Battery Range Circle

Just a thought. I’d like to see a range circle around aircraft illustrating maximum flight range time based on battery measurements with estimated time left to reach minimum safe voltage level.

I use a ground station and monitor the flight characteristics of which I monitor the battery data, but I prefer a graphical range circle that decreases as battery voltage decreases with a green range circle when battery levels are above a set minimum, then it would switch to a red flashing circle when it hits the minimum safe voltage level that is programmed in the failsafe section of mission planner.

This process would help alert pilots that they are about to flight below safe levels.

Thanks for the great support. Looking forward to all the innovated ideas and changes coming.

Doug Walmsley

I’ve seen a similar feature on apps for full sized aircraft, but it was for engine out gliding distance. It is a map that shows all the surrounding airports, and a ring around your plane that represents your gliding distance. This ring is offset to represent the wind, and its size changes with speed and altitude. If you keep an airport within the circle at all times, you can be more confident of your ability to dead stick it in to a runway.
Back to the APM. Just fantasizing here…
Two circles each a different color. The outside circle is the range based on mAh remaining, averaged wind conditions, altitude, and airspeed. The inside circle represents your power off gliding distance using the same data.

This is what I’ve been thinking should be implemented into the AndroPilot software.
I posted this already in GitHub but thought I’d keep the discussion alive and moving forward.

Range Circles

a. Planning a mission and program autopilot
i. When selecting way points
1. Use battery configuration parameters to identify estimated battery distance that the aircraft can fly and return home.
2. As additional waypoints are added, mission planner recalculates the battery distance for each way point to last way point and provides the operator indications as to whether aircraft can fly all waypoints and safely return home.

b. When Aircraft is Powered On
i. Displayed on Map surrounding Aircraft
ii. Green Range Circle – From max battery distance down to 5% battery life
emaining (recommended minimum but operator selectable to any desired level).
iii. Red Range Circle (Flashing) – from 5% to lowest voltage set in parameters.

please provide a numeric example of what you are trying to archive.


Apologize for not responding sooner. What exactly are you asking me to priovide you?

The battery remaining range circle takes telemetry information downlinked during flight to provide up-to-date range circle around aircraft showing operator distance remaining on current power draw measured by APM/Pixhawk power monitoring cable adaptor. Not sure how to address this on multicopters that do not monitor volts/amps but I think this idea is a first good start.

There seems to be others who share the same concern with not knowing that they are planning and/or flying their UAV beyond same distances. My idea was in mitigate adding to many waypoints or pushing the distance beyond the flight duration limits. This can be accomplished during mission planning phase to show operator that his waypoint planning may not be achievable based on speeds bulit-in the way points based on battery parameters plugged into Mission Planner hardware menu.

Does this make sense?


It’s an excellent idea ! But to get this working, we only can estimate the range circle with actual flight condition (ie. speed, current…). Some parameters are pretty difficult to predicate. The radius of the circle will largely depends on it… which will change during the flight. To my mind, this range should be taken with a grain of salt.

That makes me think it could be interresting in notice for every copter the exact speed (without wind) at which we can ensure the maximum range.

@ Gabriel

I believe there is enough raw data collected from telemetry feed to Mission Planner application for fairly accurate range calculations as the vehicle is in flight. Just need the 20 pound brains to pull the data and formulate the programming to make this work. Range Circle would fluctuate based on power demands and I agree they are to be take with a grain of salt in that the circles are an estimate value. Battery health/life could factor into a shorter flight regardless of configuration and in my field of work, we are taught to Aviate, Navigate, and lastly Communicate. The range circle idea is to help pilots understand that their aircraft may have to come home sooner rather than never.

As for mission planning…It would be based on certain givens such as nominal power for cruise flight (especially in auto), battery configuration, way point positions (distance between…), null winds and direction, etc… I’m sure I forgot something in this area.

We are ok, range circle is a help but may not be used with centimetric precision :slight_smile:

In this case, I think calculations will be simple : MP will receive permanently ground speed and current (from 3DR module). As we know the total capacity of the battery, it’s possible to know the time before the battery goes empty with present flight conditions.
d=vt, so present circle radius will be simply equal to present ground_speedpresent flight time left.

This takes into account parameters such as wind since it will increase present current and decrease ground speed for exemple
Obviously, battery total capacity will decrease over cycles so we may ajust that sometimes.

the only thing this doesn’t factor is wind. and that can be a major component


You said, “the only thing this doesn’t factor is wind. and that can be a major component”. From a pre-mission planning perspective I would agree. However, the telemetry data that Mission Planner application uses determines wind direction and velocity. So I’m not clear as your. comment I agree that the formula currently does not calculate winds so I will leave that to someone who’s capable of calculating a formula for this to work. Couldn’t the Mission Planner calculate the aircrafts performance/power consumption using all we discussed as well as the wind information?