/*
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/>.
*/
/*
control code for tailsitters. Enabled by setting Q_FRAME_CLASS=10
*/
#include "Plane.h"
/*
return true when flying a tailsitter
*/
bool QuadPlane::is_tailsitter(void) const
{
return available() && frame_class == AP_Motors::MOTOR_FRAME_TAILSITTER;
}
/*
check if we are flying as a tailsitter
*/
bool QuadPlane::tailsitter_active(void)
{
if (!is_tailsitter()) {
return false;
}
if (in_vtol_mode()) {
return true;
}
// check if we are in ANGLE_WAIT fixed wing transition
if (transition_state == TRANSITION_ANGLE_WAIT_FW) {
return true;
}
return false;
}
/*
run output for tailsitters
*/
void QuadPlane::tailsitter_output(void)
{
if (!is_tailsitter()) {
return;
}
if (!tailsitter_active() || in_tailsitter_vtol_transition()) {
if (tailsitter.vectored_forward_gain > 0) {
// thrust vectoring in fixed wing flight
float aileron = SRV_Channels::get_output_scaled(SRV_Channel::k_aileron);
float elevator = SRV_Channels::get_output_scaled(SRV_Channel::k_elevator);
float tilt_left = (elevator + aileron) * tailsitter.vectored_forward_gain;
float tilt_right = (elevator - aileron) * tailsitter.vectored_forward_gain;
SRV_Channels::set_output_scaled(SRV_Channel::k_tiltMotorLeft, tilt_left);
SRV_Channels::set_output_scaled(SRV_Channel::k_tiltMotorRight, tilt_right);
} else {
SRV_Channels::set_output_scaled(SRV_Channel::k_tiltMotorLeft, 0);
SRV_Channels::set_output_scaled(SRV_Channel::k_tiltMotorRight, 0);
}
if (in_tailsitter_vtol_transition() && !throttle_wait && is_flying() && hal.util->get_soft_armed()) {
/*
during transitions to vtol mode set the throttle to the
hover throttle, and set the altitude controller
integrator to the same throttle level
*/
uint8_t throttle = motors->get_throttle_hover() * 100;
SRV_Channels::set_output_scaled(SRV_Channel::k_throttle, throttle);
SRV_Channels::set_output_scaled(SRV_Channel::k_throttleLeft, throttle);
SRV_Channels::set_output_scaled(SRV_Channel::k_throttleRight, throttle);
SRV_Channels::set_output_scaled(SRV_Channel::k_rudder, 0);
pos_control->get_accel_z_pid().set_integrator(throttle*10);
}
return;
}
motors_output();
plane.pitchController.reset_I();
plane.rollController.reset_I();
if (hal.util->get_soft_armed()) {
// scale surfaces for throttle
tailsitter_speed_scaling();
}
if (tailsitter.vectored_hover_gain > 0) {
// thrust vectoring VTOL modes
float aileron = SRV_Channels::get_output_scaled(SRV_Channel::k_aileron);
float elevator = SRV_Channels::get_output_scaled(SRV_Channel::k_elevator);
/*
apply extra elevator when at high pitch errors, using a
power law. This allows the motors to point straight up for
takeoff without integrator windup
*/
int32_t pitch_error_cd = (plane.nav_pitch_cd - ahrs_view->pitch_sensor) * 0.5;
float extra_pitch = constrain_float(pitch_error_cd, -4500, 4500) / 4500.0;
float extra_sign = extra_pitch > 0?1:-1;
float extra_elevator = extra_sign * powf(fabsf(extra_pitch), tailsitter.vectored_hover_power) * 4500;
float tilt_left = extra_elevator + (elevator + aileron) * tailsitter.vectored_hover_gain;
float tilt_right = extra_elevator + (elevator - aileron) * tailsitter.vectored_hover_gain;
if (fabsf(tilt_left) >= 4500 || fabsf(tilt_right) >= 4500) {
// prevent integrator windup
motors->limit.roll_pitch = 1;
motors->limit.yaw = 1;
}
SRV_Channels::set_output_scaled(SRV_Channel::k_tiltMotorLeft, tilt_left);
SRV_Channels::set_output_scaled(SRV_Channel::k_tiltMotorRight, tilt_right);
}
