Many successful optical flow estimation methods have been proposed, but they become invalid when tested in dark scenes because low-light scenarios are not considered when they are designed and current optical flow bench-mark datasets lack low-light samples. Optical Flow uses a downward facing camera and a downward facing distance sensor for velocity estimation. It can be used to determine speed when navigating without GNSS — in buildings, underground, or in any other GNSS-denied environment. The video below shows PX4 holding position using the Ark. This article describes how to setup the PX4FLOW (Optical Flow) Sensor which can be used for Non-GPS navigation. The PX4FLOW is not yet supported in Plane or Rover. The sensor has a native resolution of 752×480 pixels, a 4-fold grading and cropping algorithm is used to calculate the optical flow, the calculation speed reaches 250Hz (daytime, outdoor), and it has a very high sensitivity. The product page says: - The Maximum range of VL53L0X is 2m, Altitude hold 0~2m @ throttle 0~100% if VL53L0X is enabled.
[PDF Version]