V5 u-turn problem

Since changing to v5 I’ve had to slow down for all my u-turns. In v4.3 I could pull off a 40 foot turn at 9mph no problem, but in v5 it seems I always have to slow down because at some point (the apex of the turn) I get a sudden change in the line and the steering goes crazy. If I watch the top of screen lightbar I go through about half the turn reading 3-4 inches off the line at most and then suddenly it says 24-30 for a second and my nice turn always has a wobbly second half. I’m sure it’s probably a setting I’ve got wrong somehow, but I don’t understand the line jumping. I get the same problem at lower speeds, it just doesn’t try to throw me out of the cab.:blush:

Does this happen both right and left?
Old AOG versions did left better than right.

Yes, it happens both ways. You are right, left turns are not as bad. Also it seems to be much worse in fields where my AB lines are going east and west than those that are north/south.

The only thing I have changed with my setup besides switching to v5 is that I’m using the CMPS now. In v4.3 I didn’t use an imu. My CMPS is is it’s own box with its own Arduino mounted on the floor beside the seat. Could it be the problem?

I am now wondering about this, I finally got AOG driving in a straight line wonderfully. Tried the u turn function to see how it works. But it under steered the first portion of the arc, then when it finally made it to the intended line it almost grabs onto it, then went crazy on all tests. Steers better the slower you go, good thing the tractor is hydro static. Was using PP

Sounds like steering motor can’t catch up. Check steer chart to see how far behind the motor is.

I measured my steering angle with gyro inclinometer. Using that value it smartened up a fair bit, but still not sure if steering angle is super correct.

The Implement is rather small 182cm, tractor wheelbase is 152cm, so I am thinking that may be causing some issue too. I find the slower I go the better chances I have of making the turn. I am at 2/3 times actually making some form of the u turn. Just under 5km/h seems to be the best. Sometimes I am mowing the lawn in figure 8’s. Sometimes U turn shuts off by itself?

Whats the normal u turn speed?

Driving in straight line is absolutely wonderful :tractor:, trying to get all the bugs worked out before putting this in all the other big machines. Especially need to wire in a relay to drop the cytrons output when steering is disabled.

@KentStuff has a Micro version that may help. I haven’t had time to test it. Maybe he will jump in here with a link, I can’t find it right now.

Try telling the settings that the wheel base is twice as large.
Turn up the steer angle, turn down the look ahead, turn off the internal. And try it again.

MicropenGPS may be better on your small tool. It is always a step or two behind the main branch.

@KentStuff I ran across a post where you made Micro mostly by changing the value of the distance of the points of the curve, also you had a small bit of code that would tighten the points automatically based off wheel base size, within the regular code.

If I cant get reliable U turn just from tuning, I will implement this snippet. The dream for me is to use the same program for guidance big or small.

My steer angle was really high and got better as I came down 45 vs 36, the manual states the tractor has 55 degrees of steering freedom so my next guess is 28. Look ahead is 2.6, higher or lower by .2 I wobble, Integral is 1, at 3 I am wobbling again.

Now that is funny!! Not really. There are a lot of little bits that need to be changed when the tool is changed. Big and small is almost two different programs. At least the settings are very different.

If changing your wheel base does not work, Micro will probably not help you. Brian made vast improvements to the dubins a while back and you don’t typically drive through the u-turn any more.

How fast is to fast for u turn? I mow at 6-7km/h, been attempting turns at under 5km/h

Try the larger wheel base. If it is a speed issue, this has been known to trick it. Double the wheel base. Also, are you pulling a trailer style or fixed tool?

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As advise
to make Uturn properly it is better to keep a similar speed or litle bit lower

Avoid Acceleration positive and negative

also radius setting need to be set higher than reality to keep margin

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Fixed three point hitch tool.

First curve outward it follows, Second curve it follows pretty close, Third curve back online is a gamble. It either gets online, picks a wrong line, or I go into orbit. I feel I am very close.

Increased U turn smoothing at 18 helped a lot. Will try your adjustments tonight.

You probably stated this, but what version are you running? When you trigger the u-turn does it immediately draw the next line or is it looking for a line?

V5.2, latest and greatest, updated everything yesterday.

I start the first row, set auto steer on, then u turn, next it waits a second or two and turns the U green, and you can see the intended path on the screen. Exiting the turn to the next intended line is where hell breaks loose.

what does the box with the “X” and the distance value mean during the u turn?

The x is cancel the turn.

Does it follow the uturn, and is it going at the intended line sharp?

It looks to be following it, until transition to the last turn, but next try I will zoom way in.

Good news is on a small tractor its easy to try lots :crossed_fingers:

If you really want to zoom in closer, use the zoom in the left menu, it gets closer than the one on the screen or the mouse wheel.