ardupilot/APMrover2/Steering.cpp
Grant Morphett f1a46c27b3 Rover: Implemented loitering at a waypoint if Param1 is non-zero
Rover now honours the Param1 setting of a time in seconds for a
NAV_WAYPOINT and the Rover will loiter at that waypoint for that
period of time.
Note that as soon as the Rover reaches that waypoint the loiter timer
will start. If you enter a different mode during this time (HOLD for
instance) the timer resets. If you then switch back to AUTO
mode and the Rover returns to that waypoint it will wait for the
loiter time configured in param1.
2015-08-19 20:03:14 +09:00

291 lines
9.9 KiB
C++

// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
#include "Rover.h"
/*****************************************
* Throttle slew limit
*****************************************/
void Rover::throttle_slew_limit(int16_t last_throttle)
{
// if slew limit rate is set to zero then do not slew limit
if (g.throttle_slewrate && last_throttle != 0) {
// limit throttle change by the given percentage per second
float temp = g.throttle_slewrate * G_Dt * 0.01f * fabsf(channel_throttle->radio_max - channel_throttle->radio_min);
// allow a minimum change of 1 PWM per cycle
if (temp < 1) {
temp = 1;
}
channel_throttle->radio_out = constrain_int16(channel_throttle->radio_out, last_throttle - temp, last_throttle + temp);
}
}
/*
check for triggering of start of auto mode
*/
bool Rover::auto_check_trigger(void)
{
// only applies to AUTO mode
if (control_mode != AUTO) {
return true;
}
// check for user pressing the auto trigger to off
if (auto_triggered && g.auto_trigger_pin != -1 && check_digital_pin(g.auto_trigger_pin) == 1) {
gcs_send_text_P(SEVERITY_LOW, PSTR("AUTO triggered off"));
auto_triggered = false;
return false;
}
// if already triggered, then return true, so you don't
// need to hold the switch down
if (auto_triggered) {
return true;
}
if (g.auto_trigger_pin == -1 && is_zero(g.auto_kickstart)) {
// no trigger configured - let's go!
auto_triggered = true;
return true;
}
if (g.auto_trigger_pin != -1 && check_digital_pin(g.auto_trigger_pin) == 0) {
gcs_send_text_P(SEVERITY_LOW, PSTR("Triggered AUTO with pin"));
auto_triggered = true;
return true;
}
if (!is_zero(g.auto_kickstart)) {
float xaccel = ins.get_accel().x;
if (xaccel >= g.auto_kickstart) {
gcs_send_text_fmt(PSTR("Triggered AUTO xaccel=%.1f"), (double)xaccel);
auto_triggered = true;
return true;
}
}
return false;
}
/*
work out if we are going to use pivot steering
*/
bool Rover::use_pivot_steering(void)
{
if (control_mode >= AUTO && g.skid_steer_out && g.pivot_turn_angle != 0) {
int16_t bearing_error = wrap_180_cd(nav_controller->target_bearing_cd() - ahrs.yaw_sensor) / 100;
if (abs(bearing_error) > g.pivot_turn_angle) {
return true;
}
}
return false;
}
/*
calculate the throtte for auto-throttle modes
*/
void Rover::calc_throttle(float target_speed)
{
// If not autostarting OR we are loitering at a waypoint
// then set the throttle to minimum
if (!auto_check_trigger() || ((loiter_time > 0) && (control_mode == AUTO))) {
channel_throttle->servo_out = g.throttle_min.get();
return;
}
float throttle_base = (fabsf(target_speed) / g.speed_cruise) * g.throttle_cruise;
int throttle_target = throttle_base + throttle_nudge;
/*
reduce target speed in proportion to turning rate, up to the
SPEED_TURN_GAIN percentage.
*/
float steer_rate = fabsf(lateral_acceleration / (g.turn_max_g*GRAVITY_MSS));
steer_rate = constrain_float(steer_rate, 0.0f, 1.0f);
// use g.speed_turn_gain for a 90 degree turn, and in proportion
// for other turn angles
int32_t turn_angle = wrap_180_cd(next_navigation_leg_cd - ahrs.yaw_sensor);
float speed_turn_ratio = constrain_float(fabsf(turn_angle / 9000.0f), 0, 1);
float speed_turn_reduction = (100 - g.speed_turn_gain) * speed_turn_ratio * 0.01f;
float reduction = 1.0f - steer_rate*speed_turn_reduction;
if (control_mode >= AUTO && wp_distance <= g.speed_turn_dist) {
// in auto-modes we reduce speed when approaching waypoints
float reduction2 = 1.0f - speed_turn_reduction;
if (reduction2 < reduction) {
reduction = reduction2;
}
}
// reduce the target speed by the reduction factor
target_speed *= reduction;
groundspeed_error = fabsf(target_speed) - ground_speed;
throttle = throttle_target + (g.pidSpeedThrottle.get_pid(groundspeed_error * 100) / 100);
// also reduce the throttle by the reduction factor. This gives a
// much faster response in turns
throttle *= reduction;
if (in_reverse) {
channel_throttle->servo_out = constrain_int16(-throttle, -g.throttle_max, -g.throttle_min);
} else {
channel_throttle->servo_out = constrain_int16(throttle, g.throttle_min, g.throttle_max);
}
if (!in_reverse && g.braking_percent != 0 && groundspeed_error < -g.braking_speederr) {
// the user has asked to use reverse throttle to brake. Apply
// it in proportion to the ground speed error, but only when
// our ground speed error is more than BRAKING_SPEEDERR.
