/* 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 . */ /* simulator connector for ardupilot version of Gazebo */ #include "SIM_Gazebo.h" #include #include #include extern const AP_HAL::HAL& hal; namespace SITL { Gazebo::Gazebo(const char *home_str, const char *frame_str) : Aircraft(home_str, frame_str), last_timestamp(0), socket_sitl{true} { fprintf(stdout, "Starting SITL Gazebo\n"); } /* Create and set in/out socket */ void Gazebo::set_interface_ports(const char* address, const int port_in, const int port_out) { // 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 if (!socket_sitl.bind("0.0.0.0", port_in)) { fprintf(stderr, "SITL: socket in bind failed on sim in : %d - %s\n", port_in, strerror(errno)); fprintf(stderr, "Aborting launch...\n"); exit(1); } printf("Bind %s:%d for SITL in\n", "127.0.0.1", port_in); socket_sitl.reuseaddress(); socket_sitl.set_blocking(false); _gazebo_address = address; _gazebo_port = port_out; printf("Setting Gazebo interface to %s:%d \n", _gazebo_address, _gazebo_port); } /* decode and send servos */ void Gazebo::send_servos(const struct sitl_input &input) { servo_packet pkt; // should rename servo_command // 16 because struct sitl_input.servos is 16 large in SIM_Aircraft.h for (unsigned i = 0; i < 16; ++i) { pkt.motor_speed[i] = (input.servos[i]-1000) / 1000.0f; } socket_sitl.sendto(&pkt, sizeof(pkt), _gazebo_address, _gazebo_port); } /* 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 (socket_sitl.recv(&pkt, sizeof(pkt), 100) != sizeof(pkt)) { send_servos(input); // Reset the timestamp after a long disconnection, also catch gazebo reset if (get_wall_time_us() > last_wall_time_us + GAZEBO_TIMEOUT_US) { last_timestamp = 0; } } const double deltat = pkt.timestamp - last_timestamp; // in seconds if (deltat < 0) { // don't use old packet time_now_us += 1; return; } // get imu stuff accel_body = Vector3f(static_cast(pkt.imu_linear_acceleration_xyz[0]), static_cast(pkt.imu_linear_acceleration_xyz[1]), static_cast(pkt.imu_linear_acceleration_xyz[2])); gyro = Vector3f(static_cast(pkt.imu_angular_velocity_rpy[0]), static_cast(pkt.imu_angular_velocity_rpy[1]), static_cast(pkt.imu_angular_velocity_rpy[2])); // compute dcm from imu orientation Quaternion quat(static_cast(pkt.imu_orientation_quat[0]), static_cast(pkt.imu_orientation_quat[1]), static_cast(pkt.imu_orientation_quat[2]), static_cast(pkt.imu_orientation_quat[3])); quat.rotation_matrix(dcm); velocity_ef = Vector3f(static_cast(pkt.velocity_xyz[0]), static_cast(pkt.velocity_xyz[1]), static_cast(pkt.velocity_xyz[2])); position = Vector3f(static_cast(pkt.position_xyz[0]), static_cast(pkt.position_xyz[1]), static_cast(pkt.position_xyz[2])); // auto-adjust to simulation frame rate time_now_us += static_cast(deltat * 1.0e6); if (deltat < 0.01 && deltat > 0) { adjust_frame_time(static_cast(1.0/deltat)); } last_timestamp = pkt.timestamp; } /* Drain remaining data on the socket to prevent phase lag. */ void Gazebo::drain_sockets() { const uint16_t buflen = 1024; char buf[buflen]; ssize_t received; errno = 0; do { received = socket_sitl.recv(buf, buflen, 0); if (received < 0) { if (errno != EAGAIN && errno != EWOULDBLOCK && errno != 0) { fprintf(stderr, "error recv on socket in: %s \n", strerror(errno)); } } else { // fprintf(stderr, "received from control socket: %s\n", buf); } } while (received > 0); } /* update the Gazebo simulation by one time step */ void Gazebo::update(const struct sitl_input &input) { send_servos(input); recv_fdm(input); update_position(); time_advance(); // update magnetic field update_mag_field_bf(); drain_sockets(); } } // namespace SITL