ardupilot/libraries/AP_Mount/AP_Mount_Servo.cpp

206 lines
8.7 KiB
C++

// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
#include "AP_Mount_Servo.h"
extern const AP_HAL::HAL& hal;
// init - performs any required initialisation for this instance
void AP_Mount_Servo::init(const AP_SerialManager& serial_manager)
{
if (_instance == 0) {
_roll_idx = RC_Channel_aux::k_mount_roll;
_tilt_idx = RC_Channel_aux::k_mount_tilt;
_pan_idx = RC_Channel_aux::k_mount_pan;
_open_idx = RC_Channel_aux::k_mount_open;
} else {
// this must be the 2nd mount
_roll_idx = RC_Channel_aux::k_mount2_roll;
_tilt_idx = RC_Channel_aux::k_mount2_tilt;
_pan_idx = RC_Channel_aux::k_mount2_pan;
_open_idx = RC_Channel_aux::k_mount2_open;
}
// check which servos have been assigned
check_servo_map();
}
// update mount position - should be called periodically
void AP_Mount_Servo::update()
{
static bool mount_open = 0; // 0 is closed
// check servo map every three seconds to allow users to modify parameters
uint32_t now = hal.scheduler->millis();
if (now - _last_check_servo_map_ms > 3000) {
check_servo_map();
_last_check_servo_map_ms = now;
}
switch(get_mode()) {
// move mount to a "retracted position" or to a position where a fourth servo can retract the entire mount into the fuselage
case MAV_MOUNT_MODE_RETRACT:
{
_angle_bf_output_deg = _state._retract_angles.get();
break;
}
// move mount to a neutral position, typically pointing forward
case MAV_MOUNT_MODE_NEUTRAL:
{
_angle_bf_output_deg = _state._neutral_angles.get();
break;
}
// point to the angles given by a mavlink message
case MAV_MOUNT_MODE_MAVLINK_TARGETING:
{
// earth-frame angle targets (i.e. _angle_ef_target_rad) should have already been set by a MOUNT_CONTROL message from GCS
stabilize();
break;
}
// RC radio manual angle control, but with stabilization from the AHRS
case MAV_MOUNT_MODE_RC_TARGETING:
{
// update targets using pilot's rc inputs
update_targets_from_rc();
stabilize();
break;
}
// point mount to a GPS point given by the mission planner
case MAV_MOUNT_MODE_GPS_POINT:
{
if(_frontend._ahrs.get_gps().status() >= AP_GPS::GPS_OK_FIX_2D) {
calc_angle_to_location(_state._roi_target, _angle_ef_target_rad, _flags.tilt_control, _flags.pan_control);
stabilize();
}
break;
}
default:
//do nothing
break;
}
// move mount to a "retracted position" into the fuselage with a fourth servo
bool mount_open_new = (get_mode() == MAV_MOUNT_MODE_RETRACT) ? 0 : 1;
if (mount_open != mount_open_new) {
mount_open = mount_open_new;
move_servo(_open_idx, mount_open_new, 0, 1);
}
// write the results to the servos
move_servo(_roll_idx, _angle_bf_output_deg.x*10, _state._roll_angle_min*0.1f, _state._roll_angle_max*0.1f);
move_servo(_tilt_idx, _angle_bf_output_deg.y*10, _state._tilt_angle_min*0.1f, _state._tilt_angle_max*0.1f);
move_servo(_pan_idx, _angle_bf_output_deg.z*10, _state._pan_angle_min*0.1f, _state._pan_angle_max*0.1f);
}
// set_mode - sets mount's mode
void AP_Mount_Servo::set_mode(enum MAV_MOUNT_MODE mode)
{
// record the mode change and return success
_state._mode = mode;
}
// private methods
// check_servo_map - detects which axis we control using the functions assigned to the servos in the RC_Channel_aux
// should be called periodically (i.e. 1hz or less)
void AP_Mount_Servo::check_servo_map()
{
_flags.roll_control = RC_Channel_aux::function_assigned(_roll_idx);
_flags.tilt_control = RC_Channel_aux::function_assigned(_tilt_idx);
_flags.pan_control = RC_Channel_aux::function_assigned(_pan_idx);
}
// status_msg - called to allow mounts to send their status to GCS using the MOUNT_STATUS message
void AP_Mount_Servo::status_msg(mavlink_channel_t chan)
{
mavlink_msg_mount_status_send(chan, 0, 0, _angle_bf_output_deg.y*100, _angle_bf_output_deg.x*100, _angle_bf_output_deg.z*100);
}
// stabilize - stabilizes the mount relative to the Earth's frame
// input: _angle_ef_target_rad (earth frame targets in radians)
// output: _angle_bf_output_deg (body frame angles in degrees)
void AP_Mount_Servo::stabilize()
{
// only do the full 3D frame transform if we are doing pan control
if (_state._stab_pan) {
Matrix3f m; ///< holds 3 x 3 matrix, var is used as temp in calcs
Matrix3f cam; ///< Rotation matrix earth to camera. Desired camera from input.
