ardupilot/ArduPlane/failsafe.cpp

95 lines
2.9 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) {
last_timestamp = tnow;
if (in_calibration) {
// tell the failsafe system that we are calibrating
// sensors, so don't trigger failsafe
afs.heartbeat();
}
if (hal.rcin->num_channels() < 5) {
// we don't have any RC input to pass through
return;
}
// pass RC inputs to outputs every 20ms
hal.rcin->clear_overrides();
int16_t roll = channel_roll->get_control_in_zero_dz();
int16_t pitch = channel_pitch->get_control_in_zero_dz();
int16_t throttle = channel_throttle->get_control_in_zero_dz();
int16_t rudder = channel_rudder->get_control_in_zero_dz();
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 (afs.should_crash_vehicle()) {
afs.terminate_vehicle();
return;
}
// 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);
SRV_Channels::set_output_scaled(SRV_Channel::k_flap_auto, 0);
// setup flaperons
flaperon_update(0);
servos_output();
}
}