int16_t AP_MotorsMulticopter::calc_thrust_to_pwm(float thrust_in) const
{
thrust_in = constrain_float(thrust_in, 0.0f, 1.0f);
return get_pwm_output_min() + (get_pwm_output_max()-get_pwm_output_min()) * (_spin_min + (_spin_max-_spin_min)*apply_thrust_curve_and_volt_scaling(thrust_in));
}
// output_armed - sends commands to the motors
// includes new scaling stability patch
// TODO pull code that is common to output_armed_not_stabilizing into helper functions
void AP_MotorsMatrix::output_armed_stabilizing()
{
int8_t i;
int16_t roll_pwm; // roll pwm value, initially calculated by calc_roll_pwm() but may be modified after, +/- 400
int16_t pitch_pwm; // pitch pwm value, initially calculated by calc_roll_pwm() but may be modified after, +/- 400
int16_t yaw_pwm; // yaw pwm value, initially calculated by calc_yaw_pwm() but may be modified after, +/- 400
int16_t throttle_radio_output; // total throttle pwm value, summed onto throttle channel minimum, typically ~1100-1900
int16_t out_min_pwm = _throttle_radio_min + _min_throttle; // minimum pwm value we can send to the motors
int16_t out_max_pwm = _throttle_radio_max; // maximum pwm value we can send to the motors
int16_t out_mid_pwm = (out_min_pwm+out_max_pwm)/2; // mid pwm value we can send to the motors
int16_t out_best_thr_pwm; // the is the best throttle we can come up which provides good control without climbing
float rpy_scale = 1.0; // this is used to scale the roll, pitch and yaw to fit within the motor limits
int16_t rpy_out[AP_MOTORS_MAX_NUM_MOTORS]; // buffer so we don't have to multiply coefficients multiple times.
int16_t motor_out[AP_MOTORS_MAX_NUM_MOTORS]; // final outputs sent to the motors
int16_t rpy_low = 0; // lowest motor value
int16_t rpy_high = 0; // highest motor value
int16_t yaw_allowed; // amount of yaw we can fit in
int16_t thr_adj; // the difference between the pilot's desired throttle and out_best_thr_pwm (the throttle that is actually provided)
// initialize limits flags
limit.roll_pitch = false;
limit.yaw = false;
limit.throttle_lower = false;
limit.throttle_upper = false;
// Ensure throttle is within bounds of 0 to 1000
int16_t thr_in_min = rel_pwm_to_thr_range(_min_throttle);
if (_throttle_control_input <= thr_in_min) {
_throttle_control_input = thr_in_min;
limit.throttle_lower = true;
}
if (_throttle_control_input >= _max_throttle) {
_throttle_control_input = _max_throttle;
limit.throttle_upper = true;
}
roll_pwm = calc_roll_pwm();
pitch_pwm = calc_pitch_pwm();
yaw_pwm = calc_yaw_pwm();
throttle_radio_output = calc_throttle_radio_output();
// calculate roll and pitch for each motor
// set rpy_low and rpy_high to the lowest and highest values of the motors
for (i=0; i<AP_MOTORS_MAX_NUM_MOTORS; i++) {
if (motor_enabled[i]) {
rpy_out[i] = roll_pwm * _roll_factor[i] * get_compensation_gain() +
pitch_pwm * _pitch_factor[i] * get_compensation_gain()+yaw_pwm*_yaw_factor[i]*(1000-m_Conv)/1000;
// record lowest roll pitch command
if (rpy_out[i] < rpy_low) {
rpy_low = rpy_out[i];
}
// record highest roll pich command
if (rpy_out[i] > rpy_high) {
rpy_high = rpy_out[i];
}
}
}
// calculate throttle that gives most possible room for yaw (range 1000 ~ 2000) which is the lower of:
// 1. mid throttle - average of highest and lowest motor (this would give the maximum possible room margin above the highest motor and below the lowest)
// 2. the higher of:
// a) the pilot's throttle input
// b) the mid point between the pilot's input throttle and hover-throttle
// Situation #2 ensure we never increase the throttle above hover throttle unless the pilot has commanded this.
