How can I avoid errors due to division by zero in Simulink?

I am using a simple model in Simulink in which I use a division on two input values using a 'Divide' block.

During my simulation, there might be a zero value fed to the denominator of the 'Divide' block. This often causes a warning, an error message, or erroneous results.

How can I avoid these problems?

Answer 1

[MathWorks Support Team]

Numerical division by zero is a common issue in programming, and its exact solution often depends on the particular application. In almost all cases, the best approach is to change the model to never feed zero to a division block.

An example of a workaround is shown below. For clarity purposes, let us call the original signal in the denominator as 'u'.

1. Use a 'switch' block to pass 'eps' instead of 'u' to the 'divide' denominator. The 'switch' must only be activated when the signal 'u' is zero.
2. Use a 'MATLAB Function' block to implement a zero-avoiding condition, such as:

       

u + (u==0)*eps

        or, if the signal 'u' is real:

u + eps*(0^u)

[Walter Roberson]

At one time, MATLAB Fcn Block was called "Embedded MATLAB Block"

Answer 2

[madhan ravi]

Or making the result to be zero when the divisor is zero using a Switch block