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3D Robotics

Eqquera+uav.gif?width=202Part of a report on the AUVSI show by the Robot Report. Also check out this NPR radio report on the same trend.

Here are a few of the companies transitioning to the civilian marketplace:
  • AeroVironment's has repurposed its Qube portable UAV for use in public safety applications such as law enforcement and first response. The system provides a portable aerial vantage point to help public safety workers perform their duties more safely and effectively.
  • Canadian start-up Eqquera demonstrated their novel and creatively designed UASs for forest fire fighting and nuclear and arctic surveillance. (shown at right)
  • HDT and The Johns Hopkins University presented their MK2 robotic arm for rehab purposes and a two-armed version with significant torque and lift capabilities for general purpose shop and factory work.
  • i2Tech, one of many electronic and vision systems providers at the show, has a line of light weight, low-power, stabilized camera and thermal imaging systems for health care, industrial testing and surveillance.
  • Both Kairos Autonomy and Brock Technologies have low-cost kits which are able to convert any existing ground vehicle into an unmanned system and Autonomous Solutions just received a patent for a kit-based autonomous clip-on tethered unmanned convoy system.
  • Israel's RoboTeam's multi-purpose line of mobile tactical ground robots were described as solutions for homeland security and public safety.
  • MDL's displayed their tiny 43-gram USB-powered micro laser module for distance metering.

  • Many additive 3D printing systems had booths and showed how their machines were able to work with exotic metal substances and to provide specialized capabilities well beyond the MakerBot 3D printers we all know and love:
  • Finally, TOR Robotics provided a long list of civilian uses for their quad-copter that are also valid for the whole UAS industry:
UAV-apps.jpg
Read more…

Complete Guide to lipo batteries

3689473394?profile=originalTaken from the page:

http://www.rcgroups.com/forums/showthread.php?t=209187

After seeing the many many posts on LiPoly's and answering similar questions time after time I've decided to put up a guide for using LiPoly batteries. 

Lithium batteries are the preferred power sources for most electric modelers today. They offer high discharge rates and a high energy storage/weight ratio. However, using them properly and charging them correctly is no trivial task. There are many things to consider before using lithium cells for e-flight. But none is more important than safety.

1. Charging/Saftey IMPORTANT!
Until you are willing to follow all saftey precautions, DO NOT use lithium batteries. If your a type of person that prefers to push the limits of products, or be haphazard about following saftey requirements. Lithium technology is not for you. Read on to find out why.

Lithium cells must be charged very differently than NiCad or NiMH. They require a special charger specifically designed to charge lithium cells. In general any charger that can charge lithium ion can charge lithium polymer, assuming that the cell count is correct. You must NEVER charge lithium cells with a NiCad or NiMH only battery charger. This is dangerous. Charging cells is the most hazardous part of using lithium batteries. EXTREME care must be taken when charging them. It is important to set your charger to the correct voltage or cell count. Failure to do this can cause the battery to spew violent flames. There have been many fires directly caused by lithium batteries. PLEASE BE RESPONSIBLE when charging lithium batteries.

Here are a few MANDATORY guidelines for charging/using LiPos (Lithium Polymer Batteries).


1. Use only a charger approved for lithium batteries. The charger may be designed for Li-Ion or Li-Poly. Both batteries are charged in exactly the same. Some older cell phone chargers may charge the batteries .1 volt to low (4.1 vs 4.2), but that will not harm the battery. However, inexpensive lithium chargers are widely available and the use of cellphone chargers is highly discouraged. 
2. Make certain that the correct cell count is set on your charger. Watch the charger very closely for the first few minutes to ensure that the correct cell count continues to be displayed. If you don't know how to do that, get a charger that you do know how or don't charge the batteries.
3. Use the Taps. Before you charge a new Lithium pack, check the voltage of each cell individually. Then do this after every tenth cycle there after. This is absolutely critical in that an unbalanced pack can explode while charging even if the correct cell count is chosen. If the cells are not within 0.1 volts of each other then charge each cell individually to 4.2 volts so that they are all equal. If after every discharge the pack is unbalanced you have a faulty cell and that pack must be replaced.
Taps are provided on most new lithium packs. Taps give you the ability to check individual cell voltages and charge one cell at a time. Make sure and get the appropriate connector to go into your taps. Don't try to stick you volt meter probes in the taps to measure voltage. They could slip and short your cells. Don't try to charge more than one cell at a time from the taps. Unless you have an isolated ground charging system, you'll short your batteries out. Refer to your individual cell maker for tap pin-outs. 
4. NEVER charge the batteries unattended. This is the number one reason for houses and cars being burned to a crisp by lithium fires.
5. Use a safe surface to charge your batteries on so that if they burst into flame no damage will occur. Vented fire safes, pyrex dishes with sand in the bottom, fireplaces, plant pots, are all good options.
6. DO NOT CHARGE AT MORE THAN 1C unless specifically authorized by the pack vendor. I have personally had a fire in my home because of violating this rule. Todays highest discharge batteries can supposedly be safely charged at greater than 1C, however so far in all cases doing so shortens the life of the pack. Better to buy 3 packs than to try to charge 1 pack 3 times quickly. This may change in the future but as of Winter 2005 1C is still the recommended charge rate. 
7. DO NOT puncture the cell, ever. If a cell balloons quickly place it in a fire safe place, especially if you were charging it when it ballooned. After you have let the cell sit in the fire safe place for at least 2 hours. Discharge the cell/pack slowly. This can be done by wiring a flashlight bulb of appropriate voltage (higher is voltage is ok, lower voltage is no) up to your batteries connector type and attaching the bulb to the battery. Wait until the light is completely off, then throw the battery away.
8. If you crash with your lithium cells they may be damaged such that they are shorted inside. The cells may look just fine. If you crash in ANY way carefully remove the battery pack from the aircraft and watch it carefully for at least the next 20 min. Several fires have been caused by damaged cells being thrown in the car and then the cells catch fire later and destroys the car completely. 
9. Charge your batteries in a open ventilated area. If a battery does rupture or explode hazardous fumes and material will spew from the battery. 
10. Keep a bucket of sand nearby when you are flying or charging batteries. This is a cost effective way to extinguish fires. This is very cheap and absolutly necessary.
11. It can happen to you, do not think to yourself that “it won't happen to me” as soon as you do that it you'll be trying to rescue your kids from your burning house or car. I'm very serious about this.

Now that we have covered that important topic let's move on to lighter matters:

2. Lithium What?
Lithium Polymer batteries are used in many electronic devices. Cell Phone, Laptops, PDA's, Hearing Aids just to name a few. Most, if not all, lithium polymer batteries are not designed for RC use, we use them in different applications than they were designed for. They are similar to Lithium Ion batteries in that they each have a nominal voltage of 3.6 volts, but dissimilar in that they do not have a hard metal casing but rather a flexible material encloses the chemicals inside. The "normal" lithium polymer batteries are thin rectangle shapes with two tabs on the top one positive one negative. The reason we use Lithium cells is that they are significantly lighter than comparable NiCad or NiMH batteries, which makes our planes fly longer and better.

3. Voltage and Cell Count:
LiPolys act differently than NiCad or NiMH batteries do when charging and discharging. Lithium batteries are fully charged when each cell has a voltage of 4.2 volts. They are fully discharged when each cell has a voltage of 3.0 volts. It is important not to exceed both the high voltage of 4.2 volts and the low voltage of 3.0 volts. Exceeding these limits can harm the battery.
The way to ensure that you do not go below 3.0 volts while flying is to set the low voltage cutoff (LVC) of your electronic speed control (ESC). It important to use a programmable ESC since the correct voltage cutoff is critical to the life of your batteries. Use the ESC's programming mode to set the LVC to 3.0 volts per cell with a hard cutoff, or 3.3 volts per cell with a soft cutoff. If your ESC does not have hard or soft cutoff, use 3.0 volts per cell. You will know when flying that it is time to land when you experience a sudden drop in power caused by the LVC. 
If your ESC has an automatic lithium mode. Use it, it will correctly sense the number of cells and set the auto cutoff appropriately. 
If you have previously been flying with NiCad or NiMH batteries, switching over to lithium polymer will result in a different number of cells being used. If you had 6 to 7 round cells then 2 lithium polymer cells will correctly duplicate the voltage of those cells. If you had 10-11 cells then 3 lithium polymer cells would be right for you. There are a lot of 8 cell flyer's out there that are stuck between 2 and 3 cells. In my experience the best option is to determine how many watts you were using before and duplicate that with your LiPos, Motor, and Prop. For example. If you were running 8 cells (9.6volts) at 10 amps on a speed 400 airplane, then you have 9.6 x10, 96 watts. So if you went with 2 lithium polymer cells (7.2 volts nominal) then you'd need to change your prop such that you used 13 amps. If you went to 3 LiPoly's (10.8 volts nominal) then you'd need to reduce the amperage to 8.9 amps. These estimates are approximate, and some experimentation is required for best results but conserving Watts is a good way to start.

