Maiden of Bush Mule and Foxeer Camera

A double maiden today, in the air at the same time in exactly the same place.

The first maiden is the Avios Bush Mule, released by hobbyking as the successor to the Sky Mule. The new Bush Mule has much larger tyres, an openable cargo door, and new lights I believe. The upshot is a twin engined STOL cargo plane which is very capable on a standard field such as ours.

The handling of the plane is excellent, out of the box needed very little trimming, the place is responsive, but can be turned down, very much in the same character of a high wing plane such as the tundra or the riot. The advantage of course is that it is a twin so has the clear forward view from the nose. This clear view, big landing gear, and loads of space inside for an autopilot system does, in my view make the plane ideal for an FPV plane, although I haven’t put the FPV gear in this plane yet.
From my flights today I haven’t gained confidence enough to slow the plane down enough on landing, so my landing were rather fast and bouncy, but I think that will come as I get more used to it.
This leads us to the second maiden which is for the Foxeer Legend 2 camera

The camera is the same form factor as the mobius, similar size, similar lens and similar weight. However the legend 2 has a frame rate up to 240 frames per second at 640×480 and a maximum resulution of 2880×2160 (UHD) at 24 frames per second, giving the nice option of 60FPS at 1080p HD. It also offer HDR (High Dynamic Range) which give better colour reproduction and Electronic Image Stabalisation (EIS). The camera also has an AV ouput making it suitable for FPV and a silicon case to offer a little protection to the camera in the event of a crash. Finally the camera can be configured via wifi from a smartphone. A quite impressive package for £53 from banggood, even more impressive when you realise this is significantly cheaper that the new Mobius which still has a maximum resolution frame rate of 1080p @ 30fps. Here is the mobius and the legend2 side by side.

Then here are 2 video taken from the bush mule on the legend2 the first video is 1080p@60fps

the second is taken at UHD@24fps although youtube did breifly show this highest resolutions when I uploaded it, it then disappeared, maybe it will re-appear later, but here it is.

Both these videos were taken with HDR and EIS turned on. Most image stabalisation seems to damp movement on the video, on this camera the most noticable effect is that fantastic stills can be taken from the video, I recommend that you click on this image to see the full size image, and just how clear it is, such little jitter and shake on the image:

An equivalent picture from a mobius

All in all I am very happy with both the plane and the camera, and I would happily recommend both anyone.

Strafing…?

It sounds more like something Scott or I would have done, but it was Norman who had a bit of a moment this weekend with his Radion, and appeared to do a bit of a strafing run on poor Steve who was minding his own business, bungee flying in the next field. You can almost see the whites of his eyes:

All joking aside, it is a reminder of the dangers inherent in our hobby, how important it is to be aware and alert to the aircraft around and how much worse this could have possibly ended.

Thank you to Norman for the video.

Slow Circle

Continuing to work on the quadcopter with Multi-Wii Pro board I added a bluetooth module to it

bluetoothmodule

and used the android application EZ-Gui Ground to communicate and upload the waypoints for a misson

Screenshot_2015-10-23-16-39-06

Starting with a simple circle of the field. This was uploaded to quad, the quad taken off and then the mission activated the quad then made its own way round the waypoints programmed as you can see from the video below:

At the end of the video you can see Scott’s Corsair, then the quad way landed manually.

 

A Game Of 2 Halves

This last weekend Mel and Adrian organised a trip to the Great Orme in Llandudno for a bit of slope soaring.

As novice soarers, Scott and I joined the trip to get some flying hours in, although we would be going only for the Saturday and Sunday where Adrian and Mel stayed for an extra day.

The weekend certainly was a game of 2 halves. Saturday after sitting on the M6 for rather longer than anyone would want to, we arrived to find a wind swept Mel and Adrian enjoying themselves on the Orme. This was one of the new planes that Scott and I bought, the Wraith (mine didn’t fare so well)

but then as the weather closed in a little we headed back to the B&B for the night

DSC_0051

The next day the wind was very light from the south east, we went up the mountain, but there just wasn’t enough wind to fly anything really, certainly not novices like me.

DSC_0053

We will leave it to Colin to describe what he is doing here

ColinsSeaView

Mr Adrian did explore the area with his bird of time trying to find any lift. Keeping with the post this is also in 2 halves…

But didn’t find any.

