Ever since we played with the original AR drone back at CES a few years ago, we’ve been keeping an eye on them. While we all agree there are better quadcopters out there, the price point for a ready-to-fly quadcopter of this size is really great with these. When the fake video from FPS Russia of the weaponized drone made the rounds earlier this year, we were surprised at how people reacted. Anyone who has messed with quadcopters recognized it as fake right off the bat (not to mention the overly cliche fake russian character). We won’t be adding a full fledged firearm to this. Mainly because it simply can’t lift the weight (There are ones that can, but we couldn’t justify the cost just for that). We do have some ideas though. Lets go over the specs of the AR Drone 2.0 first. The manufacturer is pretty good about sharing information. They have a decent breakdown of the specs as well as a full SDK available for writing apps for the AR drone. *We’re assuming they mean 1Gigabyte of RAM there on the specs.

As you can see, it has decent specs for the $299 price tag. This is partially due to the fact that it uses wi-fi for control. A decent radio system would greatly increase the distance (and probably response), but would have added another $100 to the price tag. This isn’t a full review of the AR Drone. I didn’t run it through any tough tests, nor compare it to similar sized and outfitted competitors. I just pulled it out of the box, flew it around a bit, and started thinking about how best to make it preposterously dangerous. During this time, I found that the Wi-Fi control system works fairly well. There’s not really a discernible lag between motions on the iPhone and motions on the drone. The drone was fairly stable both indoors and out, though it really didn’t like ceiling fans. I started taping things to it to see how it would respond. As you get too much weight on it, you start to see that the stabilization system twitches attempting to keep it level. This happens long before it physically can’t lift things.

It shouldn’t be an issue though as I only noticed it while attempting to hover in place. Battery life is greatly reduced though with any additional weight. This is a pain in the butt because the stock battery only offers roughly 8 min of un-weighted flight on a 1.5 hour charge. There is already a strong community of modders out there for the AR drone. Here are some common mods that I found while researching. I’ve included a few links to examples, but there are many more to be found. I’ve got some ideas. They’re not all very safe sounding, but don’t worry, I’ll take precautions to make sure no one gets hurt. They’re also not very practical, but sound really fun. Let me know your ideas. Keep in mind that if I strip this thing down, I can really only carry 100-150 grams comfortably. Also keep in mind I don’t have the time or resources to carry out massive undertakings (sorry, no AI swarms, etc )This is the second tutorial in the Up and flying with the AR.Drone and ROS series.

In this tutorial we will: In the next tutorials, we will: To complete this tutorial you will need: I also assume that you’ve completed the previous tutorial, which details how to setup the software, connect to the drone, etc. In this tutorial, we will be flying the AR.ar drone 2 toppreiseFlying inside can be dangerous. buy ar drone sydneyWhen flying inside, you should always use the propellor-guard and fly in the largest possible area, making sure to stay away from walls and delicate objects. buy ar drone orlandoEven when hovering, the drone tends to drift, so always land the drone if not being flown.ar drone price in malaysia I accept no responsibility for damages or injuries that result from flying the drone.

It has been three weeks since the launch of the first tutorial and I am very happy with the response so far. The tutorial has been viewed over 720 times and ARDroneUbuntu downloaded over 50 times. I was also given the honor of partaking in RobotGarden’s very first Quadrocoptor Workshop, where we worked through the tutorial (and ironed out the bugs) together. This response has taught me a few things about how to structure a tutorial series, and how to release a virtual machine. Based on what I have learned, I will be restructuring the source-code for the following tutorials. I will also be updating the virtual machine to reflect these changes. When writing the first tutorial, I thought it would be better to have a separate repository for each tutorial to keep everything atomic and isolated to ensure the addition of a new tutorial would not affect anything in the past – However having learned from the video-hangout with RobotGarden, I realize this could cause an update nightmare down the track.

For this reason, I have decided to operate from a single repository and will maintain a stable branch for each tutorial, with the master branch always synchronized with the stable version of the latest tutorial. The source-code for each tutorial will also contain all source-code required to run the previous tutorials. Sorry for any hassle caused by the above, I hope this new structure will allow me to more easily deliver the next tutorials! Connect to the AR.Drone as detailed in the first tutorial (remembering to disconnect other network adaptors if they use the 192.168.1.x address range) From within your Linux installation, launch two terminal windows (ARDroneUbuntu users, refer to the first tutorial if you’re not sure what I mean) In the first window, launch the KeyboardController from the first tutorial, using the command: Wait for everything to load and the video display to become active, then in the second terminal window enter the command: This command lists all active “topics”, the communication channels through which ROS programs (called “nodes”) communicate.

