ardupilot/APMrover2/sailboat.cpp

486 lines
19 KiB
C++

#include "Rover.h"
#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
- consider drag vs lift sailing differences, ie upwind sail is like wing, dead down wind sail is like parachute
- max speed paramiter and controller, for mapping you may not want to go too fast
- mavlink sailing messages
- motor sailing, some boats may also have motor, we need to decide at what point we would be better of just motoring in low wind, or for a tight loiter, or to hit waypoint exactly, or if stuck head to wind, or to reverse...
- smart decision making, ie tack on windshifts, what to do if stuck head to wind
- some sailing codes track waves to try and 'surf' and to allow tacking on a flat bit, not sure if there is much gain to be had here
- add some sort of pitch monitoring to prevent nose diving in heavy weather
- pitch PID for hydrofoils
- more advanced sail control, ie twist
- independent sheeting for main and jib
- wing type sails with 'elevator' control
- tack on depth sounder info to stop sailing into shallow water on indirect sailing routes
- add option to do proper tacks, ie tacking on flat spot in the waves, or only try once at a certain speed, or some better method than just changing the desired heading suddenly
*/
const AP_Param::GroupInfo Sailboat::var_info[] = {
// @Param: ENABLE
// @DisplayName: Enable Sailboat
// @Description: This enables Sailboat functionality
// @Values: 0:Disable,1:Enable
// @User: Standard
// @RebootRequired: True
AP_GROUPINFO_FLAGS("ENABLE", 1, Sailboat, enable, 0, AP_PARAM_FLAG_ENABLE),
// @Param: ANGLE_MIN
// @DisplayName: Sail min angle
// @Description: Mainsheet tight, angle between centerline and boom
// @Units: deg
// @Range: 0 90
// @Increment: 1
// @User: Standard
AP_GROUPINFO("ANGLE_MIN", 2, Sailboat, sail_angle_min, 0),
// @Param: ANGLE_MAX
// @DisplayName: Sail max angle
// @Description: Mainsheet loose, angle between centerline and boom
// @Units: deg
// @Range: 0 90
// @Increment: 1
// @User: Standard
AP_GROUPINFO("ANGLE_MAX", 3, Sailboat, sail_angle_max, 90),
// @Param: ANGLE_IDEAL
// @DisplayName: Sail ideal angle
// @Description: Ideal angle between sail and apparent wind
// @Units: deg
// @Range: 0 90
// @Increment: 1
// @User: Standard
AP_GROUPINFO("ANGLE_IDEAL", 4, Sailboat, sail_angle_ideal, 25),
// @Param: HEEL_MAX
// @DisplayName: Sailing maximum heel angle
// @Description: When in auto sail trim modes the heel will be limited to this value using PID control
// @Units: deg
// @Range: 0 90
// @Increment: 1
// @User: Standard
AP_GROUPINFO("HEEL_MAX", 5, Sailboat, sail_heel_angle_max, 15),
// @Param: NO_GO_ANGLE
// @DisplayName: Sailing no go zone angle
// @Description: The typical closest angle to the wind the vehicle will sail at. the vehicle will sail at this angle when going upwind
// @Units: deg
// @Range: 0 90
// @Increment: 1
// @User: Standard
AP_GROUPINFO("NO_GO_ANGLE", 6, Sailboat, sail_no_go, 45),
// @Param: WNDSPD_MIN
// @DisplayName: Sailboat minimum wind speed to sail in
// @Description: Sailboat minimum wind speed to continue sail in, at lower wind speeds the sailboat will motor if one is fitted
// @Units: m/s
// @Range: 0 5
// @Increment: 0.1
// @User: Standard
AP_GROUPINFO("WNDSPD_MIN", 7, Sailboat, sail_windspeed_min, 0),
// @Param: XTRACK_MAX
// @DisplayName: Sailing vehicle max cross track error
// @Description: The sail boat will tack when it reaches this cross track error, defines a corridor of 2 times this value wide, 0 disables
// @Units: m
// @Range: 5 25
// @Increment: 1
// @User: Standard
AP_GROUPINFO("XTRACK_MAX", 8, Sailboat, xtrack_max, 10),
// @Param: LOIT_RADIUS
// @DisplayName: Loiter radius
// @Description: When in sailing modes the vehicle will keep moving within this loiter radius
// @Units: m
// @Range: 0 20
// @Increment: 1
// @User: Standard
AP_GROUPINFO("LOIT_RADIUS", 9, Sailboat, loit_radius, 5),
AP_GROUPEND
};
/*
constructor
*/
Sailboat::Sailboat()
{
AP_Param::setup_object_defaults(this, var_info);
}
// true if sailboat navigation (aka tacking) is enabled
bool Sailboat::tack_enabled() const
{
// tacking disabled if not a sailboat
if (!sail_enabled()) {
return false;
}
// tacking disabled if motor is always on
