Archive for the ‘Urban Challenge 2007’ Category

CajunBot’s celebration

Tuesday, November 6th, 2007

Fans, Friends, and Family — here is a chance to celebrate with us.  UL is organizing a ceremony to recognize the team and its sponsors for the accomplishments of CajunBot.Date: Thursday, November 8th
Time: 11:00am
Place: Martin Hall, Parking lot

Highlight: Medallion presentation by Gov. Blanco

The ceremony is open to all. Please arrive and assemble by 10:30am.

– Arun Lakhotia

Urban Challenge final anti-climactic

Saturday, November 3rd, 2007

November 3, 2007 (2330hrs), VICTORVILLE, CA.  — The Urban Challenge Final was very anticlimactic. After the intense semifinal evaluation, we were expecting a real intense final. But it turned out, the semifinal was the real grill. The final was mellow, probably designed to prevent a repeat of 2004 GC.The controlled traffic that the finalists encountered was pretty limited. Unlike the NQE test in in Area A, there were no back to back cars at any intersection. Once one or two cars had passed there was ample time for a bot to make a turn. In any case, the traffic appeared to be limited to the loop immediately after the start. There did not appear to be any additional human traffic in the neighborhood.

The gauntlet or the neighborhood scenario, with cars parked on both side of the road, was no where to be seen. There was only one instance where one robot had to travel in a region where cars were stalled/stopped (not parked) on both sides.  The tests in Area B were an overkill, with 10-15 cars on both side of the road. A simulated neighborhood with bots traveling from both sides would have raised the bar, and made it a real challenge. In the absence of such a scenario, it sure feels we wasted a lot of time developing a capability that was irrelevant for the final.

There was only one scenario that CajunBot could possibly not handle. It was the drive through off-road terrain with very sparse waypoints. But the capability we developed for Area B took us half-way in that direction, and we had two more days to complete the work. So we would surely have had the capability in place.

The bots did not have to replan their path, a major part of the test in Area C. All they needed to do was follow precedence at intersection.

All in all, the perception of our team and others is the final event was a big let down.

– Arun Lakhotia

Cajun Cookout draws around 300 people

Saturday, November 3rd, 2007

November 3, 2007 (0630 hrs), VICTORVILLE, CA – The Cajun Cookout was a big hit. In the words of Dr. Tether, DARPA Chief, “its better than last time.”  The event was announced to be held at “Mid-day”, leaving enough flexibility for the cooks.  By 11:30 there was a crowd gathering around. Some were circling the tent, coming back every few minutes to check if the food was served.The food also drew the stunt and race car drivers. One of them asked us about video footage of him desperately cutting out of CajunBot’s path. He was promptly named by Scott as Drama Queen. The video shows his car was far enough away. The Drama Queen went into defensive, explaining that he cannot guess what the robot will do, so he has to react early enough. Which is quite fair. But his name stuck nonetheless.

The cookout drew DARPA program managers, media crew, sponsors, and other teams. Food breaks barriers, especially as good as Brother Majors cooking.

The event also gave opportunity for the university’s PR crew Christine Payton and Eric Maron to hand out UL goodies. They had plenty to give away — UL pins, Ragin’Cajun spice (only university with its own branded spice), T-shirts, and all.

Charlie “the voice of DARPA” and also the biggest fan of our team almost did not get any crawfish. He had been busy with the practice runs. By the time he was free the crawfish was almost all gone, but for a scoop saved specially for him by Brother Majors.

– Arun Lakhotia

Majors family arrives for a Cajun cookout

Friday, November 2nd, 2007

November 2, 2007 (0730hrs), VICTORVILLE, CA.  In keeping with the tradition established in the first Grand Challenge, the Majors family arrived yesterday for the Cajun Cookout. The entourage is led by Brother Ray Majors, the person who gave this project the first break. He gave us the 6-wheeled ATV that got us rolling. He is joined with his brother John Majors who, through his company Quality Transport, Inc, has been kindly supporting us by providing vehicles and trailers to haul the bots back and forth from California. Mark Majors, of MedExpress Ambulance Service, another sponsor, and his youngest son close the pack along with Danny Majors, who is part of our team.In the backdrop of the several ‘Did Not Qualifiers’ (DNQs) that have packed and left, the Majors family continuing the cookout is an anathema. But it further reinforces the Cajun spirit already very well known in the DARPA circle. We play hard, lick our wounds, and enjoy life nonetheless.

