Suppose I have a robot which can perform some work and be rewarded with a point 50-70% of the time. I want a different number of points to be collected every hour of the day. This is modelled using a function which tells me the number of points I expect to have at time
setpoint(t), which grows from 0 points in the first minute of the day to 100,000 points by the end.
My process variable is the number of points I have collected so far. The process input is the intensity of the work required to reach the desired number of points at the time.
The problem with my current error calculation (total points expected to be collected by current timestamp - points collected so far) is that the PV being twice the setpoint in the first hour results in a significantly smaller error compared to an overshoot of the same magnitude in the last hour.
How should I modify the error to minimise fluctuations caused by both SP and PV growing over time? Would
1 - PV/SV work?