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Flying Drones in Australia
Designed by Mark Little
What is the Splash Drone Fence?
The Splash Drone "Fence" uses the drone's GPS system to determine its position and height. It then calculates distance from the take-off location and the height compared to the take-off height.
If the distance from the take point exceeds the distance limit and/or the height exceeds the height limit, the drone's software takes one of three actions:
(1) Limit. This means that the drone will simply stop going and further away from the take-off point, or in the case of the height, it will simply not go any higher. The distance limit can be set to ensure that the drone does not fly out of range of the controller. The height limit can be used to ensure that the drone does not fly above the CASA limited height of 120 metres (or 400').
(2) Land. This means that if the fence limits are met, the drone will immediately land. Personally, I find this one the least useful, because it might attempt to automatically land in a area that could damage the drone, or make it difficult to retrieve.
(3) GoHome. This function is pretty self explanatory. If the drone hits the fence, it will return to its take-off location. This helps ensure that a drone that if the drone gets too far away, it will attempt to return the take-off point. It should be noted that this may not be the same place where the pilot is current located. For example, if the drone was launched from a moving boat, it will attempt to return to where the boat was when it took off, not where the boat is now.
Personally, I like to set normally set the Fence Action to Limit, because when the drone is launched from the boat, I want to stop it going too far away, but I do not want to go all the way back to the launch point to retrieve it. If I am using the drone to look for mooring spots along the river ahead of the houseboat, I set the fence distance to beyond what I would normally use, as the boat is travelling towards the drone and the distance from the boat to the drone is decreasing, even though the distance from the take-off point remains the same.
Where I am doing a land based flight, I may sometimes set the action to GoHome with the trigger range just a bit further than the expected flight range.
The GoHome action has three settings that are used to modify the GoHome Action.
(1) GoHome Heading. This setting determine whether the drone simply reverse direction and heads back to the take-off location, or whether it turns around and travels in a forward direction. Although the drone will arrive back at the same position, it will impact whether the camera is looking forward or backward when it travels, especially for cameras used by the payload release modules.
(2) Altitude(m). This setting determine the altitude that the drone will fly at to get back to the launch point. This can be important if the drone is flying in an area that has obstructions such as trees, or power lines, etc. Obviously, the drone GoHome height should be greater than the highest obstruction that it is likely to encounter going home.
(3) Landing Velocity(m/s). This setting determines how quickly the drone will descent from it GoHome Altitude when it arrives at its take-off point. Obviously, if the drone is automatically returning, there is a possibility that the drone pilot and support crew may not know exactly where the drone is, so the last thing you want is to have a drone dropping from the sky with four sets of sharp, spinning blades hitting your head.