4.10C from 3S4P? Naming conventions explained.
How fast a battery can discharge is it's maximum current capacity. Current is generally rated in C's for the battery. C is how long it takes to discharge the battery in fractions of an hour. For instance 1 C discharges the battery in 1/1 hours or 1 hour. 2 C discharges the battery in ½ or half an hour. All RC batteries are rated in milli Amp hours. If a battery is rated at 2000 mAh and you discharge it at 2000mA (or 2 amps, 1 amp = 1000mA) it will be completely discharged in one hour. The C rating of the battery is thus based on its capacity. A 2000mAh cell discharged a 2 amps is being discharged at 1C (2000mA x 1), a 2000mAh cell discharged at 6 amps is being discharged at 3C( 2000mA x 3).
All batteries have limitations on how fast they can discharge. Because of this many LiPoly batteries are put in parallel to increase the current capacity of the battery pack. When 2 batteries are wired positive to positive and negative to negative they become like one battery with double the capacity. If you have 2 2000mAh cells and you wire them in parallel then the result is the same as 1 4000mAh cell. This 4000mAh cell has the same C rating as the original 2000mAh cells did. Thus if the 2000mAh cells could discharge at a maximum of 5C, or 10 amps then the new 4000mAh cell can also discharge at 5C or (4000mA x 5) 20 amps. This method of battery pack building allows us to use LiPoly batteries at higher currents than single cells could produce. 
The naming convention that allows you to decipher how many cells are in parallel and how many are in series is the XSXP method. The number in front of the S represents the number of series cells in the pack so 3S means it's a 3 cell pack. The number in front of P means the number of cells in parallel. So a 3S4P pack of 2100mAh cells has a total of 12 cells inside. It will have the voltage of any other 3S pack since the number of cells in series determines the voltage. It will have the current handling of 4 times the maximum C rating of the 12 individual cells. So say our 3S4P pack had a maximum discharge of 6C. That means that it has a nominal voltage of 10.8 volts (3x3.6) and a maximum discharge rate of 50.4 amps (2100mAh x 6Cx4P ). 

5. Which battery should you buy?
With so many choices out there it is difficult to decipher what is marketing hype, what is brand
loyalty, and what is outright lies. Battery manufacturers are constantly trying to one up one another. While capitalism can drive prices down, it also can give cause to false claims about products. 
One great way to find out what the best battery is, is to look at graphs of the batteries performance. Looking at how low the voltage of the cell drops at various amperages will give you a metric to compare that battery to similar size/weight batteries. 
If graphs aren't your thing then simply look at what other people are using in successful setups that are similar to your application. If a lot of people are reporting long flight times and lots of power from airplane X, with power system Y, and battery Z and you do the same, then if your setup is similar the same battery will probably work well for you. 
It pays to learn something about Watts, Volts, and Amps. Understanding these concepts is beyond the scope of this document, but can serve you well in not only figuring out what battery is best but also in your electric aircraft hobby.
I'm not convinced that a 30C battery is really any better than a 10 or 20C battery. Sure a higher C rating means it can discharge faster. But at the same time a battery discharged at 20C continuously will be empty in 3 minutes. Do you really only want to use the battery for 3 minutes? I love having burst power in helicopters and boats, but in almost all other applications actually running a battery at or above 20C is useless to me. I prefer to run batteries at 8-10 C and have a little headroom if I need it.
A final note on choosing a battery. Don't cheap out. Confirm that your batteries are capable of running that the amperage level you plan to use them at. Running a cell at a higher C rating than the battery can handle can not only damage your batteries, but it can also damage your speed control. Castle Creations has an excellent article on how using a weak battery can destroy a perfectly good speed control of any brand. Better to buy a bit better battery than you need than to destroy your electronics.

6. Dealing with temperature.
Lithium batteries like heat, but not too much. In the winter time, try to keep your batteries from the cold as much as possible. Leave them in the car while your flying, or keep them in your cargo pants... etc. At the same time don't let them heat up too much. Try to keep your batteries from reaching 160F after use. This will prolong the life of the cells. A good way to measure temperature is a handheld IR meter, they can be found for around $50.00 at most hobby shops. 

If you have any suggestions for future sections or additions to the current document let me know and I'll add the information requested...if I know the answer!

Posts that have referenced a lipo cell catching fire have been categorized as to failure cause. This list most certainly does not contain all the incidents and a statistical analysis would be meaningless. It does however show that the warnings presented for lipo cells are not just legaleeze but warnings that should be heeded to prevent possible personal harm and/or property damage.

These first two posts will be updated as data is collected. 
Information was gathered from the posts referenced. Please PM me if you see any discrepancies. The listing does not include any of the many 'ballooning only' reports.

FIRE DURING CHARGING:
Operator Error-
9s pack catches fire while being charged at 10s setting. (9)
2s pack catches fire being charged as 3s (10)
2s pack catches fire when charged at 3s setting (13)
2s pack catches fire in plane while charging at 3s setting. (22)
3s pack charged at 4s voltage ignites (27)
2s pack catches fire charged at 3s (30)
2s pack ignites when charged at 10.2V (31)
Overcharged battery (34)
2s pack charged at 11.1V catches fire. (36)
2s pack charged at 3s setting (40)
2s pack charges at 11.1V burns – (44)
2s charged at 11.2V goes off in garage – (47)
2s charged at 3s voltage ignites in garage – (49)
2s charged at 3s ignites in workshop – (52)
Another count problem – Heli burns (57)
Cell count error caused fire – (61, 62)
Pack charged on NiCd setting - (66)
Run Down pack catches fire during charge – (71)
LiPo Burns during charge on 109 charger after mode mis-set (82)
Charging slightly swelled pack causes fire (86)
Li-Ion cells catch fire from charger setting error (88)
Cell catches fire during attempt to repeak - (91)
Charging puffed cell causes it to ignite – (93)
Lipo burns during attempt to restore overdischarged cell with CC/CV PS (94)
Pack ignites during charging – smoke corrodes shed and contents (98)
Possible damaged pack burns like rocket in can – (100)
Attempt to recharge dead lipo causes plane fire (103)
Charging probably fully charged 3s pack with Astro 109 result in pack ignition. (104)
2s charged as 3s ignites in safe (109)
Restart of charger resulted in wrong charge mode – (113)
Wrong charger settings burns 2 packs – (112)
LiPo burns in modelers hand after charging - (115)
Charging slightly puffed cell causes fire, plane burns (117)
Using NiCd setting causes LiPo fire. Owner forgot to switch over to LiPo setting during charge cycle (118)
Charger set on 4 cells with 3 cell pack (126)
Garage fire during charging (127)
Modeler reports 2 lipo fires from wrong cell count (129)
Lipo charged on NiCd setting ignites (130)
Auto cell count charger fire – (131)
5s2p4000 packs ignites on first charge (133)
Overvoltage charge ignition – (135)
Lipo ignites during charge causing house fire – possible charger setting error. (139).
Too high charge rate burns battery (142)
3s charged as 4s 109 with pictures of burn: (144)
3s charged as 4s burns SUV (Schulze 6-330d) (146)
Garage Burns – balancer used - (162)
Garage Burns during charging – complete loss - (163)

