How did you prevent your robot from tipping over in 2018?

Did you use software or just built your robot very stable?

We used a mix, we built the robot not to tip, but it was tippy, and then we made it only go at certain speeds when above certain heights in software. We are yet to tip over in a match using that

1 Like

Keep the CG low. Your battery is the heaviest single item on the robot. Keep it low on the robot.

Everything that goes up high on the robot needs to be looked at, can it be lighter?

Another great option is pick team RUSH, so they can bale you out when your about to fall over. :wink:

24 Likes

We had software limits on speed connected to elevator height with a pretty low CG and still tipped over when we clipped the switch wall at a moderate speed.

This year has the potential to be an absolute mess of tipped robots because there will be significant defensive contact with robots partly to fully extended up.

1 Like

We did tip a few times, but our anti tip code saved us even more. Having swerve definitely helped a lot. We would use the gyro to detect we were tipping and drive in the opposite direction. Also lowered the elevator as fast as possible.
Edit: A video of us ALMOST tipping over without the code: https://streamable.com/q97p4

10 Likes

We had a relatively low center of gravity due to a low battery and some heavy bumpers, but along with that, we reduced driver speed maxes proportional to our lift height so it was unreasonable for the driver to tip in normal play. In auto we removed most of these restrictions as we knew the robot would perform the same actions every time and the only chance of tipping was in collisions with other teams (problem areas were also slowed down in).

1 Like

The best way to prevent your robot from tipping is to keep the cg as low as possible. Try to keep stuff as low as possible in the robot. That would mean considering doing stuff like placing your battery sideways, designing gearboxes to have the motors as low down as possible, mounting all electronics at the lowest point on the robot. If you’re really scared about tipping youll want to take stuff like that into consideration.

As for software it probably wouldn’t be a bad idea to implement some way to keep the robots drivetrain from making really sudden movements that would tip it. You could figure out how much you need to adjust your ramping by driving full speed forward then instantly going reverse and finding a sweetspot that isn’t too slow but also doesn’t tip you over all the time if tipping is an issue. Of course this will be dependent on where your lifting mechanism is as full height would probably tip over a lot easier then bottom height.

are bumpers would prevent us from tipping over if we ever stopped fast but didint help if are lift was up

Limiting max speed in code is a good idea. If you’re feeling ambitious, though, you could try writing code that limits your maximum acceleration. We tried this out last year for fun, and I don’t think we ended up using it in matches, but it was a fun experiment and a good tool to have on hand.

1 Like

We had a combination of things to keep us from tipping. We had programs to limit drivetrain speed based off elevator position. Most of our weight was located at bumper level, excluding the elevator and pearl (our carriage assembly) and the climbing mechanism. We also tried to get to the limit on bumper weight with 19 lbs bumpers. A lot of it comes down to design I’d say and it’s just something you have to look at in general Int. robot design so your drivers can have the easiest time on the feild and only worry about scoring and not things like tipping. Hope this helps

Do you have a video of this?

1 Like

We had a low cg but when we had our arm up the drivers had to be sure not to bolt away from the scale with it all the way up, or at least not come to a screeching halt.

We had a low cg and also code to rumble and light up the controllers when the accelerometer sensed tipping beyond a certain point (5 degrees I think).

2 Likes

Though our elevator last year went up 10’, it was mounted on a pivot point near its base and sprung forward using two pneumatic cylinders. Our design called for this so the mast and grabber could start tilted back and fit within the frame perimeter in the starting configuration. It had the added benefit of the pneumatic cylinders acting as shocks–if we ever drove with the mast fully extended, the mast would lean back independently of the robot’s drivebase, which would remain flat on the floor.

1 Like

Correct me if I’m wrong, but I believe team 234 dropped their elevator if their bot exceeded a certain angle of tilt.

1 Like

We designed our robot with a low center of gravity and shifting the weight to the rear for heavy things (elevator in front, battery + drivetrain gearboxes in rear). We also had a speed modifier based on height so once we raised the elevator, it would slow us down.

The only time we tipped was during semis on Curie when our drivers got a little too much speed and basically ramped the edge of the platform crossing the field, flipping the robot backwards (back side hit the ground, flipping elevator around it).

1 Like

Team 5687 - The outliers implemented a similar method with lowering the elevator as fast as possible. They tipped less after implementing it mid season.

1 Like

As others said, keep the CG low. Our robot could move full speed (15-17 fps) with the elevator fully extended, and it was all but impossible to flip, unless we hit something. In software, add in deceleration curves, and if all else fails, practice driving and smashing into stuff.

RUSH catching you was probably the loudest I heard a worlds audience chuer since 330 flipped twice.

2 Likes