My line is Oil Hydraulic design.
Frequently I require a method to precisely set pressure from remote using a amplifier that is driving a proportional relief valve. All or most general amplifiers are open loop. Meaning they take in a 0-10V command and convert that to a 0-600mA current output to drive a proportional relief valve. But in this case we can only get about 5% repeatability on set value.
So recently I bought a Redlion process PID controller to generate the command in closed loop. The loop is closed by signal feedback from a Pressure Sensor.
Problem : Unable to get this working either with Manual Tuning or Auto Tune ( in AutoTune the controller does nothing ) . With lot of struggle got it going but the control was not smooth not precise. Most part it was hunting.
One reason I can think of is the response time of the proportional valve - it is less than 50mS from zero to full pressure. Whereas the Redlion controller ( Model : PXU41DE0) output cycle time can only be set for a minimum of 100mS.
So is there any general purpose PID controller that has an output update of around 5mS ( 1/10 of my process response ) [ or ] is it a matter of setting with the Redlion ??
Frequently I require a method to precisely set pressure from remote using a amplifier that is driving a proportional relief valve. All or most general amplifiers are open loop. Meaning they take in a 0-10V command and convert that to a 0-600mA current output to drive a proportional relief valve. But in this case we can only get about 5% repeatability on set value.
So recently I bought a Redlion process PID controller to generate the command in closed loop. The loop is closed by signal feedback from a Pressure Sensor.
Problem : Unable to get this working either with Manual Tuning or Auto Tune ( in AutoTune the controller does nothing ) . With lot of struggle got it going but the control was not smooth not precise. Most part it was hunting.
One reason I can think of is the response time of the proportional valve - it is less than 50mS from zero to full pressure. Whereas the Redlion controller ( Model : PXU41DE0) output cycle time can only be set for a minimum of 100mS.
So is there any general purpose PID controller that has an output update of around 5mS ( 1/10 of my process response ) [ or ] is it a matter of setting with the Redlion ??