// Situation #2b allows us to raise the throttle above what the pilot commanded but not so far that it would actually cause the copter to rise.
// We will choose #1 (the best throttle for yaw control) if that means reducing throttle to the motors (i.e. we favour reducing throttle *because* it provides better yaw control)
// We will choose #2 (a mix of pilot and hover throttle) only when the throttle is quite low. We favour reducing throttle instead of better yaw control because the pilot has commanded it
int16_t motor_mid = (rpy_low+rpy_high)/2;
out_best_thr_pwm = min(out_mid_pwm - motor_mid, max(throttle_radio_output, throttle_radio_output*max(0,1.0f-_throttle_thr_mix)+get_hover_throttle_as_pwm()*_throttle_thr_mix));
// calculate amount of yaw we can fit into the throttle range
// this is always equal to or less than the requested yaw from the pilot or rate controller
yaw_allowed = min(out_max_pwm - out_best_thr_pwm, out_best_thr_pwm - out_min_pwm) - (rpy_high-rpy_low)/2;
yaw_allowed = max(yaw_allowed, _yaw_headroom);
if (yaw_pwm >= 0) {
// if yawing right
if (yaw_allowed > yaw_pwm * get_compensation_gain()) {
yaw_allowed = yaw_pwm * get_compensation_gain(); // to-do: this is bad form for yaw_allows to change meaning to become the amount that we are going to output
}else{
limit.yaw = true;
}
}else{
// if yawing left
yaw_allowed = -yaw_allowed;
if (yaw_allowed < yaw_pwm * get_compensation_gain()) {
yaw_allowed = yaw_pwm * get_compensation_gain(); // to-do: this is bad form for yaw_allows to change meaning to become the amount that we are going to output
}else{
limit.yaw = true;
}
}
// add yaw to intermediate numbers for each motor
rpy_low = 0;
rpy_high = 0;
for (i=0; i<AP_MOTORS_MAX_NUM_MOTORS; i++) {
if (motor_enabled[i]) {
//rpy_out[i] = rpy_out[i] +
// yaw_allowed * _yaw_factor[i];
// record lowest roll+pitch+yaw command
if( rpy_out[i] < rpy_low ) {
rpy_low = rpy_out[i];
}
// record highest roll+pitch+yaw command
if( rpy_out[i] > rpy_high) {
rpy_high = rpy_out[i];
}
}
}
// check everything fits
thr_adj = throttle_radio_output - out_best_thr_pwm;
// calculate upper and lower limits of thr_adj
int16_t thr_adj_max = max(out_max_pwm-(out_best_thr_pwm+rpy_high),0);
// if we are increasing the throttle (situation #2 above)..
