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View Full Version : Who in here knows autopilots?



ritewing
13th February 2015, 03:28 PM
Hi guys please share your knowledge of what autopilots you know well and what type they are.

afishindouban
13th February 2015, 03:50 PM
PPRZ, APM, PIXHAWK, Openpilot CC3D.

P.I.Engineer
13th February 2015, 06:26 PM
apm/pixhawk, lots of testing

Hmerly
13th February 2015, 06:31 PM
I've used a Rvosd v5&6, Myflydream OSD/AP, Skylark Dianmu, Uthere Ruby, and the Naze32 with minimosd in plane mode

1320Fastback
13th February 2015, 09:50 PM
RVosd V5 only

serac
13th February 2015, 09:55 PM
ArduPlane in APM and Pixhawk + MinimOSD. Can do code modification.

Vitamin J
13th February 2015, 11:25 PM
I've used a lot but I've been building most rigs with a Pixhawk or Ruby these days.

btown2
13th February 2015, 11:38 PM
APM on Fixed wing.

https://www.youtube.com/watch?v=iPKirSqpcVk

Completely autonomous flight takeoff to landing...

https://www.youtube.com/watch?v=tJt15_bUG7A

ritewing
14th February 2015, 01:12 AM
I am wanting to dev profiles for the Drak to make it a mapper and it needs to have auto takeoff and accurate autoland capabilities. it needs to work very well. Tinkering is good, but what we need is something to be fairly tuned and polished

btown2
14th February 2015, 03:34 PM
I am wanting to dev profiles for the Drak to make it a mapper and it needs to have auto takeoff and accurate autoland capabilities. it needs to work very well. Tinkering is good, but what we need is something to be fairly tuned and polished

I'll talk about APM since it's what I know.

You need to be mindful that autopilot landings are only going to be as accurate as your gps. In my video above the the landing point is set in the middle of the runway but it actually lands about 8 feet to the side of that mark. Then you also need to consider how auto landing actually works in APM.

To land you set a waypoint at ground level where the land macro will kick in. Once the plane reaches either a configurable amount of distance or time from the way point it will initiate a flare (configurable as well) and hold that position. Presumably if everything goes ok this is 1-3 yards from the ground and you get a nice soft landing like the one in the video. This however can get tricky and a lot depends on the mission waypoints used prior to landing. For instance setting a landing at 0 ft with the previous waypoint 100 ft away at say 300ft just isnt going to work. It will overshoot the landing waypoint while holding it's flare and could possibly stall and crash. So even with the best tuning already available for customers they will still have to be able to set up a competent landing approach.

So there are little details that add in error to the landing process.
1. GPS
2. Bad landing pattern leaves too much airspeed to burn off.
3. Bad landing pattern leaves too little airspeed to make the target. I actually had one attempt where the penguin actually landed about 30 ft short of the mark and then proceeded to motor up and 'drive' the rest of the way to the mark.
4. Not re-calibrating the airspeed sensor and air pressure sensor after the apm warms up.

Auto take off on the other hand is very solid on APM. You set a target altitude and it automatically holds the heading you throw it on. The only real issue to look of for here is to get the motor spin up timing right. You certainly don't want the prop on the end to catch someones hand, but you also dont want it to take too long after the throw to actually spin up.

Just some thing to think about.

ritewing
14th February 2015, 03:43 PM
Hi , Yes I fully understand the landings, we have had pixhawk with sonar almost spot landing every time. The Ruby is no where near as accurate on landing, but its takeoffs are better.
There is give and takes with all of them.

I'll talk about APM since it's what I know.

You need to be mindful that autopilot landings are only going to be as accurate as your gps. In my video above the the landing point is set in the middle of the runway but it actually lands about 8 feet to the side of that mark. Then you also need to consider how auto landing actually works in APM.

To land you set a waypoint at ground level where the land macro will kick in. Once the plane reaches either a configurable amount of distance or time from the way point it will initiate a flare (configurable as well) and hold that position. Presumably if everything goes ok this is 1-3 yards from the ground and you get a nice soft landing like the one in the video. This however can get tricky and a lot depends on the mission waypoints used prior to landing. For instance setting a landing at 0 ft with the previous waypoint 100 ft away at say 300ft just isnt going to work. It will overshoot the landing waypoint while holding it's flare and could possibly stall and crash. So even with the best tuning already available for customers they will still have to be able to set up a competent landing approach.