So we found something else to do:

All in all a good weekend, so thank you to Mr Adrian and Mr Mel for organising the trip and thanks to Scott and Colin for making it such a fun weekend.

Norman and Junior.

Well it was Norman’s Junior (plane not son) but Adrian did the flying. A beautiful old style plane from the pioneer flying days. High dihedral, beautiful paint job, big open field landing gear, and a beautiful (but fake) single cylinder head through the top of the fuselage, it can’t help but evoke some emotion in any flier. Thanks to some fantastic flying by Adrian making some very close passes to the quad, frankly scaring the b-jesus out of me (the wide angle lens doesn’t quite show how close it seemed from the ground) there are some lovely shots of it from the air. The eagle eyed amongst you will notice that it is starting to rain, this was the last flight of the day.

Enjoy:

Thank you very much to both Adrian and Norman.

On a technical side, the change of props and tweeks of the control software has stabilised this a lot, I have also run this through some deshake software just to take the rest of the Jello and bit of vibration out of this. (The original video without being run through the deshake software can be seen here if anyone is interested: https://www.youtube.com/watch?v=7BdKX2DpEMk)

 

Bird of Time from the Air

I’ve been slowly improving my quad copter. I previously had a servo based camera mount which was less than ideal with the camera jumping a lot. So I managed to find a cheap brushless gimbal complete with controller, sensor and brushless motors.

$_14

It was designed for a gopro, but with a bit of balancing I got my mobius mounted up on in. This was the maiden test taking some shots of Adrian’s Bird of Time. Much smoother, I definately need to work on my filming technique.

The day was rather breezy and I did have some problems keeping the quad under control at various times.

A bit of deshake software does the video the world of good too:

Second Attempt at Air-to-Air Filming

This time I worked with Scott to try to film from the quad. Again flying Line Of Sight, even with a slower plane and cooperating with the pilot I simply couldn’t keep up with the plane. The quad just couldn’t get enough speed, when I increased the power to try to speed up I had to be very careful not to gain too much height. If I did gain height then I had to drop the power to come down again so couldn’t get much speed. And again with the wide angle lens the plane was a bit of a dot in the landscape.

From this I think the probability of actually successfully following a plane with the quad is quite low, fly pasts may be possible, and flying FPV may allow much closer fly pasts than line of sight flying.

Also I think the gimbal that I have used on the quad is lacking.

20141231_074407

all the weight of the gimbal and the camera is being held on the tiny screw into the front of the servo. I’ve tried with metal geared servos, and plastic geared, neither are particularly satisfactory. So I have had a new gimbal printed which uses a much larger servo for the connection to the quad.

20150323_183616

Hopefully this will be more robust, give less wobble, and if I can add some anti-vibration to it then I am hoping the video quality will improve.

First Try at Quad Air to Air Filming — Or Quads IV – A New Hope

Yes I’m now up to the 4th revision of my quadcopter (sorry Scott, I couldn’t resist carrying on your Star Wars theme). I’ve now used 3 different frames and 2 different controller boards, and this is now the latest version, now with a new frame with landing skids, turnigy 1400kv motors, 8×6 props but using the same Qbrain quad ESC and MultiWII pro controller board from the previous version.20150208_141442I try to tune the copter to make it basically flyable without using the self levelling function of the MultiWii board, this configuration needed higher P setting (around 6 to 6.5) and higher I setting (around 0.2). Although I wanted to set these higher, raising them above this level creates feedback and big wobbles. Switching on the self levelling now keeps the quad reasonably stable, having these settings lower switching on self levelling generated a ‘noticeable’ feedback wobble.

So now with my new quad trimmed and stabled out (well as good as I can get it for the moment) I gave it a bit of a more sedate test flight, and tried to do a bit of tracking of other planes in the air. Although as I was flying line of sight and trying to track other planes without specifically working with the associated pilots (so needed to try to ensure that I didn’t get it their way or crash into them). The results were limited:

Sorry for getting a little close and worrying you there Mr Mike. With the wide angle lens the planes are a bit of a small dot until I was very close, perhaps a mobius with a standard lens rather than the wide angle may be better for this type of filming. I have also tilted the camera down a little for improved FPV vision, again for this air to air filming a more horizontal position would be better. The board’s program can be updated to make this dynamic from a receiver channel, but I am out of channels both on my transmitter and receiver. Also the camera is getting quite a bit of vibration and wobble, some of this is certainly down to the fact that the camera is out on a platform stuck out of the front of the quad, so is going to always be susceptible to this, but also I think the standard analogue servos I am using would allow the platform to wobble more than I would like, so I have ordered some metal geared digital servos to replace these, they should hold the gimbal more securely. I will try again once they arrive.

