PID inside a closed loop system

[dzuliani]

Dear all
I'm a new RP user and I'd like to use the PID features to control the motion of a shake table. We use that table to calibrate the seismometers of our network. Up to now the calibration have been made without any control on the shake table. What I'm going to do is to improve the system using the RP PID for a SISO closed loop control. The output velocity of the shake table should follow the signal input (which is not a simple constant but variable with time) that drives the shake table electrical motor. For that reason I need to sum the input signal and the output velocity signal and then inject the outcoming signal to the RP PID controllers. The output of the PID will then drive the shake table electrical motor. Looking at the scheme available at the GitHub repository: https://github.com/RedPitaya/RedPitaya/ ... /src/pid.c
I just need one of the 4 available PIDs so I could adjust the MIMO PID parameters to enable just one of them. What I can't understand is how to correctly implement the sum block which drives the PID and use as inputs the shake tabkle velocity and the input signal. Probably someone else has alread solved this issue and there is a simple way to use the scheme available in pid.c.
Bye David

[newkew]

Hello all,
I have a similar project and I would like to make a PID loop with the sum of two RF channels.
I began to open and explore the fpga files projects on vivado

whats the statut of your project ?

thanks
Kew