Fix TrueFalseHold with unit impulse input signal (#3967)

* Fix issue with Dirac delta, update validation model * Update results * Split vector expression into 2 separate elsewhen clauses This is for #3967 (comment) * Update results
lbl-srg · Aug 27, 2024 · 8584e80 · 8584e80
1 parent 424a30c
commit 8584e80
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Showing 18 changed files with 144 additions and 104 deletions.
diff --git a/Buildings/Controls/OBC/CDL/Logical/TrueFalseHold.mo b/Buildings/Controls/OBC/CDL/Logical/TrueFalseHold.mo
@@ -25,6 +25,10 @@ protected
   parameter Boolean pre_u_start=false
     "Value of pre(u) at initial time"
     annotation (Evaluate=true);
+  Boolean not_u = not u
+    "Opposite of u";
+  Boolean not_y = not y
+    "Opposite of y";
   discrete Real entryTimeTrue(
     final quantity="Time",
     final unit="s")
@@ -37,20 +41,29 @@ initial equation
   pre(entryTimeTrue) = -Modelica.Constants.inf;
   pre(entryTimeFalse) = -Modelica.Constants.inf;
   pre(u) = pre_u_start;
+  pre(not_u) = not pre_u_start;
   pre(y) = u;
+  pre(not_y) = not u;
 equation
   when initial() then
     y = u;
     entryTimeTrue = if y then time else pre(entryTimeTrue);
     entryTimeFalse = if not y then time else pre(entryTimeFalse);
-  elsewhen {change(u),
-            time >= pre(entryTimeFalse) + falseHoldDuration and
-            time >= pre(entryTimeTrue) + trueHoldDuration} then
-    y=if time >= pre(entryTimeFalse) + falseHoldDuration and
-         time >= pre(entryTimeTrue) + trueHoldDuration then u
+  /*
+  The two elsewhen clauses below are kept separate to address an issue
+  with event handling in the CVODE solver.
+  */
+  elsewhen {edge(u), edge(not_u)} then
+    y = if time >= pre(entryTimeFalse) + falseHoldDuration and
+      time >= pre(entryTimeTrue) + trueHoldDuration then u
       else pre(y);
-    entryTimeTrue = if change(y) and y then time else pre(entryTimeTrue);
-    entryTimeFalse = if change(y) and not y then time else pre(entryTimeFalse);
+    entryTimeTrue = if edge(y) then time else pre(entryTimeTrue);
+    entryTimeFalse = if edge(not_y) then time else pre(entryTimeFalse);
+  elsewhen time >= pre(entryTimeFalse) + falseHoldDuration and
+    time >= pre(entryTimeTrue) + trueHoldDuration then
+    y = u;
+    entryTimeTrue = if edge(y) then time else pre(entryTimeTrue);
+    entryTimeFalse = if edge(not_y) then time else pre(entryTimeFalse);
   end when;
   annotation (
     defaultComponentName="truFalHol",
@@ -132,6 +145,12 @@ alt=\"Input and output of the block\"/>
       revisions="<html>
 <ul>
 <li>
+August 26, 2024, by Antoine Gautier:<br/>
+Resolved an issue with unit impulse signals.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/3966\">issue 3966</a>.
+</li>
+<li>
 June 13, 2024, by Antoine Gautier:<br/>
 Refactored with synchronous language elements.<br/>
 This is for

diff --git a/Buildings/Controls/OBC/CDL/Logical/Validation/TrueFalseHold.mo b/Buildings/Controls/OBC/CDL/Logical/Validation/TrueFalseHold.mo
@@ -83,13 +83,18 @@ model TrueFalseHold
     trueHoldDuration=1000)
     "The block introduces a minimal offset between the input signal rising and falling edge"
     annotation (Placement(transformation(extent={{120,-60},{140,-40}})));
-  Buildings.Controls.OBC.CDL.Logical.Not not2
-    "Negation of input signal"
+  Buildings.Controls.OBC.CDL.Logical.Not not2 "Negation of input signal"
     annotation (Placement(transformation(extent={{70,-20},{90,0}})));
   Buildings.Controls.OBC.CDL.Logical.Not not4
     "Negation of input signal"
     annotation (Placement(transformation(extent={{70,-60},{90,-40}})));
 
+  Buildings.Controls.OBC.CDL.Logical.TrueFalseHold truFalHol8(trueHoldDuration=
+        0, falseHoldDuration=1000)
+    "Hold only false value of unit impulse signal"
+    annotation (Placement(transformation(extent={{120,-90},{140,-70}})));
+  Buildings.Controls.OBC.CDL.Logical.Edge edg "Generate unit impulse signal"
+    annotation (Placement(transformation(extent={{70,-90},{90,-70}})));
 equation
   connect(booPul.y,truFalHol.u)
     annotation (Line(points={{-118,70},{-118,70},{-42,70}},color={255,0,255}));
@@ -115,6 +120,10 @@ equation
     annotation (Line(points={{42,-50},{68,-50}},color={255,0,255}));
   connect(not4.y,truFalHol7.u)
     annotation (Line(points={{92,-50},{118,-50}},color={255,0,255}));
+  connect(edg.y, truFalHol8.u)
+    annotation (Line(points={{92,-80},{118,-80}}, color={255,0,255}));
+  connect(booPul6.y, edg.u) annotation (Line(points={{42,-10},{60,-10},{60,-80},
+          {68,-80}}, color={255,0,255}));
   annotation (
     experiment(
       StopTime=7200.0,
@@ -136,6 +145,12 @@ of the input pulse, and different initial values for the input signal.
       revisions="<html>
 <ul>
 <li>
+August 26, 2024, by Antoine Gautier:<br/>
+Added a case with a unit impulse signal.<br/>
+This is for
+<a href=\"https://github.com/lbl-srg/modelica-buildings/issues/3966\">issue 3966</a>.
+</li>
+<li>
 June 14, 2017, by Michael Wetter:<br/>
 Added more tests for different initial signals and different hold values.
 </li>

diff --git a/.../Dymola/Buildings_Air_Systems_SingleZone_VAV_Examples_OptimalStart_ConventionalSpring.txt b/.../Dymola/Buildings_Air_Systems_SingleZone_VAV_Examples_OptimalStart_ConventionalSpring.txt
diff --git a/.../Dymola/Buildings_Air_Systems_SingleZone_VAV_Examples_OptimalStart_ConventionalSummer.txt b/.../Dymola/Buildings_Air_Systems_SingleZone_VAV_Examples_OptimalStart_ConventionalSummer.txt
diff --git a/.../Dymola/Buildings_Air_Systems_SingleZone_VAV_Examples_OptimalStart_ConventionalWinter.txt b/.../Dymola/Buildings_Air_Systems_SingleZone_VAV_Examples_OptimalStart_ConventionalWinter.txt
@@ -1,8 +1,8 @@
-last-generated=2023-06-16
+last-generated=2024-08-27
 statistics-initialization=
 {
   "linear": "0, 0, 0, 0, 0, 0, 0, 0",
-  "nonlinear": "42, 42, 0, 0, 0, 0, 1, 0, 0, 0, 0, 1",
+  "nonlinear": "0, 0, 0, 0, 1, 0, 0, 0, 0, 1, 42, 42",
   "numerical Jacobians": "0"
 }
 statistics-simulation=