Hi everyone, this is my trolling motor. I’ve been testing it for some time but I still can’t calibrate it for the various GPS-guided functions. Meanwhile, a brief description. I emptied the upper part and inserted the fc CC3D (in the front), the rc receiver, and two brushed esc behind it. in the upper part and far from the esc the compass with the gps. Logically, one ESC will turn the trolling motor and the other will turn the propeller. I have done all the calibrations and the steering seems to work well even in ACRO mode. The main problem concerns the loiter mode. Once set initially the steering works but when the propeller motor starts there is noticeable steering vibration and the motor loses course. As soon as I disarm the trottle everything moves perfectly. I imagine this is due to engine disturbances… However I ask if there is anything I can do or any advice. I’m attaching a video and a file if anyone wants to take a look. In the meantime, thank you. trollin motor.param (13.2 KB)
Thanks for the kind reply. I would agree with you if the fc was inside a boat. Maybe I’m wrong but the fc, being on axis, shouldn’t have any problems as it behaves like a servo. Let me explain. If the engine goes straight I imagine that the 1.5 ms pwm signal arrives at the esc. When steering the PWM increases (or decreases) but once the exact trajectory is reached the PWM returns to 1.5ms. In fact, in LOITER mode, if I turn the engine to the right the FC brings it back exactly in the desired direction. It looks good from the video but I don’t know how to publish it.
I add a further detail that makes me think of the excessive disturbance generated by the engine noise. If I try the steering in acro mode this works perfectly if the engine is disarmed. As soon as I arm the propeller motor the steering behaves senselessly. It turns in the opposite direction to the desired speed and often vibrates. Unfortunately I see that no one can help me…
With manual mode looking OK I think the next step is to actually put it on a boat. It won’t be possible to really test it probably in Acro or Loiter mode while the vehicle can’t move
Re the shaking, I would guess that this could be feedback from the servo moving the motor. So perhaps as the servo moves, the autopilot is shaking a bit. I suspect if you set ATC_STR_RAT_P and ATC_STR_RAT_I to zero the shaking will go away because the steering controller will only be using feedforward (which comes from the target direction and doesn’t use the “error”). Once it’s on a boat you’ll likely need to restore those P and I values to something higher but maybe by then the setup will be more stable.
One small thing i’ve noticed is ARMING_CHECK = 0. Clearly it’s not dangerous at the moment but the arming checks will warn of various setup issues so I think changing this param back to 1 would be a good idea
Thanks so much RMackay. I take this opportunity to ask two questions.
1- Can you confirm that the use of continuous steering can be used in my case? (see the answer I gave to geofrancis)
2-I set the values of ATC_STR_RAT_P and ATC_STR_RAT_I to 0 but the shaking (ACRO mode) does not go away and sometimes it turns in the desired direction, other times in the opposite direction. In LOITER mode it keeps changing direction (sometimes it tends to go in the opposite direction from the anchor point). The strange thing is that when I disarm it turns in the precise direction. At this point I wonder if the reason for all this is to be found in the ESC. Since it runs a 30 lb brushed motor and is not of quality,(https://it.aliexpress.com/item/1005005866547271.html?spm=a2g0o.order_list.order_list_main.199.914c3696Tj7igy&gatewayAdapt=glo2ita) would you advise me to change it ? Is it possible to check if it actually creates noise to the FC?
I will try it on a boat as soon as possible.
I thank you in advance for the time you dedicated to me.
I suspect that @geofrancis is correct. A given PWM output from the autopilot should cause the motor to move to a given angle. If instead a PWM output causes the servo to rotate at a particular speed (and not stop) then it won’t work I’m afraid.
I think I’ll hold off on thinking about item 2 because if the above is true then we’re pretty stuck.
ok. but then in this application not even a servo motor would work… in fact my trilling motor must be mounted in the bow of the boat. as mentioned previously, the compass and fc are on axis with the motor, so as soon as the motor turns, the fc board and compass also turn. if I installed a servo motor the motor would turn towards the target but, as soon as they reach the turning angle (and therefore directed towards the target), it would set the steering motor back to neutral position but the boat would not have turned completely yet… tell me if I am correct explained. I’ll add a link to what I want to get. https://youtu.be/d-6Fm3_1qzk?si=LJIEpMwN_mI-O-9t
Couldn’t the FC be mounted on the boat frame separate from the motor?
I’ve never seen someone with this setup before but I think it may work with the FC mounted on the motor. I just think that we will need to take great care with the ATC_STR_RAT_XXX parameters. I would set ATC_STR_RAT_P, I and D to 0 and then focus on getting the ATC_STR_RAT_F to a value that seems to work.
There are instructions on the turn rate controller wiki page on how to use real-time tuning. I think testing in ACRO mode would be best and if you’re struggling to get the right parameters try setting LOG_DISARMED = 1 and move the steering around a bit in acro mode and send us a log.
The biggest issue I foresee is the autopilot will have no idea where the body of the boat is. It could get so bad that the FC turns the motor all the way around 180 degrees and ends up pushing the boat backwards. Anyway, it will at least be interesting to see what happens.
Thank you again for the reply.
In fact, that’s exactly what should happen…FC shouldn’t have to worry about the position of the boat at all. What matters is the direction of the engine, the boat having the engine at the bow will simply follow it.
As soon as I try it installed in the boat (inflatable boat, 3 meters) I will try to obtain the LOG.
i am doing the same thing!!! so happy to know your post!
i use a 360 servo too!!! when pwm at 1500us, it will stop. it work 1000us to 2000us. it think servo stop is the only way to use for LM!!! bcs the gps in at the top of motor, if it is a conventiona servo， when the gps at the right direction，pwm=1500us， conventia servo will change its direction! it cant work！ the 360 servo can do this， bcs when gps at the right direction, it will stop . that it good!!
why it is shake， i think it is about the procedure,bcs at
SERVO1_FUNCTION = 26 (GroundSteering)
SERVO3_FUNCTION = 70 (Throttle)
AT this setting ,its turning need throttle and servo work together, bcs normal the gps not at the servo，it need to throttle work and turnning。 they work tegether， turnning is not alone！ so when it want to get back the direction, i think it will have some problem.
the best test ,you can do , the at the same position. you use L model, the motor should not work! and you trun the shelf , just servo 1 working, turn to the original direction and stop working,
so i think need to change code about turning, let the servo1 truning alone, need not power in. and the power juse need to work for distance.
my email is 20166333@qq.com i am from china, english too bad ! hope you understood me !
i like to disscuss with u, now i am doing the same think as u!!
actually the motor is a boat , just let the motor at the same positon, it is the motor guide !! put the motor guide on the real boat, it like two boat tegethet, if the boat of motor at the same position, then our real boat will at same position, of course the real boat will turn, bcs the water moving and wind! but we real boat need not the hold angle . bcs real boat will at one angle by the wind and water moving
Hi GPSanchor
BOAT, I actually decided to change the set up. On the advice of the legendary Rmackay9 and Geofrancis I decided to review things a bit and try to make things simpler. First of all I purchased a servo (270 degrees) and in addition I moved the FC and fixed it to the boat. It took me some time to design and print the new steering box. Now I’ll just have to try it in the water. I hope to run the tests in the next few days. I will keep you informed on the results…
