Я использую Perl для создания простой игры Lunar Lander. Все элементы работают (то есть графический интерфейс, реализованные пользователем элементы управления и т. Д.), Но я не могу заставить работать функцию «Автопилот». Эта функция должна доставить спускаемый аппарат к месту, где он может приземлиться (или к месту, обозначенному как цель для приземления), а затем благополучно приземлиться там. Ограничения, накладываемые на посадку, - это уклон места приземления и скорость, с которой он приземляется. Единственный файл, который я могу изменить - это AutoPilot.pm. Я опубликую код, с которым мне разрешено работать:
package AutoPilot;
use strict;
use warnings;
# use diagnostics;
=head1 Lunar Lander Autopilot
The autopilot is called on every step of the lunar lander simulation.
It is passed state information as an argument and returns a set of course
correction commands.
The lander world takes the surface of the moon (a circle!)
and maps it onto a rectangular region.
On the x-axis, the lander will wrap around when it hits either the
left or right edge of the region. If the lander goes above the maximum
height of the world, it escapes into the space and thus fails.
Similarly, if the lander's position goes below 0 without ever landing
on some solid surface, it "sinks" and thus fails again.
The simulation is simple in the respect that if the langer goes at a high speed
it may pass through the terrain boundary.
The y-axis has normal gravitational physics.
The goal of the autopilot is to land the craft at (or near) the landing
zone without crashing it (or failing by leaving the world).
=head2 Interface in a nutshell
When the simulation is initialized, AutoPilot::Initialize() is called.
Every clock tick, AutoPilot::ComputeLanding() is called by the simulator.
For more explanation, see below.
=cut
# if you want to keep data between invocations of ComputeLanding, put
# the data in this part of the code. Use Initialize() to handle simulation
# resets.
my $call_count = 0;
my $gravity;
my ($x_min, $y_min, $x_max, $y_max);
my ($lander_width, $lander_height, $center_x, $center_y);
my $target_x;
my ($thrust, $left_right_thrust);
my ($max_rotation, $max_left_right_thrusters, $max_main_thruster);
my $ascend_height = 980;
=head1 AutoPilot::Initialize()
This method is called when a new simulation is started.
The following parameters are passed to initialize:
$gravity, a number, describing the gravity in the world
$space_boundaries, a reference to an array with 4 numerical
elements, ($x_min, $y_min, $x_max, $y_max), describing
the world boundaries
$target_x, a number representing the target landing position
$lander_capabilities, a reference to an array with
5 elements,
($thrust, $left_right_thrust, $max_rotation, $max_left_right_thrusters, $max_main_thruster),
describing the capabilities of the lander.
$lander_dimensions, a reference to an array with
4 elements,
($lander_width, $lander_height, $center_x, $center_y),
describing the dimensions of the lander.
=head2 Details
=head3 Dimensions
The dimensions are given in 'units' (you can think of 'units' as meters).
The actual numbers can take any real value, not only integers.
=head4 World dimensions
The lander world is a square region with a lower left corner at
($x_min,$y_min) and an upper right corner at ($x_max, $y_max).
The measurement units of these dimensions will just be called units
(think about units as meters). By definition, $x_max>$x_min and
$y_max>$y_min.
The default values for the lower left and upper right corners
are (-800,0), and (800,1600), respectively.
=head4 Lander dimensions
The lander is $lander_width units wide and $lander_height high.
The coordinates of the lander are always specified with respect to its center.
The center of the lander relative to the lower left corner of the lander bounding box
is given by $center_x, $center_y. Thus, if ($x,$y) are the coordinates of the lander,
($x-$center_x,$y-$center_y) and ($x-$center_x+$lander_width,$y-$center_y+$lander_height)
specify the corners of the bounding box of the lander. (Think of the lander as completely
filling this box.) The significance of the bounding box of the lander is that a collision
occurs if the bounding box intersects with the terrain or the upper/lower edges of the world.
If a collision occurs, as described earlier, the lander might have just landed,
crashed or 'escaped' (and thus the lander failed).
The constraints on these values are: $lander_width>0, $lander_height>0,
$center_x>0, $center_y>0.
The default value for the width is 60 units, for the height it is 50,
for $center_x it is 30, for $center_y it is 25.
