namespace JSBSim {
-static const char *IdSrc = "$Id: FGPID.cpp,v 1.16 2009/10/24 22:59:30 jberndt Exp $";
+static const char *IdSrc = "$Id: FGPID.cpp,v 1.20 2012/05/10 12:10:48 jberndt Exp $";
static const char *IdHdr = ID_PID;
/*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
I_out_total = 0.0;
Input_prev = Input_prev2 = 0.0;
Trigger = 0;
+ ProcessVariableDot = 0;
+ IsStandard = false;
+ IntType = eNone; // No integrator initially defined.
+
+ string pid_type = element->GetAttributeValue("type");
+
+ if (pid_type == "standard") IsStandard = true;
if ( element->FindElement("kp") ) {
kp_string = element->FindElementValue("kp");
if ( element->FindElement("ki") ) {
ki_string = element->FindElementValue("ki");
+
+ string integ_type = element->FindElement("ki")->GetAttributeValue("type");
+ if (integ_type == "rect") { // Use rectangular integration
+ IntType = eRectEuler;
+ } else if (integ_type == "trap") { // Use trapezoidal integration
+ IntType = eTrapezoidal;
+ } else if (integ_type == "ab2") { // Use Adams Bashforth 2nd order integration
+ IntType = eAdamsBashforth2;
+ } else if (integ_type == "ab3") { // Use Adams Bashforth 3rd order integration
+ IntType = eAdamsBashforth3;
+ } else { // Use default Adams Bashforth 2nd order integration
+ IntType = eAdamsBashforth2;
+ }
+
if (!is_number(ki_string)) { // property
if (ki_string[0] == '-') {
KiPropertySign = -1.0;
}
}
+ if (element->FindElement("pvdot")) {
+ ProcessVariableDot = PropertyManager->GetNode(element->FindElementValue("pvdot"));
+ }
+
if (element->FindElement("trigger")) {
Trigger = PropertyManager->GetNode(element->FindElementValue("trigger"));
}
bool FGPID::Run(void )
{
double I_out_delta = 0.0;
- double P_out, D_out;
+ double Dval = 0;
Input = InputNodes[0]->getDoubleValue() * InputSigns[0];
if (KiPropertyNode != 0) Ki = KiPropertyNode->getDoubleValue() * KiPropertySign;
if (KdPropertyNode != 0) Kd = KdPropertyNode->getDoubleValue() * KdPropertySign;
- P_out = Kp * Input;
- D_out = (Kd / dt) * (Input - Input_prev);
+ if (ProcessVariableDot) {
+ Dval = ProcessVariableDot->getDoubleValue();
+ } else {
+ Dval = (Input - Input_prev)/dt;
+ }
// Do not continue to integrate the input to the integrator if a wind-up
// condition is sensed - that is, if the property pointed to by the trigger
// element is non-zero. Reset the integrator to 0.0 if the Trigger value
// is negative.
- if (Trigger != 0) {
- double test = Trigger->getDoubleValue();
- if (fabs(test) < 0.000001) I_out_delta = Ki * dt * Input; // Normal
- if (test < 0.0) I_out_total = 0.0; // Reset integrator to 0.0
- } else { // no anti-wind-up trigger defined
- I_out_delta = Ki * dt * Input;
+ double test = 0.0;
+ if (Trigger != 0) test = Trigger->getDoubleValue();
+
+ if (fabs(test) < 0.000001) {
+ switch(IntType) {
+ case eRectEuler:
+ I_out_delta = Ki * dt * Input; // Normal rectangular integrator
+ break;
+ case eTrapezoidal:
+ I_out_delta = (Ki/2.0) * dt * (Input + Input_prev); // Trapezoidal integrator
+ break;
+ case eAdamsBashforth2:
+ I_out_delta = Ki * dt * (1.5*Input - 0.5*Input_prev); // 2nd order Adams Bashforth integrator
+ break;
+ case eAdamsBashforth3: // 3rd order Adams Bashforth integrator
+ I_out_delta = (Ki/12.0) * dt * (23.0*Input - 16.0*Input_prev + 5.0*Input_prev2);
+ break;
+ case eNone:
+ // No integator is defined or used.
+ I_out_delta = 0.0;
+ break;
+ }
}
+
+ if (test < 0.0) I_out_total = 0.0; // Reset integrator to 0.0
I_out_total += I_out_delta;
- Output = P_out + I_out_total + D_out;
-
+ if (IsStandard) {
+ Output = Kp * (Input + I_out_total + Kd*Dval);
+ } else {
+ Output = Kp*Input + I_out_total + Kd*Dval;
+ }
+
Input_prev = Input;
Input_prev2 = Input_prev;
if (debug_lvl & 1) { // Standard console startup message output
if (from == 0) { // Constructor
if (InputSigns[0] < 0)
- cout << " INPUT: -" << InputNodes[0]->getName() << endl;
+ cout << " INPUT: -" << InputNodes[0]->GetName() << endl;
else
- cout << " INPUT: " << InputNodes[0]->getName() << endl;
+ cout << " INPUT: " << InputNodes[0]->GetName() << endl;
if (IsOutput) {
for (unsigned int i=0; i<OutputNodes.size(); i++)