Bartman
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sorry, what are you referring to?
2013 MRF Flight Control Assessment
- Thread starter Bartman
- Start date
sorry, what are you referring to?
StillHappy
Member
I believe he was referring to droider commenting on a loss
SMP
Member
Hi Bart,
the Feel comment was really related to Pilot Impression. To be candid the DJI lineup has worked quite well for me in Feature Set and "Feels" responsive and accurate in flight. Perhaps even more than I prefer as the level of correction that DJi applies in Atti/GPS is significant, meaning smooth video flights require lower gains. Manual is manual but have heard that Hoverfly is the king of smooth in Gyro modes...
Interestingly the Disco when using EZUHF w Naza "feels" sluggish and less responsive to stick input. I realize thats a bit of Apples versus Oranges but thats what I'm talking about in terms of feel.
the Feel comment was really related to Pilot Impression. To be candid the DJI lineup has worked quite well for me in Feature Set and "Feels" responsive and accurate in flight. Perhaps even more than I prefer as the level of correction that DJi applies in Atti/GPS is significant, meaning smooth video flights require lower gains. Manual is manual but have heard that Hoverfly is the king of smooth in Gyro modes...
Interestingly the Disco when using EZUHF w Naza "feels" sluggish and less responsive to stick input. I realize thats a bit of Apples versus Oranges but thats what I'm talking about in terms of feel.
I think DJI mastered the simple task of creating a stable platform at a very early stage of development. The problem is that as they made the autonomous flight options more complex, the model when flown in GPS and also atti. would try to fight you and bring it to a halt when you wanted to carry on flying your own track. Not enough information was available to explain the best way to use their product in the early days.
It's not just the Naza that feels a bit numb with EZUHF, pretty much every flight controller I've had setup on it felt the same way leading me to believe the EZUHF is slower than other long range gear. I recently put the EZ aside and started using a Turnigy 9XR with OpenLRS TX and OrangeLRS RX for my FPV quads. Much better "feel", response was much the same as using a straight 2.4 setup right up to the moment the 9XR dropped dead in the middle of a flight! Lesson learned, don't trust a $50 radio with anything of value, the TX failure led to a crash of a new build I was test flying resulting in a total loss of the frame and props when it crashed head on into a stone wall at roughly 25 mph...
Attempts to revive the 9XR were unsucessful, not that I'd ever trust it again anyway. Picked up a used Futaba 10C off eBay so I could continue to utilize the Open/OrangeLRS gear, just completed getting most of the fleet up and flying again on the new Futaba/Open combo and I have to say it's far better than the EZUHF for response and the Futaba, as much as I dislike them, is light years more stable and well built than a Turnigy TX, it actually works out to be a decent long range system since the OpenLRS module was specifically designed to fit and work in a Futaba TX. I've yet to field test it but I see no reason why it won't work as well or better than the Turnigy/OpenLRS setup did for FPV.
I also have some FRSky 2.4 telemetery capable module and RX's scheduled to be delivered today for use in the 10C. Rumor has it that the standard FRSky 2.4 gear is easily capable of over a mile in range out of the box, making it a better alternative for multirotor FPV if you want to stay with 2.4 frequencies on control, we'll see if that's truth or fiction soon enough.
On the subject of flight controllers, the DJI stuff can be made to fly smooth enough in ATTI mode, however I've never found it to work well trying to actually fly in GPS mode vs. simply using GPS to stay in a stationary hover. None of the flight controllers I have with GPS fly well with GPS turned on, that's not really the intent of that mode. While most all of them have the capability to change position with P/H engaged, none of them are particularly smooth doing it which comes down to a matter of firmware and the speed of the GPS and main processor IMO.
I've recently been playing around with a lot of Multiwii boards as well as the APM, and now the latest MK upgrade to 2.2 which I have to say has brought me back around to making MK my front line F/C for anything APV related. A simple upgrade really, just adding a much better ACC chip to the board and upgrading to the latest firmware to take advantage of the features. Right now it's only utilizing the Z axis to stabilize the altitude hold and I have to say Holger has done well with this upgrade, the A/H function works as well if not better than anything DJI that I own, now it's just a matter of waiting for the code upgrade to utilize the other two axis to tighten up the position hold by implementing predictive positioning as used bu DJI, APM, and some others.
As far as gyro only modes go, I've flown the H/F with the latest and greatest firmware and while it's a vast improvement over what it used to be I don't find it to be that much better than any of the others I have when properly tuned in manual mode. I actually find the Multiwii to be the best overall for manual flight but it's no where near as simple to setup and get to that point as the H/F, the upside being that once you do learn the knack for tuning PID parameters there are a number of advanced features you can use on the Multiwii boards that actually work well enough to not worry about what's going to happen when you flip the switch. Two of my FPV quads are setup with the Multiwii Pro series boards utilizing the Atmel 2650 processor and they do all the things the Naza does, including RTH. The only thing they don't do is autoland but I'm more concerned with the quad coming back, gravity will make it land when the battery runs down if it comes to that.
