pESAblog - the pESApod team's blog

Waiter, there's a six legged pESApod in my convention!

2008-11-24T13:00:00.014+01:00

Hi, This is Michael Sacchi from forumastronautico.it
I'm guest-posting on the pESApod blog to tell the amazing story from our point of view.
Last weekend, on November 15th-16th we had our third Astronauticon, our annual convention in Montecatini Terme (PT). Every year the convention allows the users of ForumAstronautico to gather and share their passion, with displays of model artworks, talks and speeches. This year we also announced the foundation of the Italian Space and Astronautics Association (ISAA) (isaa.it work in progress). The convention, of course, is open to anyone.
Last year our honor guest was astronaut Umberto Guidoni, and this year we had Paolo Bellutta, an engineer from JPL, in live conference from California, to talk about his experience in the team leading the efforts of the two Mars Exploration Rovers on the surface of the red planet.
But while we were working out the last details for the conference, thanks to our fellow user Rino "Lovell" Casella, we received an offer we just couldn't turn down: a live demonstration of pESApod, by the Italian team involved in the ESA Lunar Robotics Challenge, from Sant'Anna School of Advanced Studies in Pisa

What a day!
The team prepared its lovely six legged wonder on the sandy soil we provided and it's been amazing to see it move and perform in front of an audience staring in a feeling of awe. Shy comments and seldom enthusiastic exclamations broke the silence as we marvelled at what a team of smart people had been able to accomplish in just 5 months.
But it wasn't over!
Just after Paolo finished answering questions, with the power of the Internet we "took" him for a walk to see the rover from up close. Paolo and Calogero even had the opportunity to exchange a few words regarding the technicalities of the rovers..Face to face!. Unbelievable.

An amazing day, we wish the pESApod and its team all the best for the future of the rover, and look forward to see them again...maybe on the Moon!

Michael Sacchi,
Forumastronautico.it - Italian Space and Astronautics Association.

pESApod landed to the MOON

2008-11-20T02:24:00.005+01:00

Yes, you are right: pESApod landed to the Moon! What a nice view...

This beautiful picture has been taken by Matteo Negri during the conference Astronauticon3 recently held in Montecatini Terme, where the robot gave a live demonstration. The amazing editing was performed by Roberto Beltramini. Thanks Matteo and Roberto!
This is the original one...

There is water on the Moon!

2008-10-31T14:40:00.005+01:00

Eventually, we are back from "the secret location in the Canary Island" that everybody knew to be Tenerife. We are quite satisfied because our robot received much appreciation both from ESA and from the competitors. Our system was working well and we have been able to perform many successful tests at night and during daylight. Still we had some concerns with steep rises, but the rover proved to be capable of descending steep slopes, walking teleoperated via a multi-hop network and - above all - to recover a sample of gravel.

Unfortunately, bad weather did not allow us to compete. We had to abort the night test as well as the following day because of rain that has literally short-circuited many of our electric components. Still, we are happy with the whole experience as we were able to follow the proposal we presented at the CDR without modifications despite the lack of time. We guess people recognized it as we were asked "How did you manage to build such a complex rover in such a short time?". We are still asking it ourselves...

We also would like to congratulate with the CESAR team from University of Bremen that was the only robot to complete the task and with all the other teams for the friendly and collaborative atmosphere.

By now, we are only able to post some photographs but the videos will follow soon.

Consolation: there is actually no rain on the moon.

pESApod ready to start the challenge (but clouds were approaching...)

Working to recover the electronics after the first shower

The second shower

First night test

2008-10-24T14:29:00.001+02:00

We spent almost all the time yesterday trying to solve an electronic problem which turned out to be due to the extremely low temperature that features this place. Probably we will need to heat the robot - maybe with some kind of infrared lamp - before the challenge in order to avoid a dramatic change in power driver behavior.

Finally, at 11 pm we could go in the darkness to perform the first night test. The robot has been able to walk on small slopes without failures and to perform maneuvers. We have also fully tested the stereocamera actuation, the end-effector and the network-node dispenser. The end-effector dug up some terrain and is also able to release it raising the leg.
Our performance has attracted many people from other teams and the organization and we received many appreciations. "Just impressive" said the leader of one of the other teams, and that is really rewarding for all of us.
Vision proved to be very good even with just one out of 3 LED groups, thus saving even further energy. Now the robot is expected to last 2 hours with just 2.6 kg of Li-Poly batteries, which is just impressive!

