All Posts (14056)
1.Kalman filter for attitude estimate.
2.900MHz,2W RF datalink.
Although the sensor board not be modified for GPS and airspeed sensor. but I have tested the attitude estime via Kalman filter and RF datalink first. It's sad that I forgot take DV to record it. Orz
The RF made in Taiwan is stable and higher data rate that CL4790.(I have both). But It need specific command to sent data. It is not suitable for general purpose.
http://diydrones.ning.com/video/kalmanestimate-1
I am acquiring a Multiplex Easy Star to learn to fly, and to work on a UAV build. This blog post highlights my proposed configuration, which is to be incrementally upgradeable
I plan to split up my project into five parts:
- Learn to fly,
- Fly with a camera payload (just for fun),
- Fly manually with sensors, a data logger, and maybe a camera,
- Use logged data to set up an autopilot, and try turning control over to the autopilot.
- Repair plane and return to step 3.
- I have a budget of $500 to start with. This has to include AMA/club membership, airplane, electronics, IMU, autopilot, et cetera.
- I would like the plane to carry a payload that includes an IMU, an Ardupilot Mega, a Remzibi OSD or GPS, and a camera.
Other Easy Star Configurations (prior art):
http://www.diydrones.com/profiles/blogs/my-ardupilot-projects-status
Lots of Miscellaneous Questions -- here's one to start with:
Q: The ESC has a motor ESC output and a 5V output for my servos/receiver. What do I do if I want a second battery for the servos and receiver?
Stage 1 Parts List:
- Easy Star ARF ($122):
- Radio -- Futaba 6-channel (eBay)
- Undecided Battery -- Upgrade-compliant LiPo?
- Undecided Battery -- Heavy, non-upgradeable NiMH?
- Already have NTSC camera, Airwave A/V Tx/Rx modules (634 and 630)
- Ardupilot Mega
- IMU System (Razor? DIY Drones Mega Shield?)
- GPS -- mini GPS or Remzibi OSD
- Brushless Motor and ESC Upgrade
- Option 1: Upgrade Kit from Tower Hobby ($80)
- Option 2: Upgrade from Nick Sargeant's configuration http://www.diydrones.com/profile/NickSargeant
- Option 1: Upgrade Kit from Tower Hobby ($80)
There's my proposed configuration (including the undecided bits) -- I plan to meet my local club (SGVRL) to learn about flying on the local field, and later I can get a little better informed about my choices of battery before I jump in. Once I can fly, and fly with a payload, I'll pick out an IMU to play with.
It's the National Ignition Facility, the most powerful laser in the world. $4 billion. 500 Terrawatts. Enough power to feed 413,223 time machines. It requires 5 hours between each 4ns laser firing to cool down.
It was too windy to get very high. Only got 1 shot at 400ft. Angle of attack got to the abort limit where GPS could be lost & conventional control laws don't work.
Next, it was back over Pillar point.
Can't go very high in fog.
Finally, flew up over Napa again & for the 1st time, didn't crash. The wind in this area was the highest she ever flew in. Saw pretty insane angles of attack. GPS reception was real lousy. The video was made from several flights with the camera at different angles. 3 fans of freedom on the wing made strange noises in the wind.
Noted 2 anomalies in the video: a rubber band came off the camera & radio dropouts
caused several pitch ups. Got 1 in the video. Aft propeller was scraping something when it hit yaw limits.
Looking over the lwneuralnet sourcecode again, the net_begin_batch, net_train_batch, & net_end_batch functions are basically the definition of backpropagation through time with obscure wording.
The neural network is recurrent but not being trained that way. Was always a bit stumped on how to train a recurrent network to optimize its own flying. They only know how to recall ideal answers. In the past, fed tables from PID equations.
1 way is to just randomly change weights & select better performing networks over long periods of time. Maybe have a 2nd network be an emprical model of the flight characteristics. Then there's taking the times when it hit the right position & training off those.
Well, the only way we see this commissioned turkey going autonomous now is ground based machine vision. Even then, it's not going to be stable enough to fit indoors. A ground camera can sense roll. The magnetometer can sense pitch. Sonar would still be needed for position.
Golf course grass on the UAV? It happens to the best of us, just like marriage, death, & taxes. Autonomy without attitude sensing isn't going so well again. Her neural network was overloading her CPU.
Hi guys,
Today MatrixPilot controlled three more autonomous flights. All three flights were executed with the transmitter turned off. The picture above is the track of the first landing. It was aiming for the midpoint between the two fields, along a line that connects the centers of those two circles.
