Add Reset Function to Simscape Integrator Block

I am trying to add a reset input to a custom integrator block using simscape. If the reset input is 1, the integrator will function normally and if the reset input is 0 it will reset to the initial condition. To achieve this I was attempting to set variable x to the initial condition (x0) when "reset == 0" but do not know how to populate the else condition to keep x the same if "reset == 1" ("if" must be accompanied by "else" in simscape language according to documentation). I tried setting x == x but this did not work. The code I have is written below. Any help would be greatly appreciated.

inputs
  I = { 0, '1' }; % A:left
  r = { 0, '1' }; % r:left
end

outputs
  O = { 0, '1' }; % B:right
end

parameters
  x0 = { 0, '1' }; % Initial condition
end

variables(Access = public)
  x = { 0, '1' };
end

function setup
  x = x0;
end

equations
  if r <= 0
    x == x0;                       % Reset x
  else
    %Do nothing
  end 

    x.der == I * { 1, '1/s' };       

    O == x;                           % Set output
  end

[Mathew Thorne]

Hey,

Did you ever find a solution for this problem?

Using 2014b. Only solution I could think of was having an if statement, and setting the else to integrating a large positive or negative constant till i get close to zero.

But this defiantly not a good solution.

Mat

Answer 1

[Nicolas Schmit]

I am not a Simscape developer, but from what I know Simscape will not let you manually reset integrators. A work around is to use a Simulink integrator and Simulink-PS Converter blocks.

Answer 2

[David John]

In 2018 it was true that Simscape did not let you reset integrators. In a more recent release, however, you can do it using the attached code at least since R2021a.

Answer 3

[Martin]

The PS Integrator was updated in R2021a to provide this functionality. The source code is available for that block as well.

PS Integrator