Some software credits

2008-10-24T11:57:00.001+02:00

As pESApod approaches his final trial, we wish to list (and thank) the developers of the many tools we used to build our software and communication infrastructure. So, here's what it takes to build a space robot:

MATLAB and Simulink
SolidWorks, CATIA, ProEngineer WildFire and Ansys, used for mechanical modeling
The B.A.T.M.A.N. routing protocol, providing multi-hop communication
The Fonera wireless routers (be sure to check out their lively community, both the official Foneros community and the open-source projects like Rome's Ninux)
The OpenWrt linux distribution, that powers the Fonera
The GNU project, for their GCC compiler and their many tools, used to compile all of our code, from high-level teleoperation station to the low-level FPGA
Debian Linux, powering our VIA Epia board
The Nios II IDE, based on Eclipse, and of course vim and Geany, our trusted code editors (vim for Alessandro and Geany for me, of course :-)
The Quartus IDE by Altera, used to develop on our FPGAs
FAME, a fast (but somehow messy) video encoding library
libdc1394, used to read data from the high-quality Point Grey cameras
The QT 4 toolkit for the high level interface
Intel and the MMX instruction set, without which it would not have been possible to encode the video stream in real time.

A very harsh environment

2008-10-23T22:38:00.005+02:00

Today the weather has been better than yesterday, but still pretty cold. Now it's 10 pm and the clouds are beginning to fall over the crater. We are finishing to tune the robot for the night test. We will be the 6th group to compete, so we are going to start saturday night at about 11 pm.
By now, our team seems to be immune to the Canarian illness that is widespread among the other teams. However this hostile environment is proving us, too.
There is also a strong media coverage here. The following is an article published by a famous German magazine: http://www.heise.de/newsticker/Lunar-Robotic-Challenge-Letzte-Tests-bei-Dunkelheit--/meldung/117826

Moon here, please respond

2008-10-22T17:13:00.002+02:00

Hi everyone, today we were able to test our beloved pesapod on the trials ground for the first time and results were amazing. Climate is not quite lunar, but really weird actually. During the day we are facing freezing temperatures is full sunlight and sometimes a cloud gets low enough and passes right through our camp. It's the first time we ever seen such kind of "horizontal rain"

pESApod is our friend

2008-10-12T17:11:00.003+02:00

Head.

2008-10-10T21:09:00.001+02:00

"pESApod, come forth!"

2008-10-09T01:40:00.002+02:00

Sunday of control

2008-10-05T23:41:00.000+02:00

Sunday night in the lab.

Tuning the low-level controllers has been harder than expected, but we ended coming up with a satisfying dynamic performance.

pESApod is within us!

2008-10-01T17:48:00.004+02:00

This morning we have finished to assemble the robot structure. In the picture you can see pESApod standing on its own legs for the first time!

The robot has then been carried to Pontedera's lab where our control specialists are working to give it the breath of life!

As you can see, pESApod is designed to fit perfectly in a Fiat Punto boot!

Legs almost ready

2008-09-29T23:27:00.003+02:00

Mechanical assembly started!

2008-09-25T12:46:00.004+02:00

Most of the mechanical components are ready, so assembly has started on last Tuesday. Most of the time has been spent assembling oblique bearings due to interference. One foot has been completed and has been tested on soil. Also one ankle has been almost completely assembled. It is still the old design of the ankle, as the components of the new one are expected to arrive next week. There is still a lot of work to do, but as we manage to complete the first leg the other ones will take much less time.

The Communication System

2008-09-19T11:31:00.006+02:00

As we promised, here is the detailed status of our multi-hop communication system:

The low-level control FPGA boards are ready. They implement the PIDs ensuring smooth operation of drivers and sensor readings from the encoders. We devised a flexible protocol to send commands to the motors and get timely sensor readings to and from both the on-board computer and the mid-level control (pattern-generator) board. We used Altera DE2-70 boards, communication takes place over Ethernet.
With a well-defined protocol we can now begin porting the Matlab pattern-generator code to the FPGA board which will ensure real-time performance.
We are coding the software which will run on the on-board computer. Our current focus is getting good performance out of the stereocamera and delivering a reasonably good (and packet-loss ready) video stream. We are still having some difficulties with buggy libraries and fuzzy-behaving encoding software, had to write to PTgray a couple of times. We have our Linux system running on the Fanless VIA EPIA, we tested all basic interactions with the various components.
Good news from the Multi-hop communication system: our Fonera nodes are up and running with B.A.T.M.A.N., a robust multi-hop communication system. Testing shows very good range (with some hops we can communicate from side to side of our large and thick-walled historical building with only 10% packet loss) and a comfortable bandwidth of more than 500 kB/s. The home-made battery pack got us 2.5 hours of run-time in little weight.

As we reported in our previous post, we are still waiting for some equipment. As more and more subsystems get ready, our tests are becoming increasingly realistic. In a short time we'll run a complete motor tele-operation test.

