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Kurt Kreiger October 21, 2012 at 3:08pm

Is it possible to alter the channel assignments for the APM 2.5 output.

I am using PPM sum from a DragonLink and the channel assignment is JR versus the Futaba style the APM uses.

I could bypass the PPM sum and directly connect them but I was hoping for less wires. :-)

3D Robotics

Chris Anderson October 8, 2012 at 5:53pm

Ife: Good catch. Fixed!

james sowell October 4, 2012 at 4:00am

joe 4 channels plane ail. rud. thr. elv. 1 channel flight modes hope that helps

Shyam Balasubramanian August 25, 2012 at 10:26am

Is there a document that explains the ARDUPLANE source code. If you have any, I would appreciate it. Thank you !

Jeff Zika July 16, 2012 at 1:29pm

Ok here is a weird one. On long tracks between waypoints greater than 64km apart, approx every 5 minutes the autopilot goes offline resulting in a hard dive, random roll, and throttle to idle. It recovers in 1-2 seconds, stabilizes the aircraft, and continues on course. Why?

Also, is there any way to raise the limit of 127 for loiter radius and waypoint detection radius. At 65m/s with 45 deg bank maximum turn rate the minimum radius is 450m. This is way above the maximum setting of 127.

Also, is there any way to add a divide factor based on air (or ground) speed to the roll and pitch PIDs, particularly P? Settings that work at 50m/s are to sensitive at 100m/s, etc.

thanks

Jeff Zika July 10, 2012 at 11:45pm

Thank you for all the quick responses...

Like I said, I am evaluating several different systems APM just being one of them. The open source model is preferred so we have access to the source code for changes, at least at this point.

Comments on comments:

1. PID reaction does not react fast enough to handle the trim changes required. For example, landing gear extension results in a strong pitch down motion, and generally at low altitude. By the time it is compensated for, the aircraft crashes. When the gear is retracted, opposite occurs resulting in an uncommanded 2-3000ft climb. Any settings that compensate for this are two sensitive for maintaining level flight...Also, as fuel burns off trim changes which is not compensated for. What I need is for the trim settings to be updated periodically based on flight parameters. My main concern here is when the aircraft picks up the target tow there is a massive increase in weight, drag, and a strong pitch up moment. These need to be compensated for. I am working on a customization of xPlane to simulate the tow and cat launch.

2. Might be a factor of the aircraft speed when it crosses the waypoint. Cruise speed on this is 80m/s.

5. Need to have a way from the GCS to flush the APM waypoint memory that works.

6. So what settings are required to get this working? Need to maintain constant airspeed at all pitch angles.

7. Understood. Will try.

8. What I was getting at is why not use the calculated wind speed and direction, derived from heading required to hold course and airspeed required to hold track speed (over ground) recursively to calculate heading and airspeed required to track course and maintain speed? This is how airborne GPSs do these calculations.

10. Understood. reason for looking at opensource.

11. Will try tuning yaw for takeoff and see what happens in flight. Note that in operation all takeoffs will be catapult so this shouldn't be as great an issue.

Thanks again.

jz

3D Robotics

Chris Anderson July 10, 2012 at 8:32pm

Sorry, I renumbered the items when I posted to the list, skipping the ones that weren't issues. I hope you can figure it out from the responses.

Jeff Zika July 10, 2012 at 11:41am

Ok, this is the first post to Arduplane group so please bear with me.

We are evaluating and testing autopilots for a high speed target drone, as in 200knot + and up to 10000ft alt. I have been working with an APM1 running Arduplane 2.4 in HIL mode with xPlane. These are some of the comments / concerns so far.

1. Trim is a real pain in the ass. The aircraft trim changes dramatically during flight due to configuration changes, pickup of towed target, dropping target, gear retraction or extension, etc. Is there any way to automate the trim changes? As it is now, every time trim changes are required it has to be done either in manual mode and switch back to auto, or manually using parameter changes through telemetry.

2. The autopilot appears to command a switch to loiter or circle after waypoint passage if the angle between programmed tracks is greater the 90deg. This behavior is quite consistent.

3. One programmed flight to 5000m completely corrupted the APM settings in such a way that switching out of manual commanded a full power dive in all auto modes.

4. What is the maximum airspeed and altitude. The aircraft we are testing is capable of far in excess of 100m/s cruise speeds and climbs at over 7000ft per minute. (yes, it is prop!)

5. Waypoints don't seem to be written consistently. Saving waypoints to the APM some times (most times) does not overwrite existing waypoints or remove any in excess. This can be quite confusing since the aircraft takesoff in some apparent random direction that does not match the programmed route. Reading the waypoints shows the errors. This is a pretty major bug that needs to be addressed.

6. During any auto mode, descents drop the throttle to idle but keeps the decent angle consistent (as it should) thus resulting in a drop in airspeed. The throttle should be managed to maintain a constant airspeed irregardless of climb or decent angle, within the capabilities of the aircraft of course. FWIW, the throttle increases to cruise setting with speed increase once the decent and level off is completed.

7. Tracking a path between waypoints results in a snaking flight path. Tracking direct to a waypoint does not. Can't the same code be used for both?

8. Where is current wind speed and direction as derived from GPS groundtrack vs. heading available on the GCS?

9. Need to be able to specify loiter and circle direction as a parameter of a loiter waypoint.

10. Is there any way to command landing gear retraction after successful takeoff and extension after passing last waypoint before a landing waypoint?

11. The drone we are testing will use parachute recover and catapult launches. Is there anyway to set a waypoint to deploy the parachute.

12. There needs to be a way to ramp up the throttle slowly on takeoff. Full throttle at low speed results in a hard turn to the left which is NOT corrected by the APM. Normal takeoffs with this aircraft are nearly impossible because of this (prop is 24x24 4 blade... i.e. LOTS of torque)

The waypoint programming issue and autotrim (from flight data, not from RC settings) are really must haves for this to work for us. Any ideas if these can be added / fixed?

Best Regards

JZ

Developer

Michael Smith May 21, 2012 at 10:10am

Funny you should ask:

https://store.diydrones.com/3DR_RadioTelemetry_Kit_915_Mhz_p/kt-tel...

Nenad V May 18, 2012 at 3:52am

I have plank flying wing with two motors Left and Right on leading edge, and moving horizontal stabilisator back, without rudder and elevons.Radio is Futaba6EX with R617FS receiver.I use Futaba elevon mixing on CH1 and CH2 for diferential motors control and CH3 for horizontal stabilisator control.

Is it better for my flying wing to use Arduplane system with elevons mix, or Arducopter system ,tricopter version ,but vith control two motors and one servo for horizontal stabilisator.Is it possible to make setap for this?