Recently I posted three flights of my GentleLady flying with MatrixPilot running on a UAV DevBoard, but I was not able to take a video at that time. The weather cleared today, so I thought I would get three more flights, this time with the EasyStar, and with a video camera documenting the hands off takeoffs and landings. This time, since I had the video camera as proof that the plane was able to take off again after each landing, I cycled the power on the plane between flights, but all three flights were with the same battery.
The first flight was just a test flight, without the video being recorded. Wouldn't you know it, it was the best of the three. Here is the GoogleEarth kmz file of the first flight: LOG00080.kmz. It includes waypoints, attitude information, wind estimation, and the track. You can animate the flight to re-create it, using the GoolgeEarth animation tool.
The following is a picture of the track of the first flight.
The second flight was the first flight that was captured on video. It was the most interesting of the three flights because it includes a missed approach. The plane was coming in high, and it looked to me that it might land on the busy highway to the northwest of field, so I cycled the power on the transmitter on and off to reset the controls. The plane then started all over again through the pattern, with the transmitter off, this time making a successful landing. Here is the kmz file: LOG00083.kmz The following is the track of the landing:
The third flight was executed immediately after the second flight. Here is the kmz file: LOG00084.kmz Here is a picture of the landing:
The third landing was actually right at the edge of the field. The plane came to rest against a fence post, but there was not any damage done.
The target for each landing was the point midway between the centers of the two fields. The distances between the landing point and the target for each flight were:
Flight#1: 34 meters
Flight#2: 38 meters
Flight#3: 80 meters
I will leave it up to the judges which flights to include in the average. Only two flights are needed for the contest, but it is not clear to me which ones qualify:
Flight#1: "clean flight", but no video
Flight#2: autonomous takeoff, manually commanded landing abort, then a complete autonomous flight. video recorded.
Flight#3: "clean flight", landed short. Bumped into a fence post, but no damage.
Now, the video:
Autonomous Flights of EasyStar with UAV DevBoard from William Premerlani on Vimeo.
/**********************************************************************************/
Team,
Here are three more videos. The quality is much better, my son, Brian, took most of it. I was not going to publish them, because they were from an unsuccessful flight. But now that I think about it, I think you would enjoy them more, watching me make a "rooky" mistake.
Here is what happened...on the day of my first few autonomous flights, I did not get video for the first 3 flights, dead batteries in the video camera.
So, later on in the day, armed with fresh batteries, I decided to try again. This time I took my son, Brian with me to help take the videos. You will see him. We thought it was fitting for him to finally appear, since he was the one who got me started in this hobby. If it were not for him, I would be doing something else instead of diydrones. Just in case there is any confusion about who is who, I am the good looking one, he is the young one.
Between the time of the first flights and when we got back to the field, the wind direction had shifted. We would now be taking off and landing with the wind. Bad idea. I knew better. But I really wanted to get some video, so I fooled myself into thinking that, although the wind was in the wrong direction, it was not too strong. Wrong!!
So, we gave it a shot. Here is the video. Things were going fine until final approach. It was landing with the wind, coming in high and fast. I could see it was going to go long. I had to make a fast decision. The camera was rolling, and I was determined to get my video. So, I let the plane try for an automatic go around. It reached the landing waypoint, powered back up, turned toward the trees, and started to climb. It almost cleared the trees. Almost...
If you listen, you can hear the plane smack into the tree at the end. Brian says it is the sound of wood embracing wood. Oh, and cover your ears at the end, I never imagined I would ever publish this one:
Gentle Lady's flight into the trees. from William Premerlani on Vimeo.
After the GentleLady smacked into the tree, Brian and I walked down to see what we could see....It was way up in the tree, about 60 feet up.
Brian is an avid climber, I bought him a membership in an indoor rock climbing club, so he volunteered to climb up and fetch it. It wasn't easy, but he did it. He went up as high as he could, he was still about 10 feet too low. With a GentleLady, the wing is held on with rubber bands, which had popped off. Brian shook the tree, the wing finally shook loose and fell. But the tree had a firm grip on the tail, so Brian climbed up another 10 feet to fetch the rest of the plane. Here is what he looked like 60 feet up in the tree:
Brian rescues the Gentle Lady from a tree from William Premerlani on Vimeo.
The next question was what to do next. Brian vetoed the idea that we would try to complete the flight. It turned out the motor was running when the GentleLady landed in the tree, it was burned out. So, how to get the plane down? The only way was to throw it, as near as we could see. Brian was not signing up to climb down with the plane in one hand. Ever thoughtful, he took out the electronics first, and then dropped it straight down. It landed in the low branches of the tree. Here is the final step of the rescue:
Gentle Lady: the low hanging fruit from William Premerlani on Vimeo.
