The SimpleRTK3B Compass appears to use the same chipset as the CUAV hardware you referenced. You get more bang for your buck with CUAV, in that case.
The SimpleRTK2B+Heading is a nightmare. If you want F9P hardware (which is arguably the best of the choices you presented), use two separate boards instead of that thing.
The SimpleRTK3B Heading is elegant but overkill. I’ve used it. The cost isn’t justified.
I don’t know why your single point of comparison seems to be message rate. That’s a rather poor metric. ArduPilot only supports up to 10Hz, and in many cases, 5Hz is more performant.
“If I can run it without Mission Planner” is a weird statement. I don’t know what you’re talking about there.
Typing this stuff out really does help one question oneself.
I was only considering the compass as it appeared to have the flexability to (one day) take mission planner out of the loop and send corrections directly to the rover and play with depth camera fusion. I’m unlikely to use Mission Planner for anything other than the mower, so ideally Mowbius will have as few single points of failure as possible. Stepping back, sending injections via mission planner isn’t a deal breaker, and it’s problably the smartest (most straight forward) entry point. Yes, message rate is a poor encompassing metric. Hence why i quiried the group. the Cuav RKT2 HP is probably the right answer. Just need to oder it before the tariff strike…
If you want RTK GPS, you need a transport mechanism for corrections. Mission Planner provides that, but it isn’t the only option. The hardware you’re talking about doesn’t alleviate that requirement at all.
Sending the RTK corrections over to the mower without going through Mission Planner on the base computer is not difficult if you build your own base station and you are using the Simple RTK2B boards. It just requires a dedicated radio on the mower and one on the base station. Other ways of transferring the signal over to the mower like WiFi can also be used. It literally doesn’t matter if mission planner is connected or not, once the plan is loaded and all operating parameters are normal. The mower has everything it needs onboard in it’s processor and can run a mission without being connected to the computer running Mission Planner.
I use the matched turn-key radios made by Ardusimple that mount piggy back on the header of the RTK2B boards (one in the mower, and one in the base station). I am sure other radios are probably better, but these little radios seem good enough and have worked flawlessly for several years now.
I try too read all the post and there is much discussion about Huge servo’s attached to hyd motors on zero turn mowers. I have (sense 2018) used 35g servos on my 60" Cub Cadet. The hyd motor only requires 16 g when eng off and 10g when eng running. I further reduce the pull to 5g running and 8 g eng off ,by adding a 2 inch lever (a mechanical advantage of about 2 too 1) to the existing hyd motor linkage. ( pic attached)
I also removed the steering levers and seat. (without that extra weigh and me I Mow 5 acres on 2 gals of fuel) .I have a adjustable pwr supply with volt and amp meter attached. The amp draw with servos engaged is less than 1.5 amps.
I use the tiny rc receivers attached to 20 amp dc relays to control blade on/off, set throttle to what ever speed I need mow at and let the governor kick in in high grass. highly recommend many ,many fail safes. I use radio control and mechanical switch’s. plus the mechanical parking brake on the cub(the hyd motor whines if something trying to input.) anyway I just want all to know the are cheaper ways out there.
Servo torque requirement is very machine dependent. Some, like yours, require light force on the hydrostatic controls to actuate. Others require quite a bit more force (Bad Boy mowers, for example, tend to use drives with separate pumps that require a rather hefty amount of force).
If you are fortunate enough to have the integrated pump-type drives that many residential machines use, then you can get away with small, less expensive servos. It’s still likely wise to use a waterproof/weatherproof model, which increases cost a bit.
On my own mower, I find the torque requirement to be a bit more than what you describe, and if I add any linkage to increase mechanical advantage, I can’t quite get enough throw to achieve desired speeds. I do use a heavier duty servo than is absolutely required, which keeps temperatures low and should increase longevity.
Yes, very true. But my point was in some cases you can add a mechanical advantage and use cheaper servos. also If anyone has Flysky fsI 6 or 10 which is a great transmitter for the price .There is a got ya on page 5.4 in the manual under display, it tells of a scrub mode, where it will drive the servos thru full exercise from low to high. If you hit the button while engaged ,it ain’t pretty. Many thanks to you Yuri, Steve Johnson, and Kenny Trussell and all the mission planner team! A donation is on the way.
Point well made. It’s worth doing some measuring/analysis to determine the torque requirement before buying hardware.
@Swebre2023 has a machine using just about the cheapest Amazon servos of similar size/specs to yours that has hundreds of hours on it without failure. Can’t say I fully recommend that avenue (I’ve had similar servos fail quickly), but it sure has been effective for him, and it’s hard to argue with success!
