/**:
    ros__parameters:
        common:
            lid_topic: "/unilidar/cloud" 
            imu_topic: "/unilidar/imu" 
            con_frame: false # true: if you need to combine several LiDAR frames into one
            con_frame_num: 1 # the number of frames combined
            cut_frame: false # true: if you need to cut one LiDAR frame into several subframes
            cut_frame_time_interval: 0.2 # should be integral fraction of 1 / LiDAR frequency
            time_lag_imu_to_lidar: 0.0 # Time offset between LiDAR and IMU calibrated by other algorithms, e.g., LI-Init (find in Readme)
                                        # the timesample of IMU is transferred from the current timeline to LiDAR's timeline by subtracting this value

        preprocess:
            lidar_type: 5
            scan_line: 18
            timestamp_unit: 0           # the unit of time/t field in the PointCloud2 rostopic: 0-second, 1-milisecond, 2-microsecond, 3-nanosecond.
            blind: 1.0

        mapping:
            imu_en: true
            start_in_aggressive_motion: false # if true, a preknown gravity should be provided in following gravity_init
            extrinsic_est_en: false # for aggressive motion, set this variable false
            imu_time_inte: 0.005 # = 1 / frequency of IMU
            satu_acc: 30.0 # the saturation value of IMU's acceleration. not related to the units
            satu_gyro: 35.0 # the saturation value of IMU's angular velocity. not related to the units
            acc_norm: 9.81 # 1.0 for g as unit, 9.81 for m/s^2 as unit of the IMU's acceleration
            lidar_meas_cov: 0.05
            acc_cov_output: 500.0
            gyr_cov_output: 1000.0
            b_acc_cov: 0.0001 
            b_gyr_cov: 0.0001 
            imu_meas_acc_cov: 0.2
            imu_meas_omg_cov: 0.2
            gyr_cov_input: 0.05
            acc_cov_input: 0.2
            plane_thr: 0.2 # 0.05, the threshold for plane criteria, the smaller, the flatter a plane
            match_s: 50.0
            fov_degree: 180.0
            det_range: 20.0
            gravity_align: true # true to align the z axis of world frame with the direction of gravity, and the gravity direction should be specified below
            gravity: [0.0, 0.0, -9.810] # [0.0, 9.810, 0.0] # gravity to be aligned
            gravity_init: [0.0, 0.0, -9.810] # [0.0, 9.810, 0.0] # # preknown gravity in the first IMU body frame, use when imu_en is false or start from a non-stationary state
            
            # transform from imu to lidar
            extrinsic_T: [ 0.007698, 0.014655, -0.00667] # ulhk # [-0.5, 1.4, 1.5] # utbm
            extrinsic_R: [ 1.0, 0.0, 0.0,
                          0.0, 1.0, 0.0,
                          0.0, 0.0, 1.0 ] # ulhk 4 utbm 3

        odometry: 
            publish_odometry_without_downsample: false

        publish:
            path_en: true                 # false: close the path output
            scan_publish_en: true         # false: close all the point cloud output
            scan_bodyframe_pub_en: false  # true: output the point cloud scans in IMU-body-frame

        pcd_save:
            pcd_save_en: true       # save map to pcd file
            interval: -1            # how many LiDAR frames saved in each pcd file; 
                                        # -1 : all frames will be saved in ONE pcd file, may lead to memory crash when having too much frames.