if (tailsitter.input_mask_chan > 0 &&
tailsitter.input_mask > 0 &&
RC_Channels::get_radio_in(tailsitter.input_mask_chan-1) > 1700) {
// the user is learning to prop-hang
if (tailsitter.input_mask & TAILSITTER_MASK_AILERON) {
SRV_Channels::set_output_scaled(SRV_Channel::k_aileron, plane.channel_roll->get_control_in_zero_dz());
}
if (tailsitter.input_mask & TAILSITTER_MASK_ELEVATOR) {
SRV_Channels::set_output_scaled(SRV_Channel::k_elevator, plane.channel_pitch->get_control_in_zero_dz());
}
if (tailsitter.input_mask & TAILSITTER_MASK_THROTTLE) {
SRV_Channels::set_output_scaled(SRV_Channel::k_throttle, plane.channel_throttle->get_control_in_zero_dz());
}
if (tailsitter.input_mask & TAILSITTER_MASK_RUDDER) {
SRV_Channels::set_output_scaled(SRV_Channel::k_rudder, plane.channel_rudder->get_control_in_zero_dz());
}
}
}
/*
return true when we have completed enough of a transition to switch to fixed wing control
*/
bool QuadPlane::tailsitter_transition_fw_complete(void)
{
if (plane.fly_inverted()) {
// transition immediately
return true;
}
int32_t roll_cd = labs(ahrs_view->roll_sensor);
if (roll_cd > 9000) {
roll_cd = 18000 - roll_cd;
}
if (labs(ahrs_view->pitch_sensor) > tailsitter.transition_angle*100 ||
roll_cd > tailsitter.transition_angle*100 ||
AP_HAL::millis() - transition_start_ms > uint32_t(transition_time_ms)) {
return true;
}
// still waiting
return false;
}
/*
return true when we have completed enough of a transition to switch to VTOL control
*/
bool QuadPlane::tailsitter_transition_vtol_complete(void) const
{
if (plane.fly_inverted()) {
// transition immediately
return true;
}
if (labs(plane.ahrs.pitch_sensor) > tailsitter.transition_angle*100 ||
labs(plane.ahrs.roll_sensor) > tailsitter.transition_angle*100 ||
AP_HAL::millis() - transition_start_ms > 2000) {
return true;
}
// still waiting
attitude_control->reset_rate_controller_I_terms();
return false;
}
// handle different tailsitter input types
void QuadPlane::tailsitter_check_input(void)
{
if (tailsitter_active() &&
tailsitter.input_type == TAILSITTER_INPUT_PLANE) {
// the user has asked for body frame controls when tailsitter
// is active. We switch around the control_in value for the
// channels to do this, as that ensures the value is
// consistent throughout the code
int16_t roll_in = plane.channel_roll->get_control_in();
int16_t yaw_in = plane.channel_rudder->get_control_in();
plane.channel_roll->set_control_in(yaw_in);
plane.channel_rudder->set_control_in(-roll_in);
}
}
/*
return true if we are a tailsitter transitioning to VTOL flight
*/
bool QuadPlane::in_tailsitter_vtol_transition(void) const
{
return is_tailsitter() && in_vtol_mode() && transition_state == TRANSITION_ANGLE_WAIT_VTOL;
}
/*
account for speed scaling of control surfaces in hover
*/
void QuadPlane::tailsitter_speed_scaling(void)
{
const float hover_throttle = motors->get_throttle_hover();
const float throttle = motors->get_throttle();
const float scaling_max = 5;
float scaling = 1;
if (is_zero(throttle)) {
scaling = scaling_max;
} else {
scaling = constrain_float(hover_throttle / throttle, 1/scaling_max, scaling_max);
}
const SRV_Channel::Aux_servo_function_t functions[2] = {
SRV_Channel::Aux_servo_function_t::k_aileron,
SRV_Channel::Aux_servo_function_t::k_elevator};
for (uint8_t i=0; i<ARRAY_SIZE(functions); i++) {
int32_t v = SRV_Channels::get_output_scaled(functions[i]);
v *= scaling;
v = constrain_int32(v, -SERVO_MAX, SERVO_MAX);
SRV_Channels::set_output_scaled(functions[i], v);
}
}