This is a brief explanation of how any computer (even old PCs are OK!) can be used as a seed for Rawseeds’ datasets. As you will see, it’s really easy and quick. If you don’t know why you should set up a Rawseeds seed, please read here. Here we just say that setting up a seed machine is the best help that you can give to help Rawseeds live and prosper.

IMPORTANT: it is absolutely not required, for a seed PC, that it is dedicated to seeding! Seeding can occur in the background, with minimal load on CPU, RAM and internet connection, while the machine is used in the usual way. The seed PC can be your own workstation, the PC used by a colleague or a secretary, your home PC… Or you can finally find a new use for that obsolete machine that you have under the table, down there in the corner :-)

What you need

To act as a seed for Rawseeds, a machine needs only the following things:

• a working operating system
• a connection to the internet
• some disk space
• a BitTorrent client program

Any OS can be used, provided that it is not so ancient that there is no BitTorrent software for it. Nowadays BitTorrent is very popular: therefore, many clients are available, free of charge, for any platform. You can select any of them: see our BitTorrent HOWTO for further information. By the way: if you use a “desktop” Linux distribution, it’s likely that you already have a BitTorrent client installed on your machine by default.

How to set up a seed

After you have the PC, follow these steps:

1. Put on the chosen PC a copy of the compressed files you downloaded from www.rawseeds.org, or any subset of them. The files must be put in the download directory of the machine’s BitTorrent client program (you can set this directory from the program’s options). If you originally downloaded the files to this machine and did not move them, they’re already in the right place.
2. Run the BitTorrent client program.
3. (only if you did not download the files on this machine, or if you did it but you removed the torrents from the BitTorrent client) Re-click on each of the links (on the pages of www.rawseeds.org) that you used to download the files in the first place. This will start again the download of those files… but the BitTorrent client will immediately detect that a complete local copy of such files is present, and will start seeding instead of downloading.
4. Ensure that the machine is set up to automatically start the BitTorrent client program at every boot.

Er, that’s it. You have set up a working BitTorrent seed. Congratulations! And many thanks from the Rawseeds project!
The seed machine you just set up can be used normally, without any limitation. It can also, of course, be shut down whenever you wish: just make sure that the BitTorrent client is restarted at the next boot.
If you want to know how much data bandwidth your seed is contributing to Rawseeds at a given time, just look at the “upload speed” values displayed by the BitTorrent client.

Controlling upload bandwidth

You can fine-tune the maximum amount of internet bandwidth that your BitTorrent client uses for seeding. In this way, you can control the impact of the client on your PC’s resources, and ensure that it will not slow down your internet connection. To do this, just access the options of your BitTorrent client.
An upload bandwidth of a few tens of KBytes/s is perfectly good for Rawseeds: with such a setting, you should note no adverse effect on your internet connection, or on the performance of the seed PC when used for other tasks. This holds true even if the PC is a few years old and/or the upload link is slow (e.g., ADSL). Of course, higher settings (such as a few hundreds of KBytes/s) are even better for Rawseeds: any modern PC and (non-ADSL) connection should cope with them without noticeable effects. Finally… if you work in a place – such as a university – where bandwidth towards the internet is abundant, consider setting your BitTorrent client for a maximum upload bandwidth of a few MBytes/s :-) ). Please note that seeding with such an upload bandwidth could begin to slow down older machines, though that will only occur in the time intervals when the bandwidth is fully used. This is something that, whatever the success of the Rawseeds project, should happen very rarely!

Record-time setup of a seed!

Modern versions of “desktop” Linux distributions (e.g., Ubuntu, Fedora, OpenSuse, Mint, Mandriva) come with BitTorrent client programs installed by default. Moreover, they do not require modern hardware to work satisfactorily. And, of course, all of them can be downloaded for free.
The fastest way of all to set up a Rawseeds seed from scratch is to take an old PC from the trashcan, install one of these Linux distributions on it, and copy the files on its hard drive. A network cable, some clicks to let the BitTorrent client know what data it should seed… and the seed is up and running!
One hour of work overall, including a coffee break while installing the OS ;-)

What are we talking about?