Undetermined Cause While Charging 
Fire damages garage while charging pack. (7)
1500 3s pack catches fire during 1A , 11.1V initial charge. (1)
2 cell pack ignites while being charged with 2 cell charger. (11)
Car burns when pack being charged in car catches fire. (24)
2s2p pack catches fire in helicopter – possible that charger misread # of cells. (25)
2s pack ignites while on charger set for 2s. (28)
$30,000 damage to house when pack ignites during charging. (no details) (43)
3s pack burns in garage – (35)
3s pack burns at correct settings- (41)
3s pack burns at correct charger settings – (46)
3s 8000mah pack catches fire after 15min – correct settings – (53)
Helicopter and pack burns after 15min charge – (54)
Automatic cell count charger – pack catches fire (55)
Automatic cell count charger – pack catches fire (56)
Lipo rockets across room (58)
Automatic cell count charger – Lipos burn in garage (59)
Battery ignites in car seat during charging (63)
Damaged battery ignites during charge (67)
Pack balloons during charge, burns while under water (68)
11s3p pack burns during charging at correct parameters (70)
Another charging fire – (72)
Helicopter burns when LiPo ignites during charge (73)
Undetermined cause to LiPo fire during charge – (74)
Chopper burns from charging LiPo fire (76)
House fire (81)
3s Pack Ignites burning front of car during charge at correct settings. (83)
Helicopter in garage burns while charging (106)
Well used Lipo ignites under correct charging parameters (107)
SUV Vehicle burns (114)
Garage burns during charging – (119) Extensive pictures
2 fiires in 2 weeks (120)
Charging battery in plane fire with 109 – posts 97&99 (121)
Charging 3000mah with Triton catches fire in garage- (122)
Pack in plane ignites while being charged under hood of truck (123)
Fire in Basement – (136)
Lipo catches fire during charging and continues to burn in salt water (138)
Lipo charging in Helicopter ignites burning carpet, drapes and Heli (141)
Lipo charging on hood catches fire - (147)
Lipo charged on correct settings ignites (148)
Lipo fire during charging burns house. (150)
A123 pack burns(?) (152)
Possible charger failure causes lipo fire – (157)
House Fire – Cause not determined yet – (158)
Lipo in back of SUV ignites while charging – (159)
5 packs burn during charging – (165)
Battery on charger with balancer ignites (166)
Another battery on a balancing charger ignites (167)
Pack on charger causes workshop fire (169)
Very new pack with GWS CP -LP charger ignites (170)
Pack puffs on charger – taken outside where it ignites (171)
Pack gets hot on charger, ignites outside (172)

FIRE FROM PACK DAMAGE:
Cell poked with exacto knife catches fire- (2)
Dog bites pack, pack catches fire (4)
Lexus burns after pack from crashed plane put in car. (8)
Ballooned pack ignites when punctured. (20)
Repaired pack catches fire when connected to plane. (29)
Pack catches fire after plane crashes. (37)
Pack cut while shrink wrapping (39)
Pack punctured during crash burns. (64)
Plane crashes, pack removed and 10 minutes later burns (65)
Battery pack at 1V ignites while charging (71)
Puffed pack ignites during charging – (77)
Puffed Pack smokes when punctured (79)
Nicked pack catches fire (87)
Plane crashes, battery catches fire (89)
Damaged pack catches fire – (90)
Dog chews pack, chars pillow and smokes house - (95)
Battery compartment screw penetrates pack causing loss of plane (102)
Pack balloons dring mischarge, ignites when punchured (108)
Pack ignites 20 min after Heli crash – (111)\
Nicked pack “explodes in modelers hand” (116)
Intentionally punctured LiPo burns (124)
Dented Heli pack burns i min after disconnecting- (137)
Poked Lipo burst into flame (140)
Lipo Shorted for 4 sec. 3 min later it burns (143)
Lipo catches fire after crash damage. (149)
Punctured lipo catches fire – (151)
Crash causes fire – (154)
Damaged pack catches fire in flight – (156)
Dog bite shorts pack – (161)
Lid of charging container pinches battery leads and ignites (168)
Dropped pack catches fire minutes later (173)

BATTERY SHORTED FIRES:
Shorted pack catches fire (26)
Pack burns after shorting (15)
Possible Short (38)
Shorted when moved on table – (42)
Pack Shorted putting connector on and burns – (45)
Shorted pack burns hole in BMW seat – (48)
Crash causes 3s pack to short and burn – (50)
Pack ignites sometime after connector shorted for a short time (85)
Lipo Shorted for 4 sec. 3 min later it burns (143)


CAUSE UNDETERMINED:
Multi cell pack catches fire in flight (5)
Possible over discharge (33)
Lipo pack catches fire in car (60)
2s pack starts house fire (84)
In flight F3A fire reported (92)
New pack partially burns sitting on desk (96)
Pack ignites with no known cause (97)
Pack ignites after soldering wires on (101)
Pack catches fire in pick up truck (105)
In Air ignition – (125)
Pack ignites in pocket (132)
Pack ignites in car at 3AM (134)
Undamaged pack starts to burn in car – (145)
Unconnected Pack sitting on bench burns over night – (153)
In Flight Fire – (155)
Pack ignites 2 hrs after charging – not connected to anything. (160)
Unused, uncharged pack without connectors catches fire – (164)
Lipo catches fire for no apparent reason (174)
Plane lands after short flight, battery disconnected, battery ignites shortly after (175)


OTHER
2s pack connected in series with 3s pack ignites in fireball (78)
Lipo burns garage (99)
Packs used in parallel catch fire in flight (110)
Too high current draw causes fire (128)

