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
  10 // For now, make this a define
  11 // Later on, additional class variables can simulate settings such as braking power
  12 // also, the performance parameters can be tweaked a little to add some personality
  13 // to the AIAircraft.
  14 #define BRAKE_SETTING 1.6
  15
  16 PerformanceData::PerformanceData(double acceleration,
  17                                 double deceleration,
  18                                 double climbRate,
  19                                 double descentRate,
  20                                 double vRotate,
  21                                 double vTakeOff,
  22                                 double vClimb,
  23                                 double vCruise,
  24                                 double vDescent,
  25                                 double vApproach,
  26                                 double vTouchdown,
  27                                 double vTaxi) :
  28     _acceleration(acceleration),
  29     _deceleration(deceleration),
  30     _climbRate(climbRate),
  31     _descentRate(descentRate),
  32     _vRotate(vRotate),
  33     _vTakeOff(vTakeOff),
  34     _vClimb(vClimb),
  35     _vCruise(vCruise),
  36     _vDescent(vDescent),
  37     _vApproach(vApproach),
  38     _vTouchdown(vTouchdown),
  39     _vTaxi(vTaxi)
  40 {
  41     _rollrate = 9.0; // degrees per second
  42     _maxbank = 30.0; // passenger friendly bank angle
  43 }
  44
  45 // read perf data from file
  46 PerformanceData::PerformanceData( const std::string& filename)
  47 {}
  48
  49 PerformanceData::~PerformanceData()
  50 {}
  51
  52 double PerformanceData::actualSpeed(FGAIAircraft* ac, double tgt_speed, double dt) {
  53     // if (tgt_speed > _vTaxi & ac->onGround()) // maximum taxi speed on ground
  54     //    tgt_speed = _vTaxi;
  55     // bad idea for a take off roll :-)
  56
  57     double speed = ac->getSpeed();
  58     double speed_diff = tgt_speed - speed;
  59
  60     if (speed_diff > 0.0)        // need to accelerate
  61     {
  62         speed += _acceleration * dt;
  63         if ( speed > tgt_speed )
  64             speed = tgt_speed;
  65
  66     } else if (speed_diff < 0.0) { // decelerate
  67         if (ac->onGround()) {
  68             // deceleration performance is better due to wheel brakes.
  69             speed -= BRAKE_SETTING * _deceleration * dt;
  70         } else {
  71             speed -= _deceleration * dt;
  72         }
  73
  74         if ( speed < tgt_speed )
  75             speed = tgt_speed;
  76
  77     }
  78
  79     return speed;
  80 }
  81
  82 double PerformanceData::actualBankAngle(FGAIAircraft* ac, double tgt_roll, double dt) {
  83     // check maximum bank angle
  84     if (fabs(tgt_roll) > _maxbank)
  85         tgt_roll = _maxbank * tgt_roll/fabs(tgt_roll);
  86
  87     double roll = ac->getRoll();
  88     double bank_diff = tgt_roll - roll;
  89
  90     if (fabs(bank_diff) > 0.2) {
  91         if (bank_diff > 0.0) {
  92             roll += _rollrate * dt;
  93             if (roll > tgt_roll)
  94                 roll = tgt_roll;
  95         }
  96         else if (bank_diff < 0.0) {
  97             roll -= _rollrate * dt;
  98
  99             if (roll < tgt_roll)
 100                 roll = tgt_roll;
 101         }
 102         //while (roll > 180) roll -= 360;
 103         //while (roll < 180) roll += 360;
 104     }
 105
 106     return roll;
 107 }
 108
 109 double PerformanceData::actualPitch(FGAIAircraft* ac, double tgt_pitch, double dt) {
 110     double pitch = ac->getPitch();
 111     double pdiff = tgt_pitch - pitch;
 112
 113     if (pdiff > 0.0) { // nose up
 114         pitch += 0.005*_climbRate * dt / 3.0; //TODO avoid hardcoded 3 secs
 115
 116         if (pitch > tgt_pitch)
 117             pitch = tgt_pitch;
 118     } else if (pdiff < 0.0) { // nose down
 119         pitch -= 0.002*_descentRate * dt / 3.0;
 120
 121         if (pitch < tgt_pitch)
 122             pitch = tgt_pitch;
 123     }
 124
 125     return pitch;
 126 }
 127
 128 double PerformanceData::actualAltitude(FGAIAircraft* ac, double tgt_altitude, double dt) {
 129     if (ac->onGround()) {
 130         //FIXME: a return sensible value here
 131         return 0.0; // 0 for now to avoid compiler errors
 132     } else
 133         return ac->getAltitude() + ac->getVerticalSpeed()*dt/60.0;
 134 }
 135
 136 double PerformanceData::actualVerticalSpeed(FGAIAircraft* ac, double tgt_vs, double dt) {
 137     double vs = ac->getVerticalSpeed();
 138     double vs_diff = tgt_vs - vs;
 139
 140     if (fabs(vs_diff) > .001) {
 141         if (vs_diff > 0.0) {
 142             vs += _climbRate * dt / 3.0; //TODO avoid hardcoded 3 secs to attain climb rate from level flight
 143
 144             if (vs > tgt_vs)
 145                 vs = tgt_vs;
 146         } else if (vs_diff < 0.0) {
 147             vs -= _descentRate * dt / 3.0;
 148
 149             if (vs < tgt_vs)
 150                 vs = tgt_vs;
 151         }
 152     }
 153
 154     return vs;
 155 }
 156
 157 bool PerformanceData::gearExtensible(const FGAIAircraft* ac) {
 158     return (ac->altitudeAGL() < 900.0)
 159             && (ac->airspeed() < _vTouchdown * 1.25);
 160 }