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     } else if (pdiff < 0.0) { // nose down
 112         pitch -= 0.002*_descentRate * dt / 3.0;
 113
 114         if (pitch < tgt_pitch)
 115             pitch = tgt_pitch;
 116     }
 117
 118     return pitch;
 119 }
 120
 121 double PerformanceData::actualAltitude(FGAIAircraft* ac, double tgt_altitude, double dt) {
 122     if (ac->onGround()) {
 123         //FIXME: a return sensible value here
 124         return 0.0; // 0 for now to avoid compiler errors
 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         } else if (vs_diff < 0.0) {
 140             vs -= _descentRate * dt / 3.0;
 141
 142             if (vs < tgt_vs)
 143                 vs = tgt_vs;
 144         }
 145     }
 146
 147     return vs;
 148 }
 149
 150 bool PerformanceData::gearExtensible(const FGAIAircraft* ac) {
 151     return (ac->altitudeAGL() < 900.0)
 152             && (ac->airspeed() < _vTouchdown * 1.25);
 153 }