Servers by jDrones

Optical flow on Solo


(proficnc) #1

ol{margin:0;padding:0}table td,table th{padding:0}.c2{border-right-style:solid;padding:5pt 5pt 5pt 5pt;border-bottom-color:#000000;border-top-width:1pt;border-right-width:1pt;border-left-color:#000000;vertical-align:top;border-right-color:#000000;border-left-width:1pt;border-top-style:solid;border-left-style:solid;border-bottom-width:1pt;width:132pt;border-top-color:#000000;border-bottom-style:solid}.c0{border-right-style:solid;padding:5pt 5pt 5pt 5pt;border-bottom-color:#000000;border-top-width:1pt;border-right-width:1pt;border-left-color:#000000;vertical-align:top;border-right-color:#000000;border-left-width:1pt;border-top-style:solid;border-left-style:solid;border-bottom-width:1pt;width:59.2pt;border-top-color:#000000;border-bottom-style:solid}.c7{border-right-style:solid;padding:5pt 5pt 5pt 5pt;border-bottom-color:#000000;border-top-width:1pt;border-right-width:1pt;border-left-color:#000000;vertical-align:top;border-right-color:#000000;border-left-width:1pt;border-top-style:solid;border-left-style:solid;border-bottom-width:1pt;width:125.2pt;border-top-color:#000000;border-bottom-style:solid}.c6{color:#000000;font-weight:normal;text-decoration:none;vertical-align:baseline;font-size:11pt;font-family:“Arial”;font-style:normal}.c16{border-spacing:0;border-collapse:collapse;margin-right:auto}.c5{padding-top:0pt;padding-bottom:0pt;line-height:1.15;text-align:left}.c17{background-color:#ffffff;max-width:468pt;padding:72pt 72pt 72pt 72pt}.c9{font-size:23pt;font-weight:bold}.c1{color:#1cade4;font-size:7pt}.c13{font-size:17pt;font-weight:bold}.c3{orphans:2;widows:2}.c4{color:inherit;text-decoration:inherit}.c11{color:#1155cc;text-decoration:underline}.c15{padding-top:24pt}.c12{color:#1cade4}.c8{height:11pt}.c10{height:0pt}.c14{padding-bottom:4pt}.c18{page-break-after:avoid}.title{padding-top:0pt;color:#000000;font-size:26pt;padding-bottom:3pt;font-family:“Arial”;line-height:1.15;page-break-after:avoid;orphans:2;widows:2;text-align:left}.subtitle{padding-top:0pt;color:#666666;font-size:15pt;padding-bottom:16pt;font-family:“Arial”;line-height:1.15;page-break-after:avoid;orphans:2;widows:2;text-align:left}li{color:#000000;font-size:11pt;font-family:“Arial”}p{margin:0;color:#000000;font-size:11pt;font-family:“Arial”}h1{padding-top:20pt;color:#000000;font-size:20pt;padding-bottom:6pt;font-family:“Arial”;line-height:1.15;page-break-after:avoid;orphans:2;widows:2;text-align:left}h2{padding-top:18pt;color:#000000;font-size:16pt;padding-bottom:6pt;font-family:“Arial”;line-height:1.15;page-break-after:avoid;orphans:2;widows:2;text-align:left}h3{padding-top:16pt;color:#434343;font-size:14pt;padding-bottom:4pt;font-family:“Arial”;line-height:1.15;page-break-after:avoid;orphans:2;widows:2;text-align:left}h4{padding-top:14pt;color:#666666;font-size:12pt;padding-bottom:4pt;font-family:“Arial”;line-height:1.15;page-break-after:avoid;orphans:2;widows:2;text-align:left}h5{padding-top:12pt;color:#666666;font-size:11pt;padding-bottom:4pt;font-family:“Arial”;line-height:1.15;page-break-after:avoid;orphans:2;widows:2;text-align:left}h6{padding-top:12pt;color:#666666;font-size:11pt;padding-bottom:4pt;font-family:“Arial”;line-height:1.15;page-break-after:avoid;font-style:italic;orphans:2;widows:2;text-align:left}

Solo Flow

cc-by-nc

1          Parts list

Flow module:                 https://northox.myshopify.com/collections/frontpage/products/px4flow

Lidar:                         http://www.lightware.co.za/shop/en/drone-altimeters/51-sf11c-120-m.html

Housing:                 https://drive.google.com/open?id=0B-Aj3TOtcq6MakxMTU92S05zRnc

Breakout board:         https://oshpark.com/shared_projects/JAZFqfYG

Accessory connector: TX2430R6STN1E

Clikmate:                 5023820670

Mounting screws:               M2 x 30mm x4

                                    M3 x 14mm x2

2        Flow firmware

http://download.ardupilot.org/downloads/wiki/advanced_user_tools/px4flow-klt-06Dec2014.zip

3        Q Ground

http://qgroundcontrol.org/downloads

4        Solo Firmware

Latest Beta: Rebase Master….

