Figure 16 Simulations of the control algorithm’s behaviour with a constant optimum value for the control-signal. Two different sets of u and t was used.
The scenario shown in Figure 16 could also be regarded as a system without any disturbances. Since the algorithm only responds to variations, it could be regarded as a high-pass filter, and thus the effect of a constant would simply be filtered away (except for the fact that it changed the optimum of the control-signal). Regarded from this point of view, the control algorithm could be said to work well when there were no disturbances on the system. when was varied slowly, as in the simulation shown in Figure 17 where was assumed to the sum of a constant and a low-frequency sine-signal, the control-signal followed the optimum well. This scenario could also be regarded as a disturbance around a constant optimum. From this point of view the simulation showed that the controller was sensitive to large disturbances.