git.gag.com Git - debian/openrocket/blob - src/net/sf/openrocket/optimization/rocketoptimization/domains/StabilityDomain.java

   1 package net.sf.openrocket.optimization.rocketoptimization.domains;
   2
   3 import net.sf.openrocket.aerodynamics.AerodynamicCalculator;
   4 import net.sf.openrocket.aerodynamics.BarrowmanCalculator;
   5 import net.sf.openrocket.aerodynamics.FlightConditions;
   6 import net.sf.openrocket.document.Simulation;
   7 import net.sf.openrocket.masscalc.BasicMassCalculator;
   8 import net.sf.openrocket.masscalc.MassCalculator;
   9 import net.sf.openrocket.masscalc.MassCalculator.MassCalcType;
  10 import net.sf.openrocket.optimization.rocketoptimization.SimulationDomain;
  11 import net.sf.openrocket.rocketcomponent.Configuration;
  12 import net.sf.openrocket.rocketcomponent.RocketComponent;
  13 import net.sf.openrocket.rocketcomponent.SymmetricComponent;
  14 import net.sf.openrocket.util.Coordinate;
  15 import net.sf.openrocket.util.MathUtil;
  16 import net.sf.openrocket.util.Pair;
  17 import net.sf.openrocket.util.Prefs;
  18
  19 /**
  20  * A simulation domain that limits the requires stability of the rocket.
  21  *
  22  * @author Sampo Niskanen <sampo.niskanen@iki.fi>
  23  */
  24 public class StabilityDomain implements SimulationDomain {
  25
  26         /*
  27          * TODO: HIGH:  Should this rather inspect stability during flight
  28          */
  29
  30         private final double limit;
  31         private final boolean absolute;
  32
  33
  34         public StabilityDomain(double limit, boolean absolute) {
  35                 this.limit = limit;
  36                 this.absolute = absolute;
  37         }
  38
  39
  40         @Override
  41         public Pair<Double, Double> getDistanceToDomain(Simulation simulation) {
  42                 Coordinate cp, cg;
  43                 double cpx, cgx;
  44                 double reference;
  45
  46                 /*
  47                  * These are instantiated each time because this class must be thread-safe.
  48                  * Caching would in any case be inefficient since the rocket changes all the time.
  49                  */
  50                 AerodynamicCalculator aerodynamicCalculator = new BarrowmanCalculator();
  51                 MassCalculator massCalculator = new BasicMassCalculator();
  52
  53
  54                 Configuration configuration = simulation.getConfiguration();
  55                 FlightConditions conditions = new FlightConditions(configuration);
  56                 conditions.setMach(Prefs.getDefaultMach());
  57                 conditions.setAOA(0);
  58                 conditions.setRollRate(0);
  59
  60                 // TODO: HIGH: This re-calculates the worst theta value every time
  61                 cp = aerodynamicCalculator.getWorstCP(configuration, conditions, null);
  62                 cg = massCalculator.getCG(configuration, MassCalcType.LAUNCH_MASS);
  63
  64                 if (cp.weight > 0.000001)
  65                         cpx = cp.x;
  66                 else
  67                         cpx = Double.NaN;
  68
  69                 if (cg.weight > 0.000001)
  70                         cgx = cg.x;
  71                 else
  72                         cgx = Double.NaN;
  73
  74
  75                 // Calculate the reference (absolute or relative)
  76                 reference = cpx - cgx;
  77                 if (!absolute) {
  78                         double diameter = 0;
  79                         for (RocketComponent c : configuration) {
  80                                 if (c instanceof SymmetricComponent) {
  81                                         double d1 = ((SymmetricComponent) c).getForeRadius() * 2;
  82                                         double d2 = ((SymmetricComponent) c).getAftRadius() * 2;
  83                                         diameter = MathUtil.max(diameter, d1, d2);
  84                                 }
  85                         }
  86
  87                         reference = (cpx - cgx) / diameter;
  88                 }
  89
  90                 System.out.println("DOMAIN: limit=" + limit + " reference=" + reference + " result=" + (limit - reference));
  91
  92                 return new Pair<Double, Double>(limit - reference, reference);
  93         }
  94
  95 }