Ken
SMP
Member
LOL - Last line made me laugh!! No doubt, no doubt! Ken, that was perfect, THANK YOU!!! Very much appreciate the time writing that up and very good to know that sluggish feel seems to be the norm w ezuhf. Your post made me realize I've gotten far too lazy and expect way too much from that GPS mode Time to go back to flying I guess Thx mate!!!!
Time to go back to flying I guess Thx mate!!!!PeterLester
Member
You might be able to call up the specs on the 50 ohm coax of choice to determine dB loss per foot but most of the dB loss occurs at each connector (the fewer the better). Best also to put heatshrink over the connectors as the insulator between the center wire and the shield typically absorbs moisture which greatly increases dB loss at the connection points. The good news is one can often buy a higher dB gain antenna which improves radio range and therefore helps to overcome the coax cable attenuation and connector attenuation. Looking outside of the 2.4 Ghz spectrum I have tested a 10 dB gain magnetic roof antenna mounted on the roof of my van with my DJI 900Mhz datalink and the range is beyond that advertised...... only thing is that modifications such as higher gain antennas can technically exceed the legal threshold for using a 1 watt radio even fhss license free.
The FRSky gear did arrive yesterday and I spent some time during lunch testing it out. One very nice feature is the ability to do PPM to the flight controller, one wire and no birdsnest of cabling! I got the telemetry capable TX/RX plus the little display screen that shows the data returned from the RX, very nice to be able to monitor the RSSI while flying without having to resort to FPV gear and an OSD. The RX has diversity antennas built in and the telemetry display shows the RSSI level for each so I decided to do some ground level testing to see how much obstruction the gear could handle before the signal level dropped to the point of losing the link. I put a quad in the far corner of the backyard on the ground around the side of the house and walked to the far opposite end of the house and then under the overhanging roof of the basement slider. The quad was completely out of sight with a substantial amount of house and a couple sheds full of lawn and garden equipment in between TX and RX, still had an RSSI level of 75 to 80% which I have to say is impressive for 2.4 with that much obstruction. No matter what I did I was unable to make the signal level drop below 70% with as much obstruction as I could find within my property which leads me to believe it will in fact work out to a mile or more in flight.
I hope the weather cooperates over the weekend so I can get out to the flying field and put it to the test. If I go to the furthest part of the field and fly out from there I can get about 3/4 of a mile while still remaining within the bounds of the property and not flying over people or houses. If it still has 70 to 80% RSSI level at that distance then I see no reason to have a dedicated LRS system for flying a multirotor on FPV. I've calculated my maximum range on the most efficient quad I have to be roughly 2 miles maximum on outbound which would give me just enough juice in the pack to get back to the takeoff point and not much more. For all practical purposes I'll limit it to a 1 mile radius from takeoff point, there isn't much of anyplace within any reasonable driving distance where it would be possible to fly that far around here and have any chance of recovery if the multi went down in dense woodlands or not be flying over populated/builtup areas so I'm happy with knowing the 2.4 radio gear can handle that much distance without worry. Another plus is the RX outputs an RSSI signal on the servo pins when using PPM so I can pipe that into the OSD and still be able to monitor the signal level through the goggles, looks to me like the FRSky gear is win/win for multirotor FPV.
One last point, since I already had a few of the quads setup on the T10C using the OpenLRS gear via PPM, it was a straight forward swap the module in the TX and then swap the RX and do a bind, that's all that was required to change radio systems over! Nice to know I can easily swap back and forth if for whatever reason I need the extra distance that the lower frequency gear will give. And for those that care about licensing aspects, the FRSky gear carries FCC Part 15 ID numbers so it's certified for use without needing a HAM license.
Ken
I hope the weather cooperates over the weekend so I can get out to the flying field and put it to the test. If I go to the furthest part of the field and fly out from there I can get about 3/4 of a mile while still remaining within the bounds of the property and not flying over people or houses. If it still has 70 to 80% RSSI level at that distance then I see no reason to have a dedicated LRS system for flying a multirotor on FPV. I've calculated my maximum range on the most efficient quad I have to be roughly 2 miles maximum on outbound which would give me just enough juice in the pack to get back to the takeoff point and not much more. For all practical purposes I'll limit it to a 1 mile radius from takeoff point, there isn't much of anyplace within any reasonable driving distance where it would be possible to fly that far around here and have any chance of recovery if the multi went down in dense woodlands or not be flying over populated/builtup areas so I'm happy with knowing the 2.4 radio gear can handle that much distance without worry. Another plus is the RX outputs an RSSI signal on the servo pins when using PPM so I can pipe that into the OSD and still be able to monitor the signal level through the goggles, looks to me like the FRSky gear is win/win for multirotor FPV.
One last point, since I already had a few of the quads setup on the T10C using the OpenLRS gear via PPM, it was a straight forward swap the module in the TX and then swap the RX and do a bind, that's all that was required to change radio systems over! Nice to know I can easily swap back and forth if for whatever reason I need the extra distance that the lower frequency gear will give. And for those that care about licensing aspects, the FRSky gear carries FCC Part 15 ID numbers so it's certified for use without needing a HAM license.
Ken