Aside from the burned out motor, there was not much damage to the GentleLady. A new motor, a couple of drops of glue, she was out flying again the next day.
Best regards,
Bill Premerlani, June 26, 2010
It's been up for a while, but if you haven't checked out the website, here it is:
Mission Statement:
"The mission of the Congressional Unmanned Aerial Vehicle (UAV) Caucus is to educate members of Congress and the public on the strategic, tactical, and scientific value of UAVs, actively support further development and acquisition of more capable UAVs, and to more effectively engage the civilian aviation community on UAV use and safety.
As members of this Caucus, we:
- Acknowledge the overwhelming value of UAVs to the defense, intelligence, homeland security, and the scientific communities;
- Recognize the urgent need to rapidly develop and deploy more UAVs in support of ongoing operations;
- Work with the military, industry, NASA, the Department of Homeland Security, the Federal Aviation Administration (FAA), and other stakeholders to seek fair and equitable solutions to challenges created by UAV operations in the U.S. National Air Space (NAS);
- Support our world-class industrial base that engineers, develops, manufactures, and tests UAVs creating thousands of American jobs;
- Support policies and budgets that promote a larger, more robust national security UAV capability."
Random images from the ArduCopter dev team mailing list this week. They're doing world-class work--amazing to watch! Stay tuned for product announcements...
Above: Base plate prototypes made with the CNC machine, some of them anodized, some powder coated. These are anodized. (all from Ken McEwan)
Aluminum, powder coated.
Power distribution PCB, from Jani Hirvinen
Motor mount, from Sandro Benigno.
Our favorite geeks at Sparkfun have just ubergeeked out on GPS modules. Here's an overview on GPS modules and tracking, and here is a really thorough test/comparison of the modules they sell.
We like this one a lot. It's nearly as good as the uBlox module, but cheaper and smaller. We'll be supporting it as a recommended GPS module going forward.
Here's the product description:
State-of-the-art 66 channels MediaTek MT3329 GPS Engine
High sensitivity: Up to -165dBm tracking, superior urban performanceUSB/UART Interface
Build-in patch antenna for optimal sensitivity
DGPS(WAAS, EGNOS, MSAS) support (optional by firmware)
Maximum update rate : up to 10Hz (optional by firmware)
RoHS compliant
-Based on MediaTek Single Chip Architecture.
-Dimension:16mm x 16mm x 6mm
-L1 Frequency, C/A code, 66 channels
-High Sensitivity:Up to -165dBm tracking, superior urban performances
-Position Accuracy:< 3m CEP (50%) without SA (horizontal)
-Cold Start is under 35 seconds (Typical)
-Warm Start is under 34 seconds (Typical)
-Hot Start is under 1 second (Typical)
-Low Power Consumption:48mA @ acquisition, 37mA @ tracking
-Low shut-down current consumption:15uA, typical
-DGPS(WAAS, EGNOS, MSAS) support (optional by firmware)
-USB/UART Interface
-Support AGPS function ( Offline mode : EPO valid up to 14 days )
Developers of this combined project, Thanks!
Ugly and dirty, the system is ready to roll tomorrow, the bench tests all went well, although I think that the elevator amplitude (gain) isn't enough when in stabilize, which probably will happen also with RTL mode.
More to come, tomorrow.
Some month ago TI developped a watch based on there super low current 430 ic,
in it you can find a µc, a triple axis accelerometer, a pressure sensor, and a 868Mhz RF chip with antenna.
they also give the sdk for cooking custom apps...
http://processors.wiki.ti.com/index.php?title=EZ430-Chronos
And all of this is sold ... 50$...
Pretty cool, except that I had to wait 3 month to have one...
Maybe I'm not the first to do this, but I added a variometer function to the altimeter module and to the RF module to be able to send the vario Data to the computer ;)
I'll try to make a video of this ;)
Well, I figured out how to do it, and I'm here to share. Here's a video of my sample LabView VI that reads in the GPS coordinates of the mouse over the Google Earth map, captures the position of a left mouse click, and feeds it back into Google Earth through the well known network KML file.
The Source code is available at my website here
The opens the door to new GroundStation features, like "Click and Go" during a flight. Also, it could mean the retiring of ConfigTool, as all mission planning and status could be done through a single LabView VI with Google Earth.
Please visit our website!
and easy to install. Price is US$ 4.99
Specfications:
Dimensions: 42x40mm
Weight: 10g
Servo type required: 5~10g
Stock Arrival: 12/July
Pre-order here: http://www.hobbyking.com/hobbyking/store/uh_viewItem.asp?aff=5361&idProduct=12875