# ToF sensor and VOA Source: https://forum.modalai.com/topic/1725/tof-sensor-and-voa Category: VOXL 2 and VOXL 2 Mini (https://forum.modalai.com/category/26/voxl-2-and-voxl-2-mini) Tags: voxl-2 Posted: 2023-01-20 20:07:33 UTC by xav04 Replies: 8 · Views: 1706 ## xav04 · 2023-01-20 20:07:33 UTC Hi, I'd like to know if is it possible to use a ToF sensor for obstacle avoidance with voxl2. To give you more context, when I run ```voxl-inspect-tof``` I get the correct distance measurements. I modified ```/etc/modalai/voxl-vision-px4.conf``` , where "en_voa" is set to true and "voa_inouts" only accepts "tof". To verify that this is working I run ```voxl-vision-px4 -s``` but all distances are none. Please let me know how I can fix this. Also, is it possible to see objects with a shorter range using ToF, like around 1m? ![1.png](https://forum.modalai.com/assets/uploads/files/1674245368234-1.png) ![voxl-vision-px4.png](https://forum.modalai.com/assets/uploads/files/1674244991791-voxl-vision-px4.png) ## Reply by Guest · 2023-01-20 21:01:36 UTC Yes this should absolutely be possible, can you send the screenshot of your voxl-vision config file as well. As for range we usually cut off the tof data around 15 cm in front of the camera, so it usually has an effective range of ~0.15-5 meters ## Reply by xav04 · 2023-01-20 22:14:34 UTC Hi @Alex-Gardner, sure! This is the configuration of ```/etc/modalai/voxl-vision-px4.conf```. If there is any other parameter that can be improved please let me know ![2.png](https://forum.modalai.com/assets/uploads/files/1674252825280-2.png) ## Reply by xav04 · 2023-01-23 19:27:25 UTC (in reply to Guest) Hi @Alex-Gardner , is there any other file I should upload? ## Reply by xav04 · 2023-01-25 19:15:24 UTC (in reply to Guest) @Alex-Gardner I'm wondering if you can help me solve this problem or is there someone else on the development team who can provide support? ## Reply by Guest · 2023-01-25 19:21:03 UTC Hi, Can you check in voxl-portal what the pointcloud ```voxl_pc_out``` looks like? this is the VOA pointcloud before the final bit of filtering to send it to the flight controller. Also check ```/etc/modalai/extrinsics.conf``` to make sure that it matches the transforms that are on your drone. ## Reply by xav04 · 2023-01-25 21:16:38 UTC (in reply to Guest) Hi @Alex-Gardner this is the screenshot of ```voxl_pc_out``` in voxl-portal, at the same time this is the output of ```voxl-vision-px4 -s``` and this is the screenshot ```/etc/modalai/extrinsics.conf``` ![3.PNG](https://forum.modalai.com/assets/uploads/files/1674681298972-3.png) ![4.PNG](https://forum.modalai.com/assets/uploads/files/1674681306718-4.png) ![2.PNG](https://forum.modalai.com/assets/uploads/files/1674681354929-2.png) ## Reply by James Strawson (ModalAI staff) · 2023-01-25 22:34:16 UTC your image of the voa_pc_out point cloud shows that your voxl thinks the TOF is pointing out the top of the drone. This is confirmed by your extrinsics conf sensor rotation: [180 0 0] which translates to a sensor pointing straight up. ## Reply by Sarika Sharma · 2026-01-16 10:23:51 UTC (in reply to James Strawson) @James-Strawson Hii , I am also getting the same issue . Kindly look at the following details . I have defined tof in my extrinsics.conf file as given below: parent: body child: tof T_child_wrt_parent: 0.070 0.024 -0.029 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 when i run voxl-vision-hub -s i got the following slice 0 dist none back slice 1 dist none slice 2 dist none slice 3 dist none slice 4 dist none slice 5 dist none slice 6 dist none slice 7 dist none slice 8 dist none slice 9 dist none left slice 10 dist none slice 11 dist none slice 12 dist none slice 13 dist none slice 14 dist none slice 15 dist none slice 16 dist none slice 17 dist none slice 18 dist none forward slice 19 dist none slice 20 dist none slice 21 dist none slice 22 dist none slice 23 dist none slice 24 dist none slice 25 dist none slice 26 dist none slice 27 dist none right slice 28 dist none and in my vision-hub-conf