//
// We use a linear gain, with 0 gain at a ground speed error
// of braking_speederr, and 100% gain when groundspeed_error
// is 2*braking_speederr
float brake_gain = constrain_float(((-groundspeed_error)-g.braking_speederr)/g.braking_speederr, 0, 1);
int16_t braking_throttle = g.throttle_max * (g.braking_percent * 0.01f) * brake_gain;
channel_throttle->servo_out = constrain_int16(-braking_throttle, -g.throttle_max, -g.throttle_min);
// temporarily set us in reverse to allow the PWM setting to
// go negative
set_reverse(true);
}
if (use_pivot_steering()) {
channel_throttle->servo_out = 0;
}
}
/*****************************************
* Calculate desired turn angles (in medium freq loop)
*****************************************/
void Rover::calc_lateral_acceleration()
{
switch (control_mode) {
case AUTO:
nav_controller->update_waypoint(prev_WP, next_WP);
break;
case RTL:
case GUIDED:
case STEERING:
nav_controller->update_waypoint(current_loc, next_WP);
break;
default:
return;
}
// Calculate the required turn of the wheels
// negative error = left turn
// positive error = right turn
lateral_acceleration = nav_controller->lateral_acceleration();
if (use_pivot_steering()) {
int16_t bearing_error = wrap_180_cd(nav_controller->target_bearing_cd() - ahrs.yaw_sensor) / 100;
if (bearing_error > 0) {
lateral_acceleration = g.turn_max_g*GRAVITY_MSS;
} else {
lateral_acceleration = -g.turn_max_g*GRAVITY_MSS;
}
}
}
/*
calculate steering angle given lateral_acceleration
*/
void Rover::calc_nav_steer()
{
// check to see if the rover is loitering
if ((loiter_time > 0) && (control_mode == AUTO)) {
channel_steer->servo_out = 0;
return;
}
// add in obstacle avoidance
lateral_acceleration += (obstacle.turn_angle/45.0f) * g.turn_max_g;
// constrain to max G force
lateral_acceleration = constrain_float(lateral_acceleration, -g.turn_max_g*GRAVITY_MSS, g.turn_max_g*GRAVITY_MSS);
channel_steer->servo_out = steerController.get_steering_out_lat_accel(lateral_acceleration);
}
/*****************************************
* Set the flight control servos based on the current calculated values
*****************************************/
void Rover::set_servos(void)
{
static int16_t last_throttle;
// support a separate steering channel
RC_Channel_aux::set_servo_out(RC_Channel_aux::k_steering, channel_steer->pwm_to_angle_dz(0));
if (control_mode == MANUAL || control_mode == LEARNING) {
// do a direct pass through of radio values
channel_steer->radio_out = channel_steer->read();
channel_throttle->radio_out = channel_throttle->read();
if (failsafe.bits & FAILSAFE_EVENT_THROTTLE) {
// suppress throttle if in failsafe and manual
channel_throttle->radio_out = channel_throttle->radio_trim;
}
} else {
channel_steer->calc_pwm();
if (in_reverse) {
channel_throttle->servo_out = constrain_int16(channel_throttle->servo_out,
-g.throttle_max,
-g.throttle_min);
} else {
channel_throttle->servo_out = constrain_int16(channel_throttle->servo_out,
g.throttle_min.get(),
g.throttle_max.get());
}
if ((failsafe.bits & FAILSAFE_EVENT_THROTTLE) && control_mode < AUTO) {
// suppress throttle if in failsafe
channel_throttle->servo_out = 0;
}
// convert 0 to 100% into PWM
channel_throttle->calc_pwm();
// limit throttle movement speed
throttle_slew_limit(last_throttle);
}
// record last throttle before we apply skid steering
last_throttle = channel_throttle->radio_out;
if (g.skid_steer_out) {
// convert the two radio_out values to skid steering values
/*
mixing rule:
steering = motor1 - motor2
throttle = 0.5*(motor1 + motor2)
motor1 = throttle + 0.5*steering
motor2 = throttle - 0.5*steering
*/
float steering_scaled = channel_steer->norm_output();
float throttle_scaled = channel_throttle->norm_output();
float motor1 = throttle_scaled + 0.5f*steering_scaled;
float motor2 = throttle_scaled - 0.5f*steering_scaled;
channel_steer->servo_out = 4500*motor1;
channel_throttle->servo_out = 100*motor2;
channel_steer->calc_pwm();
channel_throttle->calc_pwm();
}
#if HIL_MODE == HIL_MODE_DISABLED || HIL_SERVOS
// send values to the PWM timers for output
// ----------------------------------------
channel_steer->output();
channel_throttle->output();
RC_Channel_aux::output_ch_all();
#endif
}