So there are little details that add in error to the landing process.
1. GPS
2. Bad landing pattern leaves too much airspeed to burn off.
3. Bad landing pattern leaves too little airspeed to make the target. I actually had one attempt where the penguin actually landed about 30 ft short of the mark and then proceeded to motor up and 'drive' the rest of the way to the mark.
4. Not re-calibrating the airspeed sensor and air pressure sensor after the apm warms up.

Auto take off on the other hand is very solid on APM. You set a target altitude and it automatically holds the heading you throw it on. The only real issue to look of for here is to get the motor spin up timing right. You certainly don't want the prop on the end to catch someones hand, but you also dont want it to take too long after the throw to actually spin up.

Just some thing to think about.

Beerwiser
14th February 2015, 03:58 PM
How about paparazzi? I have been using apm forever and have been happy with it, but if I were to try a different autopilot I would try the paparazzi.

afishindouban
15th February 2015, 12:52 AM
I'll talk about APM since it's what I know.

You need to be mindful that autopilot landings are only going to be as accurate as your gps. In my video above the the landing point is set in the middle of the runway but it actually lands about 8 feet to the side of that mark. Then you also need to consider how auto landing actually works in APM.

To land you set a waypoint at ground level where the land macro will kick in. Once the plane reaches either a configurable amount of distance or time from the way point it will initiate a flare (configurable as well) and hold that position. Presumably if everything goes ok this is 1-3 yards from the ground and you get a nice soft landing like the one in the video. This however can get tricky and a lot depends on the mission waypoints used prior to landing. For instance setting a landing at 0 ft with the previous waypoint 100 ft away at say 300ft just isnt going to work. It will overshoot the landing waypoint while holding it's flare and could possibly stall and crash. So even with the best tuning already available for customers they will still have to be able to set up a competent landing approach.

So there are little details that add in error to the landing process.
1. GPS
2. Bad landing pattern leaves too much airspeed to burn off.
3. Bad landing pattern leaves too little airspeed to make the target. I actually had one attempt where the penguin actually landed about 30 ft short of the mark and then proceeded to motor up and 'drive' the rest of the way to the mark.
4. Not re-calibrating the airspeed sensor and air pressure sensor after the apm warms up.

Auto take off on the other hand is very solid on APM. You set a target altitude and it automatically holds the heading you throw it on. The only real issue to look of for here is to get the motor spin up timing right. You certainly don't want the prop on the end to catch someones hand, but you also dont want it to take too long after the throw to actually spin up.

Just some thing to think about.

So good knowledge, thanks for share :D as I saw from your vid, the auto land speed is a quit high :D maybe the approach angel can be more flat. APM/PIXHawk autoland is not perfect, but fair to use. Someone has experience to use a optical-flow sensor to make autoland ? That is the way of Ebee.

serac
15th February 2015, 12:43 PM
Hi , Yes I fully understand the landings, we have had pixhawk with sonar almost spot landing every time. The Ruby is no where near as accurate on landing, but its takeoffs are better.
There is give and takes with all of them.

I think there will be LIDAR support in upcoming Pixhawk updates. This should be more robust than sonar (or at least, an alternative to sonar).

ritewing
15th February 2015, 12:46 PM
Hi Serac, yes a buddy of mine here was doing test landing with the lidar, it was interfering some with the GPS, we had some good results with the sonar.
We should talk on the ph some time. You are close to me here in AZ.
ArduPlane in APM and Pixhawk + MinimOSD. Can do code modification.

citi888
16th February 2015, 05:19 AM
Uthere Ruby save my Z2 one time due to extra wing.
The plane was impossible to control, at 1.6 km I loose the video
connection (in 5,8mhz). I cut my radio to set the RTH.
The Z2 come back against the wind to home.
I was very very impress ! So I recommand Uthere.

epic4me
18th February 2015, 11:14 AM
U there is very good; but is not easy to get support.