PID with 2 outputs

[Flavien]

Hello everyone ,

I was wondering if you already face the following situation:

A pressure regulation by two solenoid valve (one for adding pressure, one other for let it out),

I didn't used a classic PID because I didn't figure out how to program it,

I was wondering if you already face this situation and if you had an example of PID with two outputs?

Thanks,

[Emil]

Do you need to apply energy to keep the pressure on level? If so, maybe you don't need ot "touch" the exhost valve and operate PID only pressure filling one. My advice is to set relativelly high values for Pb and Ti. Maybe even Pb needs to be above 100%. Usually pressure control is very fast. When you set "slow" PID, you can control the system.

One good idea is to use HSO. With relativelly high frequency - let's say 100 Hz or more, you can use PWM. This way you will hold the valve proprotionally open and will obtain very precise control. If you want to implement this idea, please don't forget to connect reverse diodes to the valves. Without them it wil lnot work.