Implementation of PDF controller
Last week, I have deduced the expression of h(x(t)), which could be used for the calculation of both Kp and Ki. So the task of this week is to implement it into Simulink and combine with previous heating system model, in order to complete the control system. The completed block can be referred as below:
The schedule is based on the equations that obtained last week. The output h(x(t)) will then connect to the PDF controller block, aimed to produce the value of both Kp and Ki for each time step (60 seconds).
However, the simulation results becomes worse when compared with the model without control system. The results is too strange to be explained. One possible reason is the value of controlled parameters change too fast, then the system can`t be stable. Another possible reason is that the integral will not stop when the heat pump limitation is met. So I tried to add an additional judgment block, which will set the integral controlled parameter to zero. The schedule is shown below even though the results indicated its useless.
