E
I am working on replacing the spool LVDT and a Delta-P on an old servovalve-controlled hydraulic actuator (piston) and one of the things I have to replace is the differential pressure sensor that sits across the two output ports of the servovalve. I am trying to understand the impact that the new sensors will have on the system and how to adjust the controller parameters to compensate.
I notice in the electronic controller set-up that this Delta-P signal is first amplified, then passed through a High Pass filter, and then through a notch filter (very high Q with a center frequency of around 56Hz) before being summed to the LVDT output.
Can anyone please provide some insight as to the physical relevance of this Delta-P sensing (and its associated filtering) in the context of the control system theory and what is physically going on? Is the purpose of a Delta-P to measure acceleration of the piston? What is the purpose of the high pass filter (filtering "jerk")? Is the notch filter necessary to remove some natural frequency (perhaps of the piston or the hydraulic oil)?
Cheers,
Ed
I notice in the electronic controller set-up that this Delta-P signal is first amplified, then passed through a High Pass filter, and then through a notch filter (very high Q with a center frequency of around 56Hz) before being summed to the LVDT output.
Can anyone please provide some insight as to the physical relevance of this Delta-P sensing (and its associated filtering) in the context of the control system theory and what is physically going on? Is the purpose of a Delta-P to measure acceleration of the piston? What is the purpose of the high pass filter (filtering "jerk")? Is the notch filter necessary to remove some natural frequency (perhaps of the piston or the hydraulic oil)?
Cheers,
Ed
