I was tempted to post this as a challenge, but I can't offer a prize. The deal is, you build a robot which can reverse a trailer round a 90 degree corner and then in a straight line.
I mean trailer (British) I have no idea what Americans call an articulated trailer, but I believe some of you may now be thinking I'm talking about mobile homes. No. Not an aluminium house on wheels.
So, the "car" might be a tracked vehicle, but ideally it would be rack-and-pinion steering. The trailer would be unpowered. You might use IR or ultrasonic to figure out the angle between the trailer and the car. I would probably use a rotary sensor at the pivot point.
Of course it wouldn't be full-sized! The scale of the vehicle and trailer should be similar to a road going car and trailer. The corner around which the trailer should be reversed should be scaled similar to a road junction. Having reversed around the corner, the vehicle should continue to reverse in a straight line for at leasttwice the length of itself.
I have been thinking about doing this every now and then. I always figured I’d put encoders on the car’s wheels and the trailer’s wheels and then calculate their heading vectors and use those for angle calculation. It does sound a lot easier to just have an encoder at the pivot point.
Indeed! And I just happen to have a ton of mindstorms gadgets lying around (including those bloody expensive rotation sensors for the RCX)… what a coincidence!
I was a bit confused with the whole “trailer” thing so I skyped a UK friend and I have it all clear now…
Ok, A trailer is a trailer in both the UK and US. If the trailer is a box you live in it becomes a camper. Yes, americans do use the term trailer to mean both a camper and a thing you would carry stuff on but usally “trailer” means a utility trailer (not the kind you live in). If “trailer” is used to refer to a mobile home or camper you will know this from context.
(I think a camper in the UK is a caravan… I think…)
Yes, I think that what is sometimes called a "trailer" (American) is actually a "caravan" (English). As opposed to a bunch of cowboys heading west with their little mobile homes towed by their horses, which is actually a "convoy". I know that "convoy" in American is a word for a lot of guys speaking in C.B. radio 10-codes. Hah! You thought I had no culture!
The only thing I ever “published” was a servo motor I built. I didn’t even use it in any vehicle since I decided to go for differentially steered thingies.