This forum uses cookies
This forum makes use of cookies to store your login information if you are registered, and your last visit if you are not. Cookies are small text documents stored on your computer; the cookies set by this forum can only be used on this website and pose no security risk. Cookies on this forum also track the specific topics you have read and when you last read them. Please confirm whether you accept or reject these cookies being set.

A cookie will be stored in your browser regardless of choice to prevent you being asked this question again. You will be able to change your cookie settings at any time using the link in the footer.

Thread Rating:
  • 0 Vote(s) - 0 Average
  • 1
  • 2
  • 3
  • 4
  • 5
How to drive hydraulic
#1
I'm trying to dive into the requirements of adjusting my current arduino and h-bridge so it can drive a hydraulic autopilot, I have a few questions:

- In some examples I see that hydraulic drivers have 4 wires, my guess is the extra 2 are clutch?
- Do I need to change motor.ino? 
- And, do I need more outputs from the Arduino? 
- And, I know this is gonna be a weird question, but will a hydraulic configuration also be able to drive a regular tiller if the 2 extra wires will not be connected?

Thanks
Reply
#2
I am not sure which examples you are referring to, but often there are extra wires for a clutch/solenoid valve etc. Sometimes these wires are use in the armature windings of compound motors. You shouldn't need to change motor.ino, you can select the mode by grounding or not connecting D4, D5 and D6.
Reply
#3
Nice, so these pins determine regular mode and hydraulic mode? So, it is even possible to hookup a switch or something to select the modes?

Also looking at motor.ino:

Ratiometric Mode:
for D4=0 and D5=0, the adc operates over the 0-5 volt range
making it ratiometric (linearly accurate) for rudder feedback
and reduces impedance in the rudder measurement
the temperature resistors are changed to 10k and 10k ntc
voltage measurement accuracy is reduced, and the resistors used are
15k and 100k for a range of 38 volts. Pin 12 is not used in this mode.

digital pins 4 and 5 determine the current sense as folows:
pin 4 determines range
pin 5 determines high/low current (20A or 60A max)
D4 D5
1 1 .05 ohm, (or .001 ohm x 50 gain)
0 1 .01 ohm
1 0 .0005 ohm x 50 gain
0 0 .0005 ohm x 200 gain *ratiometric mode


I'm trying to understand as what the relation is between this and grounding or not connecting D4, D5 and D6.
Also I couldn't find D6 in motor.ino
Reply
#4
you can use a switch but I can't think of why you would ever want to.
The purpose of the pins is so the same code works on all of my motor controllers and the board itself grounds these pins or not depending on which controller it is.



digital pin6 determines:
1 - RC pwm:
digital pin9 pwm output standard ESC (1-2 ms pulse every 20 ms)
pin2 esc programming input/output (with arduinousblinker script)
0 - Hbridge
digital pin2 and pin3 for low side, pin9 and pin10 for high side



for the mode 2 or other changes you have to recompile
Reply
#5
Thanks, do I need different type of motor controller to drive a hydraulic driver? If so, which one would be recommended?
Reply
#6
(2020-08-23, 09:00 AM)jamos.tan@gmail.com Wrote: Thanks, do I need different type of motor controller to drive a hydraulic driver? If so, which one would be recommended?

Jamos, i think you will need to include the amperage draw of the hydraulic motor before Sean can say which one you need. I use a hydraulic motor and use the standard controller as it works up to (from memory so don't quote me) 10amps I think. My hydraulic motor rarely go beyond 5 amps and it is set to fault at that because when it hits higher amp draw that means it has hit the max turn.
Reply
#7
Thanks, I don't have a hydraulic motor yet, but my current H-bridge can go to 43A, but I've configured Pypilot to max 20A.

I didn't yet know btw that the amps setting you describe would have such an effect, this probably means that I need to set my small Autohelm st4000 tiller to a much lower setting. My presumption was, just set it as high as it "can" go for testing, not yet having properly set it to the best value for power saving.

I was planning to use a hydraulic as main and only for emergency use a tiller, still browsing on the internet for a second hand somewhere.
So in case of main autopilot failure I wanted to switch to the secondary tiller, but, use the same H-Bridge driver for it. So I was thinking of adding a hardware switch which could make this possible.
Reply
#8
(2020-08-23, 07:51 PM)jamos.tan@gmail.com Wrote: Thanks, I don't have a hydraulic motor yet, but my current H-bridge can go to 43A, but I've configured Pypilot to max 20A.