To view the currently running ROS Nodes, type: The window that appears will show a network of nodes, and how they are connected through the topics that we saw in the previous step. When you’re ready, close this window. We’re now going to have a look at the messages that are being sent between nodes. At the terminal, type: The navdata message is published by the AR.Drone driver at a rate of 50Hz. Press Ctrl-C to stop echoing the navdata message then switch to the other terminal window and press Ctrl-C again, to stop the roscore program After that whirlwind tour of the ROS communication hierarchy, lets take a look at what we’ll be building today: As shown above, today we’ll be setting up the joy_node (a standard ROS package) to listen for input from a joystick or control-pad. This input will be converted into a ROS message, then sent to our controller over the joy topic. Our controller subscribes to the joy topic and reacts to the received messages by translating joystick movement into drone movement commands, which are then published to the cmd_vel topic;

and button presses to takeoff, land, or emergency commands, which are each published to a respective channel. The ardrone_driver receives these various commands and then sends them via the wireless network to the physical drone, which in turn sends back a video stream. This video stream is published by the ardrone_driver onto the /ardrone/image_raw topic, from where it is received and subsequently displayed by our controller. Firstly, we need to connect the joystick and set it up to work with ROS. Now that we have the joystick installed, let’s check to make sure everything is working. Type the following at a terminal, substituting jsX for the joystick device you previously identified: If you are greeted with a “jstest: Permission denied” error, type: Which enables all users to read the joystick device (ARDroneUbuntu users, the password is: ardrone). After running jstest, moving the joystick should cause the numbers on the screen to update, if not, try running jstest for the other jsX devices.

Congratulations, your joystick device is working! Press Ctrl-C to exit. Now we’re ready to integrate the joystick device with the ROS ecosystem using ROS’s “Joy” package. We now have the task of identifying the various axis and buttons used to fly the drone. All in all, you will need to identify axes to control the AR.Drone’s roll, pitch, yaw-velocity and z-velocity; and buttons to trigger an emergency, command a takeoff, and command a landing. To identify the emergency button for example, press the button you would like to trigger an emergency, and watch the terminal to see which button is enabled. In my case, I use the joystick’s trigger button for emergency (being able to react quickly to an emergency is very important). With the button pressed, the following is printed in the terminal window: From this I can identify that: Emergency = Button 0 (note that indexing starts from zero). The process follows similarly for identifying an axis: From this I identify that the Roll Axis = 0 and Roll Scale = 1.

After you have identified all axes and buttons, press Ctrl-C in all terminal windows to stop the processes. In ROS, a “Launch File” is used to configure and launch a set of nodes. We’ve already seen this in the first tutorial (and at the beginning of this one), where we typed: In this command, keyboard_controller.launch configures the ARDrone driver for indoor flight, then launches both the driver and keyboard controller. Similarly in this tutorial, we will be launching the joystick controller (and related nodes) using a launch file. Go ahead and open a terminal window, then type: This will open the joystick_controller.launch file in the text editor (non ARDroneUbuntu users can use a text editor of choice). You will need to customize this file for your setup. Feel free to have a look at some of the parameters used on the drone. The drone’s control parameters can potentially be increased to allow for more aggressive flight. Once you’re happy with the settings, save this file as joystick_controller.launch, then close the geany application.

So, after that rather long endeavor (which you should only need to do once), lets fly! Connect to the drone, disconnect other network devices, then open a terminal and type: This will launch the nodes as you configured in launch file. If all goes well, you should now be able to fly the drone using your joystick. Before commanding the drone to take-off, you should first check that your emergency button works. With the drone still landed, press the emergency button once. All onboard LEDs should turn red. Pushing the button again will reset the drone, and the LEDs will once again turn green. In addition to this, whenever a (mapped) button is pressed, the joystick_controller will print a message to the terminal, such as “Emergency Button Pressed”. This is a further indication that things are working! You’re now ready to take off. The above child’s play? Heres some ideas for exploring the ROS and ARDrone environment: While the joystick controller is running, open a new terminal window and type: