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betaflight/src/main/flight/altitude.c
2017-11-19 13:20:47 +00:00

307 lines
9.5 KiB
C

/*
* This file is part of Cleanflight.
*
* Cleanflight is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* Cleanflight is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with Cleanflight. If not, see <http://www.gnu.org/licenses/>.
*/
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#include <math.h>
#include "platform.h"
#include "build/debug.h"
#include "common/axis.h"
#include "common/maths.h"
#include "config/parameter_group.h"
#include "config/parameter_group_ids.h"
#include "fc/config.h"
#include "fc/rc_controls.h"
#include "fc/rc_modes.h"
#include "fc/runtime_config.h"
#include "flight/altitude.h"
#include "flight/imu.h"
#include "flight/pid.h"
#include "rx/rx.h"
#include "sensors/sensors.h"
#include "sensors/barometer.h"
#include "sensors/sonar.h"
int32_t AltHold;
static int32_t estimatedVario = 0; // variometer in cm/s
static int32_t estimatedAltitude = 0; // in cm
#if defined(USE_ALT_HOLD)
enum {
DEBUG_ALTITUDE_ACC,
DEBUG_ALTITUDE_VEL,
DEBUG_ALTITUDE_HEIGHT
};
PG_REGISTER_WITH_RESET_TEMPLATE(airplaneConfig_t, airplaneConfig, PG_AIRPLANE_CONFIG, 0);
PG_RESET_TEMPLATE(airplaneConfig_t, airplaneConfig,
.fixedwing_althold_reversed = false
);
static int32_t setVelocity = 0;
static uint8_t velocityControl = 0;
static int32_t errorVelocityI = 0;
static int32_t altHoldThrottleAdjustment = 0;
static int16_t initialThrottleHold;
// 40hz update rate (20hz LPF on acc)
#define BARO_UPDATE_FREQUENCY_40HZ (1000 * 25)
#define DEGREES_80_IN_DECIDEGREES 800
static void applyMultirotorAltHold(void)
{
static uint8_t isAltHoldChanged = 0;
// multirotor alt hold
if (rcControlsConfig()->alt_hold_fast_change) {
// rapid alt changes
if (ABS(rcData[THROTTLE] - initialThrottleHold) > rcControlsConfig()->alt_hold_deadband) {
errorVelocityI = 0;
isAltHoldChanged = 1;
rcCommand[THROTTLE] += (rcData[THROTTLE] > initialThrottleHold) ? -rcControlsConfig()->alt_hold_deadband : rcControlsConfig()->alt_hold_deadband;
} else {
if (isAltHoldChanged) {
AltHold = estimatedAltitude;
isAltHoldChanged = 0;
}
rcCommand[THROTTLE] = constrain(initialThrottleHold + altHoldThrottleAdjustment, PWM_RANGE_MIN, PWM_RANGE_MAX);
}
} else {
// slow alt changes, mostly used for aerial photography
if (ABS(rcData[THROTTLE] - initialThrottleHold) > rcControlsConfig()->alt_hold_deadband) {
// set velocity proportional to stick movement +100 throttle gives ~ +50 cm/s
setVelocity = (rcData[THROTTLE] - initialThrottleHold) / 2;
velocityControl = 1;
isAltHoldChanged = 1;
} else if (isAltHoldChanged) {
AltHold = estimatedAltitude;
velocityControl = 0;
isAltHoldChanged = 0;
}
rcCommand[THROTTLE] = constrain(initialThrottleHold + altHoldThrottleAdjustment, PWM_RANGE_MIN, PWM_RANGE_MAX);
}
}
static void applyFixedWingAltHold(void)
{
// handle fixedwing-related althold. UNTESTED! and probably wrong
// most likely need to check changes on pitch channel and 'reset' althold similar to
// how throttle does it on multirotor
rcCommand[PITCH] += altHoldThrottleAdjustment * GET_DIRECTION(airplaneConfig()->fixedwing_althold_reversed);
}
void applyAltHold(void)
{
if (STATE(FIXED_WING)) {
applyFixedWingAltHold();
} else {
applyMultirotorAltHold();
}
}
void updateAltHoldState(void)
{
// Baro alt hold activate
if (!IS_RC_MODE_ACTIVE(BOXBARO)) {
DISABLE_FLIGHT_MODE(BARO_MODE);
return;
}
if (!FLIGHT_MODE(BARO_MODE)) {
ENABLE_FLIGHT_MODE(BARO_MODE);
AltHold = estimatedAltitude;
initialThrottleHold = rcData[THROTTLE];
errorVelocityI = 0;
altHoldThrottleAdjustment = 0;
}
}
void updateSonarAltHoldState(void)
{
// Sonar alt hold activate
if (!IS_RC_MODE_ACTIVE(BOXSONAR)) {
DISABLE_FLIGHT_MODE(SONAR_MODE);
return;
}
if (!FLIGHT_MODE(SONAR_MODE)) {
ENABLE_FLIGHT_MODE(SONAR_MODE);
AltHold = estimatedAltitude;
initialThrottleHold = rcData[THROTTLE];
errorVelocityI = 0;
altHoldThrottleAdjustment = 0;
}
}
bool isThrustFacingDownwards(attitudeEulerAngles_t *attitude)
{
return ABS(attitude->values.roll) < DEGREES_80_IN_DECIDEGREES && ABS(attitude->values.pitch) < DEGREES_80_IN_DECIDEGREES;
