dirt dog backing up from invisible object

wsngmartin

I just tried running a mission in the garage with DD, and I noticed the following:
After his initial "spiral dance" he sallies along in a straight line till he bumps into something. After that he cannot go forward, he keeps backing up like he's hitting something. I've used air-in-a-can to blow out the cliff sensors, wheel sensors, to no avail. After reading Vic's suggestions on another thread, I smacked him about the face and head smartly (on the bumper). And he does fine---until he hits something and then he does the backing up again.
He is still under warranty but I am trying to avoid a call in if it can be remedied.

vic7767 · Joined: 14 Jan 2006 Posts: 3429 Location: Louisiana

One other area to check would be the clear plastic lens that covers the IR sensors that detect the front wheel rotation. And naturally the black/white wheel should be clean of debris.

wsngmartin · Posted: June 27, 2008, 3:13 pm Post subject:

Thanks Vic
I just now went and blew out the area of the IR sensor that you pointed out (the front wheel is clean), and gave Obi (DD) another smackdown.
I also did this as Too Many Pets suggested from another thread:

Quote: Very possibly it has dirt in the bumper sensor. This makes it think it is always running into something so it backs up and tries to go another way, but again thinks it is running into something. You can try to dislodge the dirt by whacking on the bumper a few times and see if that helps. If it doesn't help, try blowing it out with compressed air. For that you need to turn it over and look deep inside where the bumper supports slide in and out. You can't see the sensors, but that's where you need to blow the air.

Obi then runs fine for awhile, maybe 10 minutes or so, then does the backing up again. He'll back himself into a corner and then stop. I'm leaning towards an intermittently problematic bumper sensor as the cause, perhaps. Maybe I could try dropping him on his head like Duf was told to do with her scooba?

vic7767 · Joined: 14 Jan 2006 Posts: 3429 Location: Louisiana

At this point Wendy, tis time to contact IRobot for a bit of warranty support. We still don't know how to place the DD into the factory test mode so it is difficult to troubleshoot any farther. And since you are still in a warrenty environment, why not ?

wsngmartin · Posted: June 27, 2008, 6:25 pm Post subject:

Vic
I tried something a bit different. After smacking it *20* times for good measure, I then used Ben's contact cleaner to spray where the bumper supports seem to slide in and out. I wasn't sure where that was exactly so I used a liberal amount for good measure. I understand that the contact cleaner has a bit of lubricating property. That seemed to do the trick till DD's battery decided it was done. Then I decided that we all needed a bit of a break (and Taco Bell). When it's all charged up I will try again.
CS is the next step. It's just been so nice not having had to call them in awhile :cry:

emdeex · Joined: 24 Jun 2008 Posts: 6

My DirtDog keeps backing up as well.

It goes fine for several minutes, then starts jerking backwards, spiralling, and then jerking backwards over and over. Sometimes it fixes itself and then goes off again fine, only to later start jerking backwards again and spiralling.

I can blow out all the sensors with compressed air, and it'll start working again for a while, then start doing it again.

What I want to know, is after cleaning the sensors etc, is there anything to do to improve the situation:

maybe sealing off the cliff sensors with clear plastic windows?
Maybe using stronger springs on the bumper bar sensor?

wsngmartin · Posted: June 30, 2008, 7:43 pm Post subject:

emdeex
after taking a couple of days off from watching obi's antics we ran him tonight.
he is a *lot* better after the contact cleaner treatment. he still does a bit of backing up after running into something so i'm guessing his bumper sensor is intermittently stuck.
resident roombatech is going to take the bumper off and clean him and his sensors off and lubricate things up and see how that goes.

vic
you probably know this already but you cannot put DD in a diagnostic mode using the 4xx remote.