New User Project

Ok guys i am really perplexed on what is going on with my sim, i have replaced the pots with better quality ones, i have fitted a flexible coupler eliminate out of alignment issues but yet i still have the same problem with the left motor, It is like it drives through the center position and then the arduino tells it to go back and the cycle continues until you stop it by hand. But here is the kicker it is only the left motor doing it. i can push the seat sate base as far backwards as it can go power up the unit and the seat returns to the centre position but the left hand motor keeps hunting. I will post a video of it.

Video of Problem

You use SMC3?

First try to ki kd ks down to a minimum. In the attempt to a lower value kp

imo that is oscillation............
the cause is not apparent to me from the video, at this point i'm guessing software settings as the mechanical looks tight.
take a screen shot of your smc3 settings on the offending motor

Ok so here might be a solution, I am using Racing matt code, as far as i can see there is no way to change settings between both motors. SMC3 never heard of it, but after looking it seems it is another code (correct) for arduino?
can someone post a link to the code and setup and i will try that, Is that what most people run for these Arduino setups? is there greater control and tune ability. My issue belongs in the code for sure i believe as i don't have sim tools running it is just the code loaded into the arduino only.
Thank you in advance for the help.

@Bruce take a look here https://www.xsimulator.net/community/threads/stuttering-motor-problem.8368/
it could help you with code. it is some info i think that is not in racingmat's thread
but you can also use SMC3 as noorbeast said above

Sry I thought you were using smc3 already. I am not familiar with the current code you are using. The smc3 is a good way to go I have used it on a 2 dof and a 6 dof. The utility is very useful to get things tuned. Follow the links provided above.

Thanks Bruce, i have seen that page and done what was suggested. But the problem is still there. might try the SMC3 way

I just need to rewire to suit the SMC3 code then i will give it a go.

Sorry to hear your having trouble with your rig Bruce. If you've set the software to exactly the same settings for both sides then the problem of hunting would be hardware in an ideal situation. Just out of curiousity how much slop do you have comparing motors? Hold the pot coupler at the gearbox side and feel how much movement you have in the seat coupling/motor gearbox before the pot coupler tries to move. Both pot couplers should not be able to move coupled into the gearbox (gearbox side of the couplers only of course). I'm guessing you have more slop in the left motor than the right? I am hoping you get this problem sorted with these motors as they look as though they are ones I may have to change to.

Hi Brassem, i have just redone the shafts for the motors and the mounts for the pots, there is absolutely no movement in the shafts when attached to the pots. I even tack welded the shafts to eliminate any movement between motor and shaft. there si no where i can see in the Racing mat code to send different commands to the individual motors??

Bugger. Well that eliminates the hardware side of things. From that it looks as though the PID values are too high for the left motor for some reason. I would start dropping your PID values in the Arduino until the motor stops hunting compared to the right motor. I was able to read up on SMC3 today and it will definitely help with diagnosing your problem.

Ok so i have installed the SMc# code and installed the utilities program, I have done the initial set up and tested to make sure that both motors are driving towards the blue line, which they both are. Is there any generic setup figures for all the KP,KI,KD,KS or just check in anything??? Also do i leave the KP at 400??

Now i have severe hunting on both motors, i believe it can be tuned just point me in the right direction. Thanks

I am about to upload a couple of videos, Couple things i notice i set the SMC3 utility software to sine, and i notice the green line is very jaggy? it is not smooth at all even when i first tune the program on the green line is fluctuating really badly. I am not sure if it is just still quality pots that is causing my issue, but 1 thing i can 100% say if there is no play in the shafts to the pots.
The Left motor is even worse, I thought my Arduino might be faulty so i put the code in a brand new unit then tested that with the same result, Then i thought it might be low power to the motors, so i am using a car battery and then a 40 amp charger on that, no voltage issues now.
I am wondering if my motor shield may be faulty as sometimes it just drops out and i need to depower it to get it to go again, also you can see on the utility software that then green lines drops out and does not follow the blue one all the time then it starts again? Dont know what that is about?

Video

what pots are you using. the green line should not have a lot of interference. this could be a number of things. bad grounding or bleed thru from the 12v side, poor quality or worn pots (use hall sensors). try turning up the deadzone. anything over 5 in the deadzone and you need new pots. also fpid should be set to 1. turn reverse down to about 50. add some kd maybe 5 to start.

I reckon there is a fault with the moto monster board i am using, just done a test by hand and the line no matter how fast i move it without the motors powered up the line is smooth and responds straight away. Therefore i am ruling out any issues with the pots or the set up of the pots, as soon as i connect the motors back up and set the utilities program to sine and let it follow motors follow it i notice the motor control is very jerky in its movements. Both motors are brand new and if i hook 12 volts they run fine forwards and backwards by reversing polarity. (Smooth as)
On the moto monster board i notice that the direction indicator light for the motors flickers and does not stay constant when the motors are running, giving the jerky movements, but when the motors are not running (powered up) i notice the light is constant all the time for either direction.
It is almost like as soon as the board is required to drive power to the motors it goes haywire. These boards are just cheap ones of ebay that i found here in Australia. I don't know a supplier for the proper boards over here otherwise i would buy a good quality one.
I do have a brand new cheap board that i will wire up and test my theory, but i would really like to get a better quality board from here in Australia if anyone knows where to get them???