if (thr_adj > 0) {
// increase throttle as close as possible to requested throttle
// without going over out_max_pwm
if (thr_adj > thr_adj_max){
thr_adj = thr_adj_max;
// we haven't even been able to apply full throttle command
limit.throttle_upper = true;
}
}else if(thr_adj < 0){
// decrease throttle as close as possible to requested throttle
// without going under out_min_pwm or over out_max_pwm
// earlier code ensures we can't break both boundaries
int16_t thr_adj_min = min(out_min_pwm-(out_best_thr_pwm+rpy_low),0);
if (thr_adj > thr_adj_max) {
thr_adj = thr_adj_max;
limit.throttle_upper = true;
}
if (thr_adj < thr_adj_min) {
thr_adj = thr_adj_min;
}
}
// do we need to reduce roll, pitch, yaw command
// earlier code does not allow both limit's to be passed simultaneously with abs(_yaw_factor)<1
if ((rpy_low+out_best_thr_pwm)+thr_adj < out_min_pwm){
// protect against divide by zero
if (rpy_low != 0) {
rpy_scale = (float)(out_min_pwm-thr_adj-out_best_thr_pwm)/rpy_low;
}
// we haven't even been able to apply full roll, pitch and minimal yaw without scaling
limit.roll_pitch = true;
limit.yaw = true;
}else if((rpy_high+out_best_thr_pwm)+thr_adj > out_max_pwm){
// protect against divide by zero
if (rpy_high != 0) {
rpy_scale = (float)(out_max_pwm-thr_adj-out_best_thr_pwm)/rpy_high;
}
// we haven't even been able to apply full roll, pitch and minimal yaw without scaling
limit.roll_pitch = true;
limit.yaw = true;
}
// add scaled roll, pitch, constrained yaw and throttle for each motor
for (i=0; i<AP_MOTORS_MAX_NUM_MOTORS; i++) {
if (motor_enabled[i]) {
motor_out[i] = out_best_thr_pwm+thr_adj +
rpy_scale*rpy_out[i];
}
}
// apply thrust curve and voltage scaling
for (i=0; i<AP_MOTORS_MAX_NUM_MOTORS; i++) {
if (motor_enabled[i]) {
motor_out[i] = apply_thrust_curve_and_volt_scaling(motor_out[i], out_min_pwm, out_max_pwm);
}
}
// clip motor output if required (shouldn't be)
for (i=0; i<AP_MOTORS_MAX_NUM_MOTORS; i++) {
if (motor_enabled[i]) {
motor_out[i] = constrain_int16(motor_out[i], out_min_pwm, out_max_pwm);
}
}
// send output to each motor
for( i=0; i<AP_MOTORS_MAX_NUM_MOTORS; i++ ) {
if( motor_enabled[i] ) {
hal.rcout->write(pgm_read_byte(&_motor_to_channel_map[i]), motor_out[i]);
}
}
}
// output_armed - sends commands to the motors
void AP_MotorsCoax::output_armed()
{
int16_t out_min = _rc_throttle.radio_min + _min_throttle;
int16_t motor_out[4];
// Throttle is 0 to 1000 only
if (_rc_throttle.servo_out <= 0) {
_rc_throttle.servo_out = 0;
limit.throttle_lower = true;
}
if (_rc_throttle.servo_out >= _max_throttle) {
_rc_throttle.servo_out = _max_throttle;
limit.throttle_upper = true;
}
// capture desired throttle and yaw from receiver
_rc_throttle.calc_pwm();
_rc_yaw.calc_pwm();
// if we are not sending a throttle output, we cut the motors
if(_rc_throttle.servo_out == 0) {
// range check spin_when_armed
if (_spin_when_armed < 0) {
_spin_when_armed = 0;
}
if (_spin_when_armed > _min_throttle) {
_spin_when_armed = _min_throttle;
}
motor_out[AP_MOTORS_MOT_3] = _rc_throttle.radio_min + _spin_when_armed;
motor_out[AP_MOTORS_MOT_4] = _rc_throttle.radio_min + _spin_when_armed;
}else{
// check if throttle is below limit
if (_rc_throttle.servo_out <= _min_throttle) { // perhaps being at min throttle itself is not a problem, only being under is
