结果仅供参考。
注意： 采集图像时，帧率控制在4帧左右
单目
rosbag record /camera/fisheye/image_raw -O images.bag双目
rosbag record /stereo/left/image_raw /stereo/right/image_raw -O images.bag单目
kalibr_calibrate_cameras \ --target april_6x6_24x24mm.yaml \ --bag images.bag --bag-from-to 5 20 \ --models pinhole-fov \ --topics /camera/fisheye/image_raw双目
kalibr_calibrate_cameras \ --target april_6x6_24x24mm.yaml \ --bag images.bag --bag-from-to 5 30 \ --models pinhole-radtan pinhole-radtan \ --topics /stereo/left/image_raw /stereo/right/image_raw重投影误差在 0.1~0.2 以内，标定结果较好，如下所示。
单目
sample file output:
cam_overlaps: [] camera_model: pinhole distortion_coeffs: [0.9183540411447179] distortion_model: fov intrinsics: [252.40344712951838, 253.29272771389083, 310.9288373770512, 227.37425906476517] resolution: [640, 480] rostopic: /camera/fisheye/image_raw双目
sample file output:
cam0: cam_overlaps: [1] camera_model: pinhole distortion_coeffs: [0.962084349711143] distortion_model: fov intrinsics: [334.23991339518517, 333.6035571693483, 368.20264278064553, 252.393048692916] resolution: [752, 480] rostopic: /stereo/left/image_raw cam1: T_cn_cnm1: - [0.9999904159643447, 0.0026734233431591698, -0.003467100673890538, -0.1172292375035688] - [-0.002666210133778015, 0.999994275307285, 0.002083428947247444, 0.0001658846059485747] - [0.003472650713385957, -0.002074164960638575, 0.9999918192349059, -0.0002328222935304919] - [0.0, 0.0, 0.0, 1.0] cam_overlaps: [0] camera_model: pinhole distortion_coeffs: [0.9617138563016285] distortion_model: fov intrinsics: [330.66005261900216, 330.07191301082963, 371.03802575515203, 231.03601204806853] resolution: [752, 480] rostopic: /stereo/right/image_rawZR300.launch 文件内容
<launch> <node pkg="imu_utils" type="imu_an" name="imu_an" output="screen"> <param name="imu_topic" type="string" value= "/camera/imu/data_raw"/> <param name="imu_name" type="string" value= "ZR300"/> <param name="data_save_path" type="string" value= "$(find imu_utils)/data/"/> <param name="max_time_min" type="int" value= "80"/> <param name="max_cluster" type="int" value= "100"/> </node> </launch>输出 ZR300_imu_param.yaml，sample file output:
%YAML:1.0 --- type: IMU name: ZR300 Gyr: unit: " rad/s" avg-axis: gyr_n: 2.7878706973951564e-03 gyr_w: 1.6503780396374297e-05 x-axis: gyr_n: 3.2763884944799469e-03 gyr_w: 1.8012497709865783e-05 y-axis: gyr_n: 2.7204386280639753e-03 gyr_w: 1.6637042617714669e-05 z-axis: gyr_n: 2.3667849696415461e-03 gyr_w: 1.4861800861542444e-05 Acc: unit: " m/s^2" avg-axis: acc_n: 2.5172832889483965e-02 acc_w: 4.4150867224248972e-04 x-axis: acc_n: 2.4450765767551903e-02 acc_w: 4.0728821351916671e-04 y-axis: acc_n: 2.1474226370935746e-02 acc_w: 2.1468705215157706e-04 z-axis: acc_n: 2.9593506529964245e-02 acc_w: 7.0255075105672530e-04根据标定结果修改 imu.yaml，其文件内容为
#Accelerometers accelerometer_noise_density: 2.52e-02 #Noise density (continuous-time) accelerometer_random_walk: 4.41e-04 #Bias random walk #Gyroscopes gyroscope_noise_density: 2.78e-03 #Noise density (continuous-time) gyroscope_random_walk: 1.65e-05 #Bias random walk rostopic: /camera/imu/data_raw #the IMU ROS topic update_rate: 200.0 #Hz (for discretization of the values above)单目 + IMU
rosbag record /camera/imu/data_raw /camera/fisheye/image_raw -O images_imu.bag双目 + IMU
rosbag record /camera/imu/data_raw /stereo/left/image_raw /stereo/right/image_raw -O images_imu.bag单目 + IMU
sample file output:
cam0: T_cam_imu: - [0.9996455719455962, 0.02441693761016358, -0.010608659071806014, -0.15423539234968817] - [-0.024769907516072436, 0.9990969029165591, -0.03452289478279192, -0.0032297199459559245] - [0.00975613505470538, 0.03477343440443987, 0.9993476002315277, 0.150153755143352] - [0.0, 0.0, 0.0, 1.0] cam_overlaps: [] camera_model: pinhole distortion_coeffs: [0.9183540411447179] distortion_model: fov intrinsics: [252.40344712951838, 253.29272771389083, 310.9288373770512, 227.37425906476517] resolution: [640, 480] rostopic: /camera/fisheye/image_raw timeshift_cam_imu: 0.7904787918609288双目 + IMU
sample file output:
cam0: T_cam_imu: - [0.0008247496568674628, 0.9999961104998093, -0.002664352314491823, 0.043041669055924436] - [-0.9999929524133787, 0.0008149826348758382, -0.003664822898610003, 0.003376471075594937] - [-0.0036626372434111396, 0.0026673560986662063, 0.9999897350972485, -0.021104195227740437] - [0.0, 0.0, 0.0, 1.0] cam_overlaps: [1] camera_model: pinhole distortion_coeffs: [0.962084349711143] distortion_model: fov intrinsics: [334.23991339518517, 333.6035571693483, 368.20264278064553, 252.393048692916] resolution: [752, 480] rostopic: /stereo/left/image_raw timeshift_cam_imu: 0.00019201226395901445 cam1: T_cam_imu: - [-0.001835964017484093, 0.999979457302906, -0.00614118948676923, -0.07410578385444819] - [-0.9999970575613598, -0.001845664547293735, -0.001574290634432294, 0.003383609126826685] - [-0.001585592869970595, 0.0061382810757381065, 0.9999799034984085, -0.021194379548050524] - [0.0, 0.0, 0.0, 1.0] T_cn_cnm1: - [0.9999904159643451, 0.00267342334315917, -0.003467100673890538, -0.1172292375035688] - [-0.0026662101337780156, 0.9999942753072855, 0.0020834289472474446, 0.0001658846059485747] - [0.003472650713385957, -0.0020741649606385755, 0.9999918192349063, -0.0002328222935304919] - [0.0, 0.0, 0.0, 1.0] cam_overlaps: [0] camera_model: pinhole distortion_coeffs: [0.9617138563016285] distortion_model: fov intrinsics: [330.66005261900216, 330.07191301082963, 371.03802575515203, 231.03601204806853] resolution: [752, 480] rostopic: /stereo/right/image_raw timeshift_cam_imu: 0.0001648708557824339