As you can read in the BitTorrent HOWTO, downloading Rawseeds’ datasets is easy. You install a BitTorrent client program (chances are that you already have it installed by default) you click on a link in Rawseeds’ website to start downloading the associated file, and that’s it. The BitTorrent client tells you when the download has finished (for very large files such as ours, this can take even days).
While you are downloading the file, you are also uploading small chunks of it to other users requesting the same file. As they too do the same for you, the net result is that each of you peers (this is the actual word) experience a much faster download. To upload the data, you use a small fraction of your available upload bandwidth. How small? You decide it: every BitTorrent client allows the user to select easily the maximum uploading bandwidth that the client can use. Some can even let you specify different values, say, for working hours, nights, and weekends.
You are beginning to see where this is going to, don’t you? The speed at which Rawseeds users download the data depends on how many users are uploading the same data at the moment. The more users act as uploaders (or, to use the correct word, as seeds) the faster every user gets her data. And for Rawseeds’ data, that comprise many huge files, speed is a key factor, if you don’t want to end up spending weeks to get the files.
So: the more time you choose to act as a seed for a particular Rawseeds file, the faster the download of that file will be for all Rawseeds users. This is the reason why you should try to keep seeding the files for the longest possible time. Without your help Rawseeds could not be possible, because obtaining acceptable (read: very high) download speeds for our files for every user would require us buying extremely costly hosting services… that we can’t afford (hey, Rawseeds is a small project!).

How can you do this “seeding” we are so insistent about?

Nothing could be more simple. When the download of the Rawseeds files you requested is completed, don’t close the BitTorrent client program; don’t move the files away from the download directory; and don’t remove the torrents associated to those files from the BitTorrent client. If your machine is not always on, also ensure that the BitTorrent client is automatically started every time the PC is turned on. This is it.
Of course you can use the data you just downloaded! Just uncompress them to wherever you like (even in the download directory, if you want) and use the contents. Only, do not remove the compressed files you downloaded from www.rawseeds.org (but you can copy them and move the copies).

What are you actually doing by seeding our data?

• you are donating some space on your hard disks to host the files to be seeded
• you are donating a fraction of your upload bandwidth to send chunks of those files to other Rawseeds users (the amount of this bandwidth can be easily set from the BitTorrent client)
• you are donating a (very small) fraction of your processor’s power to keep running the BitTorrent client
• you are giving a key contribution to Rawseeds and we *warmly thank you!*

IMPORTANT: to act as a seed for Rawseeds, a machine doesn’t need to be powerful, or modern, or good-looking. Provided that disk space is sufficient, any old PC salvaged from the junkyard is good. Leaving it in a dusty corner to seed some of Rawseeds’ files is the best present that you can do to us. Read here to learn how setting up an old PC as a seed: it’s incredibly easy.

In case you are wondering: if you accept to act as a seed for Rawseeds data, your machine will seed those files only. It is impossible for anyone (except you) to use it to seed other files.

User contributions – in any form – are what keep Rawseeds alive. We are honored to receive them and, on our part, try to do our best. Thank you again!

What is BitTorrent?

BitTorrent is a protocol for efficient peer-to-peer file sharing. The term “peer-to-peer” means that each user requesting a specific file also acts as a distributor for that file towards other users. This leads to massively faster download speed for every user, something that is very needed for the case of Rawseeds, where extremely large files have to be distributed within reasonable time. An explanation of why and how the use of BitTorrent to distribute the datasets is a key element of Rawseeds can be read here.

The key concepts behind BitTorrent are the following:

• every file to be distributed is subdivided into chunks
• the chunks are distributed to different users requesting that file
• users exchange already downloaded portions as well as downloading new ones
• “smart” distribution policies (e.g., rarest chunk first) are implemented to further speed up things

The elements of a BitTorrent system for the distribution of a file are:

1. the peers, i.e., the PCs requesting the file;
2. the seeds, i.e., the peers possessing a complete copy of the file;
3. the tracker, i.e., the PC coordinating the sharing of the file.

