ardupilot/ArduPlane/failsafe.cpp

116 lines
3.4 KiB
C++

#include "Plane.h"
/*
* failsafe support
* Andrew Tridgell, December 2011
*/
/*
* our failsafe strategy is to detect main loop lockup and switch to
* passing inputs straight from the RC inputs to RC outputs.
*/
/*
* this failsafe_check function is called from the core timer interrupt
* at 1kHz.
*/
void Plane::failsafe_check(void)
{
static uint16_t last_ticks;
static uint32_t last_timestamp;
static bool in_failsafe;
uint32_t tnow = micros();
const uint16_t ticks = scheduler.ticks();
if (ticks != last_ticks) {
// the main loop is running, all is OK
last_ticks = ticks;
last_timestamp = tnow;
in_failsafe = false;
return;
}
if (tnow - last_timestamp > 200000) {
// we have gone at least 0.2 seconds since the main loop
// ran. That means we're in trouble, or perhaps are in
// an initialisation routine or log erase. Start passing RC
// inputs through to outputs
in_failsafe = true;
}
if (in_failsafe && tnow - last_timestamp > 20000) {
// ensure we have the latest RC inputs
rc().read_input();
last_timestamp = tnow;
rc().read_input();
#if ADVANCED_FAILSAFE == ENABLED
if (in_calibration) {
// tell the failsafe system that we are calibrating
// sensors, so don't trigger failsafe
afs.heartbeat();
}
#endif
if (RC_Channels::get_valid_channel_count() < 5) {
// we don't have any RC input to pass through
return;
}
// pass RC inputs to outputs every 20ms
RC_Channels::clear_overrides();
float roll = roll_in_expo(false);
float pitch = pitch_in_expo(false);
float throttle = get_throttle_input(true);
float rudder = rudder_in_expo(false);
if (!hal.util->get_soft_armed()) {
throttle = 0;
}
// setup secondary output channels that don't have
// corresponding input channels
SRV_Channels::set_output_scaled(SRV_Channel::k_aileron, roll);
SRV_Channels::set_output_scaled(SRV_Channel::k_elevator, pitch);
SRV_Channels::set_output_scaled(SRV_Channel::k_rudder, rudder);
SRV_Channels::set_output_scaled(SRV_Channel::k_steering, rudder);
SRV_Channels::set_output_scaled(SRV_Channel::k_throttle, throttle);
// this is to allow the failsafe module to deliberately crash
// the plane. Only used in extreme circumstances to meet the
// OBC rules
#if ADVANCED_FAILSAFE == ENABLED
if (afs.should_crash_vehicle()) {
afs.terminate_vehicle();
if (!afs.terminating_vehicle_via_landing()) {
return;
}
}
#endif
// setup secondary output channels that do have
// corresponding input channels
SRV_Channels::copy_radio_in_out(SRV_Channel::k_manual, true);
SRV_Channels::set_output_scaled(SRV_Channel::k_flap, 0.0);
SRV_Channels::set_output_scaled(SRV_Channel::k_flap_auto, 0.0);
// setup flaperons
flaperon_update(0);
servos_output();
// in SITL we send through the servo outputs so we can verify
// we're manipulating surfaces
#if CONFIG_HAL_BOARD == HAL_BOARD_SITL
GCS_MAVLINK *chan = gcs().chan(0);
if (HAVE_PAYLOAD_SPACE(chan->get_chan(), SERVO_OUTPUT_RAW)) {
chan->send_servo_output_raw();
}
#endif
}
}