Reconfiguring VIO

Kris

Hello, I am trying to reconfigure one of the Seeker's stereo image sensors to be used for VIO instead of the tracking image sensor. I found the documentation on ModalAi's website, but it does not explain how to do this. Could someone please help me out with this?

Kris

I was thinking that reconfiguring this would be located in the camera configuration, but there isn’t a “ TOF + Stereo “ option here.

Chad Sweet

You are trying to configure the extrinsic parameters. See configure extrinsics for more information

Kris

@Chad-Sweet
Thank you for the response.
I’m just a little confused on where I should make the changes for this kind of setup in the extrinsics.
Should I replace the #0 and #1 child to stereo_r or stereo_l ?
Or should I add a #8 to the file with parent as body and child as one of the stereo sensors?
Could you please show me an example or template that I can look at to make sure I’m setting this up correctly?
Thank you.

Kris

@Chad-Sweet
Here are my extrinsics parameters from factory.

voxl:~$ voxl-inspect-extrinsics
#0:
    parent:                imu0
    child:                 tracking
    T_child_wrt_parent:    0.014   0.005   0.005 
    RPY_parent_to_child: -45.0     0.0     0.0  
    R_child_to_parent:     1.000  -0.000   0.000 
                           0.000   0.707   0.707 
                          -0.000  -0.707   0.707 
#1:
    parent:                imu1
    child:                 tracking
    T_child_wrt_parent:   -0.034   0.030   0.005 
    RPY_parent_to_child: -45.0     0.0     0.0  
    R_child_to_parent:     1.000  -0.000   0.000 
                           0.000   0.707   0.707 
                          -0.000  -0.707   0.707 
#2:
    parent:                body
    child:                 imu0
    T_child_wrt_parent:    0.050  -0.015   0.016 
    RPY_parent_to_child:   0.0    90.0    90.0  
    R_child_to_parent:     0.000  -0.000   1.000 
                           1.000   0.000  -0.000 
                          -0.000   1.000   0.000 
#3:
    parent:                body
    child:                 imu1
    T_child_wrt_parent:    0.046   0.033  -0.013 
    RPY_parent_to_child:   0.0    90.0    90.0  
    R_child_to_parent:     0.000  -0.000   1.000 
                           1.000   0.000  -0.000 
                          -0.000   1.000   0.000 
#4:
    parent:                body
    child:                 stereo_l
    T_child_wrt_parent:    0.055  -0.040   0.000 
    RPY_parent_to_child:   0.0    90.0    90.0  
    R_child_to_parent:     0.000  -0.000   1.000 
                           1.000   0.000  -0.000 
                          -0.000   1.000   0.000 
#5:
    parent:                body
    child:                 ground
    T_child_wrt_parent:    0.000   0.000   0.045 
    RPY_parent_to_child:   0.0     0.0     0.0  
    R_child_to_parent:     1.000  -0.000   0.000 
                           0.000   1.000  -0.000 
                           0.000   0.000   1.000 
#6:
    parent:                imu1
    child:                 imu0
    T_child_wrt_parent:   -0.048   0.037   0.002 
    RPY_parent_to_child:   0.0     0.0     0.0  
    R_child_to_parent:     1.000  -0.000   0.000 
                           0.000   1.000  -0.000 
                           0.000   0.000   1.000 
#7:
    parent:                body
    child:                 tof
    T_child_wrt_parent:    0.055   0.000   0.000 
    RPY_parent_to_child:   0.0    90.0   -90.0  
    R_child_to_parent:     0.000   0.000   1.000 
                          -1.000   0.000  -0.000 
                          -0.000  -1.000   0.000

Kris

Here is my voxl-qvio-server.conf parameters.

{                                                                                         
        "imu_name":     "imu1",                                                                                                                     
        "cam_name":     "tracking",                                                       
        "lens_cal_path":        "/data/modalai/opencv_tracking_intrinsics.yml",           
        "cam_extrinsics_name":  "tracking",                                               
        "use_second_cam_if_stereo":     false,                                            
        "odr_hz":       30,                                                               
        "use_camera_height_bootstrap":  true,                                             
        "camera_height_off_ground_m":   0.085000000894069672,                             
        "enable_init_while_moving":     false,                                            
        "cam_imu_timeshift_s":  -0.0020000000949949026,                                   
        "cam_imu_timeshift_s_uncertainty":      0.0010000000474974513,                    
        "T_cam_wrt_imu_uncertainty":    [0.00050000002374872565, 0.00050000002374872565, 0
        "R_cam_to_imu_uncertainty":     [0.00499999988824129, 0.00499999988824129, 0.00499
        "accl_fsr_ms2": 156,                                                              
        "gyro_fsr_rad": 34,                                                               
        "accl_noise_std_dev":   0.31600001454353333,                                      
        "gyro_noise_std_dev":   0.00999999977648258,                                      
        "cam_noise_std_dev":    100,                                                      
        "min_std_pixel_noise":  0.5,                                                      
        "fail_high_pixel_noise_points": 1.6650999784469604,                               
        "limited_imu_bw_trigger":       25,                                               
        "gps_imu_time_alignment_s":     0,                                                
        "T_gps_wrt_imu":        [0, 0, 0],                                                
        "enable_mapping":       true,                                                     
        "enable_gps_vel":       false,                                                    
        "show_extra_points_on_overlay": false,                                            
        "en_auto_reset":        true,                                                     
        "auto_reset_max_velocity":      10,                                               
        "auto_reset_max_v_cov_instant": 0.10000000149011612,                              
        "auto_reset_max_v_cov": 0.00999999977648258,                                      
        "auto_reset_max_v_cov_timeout_s":       0.5,                                      
        "auto_reset_min_features":      3,                                                
        "auto_reset_min_feature_timeout_s":     1                                         
}

Not sure how to set this up.
Should I name my "cam_name" to stereo_r or stereo instead of tracking?
If so, the "lens_cal_path" should be changed to "/data/modalai/opencv_stereo_intrinsics.yml" right?
Or should I enable the "use_second_cam_if_stereo" option to true instead of false?

Kris

This post is deleted!

Kris

@Chad-Sweet
Could I please get some help with this setup procedure?
I have read through the configure extrinsic instructions, but it does not explain how to setup one of the stereo cameras for VIO.

Steve Turner

Use cam name = "stereo" and there should be an option for using either the left or right stereo camera.

As Chad pointed out you will need to also configure extrinsics if they aren't already for the stereo camera.
https://gitlab.com/voxl-public/voxl-sdk/services/voxl-qvio-server/-/blob/master/server/config_file.h#L155

I have a PR to fix an issue with using a stereo camera here with the QVIO Server: https://gitlab.com/voxl-public/voxl-sdk/services/voxl-qvio-server/-/merge_requests/10 that you will need as well I believe.