Mismatch result in comparison operation in Simulink

Hi,

I am doing comparision operation of two signals as shown fig 1. In one case, sine and triangular signals are compared whose result is shown in fig 2 and in other case sine, triangular signals are phase shifted by 180 deg, performed same operation as shown in fig3. Ideally, both results should be complement to each other , but observing spikes (shown in fig 3). What can be the reason for this ?. How to achieve ideal complementary responses ?.

Fig 1: Simulink circuit of comparision of two signals

Fig 2: Sine, Triangular comparision and its result

Fig 3: Sine, Triangular comparision with 180 deg phase shift and its result.

Simulation solver settings

Answer 1

[Ganesh]

Hi @Tharun,

I understand that you expect a flat line, complimenting Fig. 1.

However, the response generated seems to be consistent with the expected results. At T=0.005, the value of Sine Wave is equal to that of the Triangular Wave, and as you have allowed the parameter to be "less than or equal to", there is a spike.

You can try changing the block to be strictly lower than if you require a graph that compliments.

To help you understand, you could try to change the relational block to "greater than or equal to" with 0 phase and you will notice a spike in that figure too.

Hope this helps!

Answer 2

[Sulaymon Eshkabilov]

The problem is caused by sine wave generator.

Try to tighten the sample time, e.g. 1e-9.