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Vivian Meazza:

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I attach the latest version  of Nimitz. The textures have been improved. A glide-path has been added, it is on by default, but can be switched off by means of the properties browser: /ai/models/ship/controls/glide-path. The origin has been adjusted to the turning pivot and approximate roll center.

Modified AiShip files are also attached. These allow the radius of the turning circle of a ship to be input. The turning circle is adjusted for speed and rudder angle. Roll has been corrected so that a ship leans out of a turn, not inwards like an aircraft. The roll angle is adjusted for speed and rudder angle (yes, application of more rudder reduces roll angle - rudders act as stabilizers).


TODO

Add a relative wind calculation so that a carrier can be turned to the appropriate launch and recovery courses.

Add a 'flight plan' so that the carrier can carry out a racetrack for flight ops.

Add a projector landing sight.

Add auto-land facilities.
This commit is contained in:
ehofman 2004-11-13 14:45:57 +00:00
parent 42322949fa
commit 2df4a3b685
1 changed files with 33 additions and 7 deletions
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40
src/AIModel/AIShip.cxx
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@ -47,12 +47,13 @@ bool FGAIShip::init() {
void FGAIShip::bind() {
FGAIBase::bind();
props->tie("surface-positions/rudder-pos-norm",
props->tie("surface-positions/rudder-pos-deg",
SGRawValuePointer<double>(&rudder));
}
void FGAIShip::unbind() {
FGAIBase::unbind();
props->untie("surface-positions/rudder-pos-deg");
}
void FGAIShip::update(double dt) {
@ -68,8 +69,8 @@ void FGAIShip::Run(double dt) {
if (fp) ProcessFlightPlan(dt);
double turn_radius_ft;
double turn_circum_ft;
double sp_turn_radius_ft;
double rd_turn_radius_ft;
double speed_north_deg_sec;
double speed_east_deg_sec;
double dist_covered_ft;
@ -92,16 +93,41 @@ void FGAIShip::Run(double dt) {
pos.setlat( pos.lat() + speed_north_deg_sec * dt);
pos.setlon( pos.lon() + speed_east_deg_sec * dt);
// adjust heading based on current rudder angle
if (rudder != 0.0) {
turn_radius_ft = 0.088362 * speed * speed
if (rudder != 0.0) {
/* rd_turn_radius_ft = 0.088362 * speed * speed
/ tan( fabs(rudder) / SG_RADIANS_TO_DEGREES );
turn_circum_ft = SGD_2PI * turn_radius_ft;
turn_circum_ft = SGD_2PI * rd_turn_radius_ft;
dist_covered_ft = speed * 1.686 * dt;
alpha = dist_covered_ft / turn_circum_ft * 360.0;
alpha = dist_covered_ft / turn_circum_ft * 360.0;*/
if (rd_turn_radius_ft <= 0) rd_turn_radius_ft = 0; // don't allow nonsense values
// cout << "speed " << speed << " turn radius " << rd_turn_radius_ft << endl;
// adjust turn radius for speed. The equation is very approximate.
sp_turn_radius_ft = 10 * pow ((speed - 15),2) + rd_turn_radius_ft;
// cout << "speed " << speed << " speed turn radius " << sp_turn_radius_ft << endl;
// adjust turn radius for rudder angle. The equation is even more approximate.
rd_turn_radius_ft = -130 * (rudder - 15) + sp_turn_radius_ft;
// cout << "rudder " << rudder << " rudder turn radius " << rd_turn_radius_ft << endl;
// calculate the angle, alpha, subtended by the arc traversed in time dt
alpha = ((speed * 1.686 * dt)/rd_turn_radius_ft) * SG_RADIANS_TO_DEGREES;
// make sure that alpha is applied in the right direction
hdg += alpha * sign( rudder );
if ( hdg > 360.0 ) hdg -= 360.0;
if ( hdg < 0.0) hdg += 360.0;
//adjust roll for rudder angle and speed
roll = - ( speed / 2 - rudder / 6 );
// cout << " hdg " << hdg << "roll "<< roll << endl;
}
// adjust target rudder angle if heading lock engaged