BZB UAS HereFlow Finger Size Optical Flow Sensor Owner’s Manual
- June 11, 2024
- BZB UAS
Table of Contents
BZB UAS HereFlow Finger Size Optical Flow Sensor
Overview
Here Flow is a finger size optical flow sensor that can be easily installed at any position without taking much space. It is smaller compared to other optical flow sensors. The Here Flow integrates a LiDAR component, an optical flow camera, and a 6D IMU (ICM20602). The LiDAR component is a power-efficient high-speed TOF range finder, which embeds the latest ST FlightSenseTM technology. The Here Flow can be set up at any node in the CAN bus without noise problems.
Specification
- Size: 28.8mm*9.5mm
Performance
Hardware Specification
- Built-in ultra-small lidar module
- CAN Protocol, which provides more reliable communication
- Built-in IMU Module
- PMW3901 Optical Flow Sensor. Effective ranges from 80 mm to infinity.
Optical Flow Sensor Specification
Type| Range| Field of view| Maximum movement speed| Minimum illumination|
Infrared emitter| Operating temperature| Interface| Power supply
---|---|---|---|---|---|---|---|---
PMW3901 Optical Flow Sensor| Effective ranges from 80 mm to infinity.| N/A|
N/A| N/A| N/A| N/A| N/A| N/A
Lidar Specification
Type| Measuring frequency| Field of view| Longest distance| Accuracy| Infrared
emitter| Operating temperature| Interface| Power supply
---|---|---|---|---|---|---|---|---
TOF range finder| 5 ms in range of 2 m| N/A| N/A| Not affected by colour or
reflection rate of the target
surface.| Latest ST FlightSenseTM technology| N/A| N/A| N/A
Installation
Connect the CAN port on the module and flight controller with the 4 Pin CAN cable. Point the Y axis of Here Flow to the nose of the aircraft. Face the camera to the ground and stick the module to the bottom of the aircraft with 3M sticker or soft sticker (with slightly vibration isolation).
DO NOT touch the electronic components on the PCB.
Touch the edge of the PCB if possible during the installation. The bottom of
the module must be clear; otherwise, the measured data will be affected.
Settings
Remark: Here Flow has not been ready on the APM firmware stable version. Master firmware is needed before the release of copter3.7.
- Connect the flight controller to a computer via USB cable. Open Mission Planner. Install the master firmware by Load custom firmware. Go to Full Parameter List and find CAN_P1_DRIVER. Change it to 1 to enable CAN.
- Find RNGFND_TYPE and set it to 24 to enable the range finder. Set RNGFND_MAX_CM (maximum distance) to 200 cm; RNGFND_MIN_CM (minimum distance) to 5 cm.
- To turn on the optical flow function: Set FLOW_TYPE to 6 to enable the optical flow camera.
- After setting the parameters, click Write Params. Go to the Actions tag in flight Data page. Select PREFLIGHT_REBOOT_SHUTDOW then click Do Action to reboot the flight controller.
- After confirming the data are normal, go to Full parameter list and change EKF2_GPS_TYPE to 3 to disable GPS. This is for testing if the optical flow is working normally. Change ARMING_CHECK to 15838 to cancel the pre-arm check of optical flow (Otherwise, you will need to rise the aircraft to at least 50 cm and then put it back to the ground to disarm). After takeoff, the aircraft can loiter normally in LOITER mode.
For more optical flow settings, you may check in Ardupilot Wiki: https://discuss.cubepilot.org/c/flow-sensor
Last modified: 9th April 2019
Overview
Here Flow is a finger size optical flow sensor. Compared with other optical
flow sensors, it is even smaller. It can be installed easily at any position
without taking much space. A LiDAR component, an optical flow camera and a 6D
IMU (ICM20602) are integrated in the Here FLOW. The LiDAR component is a power
efficient high speed TOF range finder, which embeds the latest ST FlightSense™
technology. In range of 2 m, it can acquire the distance within 5 ms. The
accuracy is not affected by colour or reflection rate of the target surface.
The Here Flow can be setup at any node in the CAN bus without noise problem.