=head4 Forces
The gravitational force is:
$g
The thrust exerted by the engine when fired is:
$thrust
The thrust exerted by the left/right thrusters when fired is:
$left_right_thrust
=head4 Limits to the controls
Within a single timestep there are limits to how many degrees the
lander may rotate in a timestep, and how many times the side thrusters,
and main thruster, can fire. These are stored in:
$max_rotation, $max_left_right_thrusters, $max_main_thruster
=head4 Target
The target landing zone that the lander is supposed to land at:
$target_x
which returns
the string "any" if any safe landing site will do, or
a number giving the x-coordinate of the desired landing site.
Note: there is no guarantee that this is actually a safe spot to land!
For more details about how the lander is controlled, see AutoPilot::ComputeLanding.
=cut
sub Initialize {
my ($space_boundaries, $lander_capabilities,$lander_dimensions);
($gravity, $space_boundaries, $target_x, $lander_capabilities, $lander_dimensions) = @_;
($x_min, $y_min, $x_max, $y_max) = @{$space_boundaries};
( $thrust, $left_right_thrust, $max_rotation,
$max_left_right_thrusters, $max_main_thruster) = @{$lander_capabilities};
($lander_width, $lander_height, $center_x, $center_y) = @{$lander_dimensions};
$call_count = 0;
}
=head1 AutoPilot::ComputeLanding()
This method is called for every clock tick of the simulation.
It is passed the necessary information about the current state
and it must return an array with elements, describing the
actions that the lander should execute in the current tick.
The parameters passed to the method describe the actual state
of the lander, the current terrain below the lander and some
extra information. In particular, the parameters are:
$fuel, a nonnegative integer describing the remaining amount of fuel.
When the fuel runs out, the lander becomes uncontrolled.
$terrain_info, an array describing the terrain below the lander (see below).
$lander_state, an array which contains information about the lander's state.
For more information, see below.
$debug, an integer encoding whether the autopilot should output any debug information.
Effectively, the value supplied on the command line after "-D",
or if this value is not supplied, the value of the variable $autopilot_debug
in the main program.
$time, the time elapsed from the beginning of the simulation.
If the simulation is reset, time is also reset to 0.
=head2 Details of the parameters
=head3 The terrain information
The array referred to by $terrain_info is either empty, or
it describes the terrain element which is just (vertically) below the lander.
It is empty, when there is no terrain element below the lander.
When it is non-empty, it has the following elements:
($x0, $y0, $x1, $y1, $slope, $crashSpeed, $crashSlope)
where
($x0, $y0) is the left coordinate of the terrain segment,
($x1, $y1) is the right coordinate of the terrain segment,
$slope is the left to right slope of the segment (rise/run),
$crashSpeed is the maximum landing speed to avoid a crash,
$crashSlope is the maximum ground slope to avoid a crash.
=head3 The state of the lander
The array referred to by $lander_state contains
the current position, attitude, and velocity of the lander:
($px, $py, $attitude, $vx, $vy, $speed)
where
$px is its x position in the world, in the range [-800, 800],
$py is its y position in the world, in the range [0, 1600],
$attitude is its current attitude angle in unit degrees,
from y axis, where
0 is vertical,
> 0 is to the left (counter clockwise),
< 0 is to the right (clockwise),
$vx is the x velocity in m/s (< 0 is to left, > 0 is to right),
$vy is the y velocity in m/s (< 0 is down, > 0 is up),
$speed is the speed in m/s, where $speed == sqrt($vx*$vx + $vy*$vy)
=head2 The array to be returned
To control the lander you must return an array with 3 values:
($rotation, $left_right_thruster, $main_thruster)
$rotation instructs the lander to rotate the given number of degrees.
A value of 5 will cause the lander to rotate 5 degrees counter clockwise,
-5 will rotate 5 degrees clockwise.
$left_right_thruster instructs the lander to fire either the left or
right thruster. Negative value fire the right thruster, pushing the
lander to the left, positive fire the left thruster, pushing to the right.
The absolute value of the value given is the number of pushes,
so a value of -5 will fire the right thruster 5 times.
$main_thruster instructs the lander to fire the main engine,
a value of 5 will fire the main engine 5 times.
Each firing of either the main engine or a side engine consumes
one unit of fuel.
When the fuel runs out, the lander becomes uncontrolled.
Note that your instructions will only be executed up until the
limits denoted in $max_rotation, $max_side_thrusters, and $max_main_thruster.
If you return a value larger than one of these maximums than the
lander will only execute the value of the maximum.