limit.throttle_lower = true;
_rc_throttle.servo_out = _min_throttle;
_rc_throttle.calc_pwm(); // recalculate radio.out
}
// motors
motor_out[AP_MOTORS_MOT_3] = _rev_yaw*_rc_yaw.pwm_out + _rc_throttle.radio_out;
motor_out[AP_MOTORS_MOT_4] = -_rev_yaw*_rc_yaw.pwm_out +_rc_throttle.radio_out;
// front
_servo1.servo_out = _rev_roll*_rc_roll.servo_out;
// right
_servo2.servo_out = _rev_pitch*_rc_pitch.servo_out;
_servo1.calc_pwm();
_servo2.calc_pwm();
// adjust for thrust curve and voltage scaling
motor_out[AP_MOTORS_MOT_3] = apply_thrust_curve_and_volt_scaling(motor_out[AP_MOTORS_MOT_3], out_min, _rc_throttle.radio_max);
motor_out[AP_MOTORS_MOT_4] = apply_thrust_curve_and_volt_scaling(motor_out[AP_MOTORS_MOT_4], out_min, _rc_throttle.radio_max);
// ensure motors don't drop below a minimum value and stop
motor_out[AP_MOTORS_MOT_3] = max(motor_out[AP_MOTORS_MOT_3], out_min);
motor_out[AP_MOTORS_MOT_4] = max(motor_out[AP_MOTORS_MOT_4], out_min);
}
// send output to each motor
hal.rcout->write(pgm_read_byte(&_motor_to_channel_map[AP_MOTORS_MOT_1]), _servo1.radio_out);
hal.rcout->write(pgm_read_byte(&_motor_to_channel_map[AP_MOTORS_MOT_2]), _servo2.radio_out);
hal.rcout->write(pgm_read_byte(&_motor_to_channel_map[AP_MOTORS_MOT_3]), motor_out[AP_MOTORS_MOT_3]);
hal.rcout->write(pgm_read_byte(&_motor_to_channel_map[AP_MOTORS_MOT_4]), motor_out[AP_MOTORS_MOT_4]);
}
int16_t AP_MotorsMulticopter::calc_thrust_to_pwm(float thrust_in) const
{
return constrain_int16((_throttle_radio_min + _min_throttle + apply_thrust_curve_and_volt_scaling(thrust_in) *
( _throttle_radio_max - (_throttle_radio_min + _min_throttle))), _throttle_radio_min + _min_throttle, _throttle_radio_max);
}
// sends commands to the motors
// TODO pull code that is common to output_armed_not_stabilizing into helper functions
void AP_MotorsTri::output_armed_stabilizing()
{
int16_t roll_pwm; // roll pwm value, initially calculated by calc_roll_pwm() but may be modified after, +/- 400
int16_t pitch_pwm; // pitch pwm value, initially calculated by calc_roll_pwm() but may be modified after, +/- 400
int16_t throttle_radio_output; // total throttle pwm value, summed onto throttle channel minimum, typically ~1100-1900
int16_t yaw_radio_output; // final yaw pwm value sent to motors, typically ~1100-1900
int16_t out_min = _throttle_radio_min + _min_throttle;
int16_t out_max = _throttle_radio_max;
int16_t motor_out[AP_MOTORS_MOT_4+1];
// initialize limits flags
limit.roll_pitch = false;
limit.yaw = false;
limit.throttle_lower = false;
limit.throttle_upper = false;
// Throttle is 0 to 1000 only
int16_t thr_in_min = rel_pwm_to_thr_range(_min_throttle);
if (_throttle_control_input <= thr_in_min) {
_throttle_control_input = thr_in_min;
limit.throttle_lower = true;
}
if (_throttle_control_input >= _max_throttle) {
_throttle_control_input = _max_throttle;
limit.throttle_upper = true;
}
// tricopters limit throttle to 80%
// To-Do: implement improved stability patch and remove this limit
if (_throttle_control_input > 800) {
_throttle_control_input = 800;
limit.throttle_upper = true;
}
roll_pwm = calc_roll_pwm();
pitch_pwm = calc_pitch_pwm();
throttle_radio_output = calc_throttle_radio_output();
