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leonardthall
  • Male
  • Fairview Park, SA
  • Australia
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Latest Activity


Developer
leonardthall replied to Randy's discussion AC-3.1 autotune support discussion
"Hi Egert, Sorry but I can't download your logs for some reason. What I suspect is happening is your default tune is too high and the copter is not recovering well from the autotune test. I would suggest you drop your roll and pitch rate P I…"
5 hours ago

Developer
leonardthall replied to Mihai's discussion LOITER and RTL crashing bug
"Mihai, The fact you are running your own version of 3.1_rc8 makes it hard to support you because it isn't the usual code and to be honest I have forgotten what has been changed and fixed in that time. If might want to reduce Angle_Rate_Max…"
Apr 9

Developer
leonardthall replied to Mihai's discussion LOITER and RTL crashing bug
"You can go even lower if you like. It is a trade off between how aggressively it will hold the point in gusty conditions and how gentle it will move around."
Apr 8

Developer
leonardthall replied to Mihai's discussion LOITER and RTL crashing bug
"Hi Mihai, Sorry, the other parameter that makes a significant difference is the HLD_LAT_P and HLD_LON_P. If you reduce them the copter will be less aggressive in the way it starts to accelerate. It will also be a little gentler in the way it reacts…"
Apr 8

Developer
leonardthall replied to Mihai's discussion LOITER and RTL crashing bug
"In reply to Oliver's question. There will be a patch out later today that includes the 7 missing characters in the code. It is also worth mentioning that this problem has been in the code since 2.9 (i think). There have been thousands of…"
Apr 7

Developer
leonardthall replied to Mihai's discussion LOITER and RTL crashing bug
"I would suggest that you do no more than drop your auto tune Stab P by 25 percent but I wouldn't even do that. The most important parameter for smooth and relaxed mission performance is low acceleration settings. I am on my mobile at the…"
Apr 7

Developer
leonardthall replied to Mihai's discussion LOITER and RTL crashing bug
"Yeh, this bug has been in the code since 2.9 so it was very unusual to have it come to the surface so reliably. I think it is because our control algorithms are getting better and able to use more and more of the motor range."
Apr 7

Developer
leonardthall replied to Mihai's discussion LOITER and RTL crashing bug
"Hi Mihai, Yeh, I came into this thread a little late when John asked me to have a look. This particular bug is a hard to find one because it is disguised behind other problems (or simply large command inputs) that you may not ever notice…"
Apr 7

Developer
leonardthall replied to Mihai's discussion LOITER and RTL crashing bug
"Hi Mihai, The bug was actually in the stability patch. This is the last bit of code that makes sure all motor outputs are in the right range and ensures that yaw and throttle doesn't stop roll and pitch from leveling the copter. So it the…"
Apr 7

Developer
leonardthall replied to Mihai's discussion LOITER and RTL crashing bug
"Sorry to hear about your crash Mihai! From what I can see your throttle did exactly what it was supposed to do. The angle boost function drops the throttle to zero as the copter roll's or pitches between 60 and 90 degrees. It looks like your…"
Apr 6

Developer
leonardthall commented on leonardthall's blog post ACRO for ArduPilot 3.1
"So what do you want to do or change? You should be able to get flying in stabilize on the defaults. "
Apr 3
Amr Lattar commented on leonardthall's blog post ACRO for ArduPilot 3.1
"yup , i have connected the APM , and i have opened the flight modes , but i don't know what to do next ! , i am stuck ! , there are the a lot of modes , stabilize mode , Althld mode , etc .. i want to know how to work on the stabilize mode ?! ,…"
Apr 3

Developer
leonardthall commented on leonardthall's blog post ACRO for ArduPilot 3.1
"what don't you get about the flight modes? Is your APM plugged in and have you connected to it? "
Apr 3
Amr Lattar commented on leonardthall's blog post ACRO for ArduPilot 3.1
"i want to ask , i am using an APM and i can't get the flight modes , i don't understand the way to work it out , i have opened the mission planner , but i can't move from there .. any help ?!"
Apr 3

Developer
leonardthall replied to Randy's discussion AC-3.1 autotune support discussion
"Thanks for your work!!! I will look through the logs. Start to post the detailed description here then copy and past it to the issues list when you are ready. Chat soon, Leonard "
Mar 29

Developer
leonardthall replied to Randy's discussion AC-3.1 autotune support discussion
"Hi Mihai, This is strange. Your copter is going to full throttle but still descending. Could you turn on motor logging and repeat the problem. The only thing I can think of that fits the symptoms is strong oscillations in your control loops. I…"
Mar 27

Profile Information

About Me:
RF Engineer with a solid understanding of filtering and control loops.
Please tell us a bit about your UAV interest
Quads and gliders.

My quad has been a quick development to take some aerial photography on a 4wd trip along the Simpson desert.