Specification
Size: 28.8mm*9.5mm
Performance
Hardware Specification
- Built-in ultra small lidar module
- CAN Protocol, which provide more reliable communication
- Built-in IMU Module
- PMW3901 Optical Flow Sensor. Effective ranges from 80 mm to infinity.
Optical Flow Sensor Specification
| Type | Parameter |
|---|---|
| Range | 80 mm to infinity |
| Field of view | 42 degree |
| Maximum movement speed | 7.4 rad/s |
| Minimum illumination | > 60 lux |
| Infrared emitter | 940 nm invisible light emission (Class1) |
| Operating temperature | -20 to +70 °C |
| Interface | CAN |
| Power supply | 5 V |
Lidar Specification
| Type | Parameter |
|---|---|
| Measuring frequency | Up to 50 Hz |
| Field of view | 27 degree |
| Longest distance | 2m |
| Accuracy | ±3 % |
| Infrared emitter | 940 nm invisible light emission (Class1) |
| Operating temperature | -20 to +70 °C |
| Interface | CAN |
| Power supply | 5 V |
Installation
Connect the CAN port on module and flight controller with the 4 Pin CAN cable. Point the Y axis of Here Flow to the nose of the aircraft. Face the camera to ground and stick the module to the bottom of aircraft by 3M sticker or soft sticker (with slightly vibration isolation).
- DO NOT touch the electronic components on the PCB. Touch the edge of the PCB if possible during the installation.
- The bottom of module must be clear, otherwise the measured data will be affected.
Settings
Remark: Here Flow has not been ready on the APM firmware stable version.
Master firmware is needed before the release of copter3.7
Firmware update instructions: https://discuss.cubepilot.org/t/can-flow-setup-
instructions-alpha-batch/341
-
Connect the flight controller to computer via USB cable. Open Mission Planner. Install the master firmware by “Load custom firmware”. Go to “Full Parameter List” and find “CAN_P1_DRIVER”. Change it to “1” to enable CAN.
-
Find “RNGFND_TYPE” and set it to “24” to enable range finder. Set “RNGFND_MAX_CM” (maximum distance) to 200 cm; “RNGFND_MIN_CM” (minimum distance) to 5 cm.
Please note: We have integrated the TOF sensor in this component due to it being VERY useful for precision landing detection. However, it is NOT suitable for height detection in outdoor conditions above 0.5 m, nor is it suitable for indoor height estimations higher than 2 m. For accurate flow navigation, we still recommend installing the SF11B lidar from Lightware, or a similar Lidar that you trust. Users may also opt to use Arducopter Mode FLOWHOLD for optical flow based position hold without rangefinder. -
To turn on optical flow function: Set “FLOW_TYPE” to “6” in order to enable optical flow camera.
-
After setting the parameters, click “Write Params”. Go to the “Actions” tag in “flight Data” page. Select “PREFLIGHT_REBOOT_SHUTDOW” then click “Do Action” to reboot the flight controller。
-
After rebooting the flight controller, reconnect to Mission Planner and go to “status” tag. Change the altitude of the aircraft to see whether “sonarrange” is changing correspondingly. If the value does not change, please check if the parameters are properly set or reboot the flight controller. Change the position of the aircraft and see whether the data of “opt_m_x”, “opt_m_y”, “opt_x”, “opt_y” are changing. If the value do not change, please check if the parameters are properly set or reboot the flight controller.
-
After confirming the data are normal, go to “Full parameter list” and change “EKF2_GPS_TYPE” to “3” to disable GPS. This is for testing if the optical flow is working normally. Change ARMING_CHECK” to 15838 to cancel the pre-arm check of optical flow (Otherwise, you will need to rise the aircraft to at lease 50 cm and then put it back to the ground to disarm. After take off, the aircraft can loiter normally in LOITER mode.
For more optical flow settings, you may check in Ardupilot Wiki: https://discuss.cubepilot.org/c/flow-sensor
Last modify: 9th April 2019
References
Read User Manual Online (PDF format)
Read User Manual Online (PDF format) >>