References
1. http://www.rcgroups.com/forums/showt...93#post1625193
2. http://www.rcgroups.com/forums/showt...&pagenumber=18
3. http://www.rcgroups.com/forums/showt...37#post1531337
4. http://www.rcgroups.com/forums/showt...99#post1531599
5. http://www.bayrc.com/boards/viewtopic.php?t=226
6. http://www.rcgroups.com/forums/attac...postid=1478616
7. http://www.rcgroups.com/forums/showt...fire+explosion
8. http://www.rcgroups.com/forums/showt...ght=lexus+fire
9. http://www.rcgroups.com/forums/showt...t=funtana+fire
10. http://www.rcgroups.com/forums/showt...ghlight=rocket
11. http://www.ikarus-modellbau.de/ubbth...b=5&o=&fpart=1
12. http://www.rcgroups.com/forums/showt...ight=lipo+fire
13. http://www.rcgroups.com/forums/showt...hreadid=160086
14. http://www.rcgroups.com/forums/showt...hreadid=160079
15. http://www.rcgroups.com/forums/showt...hreadid=160551
16. http://www.rcgroups.com/forums/showt...ight=lipo+fire
17. http://www.rcgroups.com/forums/showt...ight=lipo+fire
18. http://www.rcgroups.com/forums/showt...ight=lipo+fire
19. http://www.rcgroups.com/forums/showt...ight=lipo+fire
20. http://www.rcgroups.com/forums/showt...ight=lipo+fire
21. http://www.rcgroups.com/forums/showt...ight=lipo+fire
22. http://www.rcgroups.com/forums/showt...ight=lipo+fire
23. http://www.rcgroups.com/forums/showt...402#post806402
http://www.rcgroups.com/forums/showt...ight=lipo+fire
http://www.rcgroups.com/forums/showt...ight=lipo+fire
24. http://www.hornet-heli.com/ubb/Forum3/HTML/003428.html
25. http://www.rcgroups.com/forums/showt...ight=explosion
26. http://www.rcgroups.com/forums/showt...95#post1243595
27. http://www.rcgroups.com/forums/showt...90#post1571890
28. http://www.rcgroups.com/forums/showt...30#post1581630
29. http://www.rcuniverse.com/forum/fb.a...325&tostyle=tm
30. http://www.rcgroups.com/forums/showt...129#post844129
31. http://www.rcgroups.com/forums/showt...29#post1553429
32. http://www.rcgroups.com/forums/showt...65#post1658165
http://www.rcgroups.com/forums/showt...hreadid=185530
33. http://www.rcgroups.com/forums/showt...34#post1699734
34. http://www.rcgroups.com/forums/showt...91#post1731091
http://www.rcgroups.com/forums/showt...15#post1731915
35. http://www.rcuniverse.com/forum/fb.a...352&tostyle=tm
36. http://members.jcom.home.ne.jp/42232...%20trouble.htm
http://www.rcgroups.com/forums/showt...31#post1761331
Charging crashed pack caused pack unbalance problems - http://www.rcgroups.com/forums/showt...03#post1767503
37. Pack catches on fire after crash - http://www.rcgroups.com/forums/showt...34#post1779434
38. Possible short – undamaged pack catches fire -http://www.rcgroups.com/forums/showthread.php?postid=1810304#post1810304
39. Battery shorts and burns during shrink wrapping - http://www.rcgroups.com/forums/showt...08#post1399608
Lipo Fire Video’s
http://www.rcgroups.com/forums/showt...15#post1394715
http://www.rcstuff.us/battery/lipo/lipo_DNA.html
http://www.helihobby.com/videos/LithiumBattery.wmv
http://www.utahflyers.org/movies/Lipofires.wmv
(40) Battery catches fire, wrong charging voltage - http://www.rcgroups.com/forums/showt...22#post1898922
(41) First charge of pack - http://www.rcgroups.com/forums/showt...hreadid=180434
(42) Pack shorted on bench - http://www.rcgroups.com/forums/showt...hreadid=206095
(43) $30,000 house damage – charger error - http://www.rcgroups.com/forums/showt...90#post1816790
(44) 2s charged at 11.1V burns - http://www.rcgroups.com/forums/showt...47#post1844047
(45) Pack Shorted putting connector on and burns - http://www.rcgroups.com/forums/showt...hreadid=209532
(46) 3s Pack burns at correct charger settings - http://www.rcgroups.com/forums/showt...hreadid=209767
Picture of burned bench – German site - http://www.modellflugjugend.de/archiv/user/lipo2.jpg
(47) 2s charged at 3s goes boom in garage - http://www.rcgroups.com/forums/showt...hreadid=100803
(48) Shorted pack burns hole in BMW seat - http://www.rcgroups.com/forums/showt...86#post1199486
(49) 2s charged as 3s ignites in house - http://www.rcgroups.com/forums/showt...ghlight=rocket
(50) Crash causes 3s to short and burn 
http://www.rcgroups.com/forums/showt...82#post1863182
(52) 2s charging at 3s causes fire in garage - 
http://www.runryder.com/helicopter/...light=fire+lipo
(53) 8000 3s pack catches fire at correct settings - 
http://www.runryder.com/helicopter/...light=fire+lipo
(54) Pack catches fire after charging for 15 min - 
http://www.rotory.com/ubbthreads/sh...o=&fpart=1&vc=1
(55) Pack catches fire using automatic charger - http://www.rcgroups.com/forums/showp...6&postcount=15
(56) Pack catches fire using automatic charger - 
http://www.rcgroups.com/forums/showp...46&postcount=1
(57) Helicopter fire - http://runryder.com/helicopter/t82226/?goto=newpost
(58) LiIon pack rockets across room: http://www.rcgroups.com/forums/showp...6&postcount=11
(59) Dented Pack Catches fire - http://www.rcgroups.com/forums/showp...56&postcount=3
(60) Lipo in closed car catches fire - http://www.rcgroups.com/forums/showthread.php?t=241627
(61) Wrong cell count fire - http://www.rcgroups.com/forums/showp...97&postcount=3
(62) Wrong cell count fire – http://www.rcgroups.com/forums/showp...26&postcount=1
(63) Battery catches fire in car seat while charging - http://www.rcgroups.com/forums/showthread.php?t=248194
(64) Battery catches fire when plane crashes - http://www.rcgroups.com/forums/showthread.php?t=256098
(65) Battery catches fire after crash: http://www.rcgroups.com/forums/showp...7&postcount=12
(66) Battery ignites in under 10min on charger - http://www.rcgroups.com/forums/showp...59&postcount=1
(67) Damaged battery catches fire during charging - http://www.rcgroups.com/forums/showp...34&postcount=5
(68) LiPo Pack catches fire even tho immersed in salt water - http://www.rcgroups.com/forums/showthread.php?t=261922
(69) Lipo ignition causes house fire - http://www.rcgroups.com/forums/showp...50&postcount=4
(70) Pack catches fire for no apparent reason during charge -http://www.rcgroups.com/forums/showp...1&postcount=34
(71) Pack at 1V charged and catches fire - http://www.rcgroups.com/forums/showthread.php?t=263600
(72) Battery catches fire during charging - http://www.rcgroups.com/forums/showp...21&postcount=1
(73) Helicopter burns - http://www.rcgroups.com/forums/showthread.php?t=266337
(74) 3s Pack ignites during charge - http://www.rcgroups.com/forums/showthread.php?t=266875
(75) House fire reported in Belgium - http://www.rcgroups.com/forums/showp...1&postcount=24 CHECK OUT
(76) Plane burns during charge - http://www.rcgroups.com/forums/showp...5&postcount=47
(77) Puffed pack ignites during charging - http://www.rcgroups.com/forums/showt...64#post2560964
(78) 2s pack connected in parallel to 3s pack ignites - http://www.rcgroups.com/forums/showthread.php?t=274028
(79) Ballooned Pack Burns when punchured - http://www.rcgroups.com/forums/showthread.php?t=274557
(80) 7s pack catches fire during flight - http://www.rcgroups.com/forums/showthread.php?t=296507
(81) House fire – 3rd story burns - http://runryder.com/helicopter/t145397p1/
(82) Lipo catchs fire during charge on 109 charger. http://www.rcgroups.com/forums/showthread.php?t=307806
(83) 3s Lipo catches fire at correct settings. http://rcgroups.com/gallery/showphot...cat=500&page=1
(84) 2s pack starts house fire- reason unknown - http://www.rcgroups.com/forums/showthread.php?t=311323
(85) Pack catches fire after a short short - http://www.rcgroups.com/forums/showt...13#post3044752
(86) Charging slightly swelled pack causes fire - http://www.rcgroups.com/forums/showp...77&postcount=4
(87) Nicked cell catches fire - http://www.rcuniverse.com/forum/LiPo...tm.htm#2366986
(88) Li Ion cells ignite from charging mistake - 
http://www.rcuniverse.com/forum/LiPo...tm.htm#2427714
(89) Battery ejected from crashed plane burns - http://www.rcgroups.com/forums/showthread.php?t=289255
(90) Battery involved in crash ignites several weeks later - 
http://www.rcgroups.com/forums/showthread.php?t=273490
(91) Charging abuse causes fire - http://www.rcgroups.com/forums/showp...35&postcount=7
(92) Pack fire during F3A contest - http://www.rcgroups.com/forums/showp...8&postcount=11
(93) Slightly puffed cell catches fire during charging. http:// http://www.rcgroups.com/forums/showp...d.php?t=268523
(94) Lipo burns during attempt to restore overdischarged cell with CC/CV PS -http://www.rcgroups.com/forums/showthread.php?t=323693
(95) http://www.rcgroups.com/forums/showp...4&postcount=15
(96) New pack partially burns sitting on desk - http://www.rcgroups.com/forums/showthread.php?t=329744
(97) Pack ignites with no known cause - http://www.rcgroups.com/forums/showp...3&postcount=31
(98) Pack ignites during charging – equipment in shed corrodes -http://www.rcgroups.com/forums/showp...&postcount=177 andhttp://www.rcgroups.com/forums/showp...&postcount=187
(99) Lipo burns garage - http://www.rcgroups.com/forums/showp...6&postcount=14
(100) Lipo burns like rocket in a can during charging - http://www.rcgroups.com/forums/showthread.php?t=356474
(101) Cell ignites while soldering- http://www.rcgroups.com/forums/showthread.php?t=357380
(102) Screw penetrates pack igniting it - http://www.rcgroups.com/forums/showthread.php?t=360222
(103) Attempt to recharge “dead pack” causes plane fire - http://www.rcgroups.com/forums/showp...37&postcount=9
(104) Charged 3s (?) ignites while recharging with Astro 109 - http://www.rcgroups.com/forums/showthread.php?t=362011

