From 02eb2ac2e161a4831c33fa41db9b78679ca1adf7 Mon Sep 17 00:00:00 2001
From: Erik Hofman <erik@ehofman.com>
Date: Sat, 18 Jun 2011 17:50:47 +0200
Subject: [PATCH] Improved the calcs during trimming after a suggestion from
 Dennis

---
 .../models/flight_control/FGActuator.cpp      | 33 ++++++++-----------
 1 file changed, 14 insertions(+), 19 deletions(-)

diff --git a/src/FDM/JSBSim/models/flight_control/FGActuator.cpp b/src/FDM/JSBSim/models/flight_control/FGActuator.cpp
index e7ab6aa65..52faac0fb 100644
--- a/src/FDM/JSBSim/models/flight_control/FGActuator.cpp
+++ b/src/FDM/JSBSim/models/flight_control/FGActuator.cpp
@@ -43,7 +43,7 @@ using namespace std;
 
 namespace JSBSim {
 
-static const char *IdSrc = "$Id: FGActuator.cpp,v 1.18 2011/05/13 17:14:47 bcoconni Exp $";
+static const char *IdSrc = "$Id: FGActuator.cpp,v 1.19 2011/06/18 13:30:27 bcoconni Exp $";
 static const char *IdHdr = ID_ACTUATOR;
 
 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
@@ -114,24 +114,15 @@ bool FGActuator::Run(void )
                   // the Input will be further processed and the eventual Output
                   // will be overwritten from this perfect value.
 
-  if (!fcs->GetTrimStatus()) {
-    if (lag != 0.0)              Lag();        // models actuator lag
-    if (rate_limit != 0)         RateLimit();  // limit the actuator rate
-  }
+  if (lag != 0.0)              Lag();        // models actuator lag
+  if (rate_limit != 0)         RateLimit();  // limit the actuator rate
   if (deadband_width != 0.0)   Deadband();
-  if (!fcs->GetTrimStatus() && hysteresis_width != 0.0) Hysteresis();
+  if (hysteresis_width != 0.0) Hysteresis();
   if (bias != 0.0)             Bias();       // models a finite bias
 
   if (fail_stuck) Output = PreviousOutput;
   PreviousOutput = Output; // previous value needed for "stuck" malfunction
 
-  if (fcs->GetTrimStatus()) {
-    PreviousHystOutput = Output;
-    PreviousRateLimOutput = Output;
-    PreviousLagInput = Output;
-    PreviousLagOutput = Output;
-  }
-
   Clip();
   if (IsOutput) SetOutput();
 
@@ -152,7 +143,10 @@ void FGActuator::Lag(void)
   // "Output" on the right side of the "=" is the current frame input
   // for this Lag filter
   double input = Output;
-  Output = ca * (input + PreviousLagInput) + PreviousLagOutput * cb;
+
+  if (!fcs->GetTrimStatus())
+    Output = ca * (input + PreviousLagInput) + PreviousLagOutput * cb;
+
   PreviousLagInput = input;
   PreviousLagOutput = Output;
 }
@@ -166,10 +160,11 @@ void FGActuator::Hysteresis(void)
   // method.
   double input = Output;
   
-  if (input > PreviousHystOutput) {
-    Output = max(PreviousHystOutput, input-0.5*hysteresis_width);
-  } else if (input < PreviousHystOutput) {
-    Output = min(PreviousHystOutput, input+0.5*hysteresis_width);
+  if (!fcs->GetTrimStatus()) {
+    if (input > PreviousHystOutput)
+      Output = max(PreviousHystOutput, input-0.5*hysteresis_width);
+    else if (input < PreviousHystOutput)
+      Output = min(PreviousHystOutput, input+0.5*hysteresis_width);
   }
 
   PreviousHystOutput = Output;
@@ -183,7 +178,7 @@ void FGActuator::RateLimit(void)
   // is - for the purposes of this RateLimit method - really the input to the
   // method.
   double input = Output;
-  if (dt > 0.0) {
+  if (!fcs->GetTrimStatus()) {
     double rate = (input - PreviousRateLimOutput)/dt;
     if (fabs(rate) > rate_limit) {
       Output = PreviousRateLimOutput + (rate_limit*fabs(rate)/rate)*dt;