5        Parameters

RNGFND_GNDCLEAR 5
RNGFND_MAX_CM 5000
RNGFND_MIN_CM 5
RNGFND_SCALING 1
RNGFND_TYPE 8
SERIAL2_BAUD 19
SERIAL2_PROTOCOL 9
EK2_ALT_SOURCE 1
EK2_GPS_TYPE 3
EK2_MAG_CAL 2
FLOW_ENABLE 1
FLOW_ORIENT_YAW -9000
AHRS_GPS_USE 0
ARMING_CHECK -14
 

RNGFND_GNDCLEAR

5

RNGFND_MAX_CM

5000

RNGFND_MIN_CM

5

RNGFND_SCALING

1

RNGFND_TYPE

8

SERIAL2_BAUD

19

SERIAL2_PROTOCOL

9

EK2_ALT_SOURCE

1

EK2_GPS_TYPE

3

EK2_MAG_CAL

2

FLOW_ENABLE

1

FLOW_ORIENT_YAW

-9000

AHRS_GPS_USE

0

ARMING_CHECK

-14

 

 

 

6        Setting up your Flow module

http://ardupilot.org/copter/docs/common-px4flow-overview.html

7         Video tutorials.

Getting the flow firmware: https://www.youtube.com/watch?v=1vrcw3YA5ig   

Flow Upgrade: https://www.youtube.com/watch?v=uubicYyGJV8

Focusing the flow: https://www.youtube.com/watch?v=1MCfdDwOiNk

I2c wiring: https://www.youtube.com/watch?v=wszLl0_1FRo

Assembling the leg back in: https://www.youtube.com/watch?v=dYxEw3bt47A

Assembling Flow module into housing: https://www.youtube.com/watch?v=oM0vYgC3P98

Assembling Lidar into housing: https://www.youtube.com/watch?v=AI6w7EJ-SLc

Connecting the Flow to I2C: https://www.youtube.com/watch?v=akxxWxE846w

Connecting The module to Solo: https://www.youtube.com/watch?v=Bu87On11Frk

8        System Limitations.

Flow on Solo has limitations that must be considered.  Some of these are temporary, some are long term.

8.1           Hardware limitations

Focusing is critical on the flow, the system cannot cope with blurry images, this can cause drift, or rapid movement…. So be aware that hovering close to the ground can lead to undesired results, likewise stability at heights can be affected.

Low light.  Light is critical for the system to work.  Adding a downward facing light (IR is OK) can assist here.

Pulsing light.  Attempting to use the Flow in an area lit by Fluorescent or pulsing Lights will lead to undesired results.

Use over water.  Flow doesn’t work well over water, it will either follow the water itself, or the sky above, either way, it can lead to unexpected results, and can cause the relative position to end up quite a long way off.

8.2          Software limitations

Arducopter is not yet optimized for use with flow.  At the current time flow only works if you turn the GPS OFF….

There is work intended soon to remove this limitation and allow the use of flow and GPS together to allow for autonomous navigation where the GPS signal may be intermittent. Ie, a Cable cam, under a bridge.

Some functions are starting to be added, but are not reliable yet.

RTL, Break, and Autonomous modes.

Use at your own risk as these features come out.

 

OVERALL, THIS IS EXPERIMENTAL>>>>

 

9        Future use cases…

Flow will come into its own when we can do a cable cam, from an indoor location, to an outdoor location, predictably, every time….  To be able to run a cable, under a bridge…. Under trees…

to automatically use Flow when you arm, so you do not need to wait for GPS, and seamlessly transition when GPS is denied.

10   Why are we releasing this?

The heart of Solo is ArduPilot, ArduPilot is all about innovation.  So to encourage more people to run on the cutting edge, is what we are all about.

Happy modding!

11      Other settings of interest…

FENCE_ALT_MAX

2

RTL_ALT                 

0


FENCE_ALT_MAX 2
RTL_ALT 0

this stops the copter flying above the 2 meter limit…. This is really handy for indoor flight…

12      Ongoing work

If you are a company who is interested in this technology, feel free to contact us, we are looking for someone to sponsor the ongoing integration of the Flow into the system.

This tutorial uses the old flow module, the new module, the 2.0, uses CANBUS as the protocol, it also uses a more powerful chip, and adds target acquisition to the system, allowing for precision landing etc.  The new hardware is optimized for a wider angle lens, allowing for better target tracking.

This instructional, and all methods is released under the cc-by-nc licence, please contact me via the email below if you wish to commercialise this.

Email, info@ardupilotinitiative.com 


Loiter mode with optical flow crashing into the wall
(gmorph) #2

So your not using the sonar on the flow sensor but rather the LIDAR? Is that right?
Thanks, Grant.


(Jiro Hattori) #3

Very curious about new Flow Sensor that 3DR is not providing old version anymore.
It is bit hard to get into cutting edge with obsolete model.
Could you show more information on your development work on new sensor?


(proficnc) #4

thats correct. the Sonar is rubbish on most surfaces, and also limited in range.


(proficnc) #5

the new sensor is very similar to the old, the changes are as follows.
New processor, allows for a full frame every 1 second to be passed to a co-computer for image processing.
Can interface. better than I2C, better noise immunity.

from a usage point of view, its all very similar.


(Jiro Hattori) #6

Looking forward to see new flow sensor.


(proficnc) #7

Hi All
A quick update…

I found that on some Lenses, there is no IR cut filter…
These are needed to block the light from the LIDAR.

Please add an IR Block filter if your lens does not have one.

http://www.ebay.com.au/itm/9-5mm-Pro-2-Optical-Circular-Blocking-UV-IR-CUT-Filters-/131785045297?hash=item1eaf003531:g:g6YAAOSwiYFXFHDw '
or similar will do.

please note, that after fitting these filters, you must use a visible light if you wish to fly at night and assist the flow.


(proficnc) #8

You can now set up the focus on your Flow module using Mission planner!

Thanks Michael!


(Kurt shaw) #9

Is there any updates to instructions for using with green cube. Px4flow firmware or something. I can figure out the parameters and stuff easy. It might be a good thing to test with one of my cubes and solos


(proficnc) #10

These instructions suit the green cube perfectly :slight_smile:


(Erhan) #11

Hi,
I want to connect the PX4Flow optical flow sensor to the Pixhawk on the Solo with a Breakout board. What should be the Pixhawk parameters when I connect the PX4Flow to the breakout board via UART?


(proficnc) #12

Please follow the instructions on the solo mod club, step by step instructions