(105) Packs in truck catch fire, burn truck – unexplained - http://www.rcgroups.com/forums/showthread.php?t=368758
(106) Battery charging inside of helicopter catches fire in garage. No cause determined.http://www.runryder.com/helicopter/t177482p1/ 
(107) Well used Lipo ignites during charging under correct conditions -http://www.rcgroups.com/forums/showthread.php?t=373643
(108) Lipo charged as NiCd burns when the ballooned pouch is punchured -http://www.rcgroups.com/forums/showt...10#post3794339
(109) Charging 2s1500 with possible wrong cell count ignites in safe -http://www.rcgroups.com/forums/showt...20#post3829205
(110) Packs used in parallel catch fire in flight - http://www.rcgroups.com/forums/showthread.php?t=378566
(111) Helicopter crashes – 20 minutes later, lipos burn - http://www.rcgroups.com/forums/showthread.php?t=384490
(112) 2 packs at wrong charger settings burn - http://www.rcgroups.com/forums/showthread.php?t=384585
(113) Charger unplugged, on restart it went into different mode – lipo burns-http://www.rcgroups.com/forums/showp...45&postcount=1
(114) Battery charged in SUV burns vehicle - http://www.wattflyer.com/forums/show...09&postcount=1
(115) Battery ignites after charging in modelers hand http://www.rcgroups.com/forums/showp...83&postcount=1
(116) Nicked pack “explodes in hand” http://www.rcgroups.com/forums/showp...&postcount=155
(117) Charging slightly puffed lipo causes it to ignite in plane. http://www.rcgroups.com/forums/showthread.php?t=434713\
(118) Using NiCd setting causes LiPo to burn in garage - http://www.rcgroups.com/forums/showthread.php?t=435043
(119) Garage Burns – Cause undetermined - http://www.laureanno.com/RC/fire-pics.htm
(120) 2 fires in 2 weeks – 109 charger - http://www.rcgroups.com/forums/showthread.php?t=446313
(121) Charging battery in plane fire with 109 – posts 97&99 http://www.rcgroups.com/forums/showthread.php?t=443646
(122) Charging 3000mah with Triton catches fire in garage- http://www.one18th.com/forums/showthread.php?t=18104
(123) Pack in plane ignites while being charged under hood of truck - http://www.wattflyer.com/forums/showthread.php?t=2770
(124) Intentionally punctured LiPo burns - http://www.rcgroups.com/forums/showp...35&postcount=9
(125) In Flight LiPo Fire - http://www.rcgroups.com/forums/showthread.php?t=460823
(126) Fire under hood while charging - http://www.rcgroups.com/forums/showthread.php?t=463204
(127) Garage burns during charging – possible operator cell count error -http://www.rcgroups.com/forums/showthread.php?t=463115
(128) Lipo ignites after flying with too large prop after landing - http://www.wattflyer.com/forums/show...2&postcount=14
(129) 2 fires from wrong cell count - http://www.rcgroups.com/forums/showp...97&postcount=5
(130) Lipo charged on NiCd settings catches fire - http://www.rcgroups.com/forums/showp...8&postcount=14
(131) 3 cases of charger caused (?) fires reported - http://www.rcgroups.com/forums/showthread.php?t=473376
(132) Pack goes thermal in pamts pocket - http://www.rcgroups.com/forums/showp...6&postcount=20
(133) 5s2p 4000 ignites on first charge - http://www.rcgroups.com/forums/showthread.php?t=489495
(134) Pack ignites in car – No reason seen. http://www.rcgroups.com/forums/showt...65#post5371633
(135) Pack ignites – high charge voltage - http://www.rcgroups.com/forums/showp...6&postcount=25
(136) Lipo ignites in basement during charge - http://www.rcgroups.com/forums/showthread.php?t=519443
(137) Lipo ignites after landing - http://www.rcuniverse.com/forum/m_40...tm.htm#4118760
(138) Lipo ignites during charge, continues to burn after thrown in water -http://www.rcgroups.com/forums/showthread.php?t=261922
(139) lipo ignites during charge causing house fire. - http://www.rcgroups.com/forums/showp...50&postcount=4
(140) Poked Lipo burst into flame - http://www.rcgroups.com/forums/showp...38&postcount=4
(141) Lipo charging in Helicopter ignites burning carpet, drapes and Heli -http://www.rcgroups.com/forums/showthread.php?t=552619
(142) Too high charge rate burns battery - http://www.rcgroups.com/forums/showthread.php?t=556456
(143) Lipo Shorted for 4 sec. 3 min later it burns: http://www.rcgroups.com/forums/showp...08&postcount=1
(144) 3s charged as 4s 109 with pictures of burn: http://www.rcuniverse.com/forum/m_36...tm.htm#3694610
(145) Undamaged pack burns http://www.rcgroups.com/forums/showp...13&postcount=2
(146) 3s charged as 4s burns SUV (Schulze 6-330d) - http://www.rcgroups.com/forums/showp...8&postcount=13
(147) Lipo charging on hood catches fire, cause undetermnined - http://www.rcgroups.com/forums/showthread.php?t=614885
(148) Lipo charged on correct settings ignites - http://www.rcgroups.com/forums/showthread.php?t=654348
(149) Lipo catches fire after crash damage. - http://www.rcgroups.com/forums/showthread.php?t=662396
(150) Lipo fire during charging burns house. http://www.rcgroups.com/forums/showp...43&postcount=1
(151) Punctured lipo ignites - http://www.rcgroups.com/forums/showp...9&postcount=64
(152) A123 fire during charging – cause unknown - http://www.rcgroups.com/forums/showt...99#post8554156
(153) Cause unknown – Battery on benchtop burns http://www.rcgroups.com/forums/showthread.php?t=779431
(154) Battery ignites after crash - http://www.rcgroups.com/forums/showthread.php?t=800629
(155) Battery ignites during flight - http://www.rcgroups.com/forums/showp...&postcount=127
(156) Damaged lipo pack catches fire in flight - http://www.rcgroups.com/forums/showp...1&postcount=14
(157) Battery ignites during charge - http://www.rcgroups.com/forums/showp...&postcount=154
(158) House Burns – Lipo charging in garage. http://www.rcgroups.com/forums/showp...&postcount=191
(159) Lipo charging in back of SUV catches fire - http://www.rcgroups.com/forums/showp...&postcount=199
(160) Lipo catches fire 2 hrs after charging and off charger - http://myhobbycity.com/showthread.php?t=2883
(161) Dog bites lipo – lipo heats up but is dunked before igniting. -http://www.rcgroups.com/forums/showp...35&postcount=4
(162) Garage Burns, charging with balancer http://www.3drc.info/forum/showthread.php?t=1137
(163) Another Garage fire - complete loss - fire during charging - http://www.3drc.info/forum/showthread.php?t=888
(164) New battery catches fire – didn't have connectors on it yet.http://www.rcgroups.com/forums/showt...0#post10463160
(165) 5 packs being charged burn - http://www.rcgroups.com/forums/showp...&postcount=228
(166) Pack on charger with balancer ignites - http://www.rcgroups.com/forums/showthread.php?t=945715
(167) Pack on balancing charger ignites - http://www.rcgroups.com/forums/showthread.php?t=947656
(168) Pack catches fire when lid closed on leads. http://www.runryder.com/helicopter/t473552p1/
(169) Pack on charger causes workshop fire. http://www.rcgroups.com/forums/showthread.php?t=978810
(170) Very new pack with GWS CP -LP charger ignites - http://www.rcgroups.com/forums/showt...8#post11861155
(171) Pack puffs on charger – taken outside where it ignites - http://www.rcgroups.com/forums/showp...5&postcount=64
(172) Pack gets hot on charger, ignites outside - http://www.rcgroups.com/forums/showp...&postcount=363
(173) Dropped pack catches fire minutes later - http://www.wattflyer.com/forums/show...3&postcount=28
(174) Lipo catches fire for no apparent reason - http://www.rcgroups.com/forums/showp...11&postcount=3
(175) Plane lands after short flight, battery disconnected, battery ignites shortly after -http://www.rcgroups.com/forums/showp...&postcount=373
(176) Battery ignites in plane during charging - http://www.rcgroups.com/forums/showp...&postcount=393
(177) Pack on Display in Hobby Shop catches fire - http://www.rcgroups.com/forums/showp...98&postcount=4

I tested two different MKII chargers and the results were the same, 80% capacity of a 4.20v per cell charge.
If you fly to a higher cutoff voltage and use less of the total pack capacity, percentage of charge for the MKII would be less not more.