The Rawseeds project set up the tracker and a few seeds. However, many other seeds are needed, so your help is crucial! In fact, we are a small project: we do not have the resources to set up many seeds by ourselves, or to buy ultra-wideband hosting services. So we ask you to share a little bit of your upload bandwidth to help other users get the files (just as you were helped by previous users). How? In a nutshell, keeping your BitTorrent client (i.e., the program you used to get the data) running after you have finished the download, and ensuring that it is restarted at every boot. Read here for the details. Thank you!

What you need to get Rawseeds’ datasets

To be able to download Rawseeds’ datasets, you need two things:

1. a BitTorrent client program;
2. an open TCP port towards that program (this is only required if you want fast download).

First, let’s see what a BitTorrent client is.
It is a little program that is able to manage the exchange of data through the internet using the BitTorrent protocol. BitTorrent clients are available for free for any software platform (and particularly for Windows, Mac, Linux); actually, they have become so commonplace that they are frequently installed by default together with the OS (this is the case of many Linux distributions, for instance). Here you can find a list of available BitTorrent clients. Some of the most commonly used are μTorrent (Windows only), Transmission (Mac and Linux only), KTorrent ( Linux, Mac, Windows): however, everyone has her preferences here, so let’s just say that any of them is good for Rawseeds (if we can say a word about this… prefer open source software!). Just ask your friends and colleagues: we’re sure that some (or possibly all…) of them already use BitTorrent.

Now, let’s describe what an open TCP port is and how to get it.
Your BitTorrent client will point out to you if the port it is trying to use to receive connections is closed. If it isn’t, you don’t even need to read this paragraph. If it is closed, this means that your PC is behind a firewall (be it hardware or software, such as Windows’ own), and that an external PC cannot try and connect to your running applications unless you instruct your firewall to accept incoming connections. Incoming connections are directed to one of the 65536 ports defined by the TCP protocol, each of which is associated to a specific service or application (or to none). One of this ports is associated to your BitTorrent client: you must open it in order to receive connections from other Rawseeds users: in this way, your download speeds will be much greater.
The specific port to open is set in the Preferences (or Options or whatever) of your BitTorrent client. If you don’t have a reason to change it, use the default value set by the program. To open the port, you have to access your firewall and specify that incoming connections to that port must be allowed. Unfortunately, we can’t give you detailed instructions about this process, because it is heavily dependent on how your firewall is implemented. Usually, hardware firewalls are fitted with a web interface accessible with a web browser, while software firewalls have their own configuration menus.
Anyway, if you work in a company, an university, or any other large-scale structure the firewalls are almost surely not operated by you, but by your network administrators. So you simply have to ask them to open for your machine the port specified by the BitTorrent client you chose. A word of warning about this… network administrators do not usually like people using BitTorrent within their network. In fact, this kind of protocol is mostly used to share media such as music and movies. Therefore, be prepared to be asked by a frowning tecnician: “Exactly, why do you need this port to be opened?”.

How to get Rawseeds’ datasets

Once you have installed the BitTorrent client of your choice, you’re done.
While browsing Rawseeds’ website, if you find the link to a file you want to dowload, just click on it. As usual, you will be asked by your web browser what to do with it (e.g., save or open it). If the file has a “.torrent” extension, choose “Open with [your BitTorrent client program]. The program will open, and download of the file will begin (possibly after you have been asked for a further confirmation by the BitTorrent client itself).
The amount of resources (processor, RAM, …) used by a BitTorrent client is very small: so much so that they can be considered as negligible with a modern PC. Therefore, you can leave the program running all the time, while you do your work as usual. You can stop the BitTorrent program whenever you like, without losing the already downloaded data; you can also, of course, turn off the PC. However be sure to re-run the BitTorrent client as you turn on the PC, or the download will not resume (the best way to do this is to put the BitTorrent client in the list of applications that are automatically started every time the PC is turned on).
The BitTorrent client will put the downloaded files into a specific directory that is set by its own “Preferences” (or “Options” or whatever). It will also inform you about how much of each file you have already downloaded. For extremely large files, such as some of Rawseeds’ ones, download can take many hours or even days. Download speed for a given file depends (on the download bandwidth of your internet connection and) on how many other users are helping you by seeding the same file. This is why your help as a seed is crucial: please, take away some minutes from your work to read how easily you can become a seed for Rawseeds’ datasets and why you should do it.

