src/AIModel/performancedata.cxx

   1
   2 #ifdef HAVE_CONFIG_H
   3 #  include "config.h"
   4 #endif
   5
   6 #include "performancedata.hxx"
   7 #include "AIAircraft.hxx"
   8
   9 PerformanceData::PerformanceData(double acceleration,
  10                                  double deceleration,
  11                                  double climbRate,
  12                                  double descentRate,
  13                                  double vRotate,
  14                                  double vTakeOff,
  15                                  double vClimb,
  16                                  double vCruise,
  17                                  double vDescent,
  18                                  double vApproach,
  19                                  double vTouchdown,
  20                                  double vTaxi) :
  21     _acceleration(acceleration),
  22     _deceleration(deceleration),
  23     _climbRate(climbRate),
  24     _descentRate(descentRate),
  25     _vRotate(vRotate),
  26     _vTakeOff(vTakeOff),
  27     _vClimb(vClimb),
  28     _vCruise(vCruise),
  29     _vDescent(vDescent),
  30     _vApproach(vApproach),
  31     _vTouchdown(vTouchdown),
  32     _vTaxi(vTaxi)
  33 {
  34     _rollrate = 9.0; // degrees per second
  35     _maxbank = 30.0; // passenger friendly bank angle
  36 }
  37
  38 // read perf data from file
  39 PerformanceData::PerformanceData( const std::string& filename)
  40 {}
  41
  42 PerformanceData::~PerformanceData()
  43 {}
  44
  45 double PerformanceData::actualSpeed(FGAIAircraft* ac, double tgt_speed, double dt) {
  46     // if (tgt_speed > _vTaxi & ac->onGround()) // maximum taxi speed on ground
  47     //    tgt_speed = _vTaxi;
  48     // bad idea for a take off roll :-)
  49
  50     double speed = ac->getSpeed();
  51     double speed_diff = tgt_speed - speed;
  52
  53     if (speed_diff > 0.0)        // need to accelerate
  54     {
  55         speed += _acceleration * dt;
  56         if ( speed > tgt_speed )
  57             speed = tgt_speed;
  58
  59     } else if (speed_diff < 0.0) { // decelerate
  60         if (ac->onGround()) {
  61             // deceleration performance is better due to wheel brakes.
  62             speed -= 3 * _deceleration * dt;
  63         } else {
  64             speed -= _deceleration * dt;
  65         }
  66
  67         if ( speed < tgt_speed )
  68             speed = tgt_speed;
  69
  70     }
  71
  72     return speed;
  73 }
  74
  75 double PerformanceData::actualBankAngle(FGAIAircraft* ac, double tgt_roll, double dt) {
  76     // check maximum bank angle
  77     if (fabs(tgt_roll) > _maxbank)
  78         tgt_roll = _maxbank * tgt_roll/fabs(tgt_roll);
  79
  80     double roll = ac->getRoll();
  81     double bank_diff = tgt_roll - roll;
  82
  83     if (fabs(bank_diff) > 0.2) {
  84         if (bank_diff > 0.0) {
  85             roll += _rollrate * dt;
  86             if (roll > tgt_roll)
  87                 roll = tgt_roll;
  88         }
  89         else if (bank_diff < 0.0) {
  90             roll -= _rollrate * dt;
  91
  92             if (roll < tgt_roll)
  93                 roll = tgt_roll;
  94         }
  95         //while (roll > 180) roll -= 360;
  96         //while (roll < 180) roll += 360;
  97     }
  98
  99     return roll;
 100 }
 101
 102 double PerformanceData::actualPitch(FGAIAircraft* ac, double tgt_pitch, double dt) {
 103     double pitch = ac->getPitch();
 104     double pdiff = tgt_pitch - pitch;
 105
 106     if (pdiff > 0.0) { // nose up
 107         pitch += 0.005*_climbRate * dt / 3.0; //TODO avoid hardcoded 3 secs
 108
 109         if (pitch > tgt_pitch)
 110             pitch = tgt_pitch;
 111
 112     } else if (pdiff < 0.0) { // nose down
 113         pitch -= 0.002*_descentRate * dt / 3.0;
 114
 115         if (pitch < tgt_pitch)
 116             pitch = tgt_pitch;
 117     }
 118
 119     return pitch;
 120 }
 121
 122 double PerformanceData::actualAltitude(FGAIAircraft* ac, double tgt_altitude, double dt) {
 123     if (ac->onGround()) {
 124         //FIXME: return a value here
 125     } else
 126         return ac->getAltitude() + ac->getVerticalSpeed()*dt/60.0;
 127 }
 128
 129 double PerformanceData::actualVerticalSpeed(FGAIAircraft* ac, double tgt_vs, double dt) {
 130     double vs = ac->getVerticalSpeed();
 131     double vs_diff = tgt_vs - vs;
 132
 133     if (fabs(vs_diff) > 10.0) {
 134         if (vs_diff > 0.0) {
 135             vs += _climbRate * dt / 3.0; //TODO avoid hardcoded 3 secs to attain climb rate from level flight
 136
 137             if (vs > tgt_vs)
 138                 vs = tgt_vs;
 139
 140         } else if (vs_diff < 0.0) {
 141             vs -= _descentRate * dt / 3.0;
 142
 143             if (vs < tgt_vs)
 144                 vs = tgt_vs;
 145         }
 146     }
 147
 148     return vs;
 149 }
 150
 151 bool PerformanceData::gearExtensible(const FGAIAircraft* ac) {
 152     return (ac->altitudeAGL() < 900.0)
 153             && (ac->airspeed() < _vTouchdown * 1.25);
 154 }