}
int32_t calculateAltHoldThrottleAdjustment(int32_t vel_tmp, float accZ_tmp, float accZ_old)
{
int32_t result = 0;
int32_t error;
int32_t setVel;
if (!isThrustFacingDownwards(&attitude)) {
return result;
}
// Altitude P-Controller
if (!velocityControl) {
error = constrain(AltHold - estimatedAltitude, -500, 500);
error = applyDeadband(error, 10); // remove small P parameter to reduce noise near zero position
setVel = constrain((currentPidProfile->pid[PID_ALT].P * error / 128), -300, +300); // limit velocity to +/- 3 m/s
} else {
setVel = setVelocity;
}
// Velocity PID-Controller
// P
error = setVel - vel_tmp;
result = constrain((currentPidProfile->pid[PID_VEL].P * error / 32), -300, +300);
// I
errorVelocityI += (currentPidProfile->pid[PID_VEL].I * error);
errorVelocityI = constrain(errorVelocityI, -(8192 * 200), (8192 * 200));
result += errorVelocityI / 8192; // I in range +/-200
// D
result -= constrain(currentPidProfile->pid[PID_VEL].D * (accZ_tmp + accZ_old) / 512, -150, 150);
return result;
}
void calculateEstimatedAltitude(timeUs_t currentTimeUs)
{
static timeUs_t previousTimeUs = 0;
const uint32_t dTime = currentTimeUs - previousTimeUs;
if (dTime < BARO_UPDATE_FREQUENCY_40HZ) {
return;
}
previousTimeUs = currentTimeUs;
static float vel = 0.0f;
static float accAlt = 0.0f;
int32_t baroAlt = 0;
#ifdef USE_BARO
if (sensors(SENSOR_BARO)) {
if (!isBaroCalibrationComplete()) {
performBaroCalibrationCycle();
vel = 0;
accAlt = 0;
} else {
baroAlt = baroCalculateAltitude();
estimatedAltitude = baroAlt;
}
}
#endif
#ifdef USE_SONAR
if (sensors(SENSOR_SONAR)) {
int32_t sonarAlt = sonarCalculateAltitude(sonarRead(), getCosTiltAngle());
if (sonarAlt > 0 && sonarAlt >= sonarCfAltCm && sonarAlt <= sonarMaxAltWithTiltCm) {
// SONAR in range, so use complementary filter
float sonarTransition = (float)(sonarMaxAltWithTiltCm - sonarAlt) / (sonarMaxAltWithTiltCm - sonarCfAltCm);
sonarAlt = (float)sonarAlt * sonarTransition + baroAlt * (1.0f - sonarTransition);
estimatedAltitude = sonarAlt;
}
}
#endif
float accZ_tmp = 0;
#ifdef USE_ACC
if (sensors(SENSOR_ACC)) {
const float dt = accTimeSum * 1e-6f; // delta acc reading time in seconds
// Integrator - velocity, cm/sec
if (accSumCount) {
accZ_tmp = (float)accSum[2] / accSumCount;
}
const float vel_acc = accZ_tmp * accVelScale * (float)accTimeSum;
// Integrator - Altitude in cm
accAlt += (vel_acc * 0.5f) * dt + vel * dt; // integrate velocity to get distance (x= a/2 * t^2)
accAlt = accAlt * CONVERT_PARAMETER_TO_FLOAT(barometerConfig()->baro_cf_alt) + (float)baro.BaroAlt * (1.0f - CONVERT_PARAMETER_TO_FLOAT(barometerConfig()->baro_cf_alt)); // complementary filter for altitude estimation (baro & acc)
vel += vel_acc;
estimatedAltitude = accAlt;
}
#endif
DEBUG_SET(DEBUG_ALTITUDE, DEBUG_ALTITUDE_ACC, accSum[2] / accSumCount);
DEBUG_SET(DEBUG_ALTITUDE, DEBUG_ALTITUDE_VEL, vel);
DEBUG_SET(DEBUG_ALTITUDE, DEBUG_ALTITUDE_HEIGHT, accAlt);
imuResetAccelerationSum();
int32_t baroVel = 0;
#ifdef USE_BARO
if (sensors(SENSOR_BARO)) {
if (!isBaroCalibrationComplete()) {
return;
}
static int32_t lastBaroAlt = 0;
baroVel = (baroAlt - lastBaroAlt) * 1000000.0f / dTime;
lastBaroAlt = baroAlt;
baroVel = constrain(baroVel, -1500, 1500); // constrain baro velocity +/- 1500cm/s
baroVel = applyDeadband(baroVel, 10); // to reduce noise near zero
}
#endif // BARO
// apply Complimentary Filter to keep the calculated velocity based on baro velocity (i.e. near real velocity).
// By using CF it's possible to correct the drift of integrated accZ (velocity) without loosing the phase, i.e without delay
vel = vel * CONVERT_PARAMETER_TO_FLOAT(barometerConfig()->baro_cf_vel) + baroVel * (1.0f - CONVERT_PARAMETER_TO_FLOAT(barometerConfig()->baro_cf_vel));
int32_t vel_tmp = lrintf(vel);
// set vario
estimatedVario = applyDeadband(vel_tmp, 5);
static float accZ_old = 0.0f;
altHoldThrottleAdjustment = calculateAltHoldThrottleAdjustment(vel_tmp, accZ_tmp, accZ_old);
accZ_old = accZ_tmp;
}
#endif // USE_ALT_HOLD
int32_t getEstimatedAltitude(void)
{
return estimatedAltitude;
}
int32_t getEstimatedVario(void)
{
return estimatedVario;
}