Rawseeds chose to distribute its datasets using the BitTorrent protocol. While requiring a bit of additional effort from the users, this choice has a number of key advantages (such as the fact that otherwise Rawseeds would not have been possible :-) ).

To know what you have to do to use BitTorrent to retrieve Rawseeds’ datasets, read the BitTorrent HOWTO. Here, we will describe the reasons why we had to use a bit of lateral thinking while setting up the distribution system for Rawseeds’ datasets. And the reasons why the use of BitTorrent for that was, we think, a Really Good Idea.

The usual way to download a file via the web is, of course, to use HTTP download. This is behind the “click here to download the file” mechanism you find everywhere. Unfortunately, this method is unsuitable for Rawseeds for a couple of reasons:

1. it is reliable enough only if the files to download are not too big: say, a few hundreds of MBytes;
2. as the number of downloaders rise, the upload bandwidth required from the server hosting the files rises accordingly.

Rawseeds’ datasets include very large files, up to some tens of GBytes. You really don’t want your downloading process to stop after a full day of downloading… so HTTP was ruled out. Some of you are surely thinking, by now, “What about ftp?”. Well, ftp solves the first problem but not the second. Bandwidth (especially upwards) is costly. Rawseeds is a small project, and it really hasn’t the resources to buy an expensive hosting service capable of the uploading speeds that are needed if many users require huge files at the same time and don’t want to wait a month to have them delivered.

By distributing Rawseeds’ data using the BitTorrent peer-to-peer protocol, we are able to overcome both the problems described above, while the users also benefit from additional useful features.
A data distribution system based on BitTorrent, such as ours, has many advantages (look in the BitTorrent HOWTO for details)

• download is very reliable, even for extremely large files such as ours;
• users (called “peers”) upload data as well as downloading, and this leads to
• faster download for all the peers
• self-adjusting available bandwidth: it increases just as it is needed
• overall bandwidth available for download is not limited by the upload bandwidth of the project’s own servers
• worst-case (i.e., single user) download speed is similar to HTTP speed; in all other conditions speed is larger… and usually much larger.

Of course, a custom-designed file distribution system based on BitTorrent has a complexity of design, realization and management that far exceed those of standard, off-the-shelf systems based on HTTP click-and-download. This is our price to pay to give you a better service. What is your price to pay? Simple: please let your BitTorrent client program running for as long as possible, even after your download from Rawseeds is complete. If your machine is not always on, ensure that the client is automatically restarted as the PC is turned on. In this way, you act as a BitTorrent seed for Rawseeds’ data, i.e., you donate a small fraction (chosen by you) of your upload bandwidth to help all users of Rawseeds get faster and better service. This is very important to keep Rawseeds running!
All the details about this are here.

]]> http://www.rawseeds.org/home/2009/05/20/rawseeds-and-bittorrent-why/feed/ 0 http://www.rawseeds.org/home/2008/12/17/data-acquisition/ http://www.rawseeds.org/home/2008/12/17/data-acquisition/#comments Wed, 17 Dec 2008 10:57:20 +0000 http://rawseeds.elet.polimi.it/home/?p=259 Data-acquisition hardware on board of the Robocom robot is based on PCBricks. These are small, custom-built x86 PC modules, fitted with mini-ITX motherboards. For Rawseeds, three of them were mounted on the robot, interconnected through a TCP/IP network (also equipped with a wireless link to connect to remote machines).