Mechanical design and assembly update

2008-09-17T11:56:00.010+02:00

It has been a pretty long time since the last detailed update on mechanical design and robot assembly. It has not been a summer of relax and vacations, though! The mechanical design team has been working for the whole summer to turn the ideas we presented at CDR into feasible models and drawings that could be sent to the factories.

During this phase new technological and practical problems have been arising, so we had to perform several changes to the preliminary design. The main guidelines that lead our work were to reduce the weight as much as possible and to keep the manufacturing and assembly process as simple as possible. The time constraint has been very important, too. We avoided components that could not be delivered in time. Hereafter is a summary of the major improvements and changes.
The truss-like frame has been substituted by a carbon fiber box made stiffer by several reinforcements. The ankles have been completely re-designed to reduce encumbrance and weight and to increase the workspace. With the new design two of the three motors that power each leg will no longer be mounted in a vertical position, but they will be horizontal allowing a further reduction of complexity (conic gears are no longer required). Feet have been revolutionized, too. They are now smaller and simpler to assembly since we have greatly reduced the number of components. They also include a removable spike that can be used on less firm soils.

By now, all the components made in composite have been completed by our supplier C.R.M. Compositi in Livorno and also many of the steel components are ready. Everything is being transferred to the Micromecc factory in Ospedaletto where we will soon begin the assembly phase.

Status update

2008-09-17T11:06:00.006+02:00

Long story short: things are going well, but we still have a lot to do.

This month we have completed our Fonera-based multi-hop wireless system and we did some tests on the wireless node battery packs obtaining a satisfactory 2.5 hours uptime. We got our hands on the IMU, the spotlights and the cameras, which we got working on Linux with our streaming software (still to be completed). We have had some problems with the main battery pack shipment but the new one will arrive before the end of the month.

Mechanical parts are arriving from manufacturers and we hope to begin assembly next week. Motors have been shipped two weeks ago and low level control boards are operational and accepting commands from ethernet. Right now we are working on some communication issues between the three different control levels, and we expect to solve them in little time.

In a few days we will be ready to begin porting the pattern generator code from the Matlab dynamics simulator to the middle-level control FPGA board. We should be able to perform our first full motor control test on Monday.

Altera kindly donated us three DE2-70 FPGA boards, on which we implemented both the low and middle level control.

We also have started porting the communication and image capture software on the onboard computer (based on a VIA EPIA fanless board). Moreover, Dell has very kindly offered to donate the teleoperation station laptop, we'll get in touch shortly.

Thanks to everyone for their hard work, in the next few days we'll post the detailed status of each subsystem.

CDR - The show will go on

2008-07-11T21:40:00.008+02:00

The CDR is just over, and we are already back at work in Pisa now. A joint meeting will be held on Tuesday to give everybody a detailed report of what happened in Noordwijk and to plan the next activities.

Our team has been represented at the review by Stefano Roccella, Calogero Oddo, Nicola Vitiello and Roberto Farolfi. The CDR has been successful for everybody, so eight groups will be (hopefully) participating at the final challenge in Tenerife, October 21st - 28th. According to what stated by ESA officers, it will be a great event. Press and TV have been invited. We suggest everybody to have a holiday there during the challenge.

Yes, now it's time to unveil some details about our design. By now, you will get this nice image of the robot in the "folded" position.

Fun facts in Noordwijk

After the presentation, we decided to test our walking strategies "on the field".

Press review (while waiting for the CDR results)

2008-07-09T12:35:00.004+02:00

The Critical Design Review, for which we have been working, is scheduled to begin tomorrow. While we were giving the final touch to the various documents we've prepared, we've discovered that our work has not been unnoticed by the rest of the world.
Here's a few articles about us (and our truly dreaded derby opponent, the University of Pisa). Most of them come from Italian newspapers, so unfortunately they're written in our beloved language. We promise that after the CDR we will unveil a glimpse of our robot design. Well ... we may ;-)

The really printed press:

La Repubblica , one of the most popular Italian newspaper (and its regional issue)
AdKronos , a famous Italian press agency
La Nazione and Qn, local newspapers

And, of course, some blogs.

-4 to CDR

2008-07-05T01:07:00.003+02:00

Just 4 days to the CDR.
The time schedule has been pretty tight, but it seems that we have done more than we expected. In the last week we got the dynamic simulator working. The mechanical design team has almost finished the 3D modelling. The end-effector has been completely re-designed. The computer specialists are still trying to cope with a serious bandwidth issue, but a lot of working code has already been written.

Now we are supposed to bring all the work together and prepare the presentations for the CDR. Yeah, we are probably going to spend the next nights doing that.

See you in Noordwijk,

the pESApod team

PS: Uh, we still did not publicly disclose what actually pESApod stands for. Maybe at next update.

Hello pESApod!

2008-06-23T17:42:00.000+02:00

A new blog is born!