My hexarotor drone was flying in an autonomous mode while being controlled by an onboard companion computer. The logs then indicate it lost its GPS signal which triggered the failsafe and since it didn’t have a RC connected a descent was initiated. This is all good, only it was travelling at about 5m/s horizontally at the time, and it didn’t reduce horizontal speed during descent, so it hit the ground on an angle. Obviously this isn’t desirable so I was wondering if this is the expected behaviour, and if it is then would a PX4FLOW allow the drone to hold its position during a descent in this failsafe situation?
edit: just realised the PX4FLOW is discontinued, maybe there is another optical flow device that will allow the drone to descend vertically in failsafe mode?
I would not rely on PX4FLOW as it can be inaccurate with the rangefinder on board.
The Ark Flow is the more modern solution to what you are looking for. I have a video on testing it here
Thanks for your reply. I’m hoping for something a little more cost effective. Holybro have just brought out something they call H-Flow (Holybro H-Flow Optical Flow and Distance Sensor Module – Holybro Store) which looks good and uses the same rangefinder chip, DroneCAN, is half the price, and has what looks like an upgraded optical flow chip (https://www.pixart.com/products-detail/108/PAA3905E1-Q_ vs https://www.pixart.com/products-detail/93/PAW3902JF-TXQT
I’m just waiting for confirmation from holybro that it doesn’t require rolling back the PX4 version to 1.13.3 like their PWM3901 optical flow sensor does.
