ardupilot/APMrover2/mode.cpp

168 lines
6.0 KiB
C++

#include "mode.h"
#include "Rover.h"
Mode::Mode() :
g(rover.g),
g2(rover.g2),
channel_steer(rover.channel_steer),
channel_throttle(rover.channel_throttle),
mission(rover.mission)
{ }
void Mode::exit()
{
// call sub-classes exit
_exit();
lateral_acceleration = 0.0f;
rover.throttle = 500;
rover.g.pidSpeedThrottle.reset_I();
if (!rover.in_auto_reverse) {
rover.set_reverse(false);
}
rover.rtl_complete = false;
}
bool Mode::enter()
{
g2.motors.slew_limit_throttle(false);
return _enter();
}
void Mode::calc_throttle(float target_speed)
{
int16_t &throttle = rover.throttle;
const int32_t next_navigation_leg_cd = rover.next_navigation_leg_cd;
const AP_AHRS &ahrs = rover.ahrs;
const float wp_distance = rover.wp_distance;
float &groundspeed_error = rover.groundspeed_error;
const float ground_speed = rover.ground_speed;
const float throttle_base = (fabsf(target_speed) / g.speed_cruise) * g.throttle_cruise;
const int throttle_target = throttle_base + calc_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
const int32_t turn_angle = wrap_180_cd(next_navigation_leg_cd - ahrs.yaw_sensor);
const float speed_turn_ratio = constrain_float(fabsf(turn_angle / 9000.0f), 0.0f, 1.0f);
const float speed_turn_reduction = (100 - g.speed_turn_gain) * speed_turn_ratio * 0.01f;
float reduction = 1.0f - steer_rate * speed_turn_reduction;
if (is_autopilot_mode() && rover.mode_guided.guided_mode != ModeGuided::Guided_Velocity && wp_distance <= g.speed_turn_dist) {
// in auto-modes we reduce speed when approaching waypoints
const 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 * 100.0f) / 100.0f);
// also reduce the throttle by the reduction factor. This gives a
// much faster response in turns
throttle *= reduction;
if (rover.in_reverse) {
g2.motors.set_throttle(constrain_int16(-throttle, -g.throttle_max, -g.throttle_min));
} else {
g2.motors.set_throttle(constrain_int16(throttle, g.throttle_min, g.throttle_max));
}
if (!rover.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
const float brake_gain = constrain_float(((-groundspeed_error)-g.braking_speederr)/g.braking_speederr, 0.0f, 1.0f);
const int16_t braking_throttle = g.throttle_max * (g.braking_percent * 0.01f) * brake_gain;
g2.motors.set_throttle(constrain_int16(-braking_throttle, -g.throttle_max, -g.throttle_min));
// temporarily set us in reverse to allow the PWM setting to
// go negative
rover.set_reverse(true);
}
if (rover.mode_guided.guided_mode != ModeGuided::Guided_Velocity) {
if (rover.use_pivot_steering()) {
// In Guided Velocity, only the steering input is used to calculate the pivot turn.
g2.motors.set_throttle(0.0f);
}
}
}
void Mode::calc_lateral_acceleration()
{
calc_lateral_acceleration(rover.current_loc, rover.next_WP);
}
// calculate pilot input to nudge throttle up or down
int16_t Mode::calc_throttle_nudge()
{
// get pilot throttle input (-100 to +100)
int16_t pilot_throttle = rover.channel_throttle->get_control_in();
int16_t throttle_nudge = 0;
// Check if the throttle value is above 50% and we need to nudge
// Make sure its above 50% in the direction we are travelling
if ((fabsf(pilot_throttle) > 50.0f) &&
(((pilot_throttle < 0) && rover.in_reverse) ||
((pilot_throttle > 0) && !rover.in_reverse))) {
throttle_nudge = (rover.g.throttle_max - rover.g.throttle_cruise) * ((fabsf(rover.channel_throttle->norm_input()) - 0.5f) / 0.5f);
}
return throttle_nudge;
}
/*
* Calculate desired turn angles (in medium freq loop)
*/
void Mode::calc_lateral_acceleration(const struct Location &last_WP, const struct Location &next_WP)
{
// Calculate the required turn of the wheels
// negative error = left turn
// positive error = right turn
rover.nav_controller->update_waypoint(last_WP, next_WP);
lateral_acceleration = rover.nav_controller->lateral_acceleration();
if (rover.use_pivot_steering()) {
const int16_t bearing_error = wrap_180_cd(rover.nav_controller->target_bearing_cd() - rover.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 Mode::calc_nav_steer()
{
// add in obstacle avoidance
if (!rover.in_reverse) {
lateral_acceleration += (rover.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);
// send final steering command to motor library
g2.motors.set_steering(rover.steerController.get_steering_out_lat_accel(lateral_acceleration));
}