The veterans of the challenges, which includes DARPA officials, media, and other team members, look forward to the event. We were asked at checkin whether we were having a cookout. The same question was popped up  by many when it was announced Team CajunBot DNQed.

The Majors woke up early and took off shopping. They plan to serve about 200 people. That calls for buying and cutting a load of onions, celery, bell pepper, garlic, and sausages. While all of these ingredients will be bought locally, they have carried with them twenty (correction) pounds of Louisiana crawfish tails. In keeping with the tradition the crawfish has been sponsored by Andre Leger of Chez Francois.

The Majors will spend the next four hours cutting all the ingredients and cooking. They will cook right at our hospitality tent. Cooking with open fire outside in the hubub of activity is a very big deal. Its a big deal when you know that millions were displaced a few weeks ago by forest fires. This area is a tinder box. One spark could get the whole place aflame. But, in keeping with another tradition, DARPA went out of their way to get permit for the open fire cooking. The fire marshall is invited.

We started cranking again. Today we will work on getting CajunBot opertional again. The hit has misaligned her sensors. After realigning the sensors, we plan to do some test runs, and then bring her offroad (where a Jeep really belongs). Our goal is to collect data for conditions we cannot find in Louisiana.

– Arun Lakhotia

Finalists announced, could have made it with less aggression

Thursday, November 1st, 2007

November 1, 2007 (1600 hrs), VICTORVILLE, CA. Earlier in the day DARPA announced the finalists. As expected we were not in the list of 11 that made the cut.I have not kept up with the performance of other teams. My focus has been on moving our team forward.

But based on what we hear, it looks like we went a bit too aggressive on Area B. Our goal was to finish that area, just as we had finished the other two. We knew we could not complete one segment of Area B, and worked on developing the capabilities needed. Had we left that capabilitiy alone, CajunBot would have just reached that troublesome area and stopped. That could just have us qualified for the finals. The most overriding requirement for any vehicle to be in the challenge is SAFETY. By going aggressive we ended up violating that requirement, and getting knocked out all together.

Almost a year ago when I was getting the team together, the intent was to shoot for a win. We had already been in two challenges. In the last two challenges, we knew going in that we did not have the chance to win. We were quite happy being in the challenge. It was not the same this time. The excitement of being in the challenge had worn out. Besides, based on past experience we knew we had the capability to win. In the past we just did not shoot high enough.

We took the neighborhood scenario of Area B as a capability needed to win. Besides, since we completed the other two areas, it made sense that we complete this scenario as well.

It turns out that some of the teams that qualified for the final did not even reach the neighborhood scenario in Area B. To their credit, they were safe. If their vehicle had a chance of hitting something it would simply stop. That’s how CajunBot would have been had we not taken the neighborhood scenario seriously.

I just hope that the tests DARPA created truly reflect the actual challenge. It would be a shame if they mellow down the challenge so that someone can win.

– Arun Lakhotia

Day 4 – Got all the pieces together, but not in enough time

Wednesday, October 31st, 2007

October 31, 2007 (1900 hrs), VICTORVILLE, CA.  In case you have not heard it yet, CajunBot did not make it to the finalists. We did come very close, having finally gotten all the pieces of the puzzle. But we ran out time to do the fine tuning.CajunBot did exit the challenge with a bang, literally. She knocked a car parked on the side of the road (as part of the test environment) in Area B, shooting the car across the road, over the curb, into a house.

In this test area, DARPA had created a neighborhood scenario, with 15-20 cars parked on both sides of the road. The robots were expected to weave through these vehicles. The DARPA Urban Challenge Requirements document did mention the need for having the capability to avoid a vehicle partly protruding in the lane. But the requirement was almost mentioned as an afterthought, like something good to have. The emphasis in the requirements document, as also the site visit evaluation, was on avoiding stalled vehicles on two lane roads.

Over the last few months W\we had focused on our energies on passing vehicles stalled on a road, essentially blocking a whole lane. It turned out that capability was not even relevant for the NQE.

