src/FDM/JSBSim/models/flight_control/FGPID.h

   1 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
   2
   3  Header:       FGPID.h
   4  Author:       Jon Berndt
   5  Date started: 6/17/2006
   6
   7  ------------- Copyright (C) 2006 by Jon S. Berndt, jon@jsbsim.org -------------
   8
   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
  12  version.
  13
  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
  17  details.
  18
  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.
  22
  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.
  25
  26 HISTORY
  27 --------------------------------------------------------------------------------
  28 Initial Code 6/17/2006 JSB
  29
  30 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  31 SENTRY
  32 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  33
  34 #ifndef FGPID_H
  35 #define FGPID_H
  36
  37 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  38 INCLUDES
  39 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  40
  41 #include "FGFCSComponent.h"
  42
  43 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  44 DEFINITIONS
  45 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  46
  47 #define ID_PID "$Id: FGPID.h,v 1.13 2012/05/10 12:10:48 jberndt Exp $"
  48
  49 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  50 FORWARD DECLARATIONS
  51 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  52
  53 namespace JSBSim {
  54
  55 class FGFCS;
  56 class Element;
  57
  58 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
  59 CLASS DOCUMENTATION
  60 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
  61
  62 /** Encapsulates a PID control component for the flight control system.
  63
  64 <h3>Configuration Format:</h3>
  65
  66 @code
  67 <pid name="{string}" [type="standard"]>
  68   <kp> {number|property} </kp>
  69   <ki> {number|property} </ki>
  70   <kd> {number|property} </kd>
  71   <trigger> {property} </trigger>
  72 </pid>
  73 @endcode
  74
  75 For the integration constant element, one can also supply the type attribute for
  76 what kind of integrator to be used, one of:
  77
  78 - rect, for a rectangular integrator
  79 - trap, for a trapezoidal integrator
  80 - ab2, for a second order Adams Bashforth integrator
  81 - ab3, for a third order Adams Bashforth integrator
  82
  83 For example,
  84
  85 @code
  86 <pid name="fcs/heading-control">
  87   <kp> 3 </kp>
  88   <ki type="ab3"> 1 </ki>
  89   <kd> 1 </kd>
  90 </pid>
  91 @endcode
  92
  93
  94
  95 <h3>Configuration Parameters:</h3>
  96 <pre>
  97
  98   The values of kp, ki, and kd have slightly different interpretations depending on
  99   whether the PID controller is a standard one, or an ideal/parallel one - with the latter
 100   being the default.
 101
 102   kp      - Proportional constant, default value 0.
 103   ki      - Integrative constant, default value 0.
 104   kd      - Derivative constant, default value 0.
 105   trigger - Property which is used to sense wind-up, optional. Most often, the trigger
 106             will be driven by the "saturated" property of a particular actuator. When
 107             the relevant actuator has reached it's limits (if there are any, specified
 108             by the <clipto> element) the automatically generated saturated property will
 109             be greater than zero (true). If this property is used as the trigger for the
 110             integrator, the integrator will not continue to integrate while the property
 111             is still true (> 1), preventing wind-up.
 112   pvdot   - The property to be used as the process variable time derivative.
 113
 114
 115
 116 </pre>
 117
 118     @author Jon S. Berndt
 119     @version $Revision: 1.13 $
 120 */
 121
 122 /*%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
 123 CLASS DECLARATION
 124 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%*/
 125
 126 class FGPID  : public FGFCSComponent
 127 {
 128 public:
 129   FGPID(FGFCS* fcs, Element* element);
 130   ~FGPID();
 131
 132   bool Run (void);
 133   void ResetPastStates(void) {Input_prev = Input_prev2 = Output = I_out_total = 0.0;}
 134
 135     /// These define the indices use to select the various integrators.
 136   enum eIntegrateType {eNone = 0, eRectEuler, eTrapezoidal, eAdamsBashforth2, eAdamsBashforth3};
 137
 138 private:
 139   double Kp, Ki, Kd;
 140   double I_out_total;
 141   double Input_prev, Input_prev2;
 142   double KpPropertySign;
 143   double KiPropertySign;
 144   double KdPropertySign;
 145
 146   bool IsStandard;
 147
 148   eIntegrateType IntType;
 149
 150   FGPropertyManager *Trigger;
 151   FGPropertyManager* KpPropertyNode;
 152   FGPropertyManager* KiPropertyNode;
 153   FGPropertyManager* KdPropertyNode;
 154   FGPropertyManager* ProcessVariableDot;
 155
 156   void Debug(int from);
 157 };
 158 }
 159 #endif