1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
5 Date started: 6/17/2006
7 ------------- Copyright (C) 2006 Jon S. Berndt (jsb@hal-pc.org) -------------
9 This program is free software; you can redistribute it and/or modify it under
10 the terms of the GNU Lesser General Public License as published by the Free Software
11 Foundation; either version 2 of the License, or (at your option) any later
14 This program is distributed in the hope that it will be useful, but WITHOUT
15 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
16 FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for more
19 You should have received a copy of the GNU Lesser General Public License along with
20 this program; if not, write to the Free Software Foundation, Inc., 59 Temple
21 Place - Suite 330, Boston, MA 02111-1307, USA.
23 Further information about the GNU Lesser General Public License can also be found on
24 the world wide web at http://www.gnu.org.
27 --------------------------------------------------------------------------------
28 Initial code 6/17/2006 JSB
30 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
31 COMMENTS, REFERENCES, and NOTES
32 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
34 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
36 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
42 static const char *IdSrc = "$Id$";
43 static const char *IdHdr = ID_PID;
45 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
47 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
49 FGPID::FGPID(FGFCS* fcs, Element* element) : FGFCSComponent(fcs, element)
51 dt = fcs->GetState()->Getdt();
54 P_out = D_out = I_out = 0.0;
55 Input_prev = Input_prev2 = 0.0;
58 if (element->FindElement("kp")) Kp = element->FindElementValueAsNumber("kp");
59 if (element->FindElement("ki")) Ki = element->FindElementValueAsNumber("ki");
60 if (element->FindElement("kd")) Kd = element->FindElementValueAsNumber("kd");
61 if (element->FindElement("trigger")) {
62 Trigger = PropertyManager->GetNode(element->FindElementValue("trigger"));
65 FGFCSComponent::bind();
70 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
77 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
79 bool FGPID::Run(void )
81 Input = InputNodes[0]->getDoubleValue() * InputSigns[0];
83 P_out = Kp * (Input - Input_prev);
84 D_out = (Kd / dt) * (Input - 2*Input_prev + Input_prev2);
86 // Do not continue to integrate the input to the integrator if a wind-up
87 // condition is sensed - that is, if the property pointed to by the trigger
88 // element is non-zero.
91 double test = Trigger->getDoubleValue();
92 if (fabs(test) < 0.000001) {
93 I_out = Ki * dt * Input;
95 } else { // no anti-wind-up trigger defined
96 I_out = Ki * dt * Input;
100 Input_prev2 = Input_prev;
102 Output += P_out + I_out + D_out;
105 if (IsOutput) SetOutput();
110 //%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
111 // The bitmasked value choices are as follows:
112 // unset: In this case (the default) JSBSim would only print
113 // out the normally expected messages, essentially echoing
114 // the config files as they are read. If the environment
115 // variable is not set, debug_lvl is set to 1 internally
116 // 0: This requests JSBSim not to output any messages
118 // 1: This value explicity requests the normal JSBSim
120 // 2: This value asks for a message to be printed out when
121 // a class is instantiated
122 // 4: When this value is set, a message is displayed when a
123 // FGModel object executes its Run() method
124 // 8: When this value is set, various runtime state variables
125 // are printed out periodically
126 // 16: When set various parameters are sanity checked and
127 // a message is printed out when they go out of bounds
129 void FGPID::Debug(int from)
131 if (debug_lvl <= 0) return;
133 if (debug_lvl & 1) { // Standard console startup message output
134 if (from == 0) { // Constructor
135 if (InputSigns[0] < 0)
136 cout << " INPUT: -" << InputNodes[0]->getName() << endl;
138 cout << " INPUT: " << InputNodes[0]->getName() << endl;
140 if (IsOutput) cout << " OUTPUT: " << OutputNode->getName() << endl;
143 if (debug_lvl & 2 ) { // Instantiation/Destruction notification
144 if (from == 0) cout << "Instantiated: FGPID" << endl;
145 if (from == 1) cout << "Destroyed: FGPID" << endl;
147 if (debug_lvl & 4 ) { // Run() method entry print for FGModel-derived objects
149 if (debug_lvl & 8 ) { // Runtime state variables
151 if (debug_lvl & 16) { // Sanity checking
153 if (debug_lvl & 64) {
154 if (from == 0) { // Constructor
155 cout << IdSrc << endl;
156 cout << IdHdr << endl;