I have just bought the ArduPilot Mega 2560 Full Kit... plus the Triple Axis Magnetometer HMC5883L. I should have it built over the weekend.. then i'm off to a my mates machine shop, and i'll make the splitter plate for the lower frame onto which i am going to fit the Ardupilot. the magnetometer i'll put on the tail as suggested. I am going to use my X-cell Razor 600E. For those that dont know its around the 50 size nitro heli.
Do i need to buy any other sensors i.e. the Sonar... i can fly a helicopter all day long but this is my first time flying one with stabilisation so any tips would be gratefully appreciated.
If this works well then i am going to try and use it on my x-cell gasser. i can get up to 20 minute flights with this. But i think for the time being a battery 600 is the way to go.
i'll post some pictures when i have it all together.
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Had a few good flights today. Loiter was testing ok at first then i messed up the PID values.
Will go back to the ones i saved from yesterdays blog. Altitude hold was really good.
Best of all.... RTL worked with no problems at all, heli slowly pirroeted round while the cyclic targeted the home WP. It tracked straight to it. Then went to a Loiter mode (i think) but it held position... then the battery ran out.
So i think its time to build the 25cc Petrol heli (not nitro).
Will be building this week.
I have the same heli as this but i grabbed these from another site.
I think if that is what is required that It should be fine since it will (possibly) yield better result but this is scary if someone spool up without arming as there are no servo controls. I guess its something we have to get use to in the long run but it might be a terrifying scene for others.
Hey Malcolm (and everyone else),
I'm thinking about how to get rid of this "barometer offset problem". The situation where we see the sonar and barometer showing a difference in altitude of about 2m. We don't see this on the quad because we actually do the barometer initialisation twice...once when the code first starts, then again when you arm the motors...so by the time the user is ready to fly and "arms" the motors, the barometer has had some time to warm up and gives better values for the initialisation.
The problem is that on the heli we don't need to arm the motors because the motor is directly controlled from the radio.
I'm thinking about reintroducing this "arm" feature but it would affect the servos...so the servos wouldn't move until you "armed". Arming would be done in the same method as on the quad - you'd hold throttle (=collective pitch) down and push yaw right for 2 seconds.
What do you think? Too annoying? alternatively I could add a timer that automatically reinitialises the barometer after 5 ~ 10 seconds..and try and think of a way to check that we haven't already taken off.
These are the graphs from my blog video, you can see that the traces are a lot closer now, still need to do some fine tuning. I think i need to reduce the P slightly and increase the I. what do you think Randy?
Will try ALT_HOLD and Loiter tomorrow. If it works as well as i think then i'm going to load some way points.
@Randy. Did you get a chance to look over my latest logs. Jason has a new version out with different control laws implemented for loiter, RTL etc. what do you think Randy?
This could helps us a lot with getting it to stay in one place :)
Turns out I can include logging and still run it on the 1280! Unfortunately my problems returned today. On nearly every flight I had a significant bias build up in the elevator and aileron control. ie. I had to give it more and more aileron and/or elevator in order to keep it in a hover. For example see the the flight log below. I was hovering mostly in one location, but you can see the roll (in red) drift more and more and the pitch do the same. The helicopter was certainly not actually doing that and you can see the point where I landed and the APM eventually figured out it's true orientation.
I think there are possible three causes. Vibration, EMI, or noise on the power lines. What do you guys think? How should I narrow this down? Has anyone had a similar problem?
Think I forgot to mention that I managed to get the code to fit on my AT1280. I just had to add these two lines to the config and it loaded without problems. The first line only includes the code for my particular GPS (not for all supported GPS) and the second disables logging. It took me a while to figure out, but it is very simple to do. I won't be able to log any data, but at least I am flying!
#define GPS_PROTOCOL GPS_PROTOCOL_MTK16
#define LOGGING_ENABLED DISABLED
@ Randy.
Still having problems with loiter. It seems to just wander about and never really locks on to the Loiter WP. i'm a little lost really. Have you tried Loiter yet Randy?
I tried flying our 450 today to test the 'stabilize' function.
The helicopter went up fairly smoothly until it reached about 4 feet off the ground and then the tail started spinning. I lost control of the rudder, so I decided to land the helicopter asap. Unfortunately, the heli crashed. Would anyone here know why the tail suddenly spinned? Any ideas?
In the Mission Planner there are two different Radius settings, one for WP Radius and one is Loiter radius.
Would either of these affect my helicopter when i set Loiter mode in my Helicopter?