ardupilot/libraries/SITL/SIM_Gazebo.cpp

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2015-07-16 19:31:24 -03:00
/// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
/*
This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
simulator connector for ardupilot version of Gazebo
*/
#include <AP_HAL/AP_HAL.h>
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#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
#include "SIM_Gazebo.h"
#include <stdio.h>
extern const AP_HAL::HAL& hal;
/*
constructor
*/
Gazebo::Gazebo(const char *home_str, const char *frame_str) :
Aircraft(home_str, frame_str),
last_timestamp(0),
sock(true)
{
// try to bind to a specific port so that if we restart ArduPilot
// Gazebo keeps sending us packets. Not strictly necessary but
// useful for debugging
sock.bind("127.0.0.1", 9003);
sock.reuseaddress();
sock.set_blocking(false);
fprintf(stdout, "bind\n");
}
/*
decode and send servos
*/
void Gazebo::send_servos(const struct sitl_input &input)
{
servo_packet pkt;
pkt.motor_speed[0] = (input.servos[0]-1000) / 1000.0f;
pkt.motor_speed[1] = (input.servos[1]-1000) / 1000.0f;
pkt.motor_speed[2] = (input.servos[2]-1000) / 1000.0f;
pkt.motor_speed[3] = (input.servos[3]-1000) / 1000.0f;
sock.sendto(&pkt, sizeof(pkt), "127.0.0.1", 9002);
}
/*
receive an update from the FDM
This is a blocking function
*/
void Gazebo::recv_fdm(const struct sitl_input &input)
{
fdm_packet pkt;
/*
we re-send the servo packet every 0.1 seconds until we get a
reply. This allows us to cope with some packet loss to the FDM
*/
while (sock.recv(&pkt, sizeof(pkt), 100) != sizeof(pkt)) {
send_servos(input);
}
// get imu stuff
accel_body = Vector3f(pkt.imu_linear_acceleration_xyz[0],
pkt.imu_linear_acceleration_xyz[1],
pkt.imu_linear_acceleration_xyz[2]);
gyro = Vector3f(pkt.imu_angular_velocity_rpy[0],
pkt.imu_angular_velocity_rpy[1],
pkt.imu_angular_velocity_rpy[2]);
// compute dcm from imu orientation
Quaternion quat(pkt.imu_orientation_quat[0],
pkt.imu_orientation_quat[1],
pkt.imu_orientation_quat[2],
pkt.imu_orientation_quat[3]);
quat.rotation_matrix(dcm);
double speedN = pkt.velocity_xyz[0];
double speedE = pkt.velocity_xyz[1];
double speedD = pkt.velocity_xyz[2];
velocity_ef = Vector3f(speedN, speedE, speedD);
position = Vector3f(pkt.position_xyz[0],
pkt.position_xyz[1],
pkt.position_xyz[2]);
// auto-adjust to simulation frame rate
double deltat = pkt.timestamp - last_timestamp;
time_now_us += deltat * 1.0e6;
if (deltat < 0.01 && deltat > 0) {
adjust_frame_time(1.0/deltat);
}
last_timestamp = pkt.timestamp;
/* copied below from iris_ros.py */
/*
bearing = to_degrees(atan2(position.y, position.x));
distance = math.sqrt(self.position.x**2 + self.position.y**2)
(self.latitude, self.longitude) = util.gps_newpos(
self.home_latitude, self.home_longitude, bearing, distance)
self.altitude = self.home_altitude - self.position.z
velocity_body = self.dcm.transposed() * self.velocity
self.accelerometer = self.accel_body.copy()
*/
}
/*
update the Gazebo simulation by one time step
*/
void Gazebo::update(const struct sitl_input &input)
{
send_servos(input);
recv_fdm(input);
update_position();
}
#endif // CONFIG_HAL_BOARD