LibrePilot Forum
Users => Applications - Autonomous Flight => Topic started by: TheOtherCliff on June 11, 2016, 01:03:40 am
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When all transmitter sticks are in the center, it's effectively doing PositionHold and will stay in one place both horizontally and vertically.
Leaving the throttle stick in the middle (+-10%) and it stays locked at that altitude (as well as GPS and baro can manage). Hold the throttle stick above the middle to make it climb at a constant rate that depends on throttle stick position. Below half makes it decend. The farther away from center throttle, the faster it moves up or down. Be careful. If you move the throttle stick all the way to the bottom the motors will stop. This is a safety feature to allow you to easily stop the motors when needed. This safety feature can be overridden (not really recommended) with a little bit of high throttle trim. Now you know how to adjust your altitude. I generally set my altitude where I want it and then leave the throttle stick in the middle.
All sticks in the middle and it is in PositionHold. To make it move forward, press and hold the pitch (elevator) stick forward. It will move forward as long as you hold the pitch stick forward. Release the pitch stick and it will slow down and stop. Be careful because it doesn't stop instantly when you release the sticks back to center position. Altitude is managed automatically for you, even in forward flight.
While you are holding the pitch stick forward and it is moving forward, press and hold the yaw stick a little to the left. It will circle left. Holding right yaw will make it circle to the right. As long as you hold the pitch forward you can drive it like a car with yaw. The more yaw, the tighter the turn, just like a car. Too much yaw and you will spin out like a car doing doughnuts.
Instead of using forward pitch stick, you can use any combination of roll and pitch, for instance you can hold left roll stick and it will fly straight left as long as you hold that left roll stick. Now comes the interesting part. While flying (for instance) straight left, the yaw works exactly like when you are flying forward. Left yaw makes it circle left and right yaw makes it circle right. You are driving a car again. You don't need to remember what direction you are moving. Nothing is different than when flying forward.
The doubly interesting part is that you can fly straight left (or right) and use right (or left) yaw to fly a circle with the nose pointed inward the whole time. Great for making a video of something from all sides.
I've been doing this for a while and was talking to a friend about it. I thought I would post as an interesting flight tip. Give it a try. I highly recommend it as your first GPS flight mode. Of course there is a lot to do to get GPS flight working well and you should always have plain Attitude mode available as your takeoff and emergency mode.
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Great information Cliff. I'm going to give this flight mode a little more attention, particularly for my aerial video/photography.
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Which thrust to use with velocityroam?
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I tested the flight mode Velocityroam with the configuration shown in the photos and complementary +mag+gps outdoor . I managed to quadcopter using only the directional pitch and yaw. I wonder if I have properly configured the flight modes, or I could choose other combinations.
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Use "GPS Navigation INS13", use some form of aux mag, and get your wiring twisted / mags working (even with motors running and props on).
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Use "GPS Navigation INS13", use some form of aux mag, and get your wiring twisted / mags working (even with motors running and props on).
I have no problems with the magnetometer. I wanted to know if I can use with velocityroam the mode gpsassist and in thrust column is correct to leave manual.
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Use GPS Navigation INS13. Don't try complementary+mag+gps outdoor for this until you have it running in INS13. There was talk of making Complementary+mag+gps work for GPS modes, but I don't know it that was done.
Don't use GPS assist with any GPS mode (VelocityRoam is a GPS mode). It is designed to give a GPS Position Hold feature, to non-GPS modes, when sticks are centered.
Velocity Roam does not have a thrust column, but you can switch it between Auto (acts like Altitude Vario thrust mode) and Manual in System->Settings->VtolPathFollowerSettings->ThrustControl. Select ThrustControl, change it, reselect it, and press the red up arrow at the top of the screen. Default is Auto.
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Use GPS Navigation INS13. Don't try complementary+mag+gps outdoor for this until you have it running in INS13. There was talk of making Complementary+mag+gps work for GPS modes, but I don't know it that was done.
Don't use GPS assist with any GPS mode (VelocityRoam is a GPS mode). It is designed to give a GPS Position Hold feature, to non-GPS modes, when sticks are centered.
Velocity Roam does not have a thrust column, but you can switch it between Auto (acts like Altitude Vario thrust mode) and Manual in System->Settings->VtolPathFollowerSettings->ThrustControl. Select ThrustControl, change it, reselect it, and press the red up arrow at the top of the screen. Default is Auto.
Yesterday I flew two flights to test the velocityroam. the first flight I did it with ins13 and the second in with complementary+ mag outdoor gps. I did not notice obvious differences in flight. I just noticed that the UAV location on the map was more accurate with complementary Mag outdoor gps.
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I would like to hear from you if quadcopters keeps better a fixed position at altitude hold mode position or velocityroam 50% of stick travel.
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Altitude Hold is baro only so it drifts horizontally.
The other modes (PH and VR) use the same code when sticks are centered in VR mode.
GPS modes rely on baro a lot more than GPS for short term altitude variations so baro modes are probably about the same as GPS altitude holding modes.
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I perform take off in attitude and than switch to velocityroam. The question is if I can perform the landing in velocityroam or I must switch to attitude mode?
Inviato dal mio SM-G800F utilizzando Tapatalk
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I do that all the time. The important part is to stop the motors soon after landing. If you let motors run a while, and GPS drifts, it will try to move horizontally and tip over.