After having finished Area A and C, we finally began focusing on the requirement for Area B. Yesterday evening we did not have a clue on how to handle driving through neighborhood. Since the start of NQE we had come up with various solutions, but none were satisfactory. However, last night things started falling in place. Around 2100 hrs (9:00pm) Pablo, I think, suggested using ‘particle field’ approach. In this approach the path of the vehicle is treated as particles. Objects (like cars) on the road act as forces that push the particles. This approach sounded very promising, and I encouraged him to code it up.

Around midnight he had a solution, but it did not behave as expected. It resulted in paths that would make the vehicle go way out of the road to avoid something.

In the discussion, Daro came up with the brilliant idea of treating the path not as independent particles, but as an elastic string. The particles of the string pull each other.

Pablo coded the solution, and at some point fell asleep. Daro kept ticking, tuning the system. By about 7:00am in the morning we could see that the method worked in a simulated environment.

By 10:00am we were ready to run in Area B. The run did not go off well. The bot did not even make the progress she had made yesterday.

We got back to the motorhome, and continued fine tuning the system. We were offered to run again about 2:00pm.

This time around, CajunBot was a completely different beast. She cruised through the initial segments, areas she was earlier hesitating to go through. She was clipping at 25mph, and looked real good.

But once in the neighborhood with all the parked cars, she clipped a car while trying to avoid it.

Data from the run indicates that the method Pablo and Daro came up with worked really good. The only limitation was it was not tuned well enough. The forces exerted by the objects were a bit too weak. So while CajunBot attempted to swerve, she did not swerve hard enough. In the process she could not avoid the parked car.

The fender bender knocked CajunBot out of the challenge.

While I am disheartened, I am not disappointed. I think this small band of boys from Louisiana has shown that they can take on a challenge, and have fun with it as well.

Dr. Tether’s parting words were, “will see you next time.” We may be down, but not out, if no one wins the challenge. We have gained considerable experience, and will come back stronger next time.

– Arun Lakhotia

Day 4 – Video of Area C test run

Wednesday, October 31st, 2007

October 31, 2007 (0400 hrs), VICTORVILLE, CA,Scott has placed video from yesterday’s run on YouTube:

You’d find videos from other teams there as well.

Chris Vaughn called last night. He was at the airport in Ontario. I was not expecting him until Friday, but am glad he is here. Scott put him to work right away, to join the testing crew.

I was woken up about half hour ago. Time to get to work. The software team is stuck on a bug related to parking/unparking. I think they are too exhausted to function. Scott woke me up to join Pablo.

We plan to send a minimal launch crew to our test in Area A, and keep the software people huddled up working on issues for Area B. We are literally going down to the wire.

– Arun Lakhotia

Area A/B tests both in the morning; thirteen teams out

Tuesday, October 30th, 2007

October 30, 2007 (1900 hrs), VICTORVILLE, CA. Rumor has it that thirteen teams have been cut. Area A is serving as the chopping block. We were called to repeat Area A at 1630hrs today, but there were two other robots ahead of us when we got there. Around 1730 hrs DARPA decided that the daylight was not good enough to run the tests. We are now scheduled for Area A test in the morning.

Our Area B test has been moved up as well. With all the teams eliminated, a lot of time has opened up. We are expected to run the Area B test back-to-back with Area A test.

We feel pretty good about Area A. Little John has been doing some very aggressive tests. He has shaken the system well enough. I feel if its survived his testing, it should survive DARPAs.

We have been discussing whether we be cautious or aggressive in Area A. Cautious means running limiting the speed to 10 mph, whereas an aggreesive stance will be to run at the track limit of 15mph.

At the higher speed there is a greater chance of making a dangerous turn, which is a no-no. At lower speed, CajunBot will be safe, but may be eliminated for not satisfying the mission.

We are a bit weak in the capabilities needed for Area B. That may change by the morning. Suresh and Pablo are focused on addressing our limitations.

For old time cajunbot members, DARPA has sure upped the ante. The tests have been really very rigorous. And if we look at the activity in progress to build the track for the final, the last two challenges look like kindergarten.

As I write this Danny Majors and Big John have gone to Subway to get dinners. I have a typed document of everyone’s Subway order. So the sandwiches will be personalized. People are tired of friend chicken, pizza, and cold cuts.