I setting up my EX Mark 48 inch zero turn mower I removed the seat and all the electrical safety switches. Next thing I got was he box then he Flysky FS-i6X with a FS-1A10B receiver
CH 1 Right Arm ACTUONIX L16-100-63-6-R
CH 2 Left Arm ACTUONIX L16-100-63-6-R
CH 3 Throttle GX servo 40kg.
CH 5 SwA PTO Relay
CH 6 SwD Start Relay
CH 7 SwB Sprayer Rely
CH 8 SwC Eng KILL Rely
I have this all working buy remote control.
I what to get to make this autonomous
So far I have a
Omnibus F4V3S flight controller
BN-880 GNSS GPS
Video camera
1 set Micoair 915MHz 30M Telemetry
So when I connect the RC to the flight controller do I remove a servos off of the receiver and onto the flight controller or will the flight controller recognize it from the receiver in short where do the servos plug in.
I am new to this all I know is what I saw on YouTube about it so is there a package deal for what I need
Dean, welcome to the Ardupilot family where we build fun toys and have a great time. The EX Mark zero-turn mower is a great platform for a mower project. Be careful with how you manage the safety aspects of this mower. I personally have left all the safety systems operational on my mower and I only disable the seat switch when I am running auto. In my case, I left the seat and drive handles in tact so I can jump on it and drive it with the original drive handles for cutting in close to objects. You are responsible for your own safety so be careful. You need to start by learning more and going to the Ardupilot documentation and pouring through it. It is a bigger task than just watching a few YouTube videos. This is a big and complex undertaking. Rover Introduction — Rover documentation is a good starting point. The First Time Setup and Configuration First Time Setup and Configuration — Rover documentation and the First Drive and Tuning First Drive with Rover — Rover documentation are all very important. If you don’t address each topic in these main First Time Setup Sections, you will not be successful.
Other resources on the blogs documenting other builds are also important, like New build - dev/prod setup - Toro 60” zero turn are also important. This is not a quick process and takes determination and patience.
The equipment you have listed above is not what you need to build an RTK precision self driving autonomous mower. There is also no package deal for what you need. You first need to decide what capabilities you want to have and study what others have done. Generally you need a lot more powerful processor than the $20 model listed above, a better GPS (probably RTK of some sort), and servos instead of linear actuators (only use linear actuators if you have to do so, they are slower). You will also learn that the compass systems do not work reliably on this type of mower. Most people go to dual RTK GPS systems so the heading can be calculated from the 2 GPS positions rapidly (usually at 5hz). The correct name for this is GPS for Yaw. Everyone builds these things a little different, depending on the requirements of the base mower, the owner’s needs, experience levels, and budgets.
Here is a typical layout of an RTK mower build. It is the one for my mower. https://discuss.ardupilot.org/uploads/default/original/3X/8/f/8f01e2ff163c8a6ac2df705e23561e93fe2eccdf.jpeg
Everything connects to the flight controller and only a few communication wires go to the RC receiver from the Flight Controller.
Hey Rustey! You might consider removing the centering spring on the HydroGear drives on your mower. You don’t need it in this service and it just adds significant load to the servos.
FWIW, I have 700+ hrs on one mower with cheap no name servos. The HydroGear drives don’t need a HD servo. However, bigger servos, within reason, are almost always good idea. We are dealing with hobby grade components…. Good luck!
Thanks ,I’ve run my 35 Gram servos for 8 yrs. And the spring in the photo is a much smaller one just to insure hyds return to neutral.
You’re probably right ,it is not necessary.
Welcome to the Ardupilot community! The choice of radios for telemetry are numerous and most of them will work fine. I have used an RFD900x and that thing has been flawless. I always have strong signal as indicated by the signal strength indicator on the mower. That thing is way over kill for reaching out to my max distance (about 300 meters). Many of the mower builders use the smaller 100mw sik radios and they also work fine for those kinds of distances. I would stick to the 868 mhz options if it was me. Operating at 433 MHz generally should provide longer communication range compared to 868 MHz but they both should work.
There are a lot of options out there and most of them would probably work.
Post pictures and keep us updated on your build progress.
Welcome to the zoo @Lukas1212 ! Start a new thread on your build - you’re in capable hands here. Be sure to follow the documentation exactly. As someone who didn’t so much initially, I found it to be the most efficient way forward.
Enjoy!
BTW, I have the 500mw SiK/Holybro radios - range hasn’t been a problem…
