QuadPlane Conversion of Hobby King Bix3 Trainer

I tried QRTL today and noticed the same “porpoise” issue than you. @tridge : any idea?

Pretty distinctive behavior as can be seen in the logs (C3 forward motor, C5 to C8 quad motors):

It still made progress towards the landing area in all three X, Y Z axes. I kind of let it do its thing until it came close to 1m above the ground and took over in QSTABILIZE.

QSTABILIZE, QLAND, QHOVER, QLOITER all work well. Also, a mission in AUTO with a WAYPOINT and VTOL_LAND show no such issue. So it seems very specific to QRTL.

BIN log here, see after line 260000: https://drive.google.com/file/d/0Bz8Gb5bfp9T2X2NDcTR5Szd3Rm8/view?usp=sharing

Some params here:

THR_SLEWRATE,100
LAND_THR_SLEW,0
ALT_HOLD_RTL,10000
RTL_RADIUS,1
WP_LOITER_RAD,60

Q_A_ACCEL_P_MAX,110000
Q_A_ACCEL_R_MAX,110000
Q_A_ACCEL_Y_MAX,27000
Q_A_ANG_LIM_TC,1
Q_A_ANG_PIT_P,4.5
Q_A_ANG_RLL_P,4.5
Q_A_ANG_YAW_P,4.5
Q_A_ANGLE_BOOST,1
Q_A_RAT_PIT_D,0.0036
Q_A_RAT_PIT_FILT,10
Q_A_RAT_PIT_I,0.25
Q_A_RAT_PIT_IMAX,0.444
Q_A_RAT_PIT_P,0.25
Q_A_RAT_RLL_D,0.0036
Q_A_RAT_RLL_FILT,10
Q_A_RAT_RLL_I,0.25
Q_A_RAT_RLL_IMAX,0.444
Q_A_RAT_RLL_P,0.25
Q_A_RAT_YAW_D,0
Q_A_RAT_YAW_FILT,5
Q_A_RAT_YAW_I,0.018
Q_A_RAT_YAW_IMAX,0.222
Q_A_RAT_YAW_P,0.18
Q_A_RATE_FF_ENAB,1
Q_A_SLEW_YAW,6000
Q_A_THR_MIX_MAX,0.5
Q_A_THR_MIX_MIN,0.1
Q_ACCEL_Z,250
Q_ANGLE_MAX,3000
Q_ASSIST_ANGLE,30
Q_ASSIST_SPEED,13
Q_AZ_D,0
Q_AZ_FILT,10
Q_AZ_I,1
Q_AZ_IMAX,800
Q_AZ_P,0.3
Q_ENABLE,1
Q_ESC_CAL,0
Q_FRAME_CLASS,0
Q_FRAME_TYPE,1
Q_GUIDED_MODE,1
Q_LAND_FINAL_ALT,6
Q_LAND_ICE_CUT,1
Q_LAND_SPEED,50
Q_M_BAT_CURR_MAX,0
Q_M_BAT_CURR_TC,5
Q_M_BAT_VOLT_MAX,0
Q_M_BAT_VOLT_MIN,0
Q_M_HOVER_LEARN,2
Q_M_PWM_MAX,0
Q_M_PWM_MIN,0
Q_M_PWM_TYPE,0
Q_M_SPIN_ARM,0.1
Q_M_SPIN_MAX,0.95
Q_M_SPIN_MIN,0.15
Q_M_THST_EXPO,0.65
Q_M_THST_HOVER,0.5
Q_M_YAW_HEADROOM,200
Q_P_ACC_XY_FILT,2
Q_PXY_P,0.7
Q_PZ_P,1
Q_RC_SPEED,490
Q_RTL_ALT,12
Q_RTL_MODE,1
Q_THR_MAX_PWM,2000
Q_THR_MIN_PWM,1000
Q_TILT_MASK,0
Q_TILT_MAX,45
Q_TILT_RATE,40
Q_TRAN_PIT_MAX,3
Q_TRANSITION_MS,5000
Q_VELZ_MAX,250
Q_VFWD_ALT,0
Q_VFWD_GAIN,0.05
Q_VXY_FILT_HZ,5
Q_VXY_I,0.35
Q_VXY_IMAX,1000
Q_VXY_P,0.7
Q_VZ_P,5
Q_WP_ACCEL,100
Q_WP_ACCEL_Z,100
Q_WP_LOIT_JERK,1000
Q_WP_LOIT_MAXA,250
Q_WP_LOIT_MINA,25
Q_WP_LOIT_SPEED,500
Q_WP_RADIUS,200
Q_WP_RFND_USE,1
Q_WP_SPEED,500
Q_WP_SPEED_DN,150
Q_WP_SPEED_UP,250
Q_WVANE_GAIN,0
Q_WVANE_MINROLL,1
Q_YAW_RATE_MAX,100

Anthony,

Thanks for the additional information!

I’ll have to try replacing Hybrid RTL with a return combo of DO_VTOL_TRANSITION about 50m away, then a VTOL_LAND.

I looked into the Release Notes here for v3.7.0 and did see something interesting and maybe worth testing.

Has anyone tried it?

improved quadplane auto-landing

I use APM:Plane 3.7.0 by the way. So the QRTL issue is still there.

Ok, thanks, Anthony.