The team members have gone to take a nap until the food arrives. After that we start humming again. This could be the last night that pushes us in the final.

– Arun Lakhotia

Day 4 – DARPA speeds up elimination; six out; called in for Area A

Tuesday, October 30th, 2007

October 30, 2007 (1430 hrs), VICTORVILLE, CA.   DARPA has turned up the heat, and sped up the elimination process. Six teams have been eliminated. The schedule for other teams is being compressed. Our Area A test was due tomorrow morning. We are now scheduled for 1700hrs today. I was asked to report at 1430 hrs (now). I said I couldn’t, my launch team is sleeping. I got an extension of a few hours.Grapevine has it that Area A is the killer test. If you fail it, you are out. This test requires merging in traffic. CajunBot did well last time, so we are very hopeful. But then there are too many uncertainties when dealing with real-time systems. So cannot take anything for granted.

I have the team pulled out of bed. Actually, some of them had not slept anyway. Their mind was too occupied with the remaining tests.

Barring any unforeseen situation, I see CajunBot perform well in Area A. Our remaining weakness is Area B. We are hoping not to be called to Area B in the morning. We still have some work cut out.

– Arun Lakhotia

Day 4 – Successful run in Area C

Tuesday, October 30th, 2007

October 30, 2007 (1200 hrs), VICTORVILLE, CA. If you’ve been staying up biting nails, rest easy. CajunBot had a very successful run in Area C. This is the same area where we started our Day 1. Today’s performance was not picture perfect, but close enough.CajunBot completed the mission, which involved making eight laps around a loop. The loop had two four way stops. At each four way stop, CajunBot was to come across other vehicles. She was expected to follow the precedence rules for stop signs. Vehicles that arrive before you at the intersection have the right of way, before you.

Unlike our first run, CajunBot did perfect this time, in all except one intersection. The good news is that she did not go out of precedence. Which means none of the drivers had to hit pedal to the metal to escape her kiss, as they had to for the first run. The only exception was when she was a bit too gracious, and would not take her turn. The situation was a bit complex. Three vehicles were already at the intersection before she arrived. One vehicle left, and another (a fourth) vehicle drove up and stopped at the same place. The other two vehicles left. Now CajunBot should have moved. But she did not. Finally, the fourth vehicle moved, at which point CajunBot moved on.

For all practical purposes this appears to be a minor flaw, say in comparison to chasing a driver out his wits.

Talking about drivers, I chatted up with one, to learn how he could put himself in front of these reckless bots. He, and other drivers in Area C, are moving stunt men. They get thrill in making close calls. But I thought movie stunts are choreographed, so the risks are a lot controlled. But in these tests, there is no way to guess when a bot may go beserk. I sure do not want to be in their position. And I am sure they think they same about me.

Other than the intersections, there was one more test in this area. The bot had to detect that a road was obstructed, turn around, and find another way to get to the checkpoint. The checkpoint was on the other side of the obstruction, so she had to get to the other side, make another turn and come back.

CajunBot was perfect in replanning.

In essence we had overcome two of three issues that stumped us in the first go. We had fixed our algorithm to use sensor data to understand the world. We had fixed our replanning algorithm.

The one issue that is still not fixed is our ability to deal with imperfect GPS data. In the last test, the bot was driving on the curb but, based on GPS data, thought was on the lane. We did diagnose the reason for the GPS ‘drift’. Before the bot was launched, she is brought in a staging area. One end of the staging area has large trees with thick canopy. This was blocking a significant part of the sky, thus limiting the satellites that were in direct view.

We addressed the GPS drift at least for this run. Joshua was monitoring the GPS data in the staging area. When we started receiving error messages, we asked DARPA officials to move us to a different location. This led to a lot of radio chatter, getting approval from the higher chain of command. The request was granted. So when the bot was finally launched, she had already recovered from the temporary loss of GPS.

Several of you have sent compliments on the video from Area A. The compliments go to Scott. He is a videographer, director, and editor all rolled into one. He is working on a video from today’s run. By the evening we should have an upload.

Tomorrow we have two runs. In Area A at 0730 hrs and in Area B at 1220hrs.

Pre-run sunrise (by Adrian):

Approaching front intersection (by Adrian):

– Arun Lakhotia