=cut
sub ComputeLanding {
my ($fuel, $terrain_info, $lander_state, $debug, $time) = @_;
my $rotation = 0;
my $left_right_thruster = 0;
my $main_thruster = 0;
# fetch and update historical information
$call_count++;
if ( ! $terrain_info ) {
# hmm, we are not above any terrain! So do nothing.
return;
}
my ($x0, $y0, $x1, $y1, $slope, $crashSpeed, $crashSlope) =
@{$terrain_info};
my ($px, $py, $attitude, $vx, $vy, $speed) =
@{$lander_state};
if ( $debug ) {
printf "%5d ", $call_count;
printf "%5s ", $target_x;
printf "%4d, (%6.1f, %6.1f), %4d, ",
$fuel, $px, $py, $attitude;
printf "(%5.2f, %5.2f), %5.2f, ",
$vx, $vy, $speed;
printf "(%d %d %d %d, %5.2f), %5.2f, %5.2f\n",
$x0, $y0, $x1, $y1, $slope, $crashSpeed, $crashSlope;
}
# reduce horizontal velocity
if ( $vx < -1 && $attitude > -90 ) {
# going to the left, rotate clockwise, but not past -90!
$rotation = -1;
}
elsif ( 1 < $vx && $attitude < 90 ) {
# going to the right, rotate counterclockwise, but not past 90
$rotation = +1;
}
else {
# we're stable horizontally so make sure we are vertical
$rotation = -$attitude;
}
# reduce vertical velocity
if ($target_x eq "any"){
if (abs($slope) < $crashSlope){
if ($vy < -$crashSpeed + 6){
$main_thruster = 1;
if (int($vx) < 1 && int ($vx) > -1){
$left_right_thruster = 0;
}
if (int($vx) < -1){
$left_right_thruster = 1;
}
if (int($vx) > 1){
$left_right_thruster = -1;
}
}
}
else{
if ( $py < $ascend_height) {
if ($vy < 5){
$main_thruster=2;
}
}
if ($py > $ascend_height){
$left_right_thruster = 1;
if ($vx > 18){
$left_right_thruster = 0;
}
}
}
}
if ($target_x ne "any"){
if ($target_x < $px + 5 && $target_x > $px - 5){
print "I made it here";
if (abs($slope) < $crashSlope){
if ($vy < -$crashSpeed + 1){
$main_thruster = 1;
if (int($vx) < 1 && int ($vx) > -1){
$left_right_thruster = 0;
}
if (int($vx) < -1){
$left_right_thruster = 1;
}
if (int($vx) > 1){
$left_right_thruster = -1;
}
}
}
}
if ($target_x != $px){
if ( $py < $ascend_height) {
if ($vy < 5){
$main_thruster=2;
}
}
if ($py > $ascend_height){
$left_right_thruster = 1;
if ($vx > 10){
$left_right_thruster = 0;
}
}
}
}
return ($rotation, $left_right_thruster, $main_thruster);
}
1; # package ends
Извините за длину кода ...
Итак, я хочу, чтобы эта программа автопилота сделала несколько вещей. По порядку:
- Стабилизируйте посадочный модуль (уменьшите положение и горизонтальный дрейф до нуля, если они отличны от нуля). После стабилизации:
- Если над целью и сегментом цели безопасно приземлиться, спускайтесь по ней.
- В противном случае поднимитесь на безопасную высоту, которая превышает 1200 единиц. Вы можете с уверенностью предположить, что на этой высоте или выше нет объектов, а также, что во время прямого подъема из исходного положения спускаемый аппарат ничего не ударит.
- Оказавшись на безопасной высоте, спускаемый аппарат может начать движение горизонтально по направлению к своей цели, если цель задана, в противном случае он должен нацеливаться на первое безопасное место приземления, которое может быть обнаружено путем сканирования местности в одном направлении. Важно, чтобы спускаемый аппарат сохранял свою высоту, пока он движется горизонтально, потому что он не может чувствовать объекты рядом с ним, и могут быть объекты где-либо ниже этой высоты.
- Как только координата x цели достигнута и она безопасна для посадки, начните снижение.
- Если достигнута координата цели x, но местность небезопасна, если при движении к цели было замечено хорошее пятно, вернитесь к ней, в противном случае продолжайте поиск хорошей точки.
- Как только появится хорошее место, просто приземлитесь на нем в хорошем и безопасном месте.
Хорошо, я обновил код. Мой код теперь может приземлиться на все тесты (кроме одного, надоело, код работает достаточно близко), где нет цели. Тем не менее, у меня возникают огромные проблемы с выяснением, как заставить посадочный аппарат приземлиться на цель. Какие-нибудь идеи с моим кодом до сих пор? (фактически используемый код находится в подпрограмме ComputeLanding)