Operating system of Rawseeds’ PCBricks is Linux, heavily customized to optimize dataflow to the hard disks: in fact, the datastream produced by Rawseeds’ sensors is massive (tens of MB/s), and dropouts can occur even when not using low-power CPUs (as in the PCBricks) and 2.5″ disks (as in the PCBricks).
Initial data loss problems due to mechanical shocks and vibrations were solved by exchanging the data-storage units with Solid State Disks. In fact, shocks and vibrations experienced by the mobile robot while exploring an environment could lead magnetic disks into protection mode for brief instants, thus heavily degrading their data-transfer performances for a time long enough to force sensor data loss.

]]> http://www.rawseeds.org/home/2008/12/17/data-acquisition/feed/ 0 http://www.rawseeds.org/home/2008/02/29/data-synchronization/ http://www.rawseeds.org/home/2008/02/29/data-synchronization/#comments Fri, 29 Feb 2008 10:40:50 +0000 http://rawseeds.elet.polimi.it/home/2008/02/29/data-synchronization/ RAWSEEDS’ datasets are composed of multiple, heterogeneous data streams. These streams need to be precisely time-synchronized between each other and with respect to the ground truth data. To achieve such result, we used custom software built upon the IEEE 1588 protocol, or Precision Clock Synchronization Protocol for Networked Measurement and Control Systems (PTP).

]]> http://www.rawseeds.org/home/2008/02/29/data-synchronization/feed/ 0 http://www.rawseeds.org/home/2007/12/17/ground-truth-for-indoor-datasets-2/ http://www.rawseeds.org/home/2007/12/17/ground-truth-for-indoor-datasets-2/#comments Mon, 17 Dec 2007 12:40:03 +0000 http://www.jeia.it/rawseeds/home/2007/12/17/ground-truth-for-indoor-datasets-2/ As already explained here, indoor datasets from Rawseeds include two kinds of ground truth: executive drawings and robot trajectory. To reconstruct the trajectory of the robot through the explored environment, we used two separate systems:

• a system based on industrial cameras, visual tags mounted on the robot, and ad hoc software
• a system using a set of Laser Range Finders andad hoc software, used to localize a rectangular hull mounted on the robot

Both systems were set up to cover a subset of the explored environment (we called that region of space the “GT area”). The two trajectory-reconstruction systems worked independently one from the other (and from the sensor systems on board of the robot). Off-line, their recorded outputs were combined to generate a third stream of ground truth data with still lower error. Such combined data stream, describing the trajectory of the robot whenever it traversed the GT area, is the final one, supplied as ground truth with Rawseeds’ datasets.

The vision-based ground truth collection system was based on a multiple-camera GigE Vision system composed of Prosilica GC-series cameras, a Linux-based PC running custom software and a Gigabit Ethernet switch to concentrate all the vision data on a single network link to the PC. The LRF-based system used well-established Sick LMS200 sensors, and again a Linux-based PC running custom software.

A quantitative analysis of the performance of Rawseeds’ indoor trajectory reconstruction setup can be found in Deliverable D2.1 – part 2.

]]> http://www.rawseeds.org/home/2007/12/17/ground-truth-for-indoor-datasets-2/feed/ 0 http://www.rawseeds.org/home/2007/12/17/ground-truth-for-outdoor-datasets/ http://www.rawseeds.org/home/2007/12/17/ground-truth-for-outdoor-datasets/#comments Mon, 17 Dec 2007 11:44:22 +0000 http://www.jeia.it/rawseeds/home/2007/12/17/ground-truth-for-outdoor-datasets/

Base station for the RTK-GPS system

As already explained here, outdoor datasets from Rawseeds include two kinds of ground truth: executive drawings and robot trajectory. To reconstruct the trajectory of the robot through the explored environment, we used a high precision RTK (Real Time Kinematics) GPS system. Rawseeds’ RTK-GPS setup was composed of:

• a Trimble 5700 GPS receiver with Zephyr GPS antenna, mounted on the mobile robot (rover);
• a Trimble MS750 receiver with Zephyr antenna, mounted in a fixed location (base station);
• a Trimble PDL450 radiomodem, to transmit positioning information from the base station to the rover.

