src/AIModel/performancedata.cxx

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