In my second autonomous flight with the Bix3 QuadPlane, using APM Plane 3.6.0, I replaced the RTL or Hybrid RTL commands with a DO_VTOL_TRANSITION 3 and VTOL_LAND. This eliminated the two issues I previously had when landing.

I also enabled the Weathervaning feature with the default value of Q_WVANE_GAIN = 0.1. This feature also appeared to work great!

2 Likes

Hi Greg,
I’ve been looking for a similar 3 Axis Gimbal, can you give me the details of the one above on the Bixler 3 ?

Regards,
Kevin

Hi Kevin,

The gimbal is made by Fatshark and is sold at various places. Here are a few…

[URL=“http://www.hobbyking.com/hobbyking/store/__51068__Fatshark_3_Axis_Pan_Tilt_and_Roll_Camera_Mount_System_Supported_By_Trinity_Head_Tracker_.html?strSearch=fatshark”]Fatshark 3-Axis Pan Tilt and Roll Camera Mount System at Hobby King[/URL] $50 (backorder)
[URL=“https://www.readymaderc.com/store/index.php?main_page=product_info&cPath=11_408&products_id=2370”]Fatshark 3-Axis Pan Tilt and Roll Camera Mount System at RMRC[/URL] $35 (in stock)

I upgraded my Bix3 firmware from Plane v3.6.0 to v3.7.1. There are significant changes between the two releases but I was able to perform a nice QSTABILIZE in my backyard and hover around a bit. When I loaded my saved params from v3.6.0 into v3.7.1, many of them were not recognized and I needed to manually go through them to find several changes.

Overall, it looks like v3.7.1 is working and I will re-test some things that I did using v3.6.0 as a sanity check. I posted my two param files below.

Bix3withQuadPlaneV371.param (12.8 KB)

Bix3withQuadPlaneV360.param (12.8 KB)

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hello GregCovey thank you for your sharing, I also met such problem before .

Hi Greg, is there any reason you need to re-load your parameters after doing a firmware upgrade? Why would the existing values not be retained?

Jacques,

Sometimes the parameters change names or position in flash where they are stored. I have seen it when you don’t need to re-load parameters after a minor firmware upgrade and many times when you do need to re-load them. Sometimes, even the ACC and compass re-calibrations need to be done as well.

Greg,

What sort of flight time are you getting with your Bix 3 Quadplane setup?

I am finally starting my conversion. I will be using a DJI E305 Quad set, a similar but maybe a higher spec than your motors. I am hoping that I can sling a small mirror less camera underneath.

It seems my hover current will be a max of maybe 16A, meaning I could maybe use a 7000 mah Li ion pack weighing 400g and putting out 21A max. This maybe would allow a Sony RX100 to be added. All a bit speculative–will need to validate this with a Li Po.

It would be nice to have a hybrid system that could blend the power from a small LiPo and a larger Li-ion pack. There are chips that do this http://cds.linear.com/docs/en/design-note/dn277f.pdf I wonder if Christian Mauch would look at this. Seems there may be a good use for this in this class of UAV.

Hi Marc,

I’m using a 4s 2800mAh Zippy 30C pack that weighs 10oz. The total flying weight goal was 58oz so I am close to that or a few ounces under. Since I built my Bix3 QuadPlane as an initial test platform, I used motors and ESCs I had on hand. I also choose the 4s Zippy Lipo pack because it was similar in size and weight to my stock 9oz Multistar 3s 4AH pack for balance.

My initial tests were focused on autonomous hovering modes and transitions so I never flew more than a few circuits as a normal plane in forward flight mode. My best guess is that I can at least hover for 5 minutes and fly for 5 minutes for a 10 minute flight. Obviously, the less time you spend hovering the greater the flight duration…especially during autonomous flights. My Bix3 isn’t currently set up to measure current.

I’m not sure how much the Sony RX100 weighs but you can use the APM Throttle MID setting as a sanity check and perhaps over drive your quad system knowing that your hover periods will be short (not like a copter).

My larger Ranger EX QuadPlane conversion has a Mauch PM as does my FireFLY6 so I can analyze flights better. One tool do to this is ExMaps. The link below is from my FireFLY6 test survey which used about 1/2 of my 6s 5200mAh pack.

Mapping Survey Test 2

An RX100 is 240g (sorry I fell for that Napoleonic racket, the metric system) but with some antivibration we are at 300g. My Nex5Rs are 500-700 depending on lens choice. Too much.

I will have a Mauch pm in the Bix.

I am hoping I can get a 4s LI Ion pack with 5000-7000 in there. This may all be infeasible, of course. In theory It can supply enough current to hover and the weight savings are substantial. My concern would be that it may struggle to land on li ions at 30%.The DJI escs and motors will have no issues though.

A 1500 mah backup battery to land would be appealing but it would need customized circuitry…

We will see… …

Ok I’m in, copying this excellent build slavishly (well sort of with what I have available)

Hi Gary,

The Bix3 makes for a great conversion to a QuadPlane because it is relatively light and has plenty of lift. Being able to remove the wing with two 90 degree twist screws is a real pleasure! The new Plane v3.8.0 firmware seems to working well for most.

Cheers!

It’s an older 2 that I have, along with some very dodgy motors the size of which I am not sure! Your write up is fantastic, thanks for taking the time.

I can’t resist publishing it. It’s a token of thanks to Greg Corey for helping so much and sharing his knowledge. I join in the thanks also :grinning:

FrankenBix, I love it! :slight_smile: