From 77d1a2cfa76120edaf514d63a34d7d805d4fe4d4 Mon Sep 17 00:00:00 2001
From: Josh Davidson <joshuadavidson2000@gmail.com>
Date: Tue, 18 May 2021 13:15:09 -0400
Subject: [PATCH] Control: IAE EPR control law

---
 Models/Instruments/Upper-ECAM/Upper-ECAM.nas |   6 +-
 Systems/a320-v2527-a5-engine-fadec.xml       | 370 +++++++++++++++++--
 Systems/libraries.xml                        |   2 +-
 3 files changed, 353 insertions(+), 25 deletions(-)

diff --git a/Models/Instruments/Upper-ECAM/Upper-ECAM.nas b/Models/Instruments/Upper-ECAM/Upper-ECAM.nas
index 79ffd0df..bebd84c4 100644
--- a/Models/Instruments/Upper-ECAM/Upper-ECAM.nas
+++ b/Models/Instruments/Upper-ECAM/Upper-ECAM.nas
@@ -206,11 +206,11 @@ var canvas_upperECAM = {
 			}),
 			props.UpdateManager.FromHashValue("EPR_actual_1", 0.0001, func(val) {
 				obj["EPR1"].setText(sprintf("%1.0f", math.floor(val)));
-				obj["EPR1-decimal"].setText(sprintf("%03d", (val - int(val)) * 1000));
+				obj["EPR1-decimal"].setText(sprintf("%03d", math.round((val - int(val)) * 1000)));
 			}),
 			props.UpdateManager.FromHashValue("EPR_actual_2", 0.0001, func(val) {
 				obj["EPR2"].setText(sprintf("%1.0f", math.floor(val)));
-				obj["EPR2-decimal"].setText(sprintf("%03d", (val - int(val)) * 1000));
+				obj["EPR2-decimal"].setText(sprintf("%03d", math.round((val - int(val)) * 1000)));
 			}),
 			props.UpdateManager.FromHashValue("EPR_lim", 0.005, func(val) {
 				obj["EPR1-ylim"].setRotation((val + 90) * D2R);
@@ -279,7 +279,7 @@ var canvas_upperECAM = {
 			}),
 			props.UpdateManager.FromHashValue("eprLimit", 0.0005, func(val) {
 				obj["EPRLim"].setText(sprintf("%1.0f", math.floor(val)));
-				obj["EPRLim-decimal"].setText(sprintf("%03d", (val - int(val)) * 1000));
+				obj["EPRLim-decimal"].setText(sprintf("%03d", math.round((val - int(val)) * 1000)));
 			}),
 			props.UpdateManager.FromHashValue("n1Limit", 0.01, func(val) {
 				obj["N1Lim"].setText(sprintf("%s", math.floor(val + 0.05)));
diff --git a/Systems/a320-v2527-a5-engine-fadec.xml b/Systems/a320-v2527-a5-engine-fadec.xml
index ee918171..5da951a0 100644
--- a/Systems/a320-v2527-a5-engine-fadec.xml
+++ b/Systems/a320-v2527-a5-engine-fadec.xml
@@ -166,6 +166,14 @@
 			</function>
 		</fcs_function>
 		
+		<!-- 
+		Thrust limits on the IAE are kinda hard to do because of EPR - and we don't have a linear way to control throttle
+		The CFM's just use N1, which is linear so it works well to make the FADEC, but as stated primary param is EPR
+		So we have our thrust limits basic in N1 because its easier to calculate, then we calculate corrected EPR
+		After we round the EPR, in order to correctly control/limit thrust, we will convert it BACK to N1... annoying right?
+		Well the advantage is the plane is actually targetting EPR, so its more realistic to do this way even if its more steps
+		I think that's better than just pretending to use EPR, and actually using N1 - if you look close enough, you can tell!
+		-->
 		<fcs_function name="fadec/limit/toga-ref">
 			<function>
 				<product>
@@ -184,23 +192,6 @@
 			</function>
 		</fcs_function>
 		
-		<fcs_function name="fadec/limit/toga">
-			<function>
-				<quotient>
-					<integer>
-						<sum>
-							<product>
-								<property>fadec/limit/toga-ref</property>
-								<value>10</value>
-							</product>
-							<value>0.5</value> <!-- Make it round correctly -->
-						</sum>
-					</integer>
-					<value>10</value>
-				</quotient>
-			</function>
-		</fcs_function>
-		
 		<fcs_function name="fadec/limit/toga-epr-input">
 			<function>
 				<pow>
@@ -246,6 +237,65 @@
 			</function>
 		</fcs_function>
 		
+		<fcs_function name="fadec/limit/toga-epr-n1-ref"> <!-- Opposite of EPR Calc -->
+			<function>
+				<quotient>
+					<difference>
+						<property>fadec/limit/toga-epr</property>
+						<property>fadec/epr/c2</property>
+					</difference>
+					<max> <!-- Prevent divide by 0 -->
+						<property>fadec/epr/c1</property>
+						<value>0.001</value>
+					</max>
+				</quotient>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/toga-epr-n1"> <!-- Opposite of EPR Calc -->
+			<function>
+				<pow>
+					<table>
+						<independentVar lookup="row">fadec/limit/toga-epr-n1-ref</independentVar>
+						<tableData>
+							0.00     24743.1
+							0.03     53194.6
+							1.00  10000000.0
+						</tableData>
+					</table>
+					<quotient>
+						<value>1</value>
+						<value>3.5</value>
+					</quotient>
+				</pow>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/toga-n1">
+			<function>
+				<quotient>
+					<integer>
+						<sum>
+							<product>
+								<property>fadec/limit/toga-ref</property>
+								<value>10</value>
+							</product>
+							<value>0.5</value> <!-- Make it round correctly -->
+						</sum>
+					</integer>
+					<value>10</value>
+				</quotient>
+			</function>
+		</fcs_function>
+		
+		<switch name="fadec/limit/toga">
+			<default value="fadec/limit/toga-epr-n1"/>
+			<test logic="AND" value="fadec/limit/toga-n1"> <!-- Only if both are in N1 mode! Otherwise the degraded engine uses equivalent N1 to the other engines EPR -->
+				fadec/control-1/n1-mode gt 0
+				fadec/control-2/n1-mode gt 0
+			</test>
+		</switch>
+		
 		<fcs_function name="fadec/limit/toga-norm">
 			<function>
 				<table>
@@ -310,7 +360,86 @@
 			</test>
 		</switch>
 		
-		<fcs_function name="fadec/limit/mct">
+		<fcs_function name="fadec/limit/mct-epr-input">
+			<function>
+				<pow>
+					<property>fadec/limit/mct-ref</property>
+					<value>3.5</value>
+				</pow>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/mct-epr-ref">
+			<function>
+				<sum>
+					<product>
+						<table>
+							<independentVar lookup="row">fadec/limit/mct-epr-input</independentVar>
+							<tableData>
+								   24743.1  0.00
+								   53194.6  0.03
+								10000000.0  1.00
+							</tableData>
+						</table>
+						<property>fadec/epr/c1</property>
+					</product>
+					<property>fadec/epr/c2</property>
+				</sum>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/mct-epr">
+			<function>
+				<quotient>
+					<integer>
+						<sum>
+							<product>
+								<property>fadec/limit/mct-epr-ref</property>
+								<value>1000</value>
+							</product>
+							<value>0.5</value> <!-- Make it round correctly -->
+						</sum>
+					</integer>
+					<value>1000</value>
+				</quotient>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/mct-epr-n1-ref"> <!-- Opposite of EPR Calc -->
+			<function>
+				<quotient>
+					<difference>
+						<property>fadec/limit/mct-epr</property>
+						<property>fadec/epr/c2</property>
+					</difference>
+					<max> <!-- Prevent divide by 0 -->
+						<property>fadec/epr/c1</property>
+						<value>0.001</value>
+					</max>
+				</quotient>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/mct-epr-n1"> <!-- Opposite of EPR Calc -->
+			<function>
+				<pow>
+					<table>
+						<independentVar lookup="row">fadec/limit/mct-epr-n1-ref</independentVar>
+						<tableData>
+							0.00     24743.1
+							0.03     53194.6
+							1.00  10000000.0
+						</tableData>
+					</table>
+					<quotient>
+						<value>1</value>
+						<value>3.5</value>
+					</quotient>
+				</pow>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/mct-n1">
 			<function>
 				<quotient>
 					<integer>
@@ -327,6 +456,14 @@
 			</function>
 		</fcs_function>
 		
+		<switch name="fadec/limit/mct">
+			<default value="fadec/limit/mct-epr-n1"/>
+			<test logic="AND" value="fadec/limit/mct-n1"> <!-- Only if both are in N1 mode! Otherwise the degraded engine uses equivalent N1 to the other engines EPR -->
+				fadec/control-1/n1-mode gt 0
+				fadec/control-2/n1-mode gt 0
+			</test>
+		</switch>
+		
 		<fcs_function name="fadec/limit/mct-norm">
 			<function>
 				<table>
@@ -357,7 +494,86 @@
 			</function>
 		</fcs_function>
 		
-		<fcs_function name="fadec/limit/climb">
+		<fcs_function name="fadec/limit/climb-epr-input">
+			<function>
+				<pow>
+					<property>fadec/limit/climb-ref</property>
+					<value>3.5</value>
+				</pow>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/climb-epr-ref">
+			<function>
+				<sum>
+					<product>
+						<table>
+							<independentVar lookup="row">fadec/limit/climb-epr-input</independentVar>
+							<tableData>
+								   24743.1  0.00
+								   53194.6  0.03
+								10000000.0  1.00
+							</tableData>
+						</table>
+						<property>fadec/epr/c1</property>
+					</product>
+					<property>fadec/epr/c2</property>
+				</sum>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/climb-epr">
+			<function>
+				<quotient>
+					<integer>
+						<sum>
+							<product>
+								<property>fadec/limit/climb-epr-ref</property>
+								<value>1000</value>
+							</product>
+							<value>0.5</value> <!-- Make it round correctly -->
+						</sum>
+					</integer>
+					<value>1000</value>
+				</quotient>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/climb-epr-n1-ref"> <!-- Opposite of EPR Calc -->
+			<function>
+				<quotient>
+					<difference>
+						<property>fadec/limit/climb-epr</property>
+						<property>fadec/epr/c2</property>
+					</difference>
+					<max> <!-- Prevent divide by 0 -->
+						<property>fadec/epr/c1</property>
+						<value>0.001</value>
+					</max>
+				</quotient>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/climb-epr-n1"> <!-- Opposite of EPR Calc -->
+			<function>
+				<pow>
+					<table>
+						<independentVar lookup="row">fadec/limit/climb-epr-n1-ref</independentVar>
+						<tableData>
+							0.00     24743.1
+							0.03     53194.6
+							1.00  10000000.0
+						</tableData>
+					</table>
+					<quotient>
+						<value>1</value>
+						<value>3.5</value>
+					</quotient>
+				</pow>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/climb-n1">
 			<function>
 				<quotient>
 					<integer>
@@ -374,6 +590,14 @@
 			</function>
 		</fcs_function>
 		
+		<switch name="fadec/limit/climb">
+			<default value="fadec/limit/climb-epr-n1"/>
+			<test logic="AND" value="fadec/limit/climb-n1"> <!-- Only if both are in N1 mode! Otherwise the degraded engine uses equivalent N1 to the other engines EPR -->
+				fadec/control-1/n1-mode gt 0
+				fadec/control-2/n1-mode gt 0
+			</test>
+		</switch>
+		
 		<fcs_function name="fadec/limit/climb-norm">
 			<function>
 				<table>
@@ -462,7 +686,86 @@
 			</function>
 		</fcs_function>
 		
-		<fcs_function name="fadec/limit/mrev">
+		<fcs_function name="fadec/limit/mrev-epr-input">
+			<function>
+				<pow>
+					<property>fadec/limit/mrev-ref</property>
+					<value>3.5</value>
+				</pow>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/mrev-epr-ref">
+			<function>
+				<sum>
+					<product>
+						<table>
+							<independentVar lookup="row">fadec/limit/mrev-epr-input</independentVar>
+							<tableData>
+								   24743.1  0.00
+								   53194.6  0.03
+								10000000.0  1.00
+							</tableData>
+						</table>
+						<property>fadec/epr/c1</property>
+					</product>
+					<property>fadec/epr/c2</property>
+				</sum>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/mrev-epr">
+			<function>
+				<quotient>
+					<integer>
+						<sum>
+							<product>
+								<property>fadec/limit/mrev-epr-ref</property>
+								<value>1000</value>
+							</product>
+							<value>0.5</value> <!-- Make it round correctly -->
+						</sum>
+					</integer>
+					<value>1000</value>
+				</quotient>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/mrev-epr-n1-ref"> <!-- Opposite of EPR Calc -->
+			<function>
+				<quotient>
+					<difference>
+						<property>fadec/limit/mrev-epr</property>
+						<property>fadec/epr/c2</property>
+					</difference>
+					<max> <!-- Prevent divide by 0 -->
+						<property>fadec/epr/c1</property>
+						<value>0.001</value>
+					</max>
+				</quotient>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/mrev-epr-n1"> <!-- Opposite of EPR Calc -->
+			<function>
+				<pow>
+					<table>
+						<independentVar lookup="row">fadec/limit/mrev-epr-n1-ref</independentVar>
+						<tableData>
+							0.00     24743.1
+							0.03     53194.6
+							1.00  10000000.0
+						</tableData>
+					</table>
+					<quotient>
+						<value>1</value>
+						<value>3.5</value>
+					</quotient>
+				</pow>
+			</function>
+		</fcs_function>
+		
+		<fcs_function name="fadec/limit/mrev-n1">
 			<function>
 				<quotient>
 					<integer>
@@ -479,6 +782,14 @@
 			</function>
 		</fcs_function>
 		
+		<switch name="fadec/limit/mrev">
+			<default value="fadec/limit/mrev-epr-n1"/>
+			<test logic="AND" value="fadec/limit/mrev-n1"> <!-- Only if both are in N1 mode! Otherwise the degraded engine uses equivalent N1 to the other engines EPR -->
+				fadec/control-1/n1-mode gt 0
+				fadec/control-2/n1-mode gt 0
+			</test>
+		</switch>
+		
 		<fcs_function name="fadec/limit/mrev-norm">
 			<function>
 				<table>
@@ -1295,7 +1606,24 @@
 			</test>
 		</switch>
 		
-		<switch name="fadec/limit/active-n1">
+		<switch name="fadec/limit/active-epr">
+			<default value="0"/>
+			<test value="fadec/limit/mrev-epr">
+				fadec/limit/active-mode-int eq 4
+			</test>
+			<test value="fadec/limit/toga-epr">
+				fadec/limit/active-mode-int eq 0
+			</test>
+			<test logic="OR" value="fadec/limit/mct-epr">
+				fadec/limit/active-mode-int eq 1
+				fadec/limit/active-mode-int eq 3
+			</test>
+			<test value="fadec/limit/climb-epr">
+				fadec/limit/active-mode-int eq 2
+			</test>
+		</switch>
+		
+		<switch name="fadec/limit/active-n1"> <!-- Converted from EPR or direct N1, depending on N1 Mode -->
 			<default value="0"/>
 			<test value="fadec/limit/mrev">
 				fadec/limit/active-mode-int eq 4
diff --git a/Systems/libraries.xml b/Systems/libraries.xml
index 851be919..f9b7e92b 100644
--- a/Systems/libraries.xml
+++ b/Systems/libraries.xml
@@ -29,7 +29,7 @@
 				<difference>
 					<table>
 						<property>/position/altitude-ft</property>
-						<entry><ind>    0</ind><dep>0.9857</dep></entry>
+						<entry><ind>    0</ind><dep>0.9852</dep></entry>
 						<entry><ind>43000</ind><dep>0.8584</dep></entry>
 					</table>
 					<table>