file i have the folloeing set up: "en_vio": true, "vio_pipe": "qvio", "secondary_vio_pipe": "ov", "vfc_vio_pipe": "ov", "en_reset_vio_if_initialized_inverted": true, "vio_warmup_s": 3, "send_odom_while_failed": true, "horizon_cal_tolerance": 0.5, "en_hitl": false, "offboard_mode": "figure_eight", "follow_tag_id": 0, "figure_eight_move_home": true, "robot_radius": 0.300000011920929, "collision_sampling_dt": 0.1, "max_lookahead_distance": 1, "backtrack_seconds": 60, "backtrack_rc_chan": 8, "backtrack_rc_thresh": 1500, "wps_move_home": true, "wps_stride": 0, "wps_timeout": 0, "wps_damp": 1, "wps_vfc_mission": true, "wps_vfc_mission_loop": false, "wps_vfc_mission_to_ramp": 25, "wps_vfc_mission_to_kp": 0.10000000149011612, "wps_vfc_mission_cruise_speed": 1, "en_tag_fixed_frame": false, "fixed_frame_filter_len": 5, "en_transform_mavlink_pos_setpoints_from_fixed_frame": false, "vfc_rate": 100, "vfc_rc_chan_min": 980, "vfc_rc_chan_max": 2020, "vfc_thrust_ch": 3, "vfc_roll_ch": 1, "vfc_pitch_ch": 2, "vfc_yaw_ch": 4, "vfc_submode_ch": 6, "vfc_alt_mode_rc_min": 0, "vfc_alt_mode_rc_max": 0, "vfc_flow_mode_rc_min": 0, "vfc_flow_mode_rc_max": 0, "vfc_hybrid_flow_mode_rc_min": 0, "vfc_hybrid_flow_mode_rc_max": 0, "vfc_position_mode_rc_min": 0, "vfc_position_mode_rc_max": 2100, "vfc_traj_mode_rc_min": 0, "vfc_traj_mode_rc_max": 0, "vfc_yaw_deadband": 30, "vfc_vxy_deadband": 50, "vfc_vz_deadband": 150, "vfc_min_thrust": 0, "vfc_max_thrust": 0.800000011920929, "vfc_tilt_max": 0.43599998950958252, "vfc_yaw_rate_max": 3, "vfc_thrust_hover": 0.5, "vfc_vz_max": 1, "vfc_kp_z": 5.2899999618530273, "vfc_kd_z": 5.9800000190734863, "vfc_vxy_max": 3, "vfc_kp_xy": 0.63999998569488525, "vfc_kd_xy": 2.559999942779541, "vfc_kp_z_vio": 5.2899999618530273, "vfc_kd_z_vio": 5.9800000190734863, "vfc_kp_xy_vio": 3.2400000095367432, "vfc_kd_xy_vio": 3.9600000381469727, "vfc_w_filt_xy_vio": 10, "vfc_w_filt_xy_flow": 3, "vfc_vel_ff_factor_vio": 0.899999976158142, "vfc_xy_acc_limit_vio": 2.5, "vfc_max_z_delta": 3, "vfc_att_transition_time": 0.5, "vfc_stick_move_threshold": 30, "vfc_flow_transition_time": 1, "vfc_q_min": 10, "vfc_points_min": 7, "vfc_en_submode_announcement": 1, "vfc_disable_fallback": false, "vfc_traj_csv": "/data/voxl-vision-hub/traj.csv", "en_voa": true, "voa_upper_bound_m": -0.15000000596046448, "voa_lower_bound_m": 0.15000000596046448, "voa_memory_s": 1, "voa_max_pc_per_fusion": 100, "voa_pie_max_dist_m": 20, "voa_pie_min_dist_m": 0.25, "voa_pie_under_trim_m": 1, "voa_pie_threshold": 3, "voa_send_rate_hz": 20, "voa_pie_slices": 36, "voa_pie_bin_depth_m": 0.15000000596046448, "voa_inputs": [{ "enabled": false, "type": "point_cloud", "input_pipe": "dfs_point_cloud", "frame": "stereo_l", "max_depth": 8, "min_depth": 0.300000011920929, "cell_size": 0.079999998211860657, "threshold": 4, "x_fov_deg": 68, "y_fov_deg": 56, "conf_cutoff": 0 }, { "enabled": false, "type": "point_cloud", "input_pipe": "stereo_front_pc", "frame": "stereo_front_l", "max_depth": 8, "min_depth": 0.300000011920929, "cell_size": 0.079999998211860657, "threshold": 4, "x_fov_deg": 68, "y_fov_deg": 56, "conf_cutoff": 0 }, { "enabled": false, "type": "point_cloud", "input_pipe": "stereo_rear_pc", "frame": "stereo_rear_l", "max_depth": 8, "min_depth": 0.300000011920929, "cell_size": 0.079999998211860657, "threshold": 4, "x_fov_deg": 68, "y_fov_deg": 56, "conf_cutoff": 0 }, { "enabled": true, "type": "tof", "input_pipe": "tof", "frame": "tof", "max_depth": 6, "min_depth": 0.15000000596046448, "cell_size": 0.079999998211860657, "threshold": 3, "x_fov_deg": 106.5, "y_fov_deg": 85.0999984741211, "conf_cutoff": 125 }, { "enabled": false, "type": "rangefinder", "input_pipe": "rangefinders", "frame": "body", "max_depth": 8, "min_depth": 0.300000011920929, "cell_size": 0.079999998211860657, "threshold": 4, "x_fov_deg": 68, "y_fov_deg": 56, "conf_cutoff": 0 }], "voa_voa_memory_s": 1 } ![Screenshot from 2026-01-16 16-01-23.png](https://forum.modalai.com/assets/uploads/files/1768559497610-screenshot-from-2026-01-16-16-01-23.png)