I am on my second frame design that now folds up nice and tight and also carries the go pro effectively. It has pitch compensation through the ARM2 and 5.8GHz video feed back to some Fatshark goggles.

I am happy with the pids but I feel like loiter could be improved. Most of my tuning problems have come from the absence of the latest control loop descriptions on the wiki. But that goes with a community development like this. Maybe when I have time to go through the code I can draw up some new diagrams for the wiki.

I have broken 6 props, 5 on parts of my body an 1 on the ground. I had an esc cut out and tilt the quad into my legs on landing. I reset the esc's and forgot to reset the cut-out. I then had a mystery takeoff at my feet as I was downloading logs. I had plugged the battery in because I sometimes have trouble connecting when only powered by usb. Stupid mistakes....

All in all I am happy with my first attempt, especially as I really only spent about 4 days over the last 4 weeks working on this and it is my first quad attempt.

I would like to thank the DIY drones team for a fantastic job and I hope I can help in the future.
Hometown:
Adelaide

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Leonardthall's Blog

ACRO for ArduPilot 3.1

Posted on June 29, 2013 at 2:42am 142 Comments

Hi all,

My motivation to get involved in the development team was to bring a good ACRO mode to ArduCopter. Three or four months ago Robert Lefebvre suggested that we could integrate the rate error and use it to correct the platform in the body frame. He went on to demonstrate this…

Continue

ArduCopter 2.9 PID Loops for STABILIZE, ACRO and ALT_HOLD

Posted on January 20, 2013 at 4:30am 17 Comments

Hi all,

I thought I would attempt to draw up a couple of diagrams of the PID loop in the ArduCopter 2.9 release.…

Continue

New Throttle PID Idea

Posted on October 24, 2012 at 3:39am 16 Comments

Hi All,

I have been thinking about the way we have implemented our throttle and the performance issues that we have observed. First of all I would like to say that I get great altitude hold. I can cruise around at 1 or 2 meters above the ground with no problems. It is only when I start to get…

Continue

Yaw Control, ESC Linearization, and Hover (Reconstruction)

Posted on September 17, 2012 at 9:23pm 0 Comments

I lost this post so I have attempted to reconstruct what I can of everybody’s replies. I think I did ok in the end. I continued my discussion of the topic here:…

Continue

Comment Wall (6 comments)

At 6:28am on November 25, 2012, Hans Jakob Bosshard said…

Hi Leonard,

Thanks for your comment! Thats really interesting. Are you working in research or on applications? I my younger days I worked in the domain of the good old stripline technique for mw oscillators and amplifiers at the ETH Zurich and later on mw transmission systems for telephony and video for a swiss telecom operator. Also some years in mainly system aspects for high bitrate fiber transmission systems  Now I am early retired due to restruction at this operator.

Is it possible for me to receive a copy of your Matlab / Simulink simulation software to get a feeling? I am not yet enough used to rebuild up your models including the quad in Matlab / Simulink.

By the way  I attached the sonar sensor some 8 cm away from the center (see attached photo). Now the noise and spikes are reduced quite substantially. A further reduction is expected when connecting the APM 2 to the BEC I received from the DIY Drone shop. Best regards Jack

 

At 6:47am on November 25, 2012, Hans Jakob Bosshard said…

Hi Leonard,

Another question concerning your Matlab/Simualtion sofware. Did you determine the quadrotor model i.e. inertia values by experiments? If yes, which way? I found recently indications that someone used a so called trifilar pendulum method (see Harris' Shock and Vibration Handbook).

Regards

Jack 

At 8:30am on December 8, 2012, Hans Jakob Bosshard said…

Hi Leonard,

With the new seperate BEC from the DiYDrone shop and placing the sonar sensor a few centimeters away from the electronic "center" the noise and observed spikes (when changing throttle) diminshed quite a lot. I am awaitung better times (without snow and rain) for a first fly outside for experiments and tuning.

Did you see already my last comment concerning receiving a copy of your matlab simulation program and determination of the drone i.e. inertia parameters and thrust?

Best regards

Jack 

At 11:47pm on February 28, 2013, zhang xu said…

Hi leonardthall, really thanks for that paper,  I'll try to figure out how it works and  try to use it fusing other sensors like Optical Flow and GPS or ACC. That filter is  really a fantastic magic, i'll learn how to perform that magic by my self. 

At 2:47am on March 1, 2013,
Developer
leonardthall
said…

Let me know if you want to have a chat about it over skype some time.

At 11:29am on May 2, 2013, Thomas Kranz said…

Hi Leonard,

since you developed the V-code please have a look here http://www.diydrones.com/forum/topics/custom-motor-config-for-quad-v-frame-need-help-to-configure-ap-1

thanks for your support

cheers from Germany

Thomas

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