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Rover: Sailboat tacking improvements

This commit is contained in:
Peter Hall 2019-09-11 01:08:40 +01:00 committed by Randy Mackay
parent 7cd6aec799
commit d83745e305
3 changed files with 83 additions and 44 deletions
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4
APMrover2/mode.cpp
View File

@ -402,7 +402,9 @@ void Mode::navigate_to_waypoint()
if (g2.sailboat.use_indirect_route(desired_heading_cd)) {
// sailboats use heading controller when tacking upwind
desired_heading_cd = g2.sailboat.calc_heading(desired_heading_cd);
calc_steering_to_heading(desired_heading_cd, g2.wp_nav.get_pivot_rate());
// use pivot turn rate for tacks
const float turn_rate = g2.sailboat.tacking() ? g2.wp_nav.get_pivot_rate() : 0.0f;
calc_steering_to_heading(desired_heading_cd, turn_rate);
} else {
// call turn rate steering controller
calc_steering_from_turn_rate(g2.wp_nav.get_turn_rate_rads(), desired_speed, g2.wp_nav.get_reversed());

113
APMrover2/sailboat.cpp
View File

@ -2,6 +2,8 @@
#define SAILBOAT_AUTO_TACKING_TIMEOUT_MS 5000 // tacks in auto mode timeout if not successfully completed within this many milliseconds
#define SAILBOAT_TACKING_ACCURACY_DEG 10 // tack is considered complete when vehicle is within this many degrees of target tack angle
#define SAILBOAT_NOGO_PAD 10 // deg, the no go zone is padded by this much when deciding if we should use the Sailboat heading controller
#define TACK_RETRY_TIME_MS 5000 // Can only try another auto mode tack this many milliseconds after the last is cleared (either competed or timed-out)
/*
To Do List
- Improve tacking in light winds and bearing away in strong wings
@ -221,16 +223,17 @@ void Sailboat::get_throttle_and_mainsail_out(float desired_speed, float &throttl
// https://en.wikipedia.org/wiki/Velocity_made_good
float Sailboat::get_VMG() const
{
// return 0 if not heading towards waypoint
if (!rover.control_mode->is_autopilot_mode()) {
return 0.0f;
}
// return zero if we don't have a valid speed
float speed;
if (!rover.g2.attitude_control.get_forward_speed(speed)) {
return 0.0f;
}
// return speed if not heading towards a waypoint
if (!rover.control_mode->is_autopilot_mode()) {
return speed;
}
return (speed * cosf(wrap_PI(radians(rover.g2.wp_nav.wp_bearing_cd() * 0.01f) - rover.ahrs.yaw)));
}
@ -244,12 +247,17 @@ void Sailboat::handle_tack_request_acro()
currently_tacking = true;
tack_heading_rad = wrap_2PI(rover.ahrs.yaw + 2.0f * wrap_PI((rover.g2.windvane.get_true_wind_direction_rad() - rover.ahrs.yaw)));
auto_tack_request_ms = AP_HAL::millis();
tack_request_ms = AP_HAL::millis();
}
// return target heading in radians when tacking (only used in acro)
float Sailboat::get_tack_heading_rad() const
float Sailboat::get_tack_heading_rad()
{
if (fabsf(wrap_PI(tack_heading_rad - rover.ahrs.yaw)) < radians(SAILBOAT_TACKING_ACCURACY_DEG) ||
((AP_HAL::millis() - tack_request_ms) > SAILBOAT_AUTO_TACKING_TIMEOUT_MS)) {
clear_tack();
}
return tack_heading_rad;
}
@ -261,7 +269,7 @@ void Sailboat::handle_tack_request_auto()
}
// record time of request for tack. This will be processed asynchronously by sailboat_calc_heading
auto_tack_request_ms = AP_HAL::millis();
tack_request_ms = AP_HAL::millis();
}
// clear tacking state variables
@ -269,7 +277,8 @@ void Sailboat::clear_tack()
{
currently_tacking = false;
tack_assist = false;
auto_tack_request_ms = 0;
tack_request_ms = 0;
tack_clear_ms = AP_HAL::millis();
}
// returns true if boat is currently tacking