The change to the faster motors and smaller props seem to make the quad a little more difficult to tune, they certainly use battery life more quickly, but other than this don’t make a huge amount of difference to the quad.

 

Update 16/02/2015

 

Over the hills and far away

I wanted to test the camera gimbal on my quad, and I certainly did that.

After a quick orientation I decided to get a bit of height, see how quickly it can climb, get a bit of speed and generally give it a bit of a shake down. At ground level there was very little wind, so I didn’t anticipate just how much wind there was at height. This was recorded from the ground station, I think the only reason that I got such a good range from it was because of the height that the quad ended up at.

The speed is shown on the left, with the maximum recorded speed shown above the slider, the height shown on the right, again with the maximum recorded height above the slider. Sorry I haven’t removed the sound so please turn the sound off before playing it.

As you can see the maximum recorded speed appears to be 61mph at a height of almost 1000ft.

We did a significant amount of searching both on my own and then with Scott and Tracey by car, with no luck. After returning home and using a better internet connection I used the last frames recorded, converted the coordinates to full decimal format, which google seems to like displaying better, this was a location that we didn’t search. (click the image to open google maps to that location)

lostquad

So I made my way back and there it was, almost exactly in this location (just over 1.1 miles from the takeoff point):20150125_153608

Needs a little work, but at least everything has been retrieved.

On the bright side the gimbal appears to work perfectly.

Improving the Quadcopter

Since first building the quadcopter with the HobbyKing flight controller board we had a few issues with stability. Robert purchased the MultiWii-Pro board, and was having some issues with the configuration software, so has lent me a second board he purchased. The MultiWii board has many advantages over the KK base HobbyKing controller board. Over the 3 axis giros which are fitted to both boards, the MultiWii has 3 axis accelerometers, magnetometer (compass), barometer and GPS capabilities, although the MultiWii pro normally comes with a GPS unit, they are sensitive to being wired up wrong which is why Robert bought a second unit and this one doesn’t have a GPS. So I purchased a Crius Neo 6 version 3.1 which is based on the U-blox Neo 6M chipset. This is capable of outputting navigation data 5 times per second and an accuracy down to about 2 meters, although the configuration needs updating. This was done by connecting it to a computer through a USB FTDI serial adapter (or similar) and the U-Centre software from U-blox (http://www.u-blox.com/en/evaluation-tools-a-software/u-center/u-center.html).

The default baud rate of the board is 9600, I connected up, used the View->Configuration view and updated the baud rate to 38400 baud (in the ports section), above this tends to introduce errors, this rate gives a good transfer of data with fewer errors. Once this was updated I updated the baud rate of the connection and reconnected. The Updated the navigation update rate (in the rates section) to 5 times per second (200ms). Updated the SBAS settings to apply SBAS correction data. This improves the accuracy of the GPS unit, but it does require a bit longer to get a full fix. I then went to the NAV5 section and updated the Dynamic model to ‘Pedestrian’. This seems to be the recommended settings for using these on quadcopters and similar. Clicking send updates these settings on the GPS unit, going to Receiver->Action->Save Configuration then also saves the configuration to the non volatile memory on the GPS unit so the settings remain even after the unit is powered down.ucentre

 

The GPS was then connected to the MultiWii board.

Looking round on the web I found this guide to updating the software and settings on the board https://www.youtube.com/watch?v=9TIUif3PE9U

So I downloaded the code from https://code.google.com/p/mw-wingui/downloads/list downloading the files MultiWi2_3-navi-b5-baro_fix.zip and WinGUI_2.3pre8(b5).zip. Then downloaded the IDE for Arduino boards from here: http://arduino.cc/en/Main/Software (http://arduino.cc/download.php?f=/arduino-1.0.6-windows.exe)