if (motor_state == UseMotor::USE_MOTOR_ALWAYS) {
return false;
}
// disable tacking if motor is available and wind is below cutoff
if (motor_assist_low_wind()) {
return false;
}
// otherwise tacking is enabled
return true;
}
void Sailboat::init()
{
// sailboat defaults
if (sail_enabled()) {
rover.g2.crash_angle.set_default(0);
}
if (tack_enabled()) {
rover.g2.loit_type.set_default(1);
}
// initialise motor state to USE_MOTOR_ASSIST
// this will silently fail if there is no motor attached
set_motor_state(UseMotor::USE_MOTOR_ASSIST, false);
}
// initialise rc input (channel_mainsail), may be called intermittently
void Sailboat::init_rc_in()
{
// get auxiliary throttle value
RC_Channel *rc_ptr = rc().find_channel_for_option(RC_Channel::AUX_FUNC::MAINSAIL);
if (rc_ptr != nullptr) {
// use aux as sail input if defined
channel_mainsail = rc_ptr;
channel_mainsail->set_angle(100);
channel_mainsail->set_default_dead_zone(30);
} else {
// use throttle channel
channel_mainsail = rover.channel_throttle;
}
}
// decode pilot mainsail input and return in steer_out and throttle_out arguments
// mainsail_out is in the range 0 to 100, defaults to 100 (fully relaxed) if no input configured
void Sailboat::get_pilot_desired_mainsail(float &mainsail_out)
{
// no RC input means mainsail is moved to trim
if ((rover.failsafe.bits & FAILSAFE_EVENT_THROTTLE) || (channel_mainsail == nullptr)) {
mainsail_out = 100.0f;
return;
}
mainsail_out = constrain_float(channel_mainsail->get_control_in(), 0.0f, 100.0f);
}
// calculate throttle and mainsail angle required to attain desired speed (in m/s)
// returns true if successful, false if sailboats not enabled
void Sailboat::get_throttle_and_mainsail_out(float desired_speed, float &throttle_out, float &mainsail_out)
{
if (!sail_enabled()) {
throttle_out = 0.0f;
mainsail_out = 0.0f;
return;
}
// run speed controller if motor is forced on or motor assistance is required for low speeds or tacking
if ((motor_state == UseMotor::USE_MOTOR_ALWAYS) ||
motor_assist_tack() ||
motor_assist_low_wind()) {
// run speed controller - duplicate of calls found in mode::calc_throttle();
throttle_out = 100.0f * rover.g2.attitude_control.get_throttle_out_speed(desired_speed,
rover.g2.motors.limit.throttle_lower,
rover.g2.motors.limit.throttle_upper,
rover.g.speed_cruise,
rover.g.throttle_cruise * 0.01f,
rover.G_Dt);
} else {
throttle_out = 0.0f;
}
//
// mainsail control
//
// if we are motoring or attempting to reverse relax the sail
if (motor_state == UseMotor::USE_MOTOR_ALWAYS || !is_positive(desired_speed)) {
mainsail_out = 100.0f;
} else {
// + is wind over starboard side, - is wind over port side, but as the sails are sheeted the same on each side it makes no difference so take abs
float wind_dir_apparent = fabsf(rover.g2.windvane.get_apparent_wind_direction_rad());
wind_dir_apparent = degrees(wind_dir_apparent);
// set the main sail to the ideal angle to the wind
float mainsail_angle = wind_dir_apparent -sail_angle_ideal;
// make sure between allowable range
mainsail_angle = constrain_float(mainsail_angle,sail_angle_min, sail_angle_max);
// linear interpolate mainsail value (0 to 100) from wind angle mainsail_angle
float mainsail_base = linear_interpolate(0.0f, 100.0f, mainsail_angle,sail_angle_min,sail_angle_max);
// use PID controller to sheet out
const float pid_offset = rover.g2.attitude_control.get_sail_out_from_heel(radians(sail_heel_angle_max), rover.G_Dt) * 100.0f;
mainsail_out = constrain_float((mainsail_base + pid_offset), 0.0f ,100.0f);
}
}
// Velocity Made Good, this is the speed we are traveling towards the desired destination
// only for logging at this stage
// https://en.wikipedia.org/wiki/Velocity_made_good
float Sailboat::get_VMG() const
{
// 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)));
}
// handle user initiated tack while in acro mode
void Sailboat::handle_tack_request_acro()
{
if (!tack_enabled() || currently_tacking) {
return;
}
// set tacking heading target to the current angle relative to the true wind but on the new tack
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)));
tack_request_ms = AP_HAL::millis();
}
// return target heading in radians when tacking (only used in acro)