I didn't yet know btw that the amps setting you describe would have such an effect, this probably means that I need to set my small Autohelm st4000 tiller to a much lower setting. My presumption was, just set it as high as it "can" go for testing, not yet having properly set it to the best value for power saving.

I was planning to use a hydraulic as main and only for emergency use a tiller, still browsing on the internet for a second hand somewhere.
So in case of main autopilot failure I wanted to switch to the secondary tiller, but, use the same H-Bridge driver for it. So I was thinking of adding a hardware switch which could make this possible.

I have this exact setup but in my case I have a hydraulic motor on my main and an electric cable steer on my "kicker" motor. I have a Dual pole dual throw switch which selects between the main and the kicker. They actually make one that fit right in my switch panel and it matches my other switches.
Reply
#9
(2020-08-23, 07:51 PM)jamos.tan@gmail.com Wrote: Thanks, I don't have a hydraulic motor yet, but my current H-bridge can go to 43A, but I've configured Pypilot to max 20A.

I didn't yet know btw that the amps setting you describe would have such an effect, this probably means that I need to set my small Autohelm st4000 tiller to a much lower setting. My presumption was, just set it as high as it "can" go for testing, not yet having properly set it to the best value for power saving.

I was planning to use a hydraulic as main and only for emergency use a tiller, still browsing on the internet for a second hand somewhere.
So in case of main autopilot failure I wanted to switch to the secondary tiller, but, use the same H-Bridge driver for it. So I was thinking of adding a hardware switch which could make this possible.

think of the max current setting as a software fuse.   So it won't help you save power or anything like that, it will trigger if the motor stalls, so it needs to be low enough to trigger without stressing the drive too much but high enough that it won't trigger unless you hit the end of travel or the drive is jammed or the wires get shorted somehow.
Reply
#10
(2020-08-23, 08:58 PM)rastam4n Wrote:
(2020-08-23, 07:51 PM)jamos.tan@gmail.com Wrote: Thanks, I don't have a hydraulic motor yet, but my current H-bridge can go to 43A, but I've configured Pypilot to max 20A.

I didn't yet know btw that the amps setting you describe would have such an effect, this probably means that I need to set my small Autohelm st4000 tiller to a much lower setting. My presumption was, just set it as high as it "can" go for testing, not yet having properly set it to the best value for power saving.

I was planning to use a hydraulic as main and only for emergency use a tiller, still browsing on the internet for a second hand somewhere.
So in case of main autopilot failure I wanted to switch to the secondary tiller, but, use the same H-Bridge driver for it. So I was thinking of adding a hardware switch which could make this possible.

I have this exact setup but in my case I have a hydraulic motor on my main and an electric cable steer on my "kicker" motor. I have a Dual pole dual throw switch which selects between the main and the kicker. They actually make one that fit right in my switch panel and it matches my other switches.

Nice! So you have a switch on the digital pins that Sean describes? And then also a switch on both poles of the h-bridge, so one direction goes to your hydraulic and one to your kicker? Would love to see your setup!

(2020-08-24, 02:43 AM)seandepagnier Wrote:
(2020-08-23, 07:51 PM)jamos.tan@gmail.com Wrote: Thanks, I don't have a hydraulic motor yet, but my current H-bridge can go to 43A, but I've configured Pypilot to max 20A.

I didn't yet know btw that the amps setting you describe would have such an effect, this probably means that I need to set my small Autohelm st4000 tiller to a much lower setting. My presumption was, just set it as high as it "can" go for testing, not yet having properly set it to the best value for power saving.

I was planning to use a hydraulic as main and only for emergency use a tiller, still browsing on the internet for a second hand somewhere.
So in case of main autopilot failure I wanted to switch to the secondary tiller, but, use the same H-Bridge driver for it. So I was thinking of adding a hardware switch which could make this possible.

think of the max current setting as a software fuse.   So it won't help you save power or anything like that, it will trigger if the motor stalls, so it needs to be low enough to trigger without stressing the drive too much but high enough that it won't trigger unless you hit the end of travel or the drive is jammed or the wires get shorted somehow.

Wow thanks! That really clarifies it! Smile
Reply


Forum Jump:


Users browsing this thread: 1 Guest(s)