@ -286,11 +295,17 @@ bool Sailboat::use_indirect_route(float desired_heading_cd) const
return false;
}
// use sailboat controller until tack is completed
if (currently_tacking) {
return true;
}
// convert desired heading to radians
const float desired_heading_rad = radians(desired_heading_cd * 0.01f);
// check if desired heading is in the no go zone, if it is we can't go direct
return fabsf(wrap_PI(rover.g2.windvane.get_true_wind_direction_rad() - desired_heading_rad)) <= radians(sail_no_go);
// pad no go zone, this allows use of heading controller rather than L1 when close to the wind
return fabsf(wrap_PI(rover.g2.windvane.get_true_wind_direction_rad() - desired_heading_rad)) <= radians(sail_no_go + SAILBOAT_NOGO_PAD);
}
// if we can't sail on the desired heading then we should pick the best heading that we can sail on
@ -300,59 +315,85 @@ float Sailboat::calc_heading(float desired_heading_cd)
if (!tack_enabled()) {
return desired_heading_cd;
}
bool should_tack = false;
// find witch tack we are on
const AP_WindVane::Sailboat_Tack current_tack = rover.g2.windvane.get_current_tack();
// convert desired heading to radians
const float desired_heading_rad = radians(desired_heading_cd * 0.01f);
// if the desired heading is outside the no go zone there is no need to change it
// this allows use of heading controller rather than L1 when desired
// this is used in the 'SAILBOAT_NOGO_PAD' region
const float true_wind_rad = rover.g2.windvane.get_true_wind_direction_rad();
if (fabsf(wrap_PI(true_wind_rad - desired_heading_rad)) > radians(sail_no_go) && !currently_tacking) {
// calculate the tack the new heading would be on
const float new_heading_apparent_angle = wrap_PI(true_wind_rad - desired_heading_rad);
AP_WindVane::Sailboat_Tack new_tack;
if (is_negative(new_heading_apparent_angle)) {
new_tack = AP_WindVane::Sailboat_Tack::TACK_PORT;
} else {
new_tack = AP_WindVane::Sailboat_Tack::TACK_STARBOARD;
}
// if the new tack is not the same as the current tack we need might need to tack
if (new_tack != current_tack) {
// see if it would be a tack, the front of the boat going through the wind
// or a gybe, the back of the boat going through the wind
const float app_wind_rad = rover.g2.windvane.get_apparent_wind_direction_rad();
if (fabsf(app_wind_rad) + fabsf(new_heading_apparent_angle) < M_PI) {
should_tack = true;
}
}
if (!should_tack) {
return desired_heading_cd;
}
}
// check for user requested tack
uint32_t now = AP_HAL::millis();
if (auto_tack_request_ms != 0) {
if (tack_request_ms != 0 && !should_tack && !currently_tacking) {
// set should_tack flag is user requested tack within last 0.5 sec
should_tack = ((now - auto_tack_request_ms) < 500);
auto_tack_request_ms = 0;
}
// calculate left and right no go headings looking upwind
const float true_wind_rad = rover.g2.windvane.get_true_wind_direction_rad();
const float left_no_go_heading_rad = wrap_2PI(true_wind_rad + radians(sail_no_go));
const float right_no_go_heading_rad = wrap_2PI(true_wind_rad - radians(sail_no_go));
// calculate current tack, Port if heading is left of no-go, STBD if right of no-go
Sailboat_Tack current_tack;
if (is_negative(rover.g2.windvane.get_apparent_wind_direction_rad())) {
current_tack = TACK_PORT;
} else {
current_tack = TACK_STARBOARD;
should_tack = ((now - tack_request_ms) < 500);
tack_request_ms = 0;
}
// trigger tack if cross track error larger than waypoint_overshoot parameter
// this effectively defines a 'corridor' of width 2*waypoint_overshoot that the boat will stay within