This system has – in best conditions of satellite signal reception – a positioning precision of 1cm horizontal and 2cm vertical. In all the locations where data acquisition occurred, the base station has been set in elevated points to maximize satellite visibility, i.e. on the top of tall buildings with no obstructions in their vicinity.

In actual use, satellite visibility has never been a problem for the base station, while it proved to be extremely critical for the rover. The presence of buildings, structures or even trees in the vicinity of the rover heavily disturbed the reception of satellite signals. Despite careful setup and planning of the acquisition sessions with reference to the visibility of satellite constellations (which evolve quickly through the day, and change slowly from day to day), RTK-GPS technology in urban settings proved to suitable for Rawseeds’ requirements, but very critical and sensible to setup issues. Even in quite sparse urban environments, such as the Polimi-Durando location, the best positioning quality (corresponding to the so-called RTK fixed integers mode of operation) was available only on limited parts of the robot’s trajectory. This was expected, but we hoped for a wider tolerance. Lower-grade positioning precisions (within a few centimeters of error, so still compliant with Rawseeds’ specifications) were available through significant parts of the robot’s path: therefore it has been possible for Rawseeds to gather good ground truth data in outdoor environments. However, our experience showed that RTK-GPS technology is too costly and prone to setup and reception issues to be considered as a not-auxiliary sensor in robotics applications.

A quantitative analysis of the ground truth data provided by the RTK-GPS system of Rawseeds is available in Deliverable AD2.3.

]]> http://www.rawseeds.org/home/2007/12/17/ground-truth-for-outdoor-datasets/feed/ 0 http://www.rawseeds.org/home/2007/12/17/ground-truth-for-indoor-datasets/ http://www.rawseeds.org/home/2007/12/17/ground-truth-for-indoor-datasets/#comments Mon, 17 Dec 2007 11:43:50 +0000 http://www.jeia.it/rawseeds/home/2007/12/17/ground-truth-for-indoor-datasets/ Together with each of the datasets, Rawseeds provides the associated ground truth. This is a set of information describing the real environments explored by the robot, and the trajectory followed by the robot within such environment. Ground truth is used as a reference, against which the results obtained by a Benchmark Solution can be evaluated.
For each dataset, two different kinds of ground truth are provided:

• the trajectory of the robot during (parts of) the data-gathering session
• the executive drawings describing the environments explored by the robot

In addition to the above, each dataset includes a list of positions of suitable features extracted from the executive drawings. These position are used when applying some of the performance metrics specified by the Benchmark Problems.
Ground truth data have been collected by means that are separate from the sensors mounted aboard the robot, in order to be completely independent from the datasets included in the BPs. In the case of trajectories, ground truth information are time-sinchronized with the datasets.

]]> http://www.rawseeds.org/home/2007/12/17/ground-truth-for-indoor-datasets/feed/ 0 http://www.rawseeds.org/home/2007/12/15/bicocca/ http://www.rawseeds.org/home/2007/12/15/bicocca/#comments Fri, 14 Dec 2007 23:10:04 +0000 http://www.jeia.it/rawseeds/home/2007/12/15/bicocca/ The inside of a pair of the buildings belonging to the campus of the University of Milano-Bicocca (Bicocca is an area of the city of Milan, Italy). This location includes conventional office-like features (corridors, halls, rooms; doors, windows; normal and automatic stairs, elevators; tables, chairs, desks) along with more unusual elements, such as a fully windowed bridge between the two buildings and a library.

Chapter 4 of Rawseeds’ Deliverable D1.1 includes maps and images of the Bicocca location.

