Hi I am looking for any tips and advice, I want to make my skid steer work in open grade. My main goal is know the location of the cutting edge on the bucket and I think the way to do that is putting a imu on the bucket and a rover on the roof of the machine and fuse the data together so when the imu moves it moves the location of the rover, then send the NMEA to opengrade and put in the offsets from the rover to the cutting edge.
It would be cool to get data from cats integrated imu that tracks the bucket but I would probably test using a bno but the more expensive imus ones come with software to fuse the data which could be easier for a newbie like me. I would put the imu somewhere around the integrated imu
I would use a ublox f9p for the rover.
I’ll keep researching the best ways to do this but Thanks for any advice I’ll need it!
You’re right, I do need other imu on the loader arms and maybe an other one for the chassis itself. Or maybe do dual gnsss instead? For measuring everything up I’m still thinking and researching how to do it but I do think I Measure the distance from rover to the cutting edge and the imu on the arm. I think I also need to calibrate all the angles and put all that info into code or software.
Personally, I’d put a receiver with maybe a foot or two mast on the loader arm, and then a wheel (bucket) angle sensor on the pivot between the loader and the bucket.
Unless you plan to have the bucket level at all times, then a receiver on the bucket, and an IMU to make sure it’s level would certainly be easier!
Wow your recommendation simplifies a lot and those wheel sensors are more accurate than imu anyways. I do wonder putting the rover on the arm of the machine would effect satellite quality fix. And I wouldn’t be able to move the arms right? Or it would mess everything up or does the wheel sensor fix that?
I would like to know the cutting edge location with my arms up or down
As long as the wiring was done carefully enough to avoid pinching, you could move the arms up and down. The height difference due to changing tilt would only change very slightly. The dirt movers around here don’t even use an IMU on their scraper setups. I don’t know how much the Satellite quality would be effected. Probably only trial and error would resolve that.
Have you seen anyone try imu set up on the bucket and arm and dual gnss on the roof? I’m sure it’s not easy but is it possible to get all of that data to work together to show the exact location of the cutting edge no matter what the machine is doing?
No I haven’t. I suppose anything is possible with math, but that’s a lot of calculations, and data, and angles. I don’t know how good the data would be by the time you were done with all the calculations. You might be better off with an IMU, than dual receivers, as dual can only measure roll one way, and an IMU can measure both roll and pitch.
This would be down the same line as I’m interested in. I’d like to put it on an excavator. The hardware doesn’t loook as bleak to me as figuring out how to get the proper offset position in OG. My thought was to have an arduino doing the the calculations (trigonometry) for height and distance from receiver even angle then send those numbers to OG and have it map the position, but like I say I’m stumped with getting it into OG at the right place to be of use.
I even have an Arduino sketch somewhere using COS and theta out putting the correct position base on input arm lengths.
You want OG to guide your blade height or just a visual reference on screen?
To start, you’d need to convert all the angles into a blade position nmea output, GGA & VTG. I’m not even sure VTG is used but that’s how the receivers get configured.
I think it gets more complicated if OG is supposed to control the blade. I don’t do much digging with an excavator, which hyd lever would OG control or would you give it control of multiple hyd channels?
The version I was working on for laser was a pole mounted on the bucket, IMU and a separate sketch keeping the bucket level, injecting oil from my auxiliary button (finger button used to power attachments) Then pulling the outer arm in via joystick, also inject or remove oil from the main arm to control the height automatically.
I don’t care for auto machine control. I just want to know the exact location of the tip of my bucket no matter what the machine is doing. I’d like to do this with an excavator to.
My approach would be like shown in the picture.
The main pivot would be the reference point for elevation.
The blade tip elevation could be calculated by two triangles.
Should not be too much math.
If required a IMU 3 could be attached to the machine frame so you could compensate for uneven ground as well.