The MKII is a nice safe charger for Lipo, but unless there was a revision change(?) it can’t charge a 3-cell pack to 12.4v because it terminates the charge at a lithium-ion safe 4.1v per cell or 12.3v. 

This is a test I did for capacity vs. Resting voltage.

72 degree pack and room temp.
The (999mAh) pack was discharged each time at 1C, to a 3v per cell cutoff.
Then I added a fixed percentage of charge, and measured the resting voltage after 12 hours.
Next I discharged the pack and verified the percentage of capacity.
At the end of all testing I charged the pack fully and did a accuracy / repeatability test.
The repeatability of the test was over 98%.

4.20v = 100%
4.03v = 76%
3.86v = 52%
3.83v = 42%
3.79v = 30%
3.70v = 11%
3.6?v = 0%

Capacity below 3.7v "resting" is not usable for flying, it's where the battery voltage dump begins.

 

Read more…
Developer

FreePilot Pre-Maiden Status

IMG_5625.JPG?dl=1

Hi Guys,

Its been some time since I gave any public updates to you people (contributors have got weeklies) on the status of the FreePilot project. Now as the project nears completion, I am posting photos and the current status for you people to comment on , advise, criticize , etc. I have run into some issues, most of which have been solved, but still need some help on the others.

Status:

  • All body work finished except canopy.
  • Everything bench tested.
  • Some ESC issues (summarized below)
  • XBee joystick control perfected.
  • Latest ArduPlane 2.5 (with modifications) loaded.
  • Battery and voltage sensor connected to APM on-bench.
  • Airelons tested to breaking point (still works perfectly)
  • Custom control rods attached (flexible plastic)
  • On the inside, spruce spars in original design replaced with fiberglass.
  • Everything else to get it flying.

To Do and Issues:

  • Make the canopy (almost finished)
  • Fix ESC heating issues: The 20A JDrones ESC is overheating on bench, without the motor running and just APM drawing from the BEC. My battery is a 11.1v 25C 2200mAh Turnigy pack, which should be suited for the ESC, but it still heats up, even after adding a beefy heat-sink on top. The MOSFETs on the bottom cannot be touched after a minute. I think I need a beefier ESC.

Photos:

IMG_5604.JPG?dl=1&width=450

Heat-sinked ESC (which still gets too hot)

IMG_5606.JPG?dl=1&width=450

 

Just-arrived Turnigy LiPo recessed in the body

IMG_5611.JPG?dl=1&width=450

APM, GPS and Xbee recessed in the body

IMG_5601.JPG?dl=1&width=450

Servo connected to right aileron using my 'specialized' push rods

IMG_5597.JPG?dl=1&width=450

Top View without Canopy

Let me know what you guys think, whether it will it fly or not, etc. 

If you want a photo-log of the entire project, its down below :

Parts Arrived (courtesy of Martin)

Electronics Assembled

Airframe 1

Airframe 2

Battery and Charger (courtesy of Sandesh)

Pre-Maiden

If anyone is interested in contributing towards the advancement of FreePilot please PM me!

This project would not have been possible without the generous contribution of :

  • Sandesh (for batteries and charger)
  • Martin (for APM, servos, Xbees, Motor, ESC and more)
  • Crasher (ESC and motors pledged)
  • Jaron (for airframe design which I have modified to suit my needs)
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3689473537?profile=originalA group of South Korean scientists has developed a new material for a secondary or rechargeable battery that can be fully recharged in just a matter of minutes, the science ministry said Monday.

A group of South Korean scientists has developed a new material for a secondary or rechargeable battery that can be fully recharged in just a matter of minutes, the science ministry said Monday.


This cuts down on the time needed to recharge the new type of battery to between 1/30 and 1/120 of that of existing rechargeable batteries, according to the ministry.

Read the complete article here: http://english.yonhapnews.co.kr/techscience/2012/08/13/8/0601000000AEN20120813001600320F.HTML

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Wiki Ninja

Videos of APM 2.0/ 1.4 1280 & 2560 machines

(Moderators- Notified user of pics and video requirement to be approved for posting)

 

Hey DIY Droners,

There's a dearth of videos from DIY Droners as I've observe. I'm just wondering how come we don't put out much videos of our machines equipped with APM 2.0s/1.4 1280 & 2560 machines on Youtube and/ or Vimeo and some other video hosting sites. 

When you search APM 2.0 at YT, the result at the top is the video of the APM 2.0 equipped Multiplex Fun Cub that I made last January yet. I am hoping that by now, the count of that video should have been surpassed by some other awesome production of an APM equipped machine. C'mon guys, crank out videos and clips of your quads, helis and airplanes out there. We need to get the good word out! Peace!

 

Gent  

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Attack of the Clones!

3689473405?profile=originalI was pilfering through ebay for some good deals on camera gimbals and I stumbled upon a store called gadgetinfinite.  They are selling several 3DR clones on their site.  I also noticed another one called game-jmt that is selling 3DR radios.  It seems there is an endless cycle of clones coming from China with no end in site.  Even though 3DR hardware is open sourced they are intent on selling this hardware using the 3DR name, trying to pass it off as original, but I highly doubt it is.  

I have read several debates about the pros and cons about Chinese companies cloning U.S. merchandise.  Personally I don't see any pros.  Most of these rogue companies are only cloning to profit and not innovate.  Will there ever be any way to regulate this? Should it?  It makes it awfully discouraging for anyone wanting to bring an innovative product to market knowing that there is little they can do to keep foreign companies from cloning their ideas. 

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Mapping a Larger Area

3689473268?profile=original

I got a chance to make a larger map with the E382 a few weeks ago and I ran it through Agisoft Photoscan for the postprocessing.

 

Platform: E382

Camera: SX230 HS with CHDK

Mapping Time: 30 minutes

Flight Time: 33-34 minutes

Images used: 341

Processing Time: ~12 hours of computer time, <30 minutes operator time

Area covered: 350 acres, 1.41km2  –  1550 x 910m rectangle

Area measured with QGIS

3689473281?profile=original

3d DEM viewed in GlobalMapper

3689473182?profile=original

Always have to try out the global warming tool

3689473350?profile=original

The only tips I have for those mapping larger areas is to first of all make sure you're spacing your flight lines appropriately based on your altitude. You can find good data on how much ground area is covered per image from Krzysztof Bosak's ebook The Secrets of Aerial PhotoMapping. Be sure to run through the images once before you process them and remove the blurry ones. Also make sure you're taking plenty of pictures so that removing the blurry ones doesn't leave any gaps in coverage.

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3689473322?profile=original

MIT grad students studying Robust Robotics designed a plane that can operate in tight spots — avoiding pillars and low ceilings — without a GPS or outside help. The plane uses an on-board laser range finder and inertial sensors to fly right. To demonstrate just how accurate the on-board navigation systems are, the team of scientists took the autonomous plane to a parking garage with ceilings just 2.5 meters high.

 

See the plane in action:

https://www.youtube.com/watch?v=kYs215TgI7c&feature=player_detailpage#t=0s

 

See the full article here:

MIT News Article

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100KM

techpod test flight #2

3689473122?profile=original

 I went out to the field at the cascade rc airfield on tuesday 8-7-12. located in snohomish ,wa . today it was me and nick weber . we got to the field and got all the fpv gear set up and the techpod ready .nick tossed it it the air for me and it climbed out nicely . i did a couple laps and at one point the throttle cut and was unresponsive . It came back after a second and i brought it in for a landing . while i was landing i lost throttle again . Luckily the techpod glides well and i greased her it near the end of the runway .here is a picture of the launch and the in flight video . much more to come after sunday . read more about the techpod at hobbyuav.com enjoy :-)


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I have now set up my battery charger power supply unit with a cable long enough to supply power for my small quad copter for inside testing. This will save the life of the batteries as well avoid the hassle of swapping them over constantly for when doing PID tuning etc. Only thing its not powerful enough to fly my X8 quad and trips the over load at about 29amps. Ill try see if ii will run my hex next. Here is the video of the small quad run

https://www.youtube.com/watch?v=PM4oZEulyqg&feature=youtu.be

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3689472936?profile=originalHi guys,

The Smart MOSFETs are now really smart enough to use them in such applications as RC High Current switches. More, they have a current sensing output, which could be used for current sensing instead of commonly used Schunt+IC .