yaw_radio_output = calc_yaw_radio_output();
// if we are not sending a throttle output, we cut the motors
if( is_zero(_throttle_control_input) ) {
// range check spin_when_armed
if (_spin_when_armed_ramped < 0) {
_spin_when_armed_ramped = 0;
}
if (_spin_when_armed_ramped > _min_throttle) {
_spin_when_armed_ramped = _min_throttle;
}
motor_out[AP_MOTORS_MOT_1] = _throttle_radio_min + _spin_when_armed_ramped;
motor_out[AP_MOTORS_MOT_2] = _throttle_radio_min + _spin_when_armed_ramped;
motor_out[AP_MOTORS_MOT_4] = _throttle_radio_min + _spin_when_armed_ramped;
}else{
int16_t roll_out = (float)(roll_pwm * 0.866f);
int16_t pitch_out = pitch_pwm / 2;
// check if throttle is below limit
if (_throttle_control_input <= _min_throttle) {
limit.throttle_lower = true;
_throttle_control_input = _min_throttle;
throttle_radio_output = calc_throttle_radio_output();
}
// TODO: set limits.roll_pitch and limits.yaw
//left front
motor_out[AP_MOTORS_MOT_2] = throttle_radio_output + roll_out + pitch_out;
//right front
motor_out[AP_MOTORS_MOT_1] = throttle_radio_output - roll_out + pitch_out;
// rear
motor_out[AP_MOTORS_MOT_4] = throttle_radio_output - pitch_pwm;
// Tridge's stability patch
if(motor_out[AP_MOTORS_MOT_1] > out_max) {
motor_out[AP_MOTORS_MOT_2] -= (motor_out[AP_MOTORS_MOT_1] - out_max);
motor_out[AP_MOTORS_MOT_4] -= (motor_out[AP_MOTORS_MOT_1] - out_max);
motor_out[AP_MOTORS_MOT_1] = out_max;
}
if(motor_out[AP_MOTORS_MOT_2] > out_max) {
motor_out[AP_MOTORS_MOT_1] -= (motor_out[AP_MOTORS_MOT_2] - out_max);
motor_out[AP_MOTORS_MOT_4] -= (motor_out[AP_MOTORS_MOT_2] - out_max);
motor_out[AP_MOTORS_MOT_2] = out_max;
}
if(motor_out[AP_MOTORS_MOT_4] > out_max) {
motor_out[AP_MOTORS_MOT_1] -= (motor_out[AP_MOTORS_MOT_4] - out_max);
motor_out[AP_MOTORS_MOT_2] -= (motor_out[AP_MOTORS_MOT_4] - out_max);
motor_out[AP_MOTORS_MOT_4] = out_max;
}
// adjust for thrust curve and voltage scaling
motor_out[AP_MOTORS_MOT_1] = apply_thrust_curve_and_volt_scaling(motor_out[AP_MOTORS_MOT_1], out_min, out_max);
motor_out[AP_MOTORS_MOT_2] = apply_thrust_curve_and_volt_scaling(motor_out[AP_MOTORS_MOT_2], out_min, out_max);
motor_out[AP_MOTORS_MOT_4] = apply_thrust_curve_and_volt_scaling(motor_out[AP_MOTORS_MOT_4], out_min, out_max);
// ensure motors don't drop below a minimum value and stop
motor_out[AP_MOTORS_MOT_1] = MAX(motor_out[AP_MOTORS_MOT_1], out_min);
motor_out[AP_MOTORS_MOT_2] = MAX(motor_out[AP_MOTORS_MOT_2], out_min);
motor_out[AP_MOTORS_MOT_4] = MAX(motor_out[AP_MOTORS_MOT_4], out_min);
}
hal.rcout->cork();
// send output to each motor
hal.rcout->write(AP_MOTORS_MOT_1, motor_out[AP_MOTORS_MOT_1]);
hal.rcout->write(AP_MOTORS_MOT_2, motor_out[AP_MOTORS_MOT_2]);
hal.rcout->write(AP_MOTORS_MOT_4, motor_out[AP_MOTORS_MOT_4]);
// send out to yaw command to tail servo
hal.rcout->write(AP_MOTORS_CH_TRI_YAW, yaw_radio_output);
hal.rcout->push();
}
int16_t AP_MotorsMulticopter::calc_thrust_to_pwm(float thrust_in) const
{
thrust_in = constrain_float(thrust_in, 0, 1);
return constrain_int16((get_pwm_output_min() + _min_throttle + apply_thrust_curve_and_volt_scaling(thrust_in) *
(get_pwm_output_max() - (get_pwm_output_min() + _min_throttle))), get_pwm_output_min() + _min_throttle, get_pwm_output_max());
}
