Allright there are three separations to make and tune.
- GPS/GNSS reciever / Shipmodul
- Guidance Parameters and Computation
- Limitations of your Equipment / (steering play, hydraulic speed, ground conditions, Implement drag.)
1 The tuning of the Emlid is not tough, you do have RS+ they work good but there is a reason that the RS2 came out. RS+ is only L1 GNSS, it takes longer to get and hold a fix compared to the RS2. When i was working with the M+ I could sit around for 5 or 10min to get a fix, and if lost the fix would take some time to regain. Then M2 is L1/L2/L5 and fixes almost instantly once warmed up.
If your Guidance can take 10hz Set all of the RTK rates in the Rover to 10hz that you can use. I am in Northern Alberta so i leave QZSS unchecked as i will never see it high enough on the horizon to be useful. Leave any setting you are not using off or unchecked to save processing power.
I found a quirk with the shipmodul, if you are inputting data to it at 57600bps for example and the unused inputs are set at 4800 all of a sudden it is using high buffer. set all inputs even if not used to 57600bps to match the used input. Then no buffering occurs. click the box “real time data” on the input you are using. Make sure your output filter is only sending the sentences you need to the output. I also found some added success recently changing to a ttl to 422 converter for the Emlid to shipmodul input. Though they let you creatively wire in 232, it is much more solid at the higher input voltage of 422.
The shipmodul may be the weak link. I am only running 5hz, but the emlid NMEA dumps so many sentences into it that i am sure the shipmodul is having fun getting all the data sorted out at 57600 which is high as mine can go. Once Emlid allows NMEA sentence selection and talker code transformation we can drop these multiplexers all together, and probably see yet more steering improvement.
Try some sort of vibration isolation on the RS+ Rover, the GNSS is so precise it ends up calculating vibration as position. Reducing any amount of vibration will reduce the calculation load on the processor.
Base settings for Alberta are GPS+GLONASS+GALILEO+BEIDOU 1HZ , Plus ARP 0.1Hz, Lora set to max data rate and max db.
The Emlid Loras will clip and drop connection with corrections set higher than 1hz on the M2.
Your Rover Setting would be GPS+GLONASS+GALILEO+BEIDOU 10 HZ
This automatically sets your NMEA to 10Hz
In the shipmodul make sure it is only transmitting out the needed sentences, for example the 150 only needs GPGGA and GPVTG.
If its only two or three sentences 38400 is requested in the manual at 5hz by Trimble, if it was at 10hz I would expect to be running at 57600 or 115200. The idea is to get the data in as fast as possible so it can start its position calculation and finish before you have moved.
- Your WAAS tuning will not work for RTK, this is expected.
I would start from scratch and precision measure your equipment again. This is the #1 reason on all guidance platforms that I have fixed that were not working properly. If the tractors measurements are garbage it will control like garbage. The biggest error every time is the wheelbase of an articulated 4wd Tractor, they measure only one side and get it very wrong. Measure front of rim to front of rim on both sides, Add those together and divide by 2. Now you have the correct wheelbase, all of a sudden their steering improves.
Tuning to WAAS is like trying to shoot a duck that cannot figure out which way it wants to fly. The position input hops back and forth so badly that you are hoping that half the time you are steering to the middle. RTK is precise so now you have to tune to an actual position, it really changes the dynamics of the tuning. But once you have it nailed down to cm steering, it never changes.
Watch your correction age it should be 1-2 seconds old max, if it is going higher you have radio setting issues.
I am not sure how a Raven tunes. But the Trimble for example my steering angle went from 12 to 18, WAAS vs RTK. I finally found my steering free play settings were far greater than I first imagined on a tractor with under 1000 hours. Aggressiveness is the very last thing to tune to field conditions.
My RTK tuning steps for Trimble 150 are:
- Set aggressiveness to 120
- Set steering motor to max speed
- Set steering free play to a minimum of 2.5"
- Decrease the steering angle until you start oscillating, then add 2 or 3 Degrees more.
- If the Tractor is running to the left of the line constantly, you have to get it to turn right. Slowly add more to Right free play until tractor adjusts toward the line. Same goes for left. Left and right free play are rarely the same number. Free Play is the most important setting of them all.
- Lastly increase aggressiveness till you notice it is hunting back and forth. Then slowly reduce until you are running a smooth straight line.
If the raven has auto tune use the auto tune wizard with the RTK, it will come up with far different numbers than WAAS.
- Depending on age, wear of components, speed of hydraulics, other oddities you may not be able to achieve perfect steering but pretty close to it.
I find that if you are using a steering wheel motor, rubberizing the foam roller really helps on slippery Deere steering wheels. I use a couple wraps of rubber tape just tight enough to stay on. The added traction really improves performance. Rubber tape is also called splice tape and has no adhesive it only sticks to itself, used for waterproofing splices. It is not Electrical tape, that goes over splice tape.
Hopefully this helps you out.
I will be updating the Trimble 150 Conversion thread pretty soon. I have added the ability to hook up to an external 232 corrections radio. Still testing lol. 