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;
}
// handle user initiated tack while in autonomous modes (Auto, Guided, RTL, SmartRTL, etc)
void Sailboat::handle_tack_request_auto()
{
if (!tack_enabled() || currently_tacking) {
return;
}
// record time of request for tack. This will be processed asynchronously by sailboat_calc_heading
tack_request_ms = AP_HAL::millis();
}
// clear tacking state variables
void Sailboat::clear_tack()
{
currently_tacking = false;
tack_assist = false;
tack_request_ms = 0;
tack_clear_ms = AP_HAL::millis();
}
// returns true if boat is currently tacking
bool Sailboat::tacking() const
{
return tack_enabled() && currently_tacking;
}
// returns true if sailboat should take a indirect navigation route to go upwind
// desired_heading should be in centi-degrees
bool Sailboat::use_indirect_route(float desired_heading_cd) const
{
if (!tack_enabled()) {
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
// 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
// this function assumes the caller has already checked sailboat_use_indirect_route(desired_heading_cd) returned true
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 (tack_request_ms != 0 && !should_tack && !currently_tacking) {
// set should_tack flag is user requested tack within last 0.5 sec
should_tack = ((now - tack_request_ms) < 500);
tack_request_ms = 0;
}
// trigger tack if cross track error larger than xtrack_max parameter
// this effectively defines a 'corridor' of width 2*xtrack_max that the boat will stay within
const float cross_track_error = rover.g2.wp_nav.crosstrack_error();
if ((fabsf(cross_track_error) >= xtrack_max) && !is_zero(xtrack_max) && !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 == 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 == 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 && (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 AP_WindVane::Sailboat_Tack::TACK_PORT:
tack_heading_rad = right_no_go_heading_rad;
break;
case AP_WindVane::Sailboat_Tack::TACK_STARBOARD:
tack_heading_rad = left_no_go_heading_rad;
break;
}
currently_tacking = true;
auto_tack_start_ms = now;
}
// if we are tacking we maintain the target heading until the tack completes or times out
if (currently_tacking) {
// check if we have reached target
if (fabsf(wrap_PI(tack_heading_rad - rover.ahrs.yaw)) <= radians(SAILBOAT_TACKING_ACCURACY_DEG)) {
clear_tack();
} else if ((now - auto_tack_start_ms) > SAILBOAT_AUTO_TACKING_TIMEOUT_MS) {
// tack has taken too long
if ((motor_state == UseMotor::USE_MOTOR_ASSIST) && (now - auto_tack_start_ms) < (3.0f * SAILBOAT_AUTO_TACKING_TIMEOUT_MS)) {
// if we have throttle available use it for another two time periods to get the tack done
tack_assist = true;
} else {
gcs().send_text(MAV_SEVERITY_INFO, "Sailboat: Tacking timed out");
clear_tack();
}
}
// return tack target heading
return degrees(tack_heading_rad) * 100.0f;
}
// 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;
}
}
// set state of motor
void Sailboat::set_motor_state(UseMotor state, bool report_failure)
{
// always allow motor to be disabled
if (state == UseMotor::USE_MOTOR_NEVER) {
motor_state = state;
return;
}
// enable assistance or always on if a motor is defined
if (rover.g2.motors.have_skid_steering() ||
SRV_Channels::function_assigned(SRV_Channel::k_throttle) ||
rover.get_frame_type() != rover.g2.motors.frame_type::FRAME_TYPE_UNDEFINED) {
motor_state = state;
} else if (report_failure) {
gcs().send_text(MAV_SEVERITY_WARNING, "Sailboat: failed to enable motor");
}
}
// true if motor is on to assist with slow tack
bool Sailboat::motor_assist_tack() const
{
// throttle is assist is disabled
if (motor_state != UseMotor::USE_MOTOR_ASSIST) {
return false;
}
// assist with a tack because it is taking too long
return tack_assist;
}
// true if motor should be on to assist with low wind
bool Sailboat::motor_assist_low_wind() const
{
// motor assist is disabled
if (motor_state != UseMotor::USE_MOTOR_ASSIST) {
return false;
}
// assist if wind speed is below cutoff
return (is_positive(sail_windspeed_min) &&
rover.g2.windvane.wind_speed_enabled() &&
(rover.g2.windvane.get_true_wind_speed() < sail_windspeed_min));
}