const float cross_track_error = rover.g2.wp_nav.crosstrack_error();
if ((fabsf(cross_track_error) >= rover.g2.wp_nav.get_overshoot()) && !is_zero(rover.g2.wp_nav.get_overshoot()) && !currently_tacking) {
if ((fabsf(cross_track_error) >= rover.g2.wp_nav.get_overshoot()) && !is_zero(rover.g2.wp_nav.get_overshoot()) && !should_tack && !currently_tacking) {
// make sure the new tack will reduce the cross track error
// if were on starboard tack we are traveling towards the left hand boundary
if (is_positive(cross_track_error) && (current_tack == TACK_STARBOARD)) {
if (is_positive(cross_track_error) && (current_tack == AP_WindVane::Sailboat_Tack::TACK_STARBOARD)) {
should_tack = true;
}
// if were on port tack we are traveling towards the right hand boundary
if (is_negative(cross_track_error) && (current_tack == TACK_PORT)) {
if (is_negative(cross_track_error) && (current_tack == AP_WindVane::Sailboat_Tack::TACK_PORT)) {
should_tack = true;
}
}
// calculate left and right no go headings looking upwind, Port tack heading is left no-go, STBD tack is right of no-go
const float left_no_go_heading_rad = wrap_2PI(true_wind_rad + radians(sail_no_go));
const float right_no_go_heading_rad = wrap_2PI(true_wind_rad - radians(sail_no_go));
// if tack triggered, calculate target heading
if (should_tack) {
if (should_tack && (now - tack_clear_ms) > TACK_RETRY_TIME_MS) {
gcs().send_text(MAV_SEVERITY_INFO, "Sailboat: Tacking");
// calculate target heading for the new tack
switch (current_tack) {
case TACK_PORT:
case AP_WindVane::Sailboat_Tack::TACK_PORT:
tack_heading_rad = right_no_go_heading_rad;
break;
case TACK_STARBOARD:
case AP_WindVane::Sailboat_Tack::TACK_STARBOARD:
tack_heading_rad = left_no_go_heading_rad;
break;
}
currently_tacking = true;
auto_tack_start_ms = AP_HAL::millis();
auto_tack_start_ms = now;
}
// if we are tacking we maintain the target heading until the tack completes or times out
@ -374,8 +415,8 @@ float Sailboat::calc_heading(float desired_heading_cd)
return degrees(tack_heading_rad) * 100.0f;
}
// return closest possible heading to wind
if (current_tack == TACK_PORT) {
// return the correct heading for our current tack
if (current_tack == AP_WindVane::Sailboat_Tack::TACK_PORT) {
return degrees(left_no_go_heading_rad) * 100.0f;
} else {
return degrees(right_no_go_heading_rad) * 100.0f;

10
APMrover2/sailboat.h
View File

@ -49,7 +49,7 @@ public:
void handle_tack_request_acro();
// return target heading in radians when tacking (only used in acro)
float get_tack_heading_rad() const;
float get_tack_heading_rad();
// handle user initiated tack while in autonomous modes (Auto, Guided, RTL, SmartRTL, etc)
void handle_tack_request_auto();
@ -97,16 +97,12 @@ private:
AP_Float sail_no_go;
AP_Float sail_windspeed_min;
enum Sailboat_Tack {
TACK_PORT,
TACK_STARBOARD
};
RC_Channel *channel_mainsail; // rc input channel for controlling mainsail
bool currently_tacking; // true when sailboat is in the process of tacking to a new heading
float tack_heading_rad; // target heading in radians while tacking in either acro or autonomous modes
uint32_t auto_tack_request_ms; // system time user requested tack in autonomous modes
uint32_t tack_request_ms; // system time user requested tack
uint32_t auto_tack_start_ms; // system time when tack was started in autonomous mode
uint32_t tack_clear_ms; // system time when tack was cleared
bool tack_assist; // true if we should use some throttle to assist tack
UseMotor motor_state; // current state of motor output
};