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Hello there. In VR mode with throttle midstick and starting to move forward and keep going (or any direction horizontally) the copter loses height (about 2m). When you let go of the stick, the copter slows and stops and then climbs back to its its initial height (climbs about 2m). The copter maintains altitude perfectly when sticks are centered.
Is there a way to minimize this decrease in altitude during horizontal movement?
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Hi. I think that thi s loses of hight is depending by the max tilt that you have decided in gcs setup. If the angle falls the fc will make less effort to keep the high . Or the problem is related to the quality of the baro. But I think it is not the last hypothesis.
Inviato dal mio SM-G800F utilizzando Tapatalk
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It could be the CruiseControl max boost setting (default 100% IIRC), but this kind of drop is often caused by wind blowing on the baro and it seeing lower pressure and thinking it is too high and reducing the altitude.
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Hi, the baro is fine. It's a miniRevo (in a case with foam on the baro) and the fc has a canopy on it. PH is rock solid. 8)
Max tilt is default, I didn't adjust this.
Under Settings\Control\StabilizationSettings there are 6 CruiseControl.... settings.
Some are at 100%. Can these be set to beyond 100%?
There is no balloon help, can I find explanation of these somewhere?
youtu.be/cuvGy3NN7-8?t=20 I bank to the left and the copter drops when I let go of the stick and then slowly climbs back to its initial altitude. This is a short example at low altitude. If I kept banking left, it would drop during banking (about 2m).
I'm just curious if there is a way to tune this.
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When it is banking and when it is moving the air is flowing differently and that does make a difference as to how much hits the baro.
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Hi Cliff,
Do you have a video, showing the VelocityRoam mode?
Thanks
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Hmmm. Sorry, I don't. At least I don't have one where I explain what the sticks are doing while it is flying in the video. :( An FPV video would show it flying straight forward at constant altitude and speed and then, while maintaining speed and altitude, making wide, graceful turns to come to a new direction forward.
Maybe I can explain a little. With all sticks in the center, VR is just PositionHold. All the sensors act together to keep it in the same place (including altitude) and pointing in the same direction.
Now hold a little yaw and it rotates in place to change direction, but still without changing location. Use full yaw stickj for a few seconds to see it spin like a top. Release the yaw stick.
Now, constantly hold a "small" amount of forward pitch stick and you have commanded it to constantly travel straight forward at a constant "small" speed (not a certain bank angle). If you constantly hold left roll stick instead of forward pitch stick, it is commanded to fly sideways at a constant speed. While doing this, everything else stays the same. Altitude stays the same (and is held "exactly" there by baro and GPS data). Yaw stays the same, so it remains pointed in the same direction.
The fun part starts by constantly holding a little forward pitch stick so you are constantly travelling forward slowly. Hold the forward pitch constantly from now on. Now move the yaw a little to come to a new heading. You are now travelling forward in a new direction. The yaw acts just like a steering wheel in a car. Too much yaw and it even slides out like a car in a tight corner (but much less violently :) ).
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Holy moly , !
Tried Velocity Roam on new - to - me camera ship with small fpv rig on board
- tried that " pitch forward ,then steer like a car with yaw "
Awesome.
Thanks for the tip.
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Now try roll left (simply makes you fly left) instead of pitch forward (which would make you fly forward) and discover that you can still steer it with yaw and you don't have to even think about the fact that it is going left instead of going forward. It acts the same.
Then use constant roll left to fly left combined with a small constant amount of yaw right (to make a circle to the right). This combination makes a circle with the nose always pointed inward. This is great for making a video of something from all sides. :)
And it works the other way too. Roll right and yaw left.
If you find that the point of interest you are trying to circle is not perfectly in the middle of your circle, you can open the circle up (less yaw) or tighten it up (more yaw) to get your point of interest back in the center of the video you are taking.
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I've read that if the throttle is brought to the maximum, the engines turn off. why?
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Minimum stops motors as a safety feature.
If it is about to crash into your best friend, you don't want to have to hunt for a disarming switch. :(
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Minimum stops motors as a safety feature.
If it is about to crash into your best friend, you don't want to have to hunt for a disarming switch. :(
sorry but maybe I did not understand. you tell me that for a safety function if you move the engine lever at maximum speeds, do the engines stop it? but then the quadricopter would fall like a stone without being able to put it back to the top
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Maximum simply climbs at maximum rate. In this mode, the throttle stick controls a climb/descend rate. The default value (in vtolpathfollowersettings) is 4 meters per second so max is climb at 4 m/s (this is not full throttle for most quads).
Just above lowest throttle stick descends at 4 m/s. Lowest throttle stick stops motors. Does not disarm. Simply bump throttle to a setting above the bottom to restart motors.
Middle throttle stick (+-10%) is exactly the same as AltitudeHold and is not supposed to drift at all.
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Maximum simply climbs at maximum rate. In this mode, the throttle stick controls a climb/descend rate. The default value (in vtolpathfollowersettings) is 4 meters per second so max is climb at 4 m/s (this is not full throttle for most quads).
Just above lowest throttle stick descends at 4 m/s. Lowest throttle stick stops motors. Does not disarm. Simply bump throttle to a setting above the bottom to restart motors.
Middle throttle stick (+-10%) is exactly the same as AltitudeHold and is not supposed to drift at all.
Ok now I understand. sorry but I was badly interpreted.