Matrix3f gimbal_target; ///< Rotation matrix from plane to camera. Then Euler angles to the servos.
m = _frontend._ahrs.get_dcm_matrix();
m.transpose();
cam.from_euler(_angle_ef_target_rad.x, _angle_ef_target_rad.y, _angle_ef_target_rad.z);
gimbal_target = m * cam;
gimbal_target.to_euler(&_angle_bf_output_deg.x, &_angle_bf_output_deg.y, &_angle_bf_output_deg.z);
_angle_bf_output_deg.x = _state._stab_roll ? degrees(_angle_bf_output_deg.x) : degrees(_angle_ef_target_rad.x);
_angle_bf_output_deg.y = _state._stab_tilt ? degrees(_angle_bf_output_deg.y) : degrees(_angle_ef_target_rad.y);
_angle_bf_output_deg.z = degrees(_angle_bf_output_deg.z);
} else {
// otherwise base mount roll and tilt on the ahrs
// roll/tilt attitude, plus any requested angle
_angle_bf_output_deg.x = degrees(_angle_ef_target_rad.x);
_angle_bf_output_deg.y = degrees(_angle_ef_target_rad.y);
_angle_bf_output_deg.z = degrees(_angle_ef_target_rad.z);
if (_state._stab_roll) {
_angle_bf_output_deg.x -= degrees(_frontend._ahrs.roll);
}
if (_state._stab_tilt) {
_angle_bf_output_deg.y -= degrees(_frontend._ahrs.pitch);
}
// lead filter
const Vector3f &gyro = _frontend._ahrs.get_gyro();
if (_state._stab_roll && !is_zero(_state._roll_stb_lead) && fabsf(_frontend._ahrs.pitch) < M_PI_F/3.0f) {
// Compute rate of change of euler roll angle
float roll_rate = gyro.x + (_frontend._ahrs.sin_pitch() / _frontend._ahrs.cos_pitch()) * (gyro.y * _frontend._ahrs.sin_roll() + gyro.z * _frontend._ahrs.cos_roll());
_angle_bf_output_deg.x -= degrees(roll_rate) * _state._roll_stb_lead;
}
if (_state._stab_tilt && !is_zero(_state._pitch_stb_lead)) {
// Compute rate of change of euler pitch angle
float pitch_rate = _frontend._ahrs.cos_pitch() * gyro.y - _frontend._ahrs.sin_roll() * gyro.z;
_angle_bf_output_deg.y -= degrees(pitch_rate) * _state._pitch_stb_lead;
}
}
}
// closest_limit - returns closest angle to 'angle' taking into account limits. all angles are in degrees * 10
int16_t AP_Mount_Servo::closest_limit(int16_t angle, int16_t angle_min, int16_t angle_max)
{
// Make sure the angle lies in the interval [-180 .. 180[ degrees
while (angle < -1800) angle += 3600;
while (angle >= 1800) angle -= 3600;
// Make sure the angle limits lie in the interval [-180 .. 180[ degrees
while (angle_min < -1800) angle_min += 3600;
while (angle_min >= 1800) angle_min -= 3600;
while (angle_max < -1800) angle_max += 3600;
while (angle_max >= 1800) angle_max -= 3600;
// TODO call this function somehow, otherwise this will never work
//set_range(min, max);
// If the angle is outside servo limits, saturate the angle to the closest limit
// On a circle the closest angular position must be carefully calculated to account for wrap-around
if ((angle < angle_min) && (angle > angle_max)) {
// angle error if min limit is used
int16_t err_min = angle_min - angle + (angle<angle_min ? 0 : 3600); // add 360 degrees if on the "wrong side"
// angle error if max limit is used
int16_t err_max = angle - angle_max + (angle>angle_max ? 0 : 3600); // add 360 degrees if on the "wrong side"
angle = err_min<err_max ? angle_min : angle_max;
}
return angle;
}
// move_servo - moves servo with the given id to the specified angle. all angles are in degrees * 10
void AP_Mount_Servo::move_servo(uint8_t function_idx, int16_t angle, int16_t angle_min, int16_t angle_max)
{
// saturate to the closest angle limit if outside of [min max] angle interval
int16_t servo_out = closest_limit(angle, angle_min, angle_max);
RC_Channel_aux::move_servo((RC_Channel_aux::Aux_servo_function_t)function_idx, servo_out, angle_min, angle_max);
}