An example for such a device is BTS50015 - BTS50015-1TAA-Data-Sheet-11-Infineon.pdf

The very low Rds of less than 1.5mOhm and 3.3-5V drive voltage capabilities make it a nice device for further researches. The ICs could be also connected in parallel for higher currents.

Here is a typical current sensing diagram from IS pin:

3689473105?profile=originaland a typical application:

3689473157?profile=originalI'm going to design some prototypes based on BTS50015 and BTS555 and after testing them I'll post the results.

Enjoy and have fun!

Nick

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Developer

More pics from AUVSI 2012

3689472679?profile=originalThe Unmanned Innovations QuadCopter.  They mostly focus on building custom autopilots for quads mostly but they are also working on adding support for hexa, octa, traditional helicopters.  My understanding is when you buy their quad, they also give you the source code that it's flying.  A very technical bunch who really seemed to know their stuff and were happy to talk about the details of quad copter control algorithms.  They backed up the our current theory on the cause of the altitude jump that some of us see when yawing arducopter is most likely caused by the non-linearity of pwm vs thrust in the ESCs/motors.

 

3689472710?profile=original

The MicroFlown microphone that could determine the exact direction of loud sounds (like a person clapping their hands).  In their demonstration video it was mounted in the plane shown and then flown overhead.  As it flew it would determine the location of simluated gunshots on a ground station.  Yours for around $25k.

 

 

3689472694?profile=original

Left is a Carl Hayden Falcon Robotics (highschool!!) student who along with the rest of his class had put together a functional underwater uav.  The pros must be worried when they see even highschool students are building UAVs these days!  The robot was driving around in a water tank at various times during the 3 day event (video here).

Right: some innovative work on a monocopter by a team of 3 Embry-Riddle University students.  The blades were 3d printed and apparently it flies although they did not have a demostration video.

 

3689472761?profile=original

JDI's hexa and fancy camera mount.  Why does it have slightly upturned arms?  Presumably for added stability.  $6k which compared to the military quads (all >$30k+) suddenly seemed like a bargain. The reps I talked to were all business, there to sell and not actually much fun to talk to but it was a nice looking system and they were one of the few teams actually doing real flight demos.

 

3689472723?profile=original

Two DIYDrones comrades, on the left, FalconUAV which uses the procerus (now lockheed martin) autopilot aimed for use by law enforcements.  On the right, ScionUAS's latest traditional helicopter UAS using a custom autopilot.  Both systems were demostrated at the recent Colorado Multicopter Rodeo as well by the way.

 

3689472816?profile=original
The Aeryon Quad and accompanying ground station which can be yours for around 100k.  As many of you know it has no RC style controller, it's all done through the IPAD like ground station software.  It's strong point is that it can still fly in very strong winds and easily replaceable arms which simply snap on and off (i.e. no wires to fiddle with).  It was surprisingly light and seemed mostly made of plastic.


3689472772?profile=originalCastle Creations displays Ed Kirk's (a DIYDrones member's) tricopter and their prototype device that provide feedback of the motor's RPM, current, etc to the microcontroller.  They also appear to be working on ESCs that are specifically suited to multicopters.


3689472790?profile=originalUAVFactory's plane platform (i.e. no autopilot) and groundstation (not including computer) priced at around $16k and $9k respectively.  The plane boasts a flight time of >50hours and they claim 70+ are in operation around the world.

 

3689472833?profile=originalMicroDrones's quadcopter boasting 90min flight time.  Even in outdoor (i.e. non ideal) conditions the rep claimed an hour is very possible.  They sadly wouldn't divulge any details of how they accomplished this but some other attendees believed it was accomplished mosty with an incredibly light frame, no payload and by sacrificing maneuverability and control for the sake of flight time.  I think a T3 contest on DIYDrones is in order to see how well we can do.

 

3689472740?profile=originalOn the Left is MicroPilot's based autopilot line-up (about 1.2k ~ 5k I believe) for a variety of platforms including traditional helicopters and airplanes.

On the right is VectorNav's AHRSs which are incredibly small despite including the 3-axis accel, gyros, sensor fusion processor and a GPS!  The silver ones are the SMD versions, the red ones are the same tech but enclosed in a case and are meant to be attached to your navigation controller via a (serial?) cable.  These guys were great fun to talk to as they were very technical and happy to get into the details.  In fact, like ArduPilot they use the Invense MPU60XX for the accel/gyro and a ublox for the GPS but their value add is the sensor fusion algorithms (12 or 13 stage kalman filter - they don't rely on the DMP) and the chips come all pre-calibrated (temp and drift).

 

3689472851?profile=originalTop Left: LiquidRobotic's Long distance wave powered research platform.  These travel at only 2mph but because they require no fuel they are sent out to sea on up to one year missions to gather data.  Solar panels on the top power the sensors and autopilot.  Iridium is used for two way data transfer including current location back to the ground station and way point updates.  There's apparently 4 floating about as we speak, one on it's way to Japan.

Top Right: MorrisTech displays their 3d printed titanium creations.

Bottom Left: IRobot's not just making vacuum cleaners anymore.  The special bit is the articulated track which allows to climb over rocks easily.

Bottom Right: Fly-N-Sense's coaxial copter designed for safety.  Besides tech hurdles, they're looking at the legal hurdles faced trying to getting permission to fly over crowds.

 

Generally people I talked to thought the tech's advanced a lot in the past year.  Most people have a system that does waypoints and provides live video so to stand-out you need something extra or you need to show how you're taking that tech and putting it into real applications.  Despite that I didn't see any cooperating robots or robots that can perform a more vaguely defined mission completely on their own (like filming a crime scene from every angle)...maybe next year!

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The sun was out, the winds were light, the temperature was about 85F, it was my birthday. There was nothing else to do but discover if all the time, money, energy, planning, and hope would work out.

It was a qualified success! Qualified in that I think pitch is reversed but in the case of today's short effort, it was another event of discovery on the road to longer flights.

 

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The good news was I did not break a prop! The casualty of the trials was a leg! Anyone out there want to report how the stock 3DR legs break? They do sell spares at the store so I suspect one or two have failed.

 

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The leg breaking may have been encouraged by the tether arrangement. The quad was blown while the line was taught and circled into the yard while I lowered the throttle. It impacted on the leg sideways moderately hard. The ground was wet and the toe stuck in the dirt while the copter kept rotating. The break was where one might expect it, at the through hole for the cross brace. If it had been on the driveway, I suspect it would have just skidded.

From my previous blog posts you would have known that while cutting legs out with my home brew CNC mill, I made plenty of extra legs. 10 minutes on the bench later and the Arudcopter was ready to go again. Unfortunately it was time to pack up and go see the grandchildren.

The tether weight was an old lamp ballast I use for a glue weight. I didn't think the copter could drag it anywhere especially with the small 'purple' motors (3DR sourced).

While driving to Tennessee to see the kids, it occurred to me that some sort of telescope/tilt platform would be a good tool for a copter-in-adjustment. All too often I read posts of noobs like me wanting to blame the APM or code for a setup issue. I suspect some form of gimbal jig to allow a tethered hoover would confirm if a command axis is reversed.

Throttle was good with liftoff around 52% of stick. Yaw seemd correct but the tether would yaw the quad when wind blew it to the rope end.

All in all, I am pleased and it was not a bad way to spend my 54th birthday.

