Search found 8 matches

by gusep
Fri Jun 29, 2018 4:06 am
Forum: Velocity and Position Control
Topic: Motor to drive flow meter
Replies: 14
Views: 4624

Re: Motor to drive flow meter

Today tested running assembly. If I keep the acceleration very low, then the RPM stabilizes to a given flow. Problem that any changes in flow is very slow. Fast acceleration and the RPM fluctuates over and under like classic too much gain. So on analysis I need some proportionality in the photo tran...
by gusep
Fri Jun 22, 2018 5:38 am
Forum: Velocity and Position Control
Topic: Motor to drive flow meter
Replies: 14
Views: 4624

Re: Motor to drive flow meter

Finally assembled complete pump, motor and electronics. Would not work correctly. After pulling my hair out I read many posts in this forum. On the bench I was using a fixed pot as my demand speed.So every time I powered up, the pot was always very close to 1.0V. All working as expected. But in the ...
by gusep
Sat Mar 24, 2018 5:03 am
Forum: Velocity and Position Control
Topic: Motor to drive flow meter
Replies: 14
Views: 4624

Re: Motor to drive flow meter

Tonight I worked on PID. Using simple serial 18 RPM with almost no stopping. Reasonably stiff to speed/load. Just not good enough. Will place a planetary gear speed reduction of 2 > 3 :1 OR a smaller gear pump I am trying to achieve a 1000 turn down ratio of flow. Included in my Integral circuit is ...
by gusep
Fri Mar 23, 2018 4:59 am
Forum: Velocity and Position Control
Topic: Motor to drive flow meter
Replies: 14
Views: 4624

Re: Motor to drive flow meter

Actually came across this video on very slow control of DC motor
https://www.youtube.com/watch?v=H36oAtkAb7w
Requires some different code on RoboClaw
by gusep
Fri Mar 23, 2018 4:54 am
Forum: Velocity and Position Control
Topic: Motor to drive flow meter
Replies: 14
Views: 4624

Re: Motor to drive flow meter

Scoped the encoder signals 0 to 4 Volts. No noise Used the simple serial and tried minimum speed. 50RPM. Not smooth Changed different PWM control. No difference Changed all PID settings. No improvements Motor voltage 15.8Volts. I have a full size NC mill and it can go ever so slow if required. Yes d...
by gusep
Wed Mar 21, 2018 4:25 am
Forum: Velocity and Position Control
Topic: Motor to drive flow meter
Replies: 14
Views: 4624

Re: Motor to drive flow meter

Completed integrator circuit but not connected yet. I am having trouble making the motor run smoothly at below 60RPM 1000 line encoder. Just used the A+ and B+ Cannot use the A- and B- S1 connected to 50k pot and 75k series resistor P = 50 I = 1 D = 0 Tried smaller but no better. Maybe the S1 voltag...
by gusep
Tue Mar 20, 2018 3:34 am
Forum: Velocity and Position Control
Topic: Motor to drive flow meter
Replies: 14
Views: 4624

Re: Motor to drive flow meter

I have done a little more thinking The photo diode voltage is buffered, attenuated, level shifted and sent to an integrator. Limited from 1V to 2 V OR 0V to 1V Need to make sure Motor never goes reverse So if the pressure difference is +ve over set level, the integrator voltage rises at a rate deter...
by gusep
Sun Mar 18, 2018 5:05 am
Forum: Velocity and Position Control
Topic: Motor to drive flow meter
Replies: 14
Views: 4624

Motor to drive flow meter

I have a hydraulic small gear oil pump driven by a DC motor with encoder utilizing Roboclaw 2 x 15A Basically if you drive a gear pump with no differential pressure across the pump it becomes a very accurate long lasting flow meter. Encoder pulse freq output being fuel flow rate. High turn down rati...