After unpacking the MultiWi2_3-navi-b5-baro_fix.zip file and installing the arduino ide software, I opened the multiwii software, (file, open, find the unpacked software and open the MultiWii.ino file) selected config.h file from the down arrow on the right of the screen and updated the config.h file, to my GPS baud rate, I also updated the setting #define MOTOR_STOP which changes the default idle spin up of the motors when the unit is armed, and updated various other settings for this specific board and the X configuration quad copter (my final config.h is available lower down this post). From Tools->Board, selected Arduino Mega 2560 or Mega ADK selected the serial port that the board had been assigned by windows and clicked upload. This compiles and uploads the code to the board.

aduino

I then ran the WinGUI software connected and updated the flight tuning parameters to set the P values to 5.0, 5.0 and 8.0 for roll, pitch and yaw respectively. Click write settings to update these settings to the board.

flighttuning

Then go to RC Control settings, I have a 6 channel receiver, so have 2 extra channels which I can use to change the various flight modes. Each channel can be used in 3 positions, low medium and high. I used the first channel to add the ‘Horizon’ (self leveling) mode to the mid and high position, and ‘Mag’ (heading hold) to the high position this way on the flap switch I can use off as just giro stabalisation, mid position as self leveling and high position as self leveling and heading hold. I then used the second channel mid position (only) for GPS hold, and high position for Return to Home. Again write the setting to the board.

flightcontrol

The MultiWii board also has connections for a camera gimbal, to keep the camera level regardless of the orientation of the quadcopter (within normal flight conditions obviously). I managed to get the gimbal pictured below 3d printed. To activate it this needed more updates to the config.h file enabling the #define SERVO_TILT setting, and also going to the windows gui and enabling the camera stabalisation, since I didn’t have any more channels, I added it to channel 1 on all 3 positions so it was always on.

20141231_074407I did find that the software didn’t seem to work very well, shifting the platform in the wrong direction and not to the appropriate proportion, looking at the software this seemed to be changed by the Servo Rates settings, but I couldn’t get this to work, so I made these changes to the output.cpp file:

Changing:

#if defined(SERVO_TILT)
servo[0] = get_middle(0);
servo[1] = get_middle(1);
if (rcOptions[BOXCAMSTAB]) {
servo[0] += (int32_t)conf.servoConf[0].rate) * att.angle[PITCH]) /50L;
servo[1] += (int32_t)conf.servoConf[1].rate * att.angle[ROLL]) /50L;
}
#endif

to:

#if defined(SERVO_TILT)
servo[0] = get_middle(0);
servo[1] = get_middle(1);
float camTiltPitchProp=1;
float camTiltRollProp=1;
#if defined(TILT_PITCH_PROP)
camTiltPitchProp=TILT_PITCH_PROP;
#endif
#if defined(TILT_ROLL_PROP)
camTiltRollProp=TILT_PITCH_PROP;
#endif
if (rcOptions[BOXCAMSTAB]) {
servo[0] += ((int32_t)(camTiltPitchProp*(float)conf.servoConf[0].rate) * att.angle[PITCH]) /50L;
servo[1] += ((int32_t)(camTiltRollProp*(float)conf.servoConf[1].rate) * att.angle[ROLL]) /50L;
}
#endif

This allowed me to add the settings #define TILT_PITCH_PROP -2.00 and #define TILT_ROLL_PROP -1.00
to the config.h file which I set to be -2.0 and -1.0 for pitch and roll respectively after a bit of testing this seemed to the appropriate setting to make the platform correctly counter the pitch and roll of the quad.

My current output.cpp and config.h can be found here:

http://blog.smfc.co.uk/wp-content/uploads/2015/01/config.h

http://blog.smfc.co.uk/wp-content/uploads/2015/01/output.cpp

 

2 weeks ago in the fog I gave it a quick test:

As you can see the pitch seems ok, you can see the rotors moving up and down in the frame as the copter’s frame pitches forwards, but the horizon stays quite well level, the roll is far further out, although there is some effect, it is not enough and the camera is rolling with the frame

I was very glad at one point that the return to home worked as I lost it in the fog, fortunately it managed to find its own way back. As you can see the roll was much too low, I think the roll setting was slightly too low, so I updated both pitch and roll to -2.0 although last week the weather was a bit windy to make another test flight, and this week I couldn’t make it.

I would like to test this, and record with the GPS on screen data to get some idea of the speed and fly-ability of the quad, hopefully it is not far from being able to do some air to air recording. I will update this post with details and videos as I get them.