]]> http://www.rawseeds.org/home/2007/12/15/bicocca/feed/ 0 http://www.rawseeds.org/home/2007/12/15/polimi-durando/ http://www.rawseeds.org/home/2007/12/15/polimi-durando/#comments Fri, 14 Dec 2007 23:09:30 +0000 http://www.jeia.it/rawseeds/home/2007/12/15/polimi-durando/ The Politecnico di Milano campus set in via Durando, Milan, Italy. (“Bovisa” is the name of the zone of the city where it is located.) This location comprises a set of buildings that once housed a factory. It has been modified for its new use trying to retain as much as possible of its original character, so it has a very composite (and interesting for Rawseeds) nature, which closely mimics that of a typical (small) city. Buildings of different kind and style are included in the campus, as well as slopes, passages of various widths, external stairs. The presence of parked (and occasionally moving) cars, sidewalks, poles and of moving people (students) closely approaches that of a typical urban road.

Chapter 4 of Rawseeds’ Deliverable D1.2 includes maps and images of the Bovisa location.

]]> http://www.rawseeds.org/home/2007/12/15/polimi-durando/feed/ 0 http://www.rawseeds.org/home/2007/12/15/ultrasonic-sensors/ http://www.rawseeds.org/home/2007/12/15/ultrasonic-sensors/#comments Fri, 14 Dec 2007 23:07:45 +0000 http://www.jeia.it/rawseeds/home/2007/12/15/ultrasonic-sensors/ For indoor acquisition, our plarforms are equipped with a sonar belt composed of 12 Maxbotix EZ-2 ultrasound transducers. The sensors are positioned all around the robot; they are activated in groups, so to prevent crosstalk. The control electronics interfacing the transducer with the data-acquisition PC has been designed and built by POLIMI.
These sensors have limited range: therefore, they were not used for outdoor and mixed data-acquisition sessions.

]]> http://www.rawseeds.org/home/2007/12/15/ultrasonic-sensors/feed/ 0 http://www.rawseeds.org/home/2007/12/15/inertial-measurement-units/ http://www.rawseeds.org/home/2007/12/15/inertial-measurement-units/#comments Fri, 14 Dec 2007 23:06:27 +0000 http://www.jeia.it/rawseeds/home/2007/12/15/inertial-measurement-units/ The sensors mounted on the data-acquisition robot platform include an Inertial Measurement Unit (IMU) providing 3-axis angular orientation, acceleration, rate-of-turn and Earth magnetic field data. We used an Xsense MTi device, selecting the version with 1,7g full scale acceleration and 150deg/s full scale rate of turn.

]]> http://www.rawseeds.org/home/2007/12/15/inertial-measurement-units/feed/ 0 http://www.rawseeds.org/home/2007/12/15/cameras/ http://www.rawseeds.org/home/2007/12/15/cameras/#comments Fri, 14 Dec 2007 23:05:44 +0000 http://www.jeia.it/rawseeds/home/2007/12/15/cameras/ Rawseeds’ sensor suite includes many vision components. Specifically, we used:

• binocular and trinocular black-and-white (B/W) vision;
• normal perspective, color and B/W cameras;
• omnidirectional color vision with hyperbolic mirror.

The binocular vision system is composed of a two-camera Videre Design STH-DCSG-VAR system (two FireWire, B/W, 640×480 pixel cameras mounted on a common mechanical frame that allows for an adjustable baseline).
Trinocular vision is obtained by combining the binocular STH-DCSG-VAR with an additional Videre Design DCSG camera (the same camera mounted by the STH-DCSG-VAR).
All three cameras of the trinocular system are forward-looking, and provide B/W monocular data streams. Color monocular vision (also forward-looking) is covered by an Unibrain Fire-i 400 camera (FireWire, color, 640×480 pixel). This is a lower-cost device, mounted on the robot to cover the kind of vision sensors that are most likely to be considered for commercial service robotics applications.
Finally, omnidirectional color vision is obtained by using a Prosilica GC1020C camera, configured with a Region Of Interest of 640×640 pixel and fitted with a hyperbolic mirror built by Vstone.
All cameras except the Unibrain one were set to a frame rate of 15Hz; the Unibrain camera operated with a 30Hz frame rate.

]]> http://www.rawseeds.org/home/2007/12/15/cameras/feed/ 0