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3D Robotics

Farm robots only pick the ripe strawberries

3689472866?profile=originalOne of the biggest commercial opportunities for robotics is agriculture, which I find endlessly fascinating (probably because I know nothing about farming!).  This isn't exactly drone-related (although lots of farmers are using drones for everything from multispectral imaging to crop-spraying), but Forbes has a good roundup of some recent developments:

A new project that’s part of the European Union Seventh Framework Program (FP7) cRops (Clever Robots for Crops) is focusing on creating robots to harvest high value crops.

The cRops robotic platform will be capable of site-specific spraying (targeted spraying only on foliage and selected targets) and selective harvesting of fruit. The robots will be able to detect the fruit, sense its ripeness, then move to grasp and softly detach only the ripe fruit. Another objective of cRops is to develop techniques for reliable detection and classification of obstacles and other objects to enable successful autonomous navigation and operation in plantations and forests.

...

Harvest Automation, based in Boston, MA, raised $7.8 million in a series B funding round in November 2011. Harvest is focusing on agricultural robotics and focusing on greenhouse and nursery automation. They want to resolve acute manual labor problems across multiple industries but are starting with agriculture.  The Harvest Automation robot costs around $25 to $50k and because the manipulation requirements of the robots are lower in this sector, the company focus on creating a viable business, reducing costs and higher yields, rather than worrying about how to incorporate expensive robot arms into their operations.

...In Japan in 2010 the Institute of Agricultural Machinery’s Bio-oriented Technology Research Advancement Institution, created a strawberry picking robot with a stereo camera system that images the strawberries in 3D and image-processing algorithms determine their ripeness. If a strawberry is at least 80 percent red, the machine snips it at the stem and puts it in a padded bin. It can harvest 60% of the strawberry crop, taking only nine seconds to pick a strawberry. But, according to a machine-vision specialist who worked on the strawberry picking project, this robot won’t happen without government subsidies.

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3D Robotics

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From the LA Times. The product datasheet is here. Does anyone know how they achieve the GPS spoofing protection?

LAS VEGAS -- Two of the major challenges the government faces in attempting to allow thousands of small drones into U.S. airspace are knowing where the aircraft are in relation to other aircraft flying nearby and making sure they're safe from hacker attacks.

Rockwell Collins Inc.  believes it has addressed both concerns with a device that's slightly larger than a postage stamp.

The company's unassuming MicroGRAM device promises to provide precise and secure GPS technology for the kind of small drones that police agencies want to use to spot runaway criminals.

"It's the smallest device out there with this kind of capability," said Dave Schreck, Rockwell's director of unmanned aerial systems and control technologies.

MicroGRAM has been in production since March, but Rockwell spoke about its capabilities Tuesday at this week's Assn. for Unmanned Vehicle Systems trade show in Las Vegas. Hundreds of robot makers have gathered here to show off their wares.

The device provides anti-jamming and anti-spoofing protection. So if a hacker tries to commandeer the drone by sending false GPS signals to trick the aircraft's receiver -- like what was recentlydemonstrated at University of Texas  at Austin -- the ne'er-do-wells will be locked out.

Drone hacking is a concern that has risen ever since the government revealed plans to integrate drones into U.S. airspace by 2015.

Rockwell's MicroGRAM is currently on drones built by AeroVironment Inc. of Monrovia, the nation's biggest supplier of small robotic planes.

"When people see how small it is, I hear them gasp," said Trevor Overton, Rockwell's MicroGRAM program manager. "We think this device provides the kind of capabilities that the unmanned aircraft community is interested in."

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3D Robotics

MIT research on indoor navigation with UAVs

From the MIT press release:

MIT’s Robust Robotics Group — which fielded the team that won the last AUVSI contest — has set itself an even tougher challenge: developing autonomous-control algorithms for the indoor flight of GPS-denied airplanes. At the 2011 International Conference on Robotics and Automation (ICRA), a team of researchers from the group described an algorithm for calculating a plane’s trajectory; in 2012, at the same conference, they presented an algorithm for determining its “state” — its location, physical orientation, velocity and acceleration. Now, the MIT researchers have completed a series of flight tests in which an autonomous robotic plane running their state-estimation algorithm successfully threaded its way among pillars in the parking garage under MIT’s Stata Center.

“The reason that we switched from the helicopter to the fixed-wing vehicle is that the fixed-wing vehicle is a more complicated and interesting problem, but also that it has a much longer flight time,” says Nick Roy, an associate professor of aeronautics and astronautics and head of the Robust Robotics Group. “The helicopter is working very hard just to keep itself in the air, and we wanted to be able to fly longer distances for longer periods of time.”

With the plane, the problem is more complicated because “it’s going much faster, and it can’t do arbitrary motions,” Roy says. “They can’t go sideways, they can’t hover, they have a stall speed.”

Found in translation

To buy a little extra time for their algorithms to execute, and to ensure maneuverability in close quarters, the MIT researchers built their own plane from scratch. Adam Bry, a graduate student in the Department of Aeronautics and Astronautics (AeroAstro) and lead author on both ICRA papers, consulted with AeroAstro professor Mark Drela about the plane’s design. “He’s a guy who can design you a complete airplane in 10 minutes,” Bry says. “He probably doesn’t remember that he did it.” The plane that resulted has unusually short and broad wings, which allow it to fly at relatively low speeds and make tight turns but still afford it the cargo capacity to carry the electronics that run the researchers’ algorithms.

Because the problem of autonomous plane navigation in confined spaces is so difficult, and because it’s such a new area of research, the MIT team is initially giving its plane a leg up by providing it with an accurate digital map of its environment. That’s something that the helicopters in the AUVSI challenges don’t have: They have to build a map as they go.

But the plane still has to determine where it is on the map in real time, using data from a laser rangefinder and inertial sensors — accelerometers and gyroscopes — that it carries on board. It also has to deduce its orientation — how much it’s tilted in any direction — its velocity, and its acceleration. Because many of those properties are multidimensional, to determine its state at any moment, the plane has to calculate 15 different values.

That’s a massive computational challenge, but Bry, Roy and Abraham Bachrach — a grad student in electrical engineering and computer science who’s also in Roy’s group — solved it by combining two different types of state-estimation algorithms. One, called a particle filter, is very accurate but time consuming; the other, called a Kalman filter, is accurate only under certain limiting assumptions, but it’s very efficient. Algorithmically, the trick was to use the particle filter for only those variables that required it and then translate the results back into the language of the Kalman filter.

Confronting doubt

To plot the plane’s trajectory, Bry and Roy adapted extremely efficient motion-planning algorithms developed by AeroAstro professor Emilio Frazzoli’s Aerospace Robotics and Embedded Systems (ARES) Laboratory. The ARES algorithms, however, are designed to work with more reliable state information than a plane in flight can provide, so Bry and Roy had to add an extra variable to describe the probability that a state estimation was reliable, which made the geometry of the problem more complicated.

Paul Newman, a professor of information engineering at the University of Oxford and leader of Oxford’s Mobile Robotics Group, says that because autonomous plane navigation in confined spaces is such a new research area, the MIT team’s work is as valuable for the questions it raises as the answers it provides. “Looking beyond the obvious excellence in systems,” Newman says, the work “raises interesting questions which cannot be easily bypassed.”

But the answers are interesting, too, Newman says. “Navigation of lightweight, dynamic vehicles against rough prior 3-D structural maps is hard, important, timely and, I believe, will find exploitation in many, many fields,” he says. “Not many groups can pull it all together on a single platform.”

The MIT researchers’ next step will be to develop algorithms that can build a map of the plane’s environment on the fly. Roy says that the addition of visual information to the rangefinder’s measurements and the inertial data could make the problem more tractable. “There are definitely significant challenges to be solved,” Bry says. “But I think that it’s certainly possible.”

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Moderator

Important CAP 722 update for UK UA drivers

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Well worth a read, no really don't ignore it if you are in the UK. Yes you can fly for fun and do nothing but if you turn a penny or pint you need to comply.

http://www.caa.co.uk/docs/33/CAP722.pdf

If you are in the USA you might read it and cross your fingers that you are going to get such sensible regs, sadly after the AUVSI conference it would seem not! Just keep remembering ASTM F-38....

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