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LibrePilot/flight/modules/Stabilization/stabilization.c
Cliff Geerdes ccc09721cd OP-1154 Initial version with UAVO's but no GCS GUI
2014-01-11 16:22:20 -05:00

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/**
******************************************************************************
* @addtogroup OpenPilotModules OpenPilot Modules
* @{
* @addtogroup StabilizationModule Stabilization Module
* @brief Stabilization PID loops in an airframe type independent manner
* @note This object updates the @ref ActuatorDesired "Actuator Desired" based on the
* PID loops on the @ref AttitudeDesired "Attitude Desired" and @ref AttitudeState "Attitude State"
* @{
*
* @file stabilization.c
* @author The OpenPilot Team, http://www.openpilot.org Copyright (C) 2010.
* @brief Attitude stabilization module.
*
* @see The GNU Public License (GPL) Version 3
*
*****************************************************************************/
/*
* This program 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.
*
* This program 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 this program; if not, write to the Free Software Foundation, Inc.,
* 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <openpilot.h>
#include <pios_struct_helper.h>
#include "stabilization.h"
#include "stabilizationsettings.h"
#include "actuatordesired.h"
#include "ratedesired.h"
#include "relaytuning.h"
#include "relaytuningsettings.h"
#include "stabilizationdesired.h"
#include "attitudestate.h"
#include "airspeedstate.h"
#include "gyrostate.h"
#include "flightstatus.h"
#include "manualcontrol.h" // Just to get a macro
#include "taskinfo.h"
// Math libraries
#include "CoordinateConversions.h"
#include "pid.h"
#include "sin_lookup.h"
// Includes for various stabilization algorithms
#include "relay_tuning.h"
#include "virtualflybar.h"
// Includes for various stabilization algorithms
#include "relay_tuning.h"
// Private constants
#define MAX_QUEUE_SIZE 1
#if defined(PIOS_STABILIZATION_STACK_SIZE)
#define STACK_SIZE_BYTES PIOS_STABILIZATION_STACK_SIZE
#else
#define STACK_SIZE_BYTES 724
#endif
#define TASK_PRIORITY (tskIDLE_PRIORITY + 4)
#define FAILSAFE_TIMEOUT_MS 30
// The PID_RATE_ROLL set is used by Rate mode and the rate portion of Attitude mode
// The PID_RATE set is used by the attitude portion of Attitude mode
// The PID_RATEA_ROLL set is used by Rattitude mode because it needs to maintain
// - two independant rate PIDs because it does rate and attitude simultaneously
enum { PID_RATE_ROLL, PID_RATE_PITCH, PID_RATE_YAW, PID_ROLL, PID_PITCH, PID_YAW, PID_RATEA_ROLL, PID_RATEA_PITCH, PID_RATEA_YAW, PID_MAX };
// Private variables
static xTaskHandle taskHandle;
static StabilizationSettingsData settings;
static xQueueHandle queue;
float gyro_alpha = 0;
float axis_lock_accum[3] = { 0, 0, 0 };
uint8_t max_axis_lock = 0;
uint8_t max_axislock_rate = 0;
float weak_leveling_kp = 0;
uint8_t weak_leveling_max = 0;
bool lowThrottleZeroIntegral;
bool lowThrottleZeroAxis[MAX_AXES];
float vbar_decay = 0.991f;
struct pid pids[PID_MAX];
static uint8_t rattitude_anti_windup;
static float cruise_control_min_throttle;
static float cruise_control_max_throttle;
static uint8_t cruise_control_max_angle;
static float cruise_control_max_power_factor;
static float cruise_control_power_trim;
static int8_t cruise_control_inverted_power_switch;
static float cruise_control_neutral_thrust;
// Private functions
static void stabilizationTask(void *parameters);
static float bound(float val, float range);
static void ZeroPids(void);
static void SettingsUpdatedCb(UAVObjEvent *ev);
static float stab_log2f(float x);
static float stab_powf(float x, uint8_t p);
/**
* Module initialization
*/
int32_t StabilizationStart()
{
// Initialize variables
// Create object queue
queue = xQueueCreate(MAX_QUEUE_SIZE, sizeof(UAVObjEvent));
// Listen for updates.
// AttitudeStateConnectQueue(queue);
GyroStateConnectQueue(queue);
StabilizationSettingsConnectCallback(SettingsUpdatedCb);
SettingsUpdatedCb(StabilizationSettingsHandle());
// Start main task
xTaskCreate(stabilizationTask, (signed char *)"Stabilization", STACK_SIZE_BYTES / 4, NULL, TASK_PRIORITY, &taskHandle);
PIOS_TASK_MONITOR_RegisterTask(TASKINFO_RUNNING_STABILIZATION, taskHandle);
#ifdef PIOS_INCLUDE_WDG
PIOS_WDG_RegisterFlag(PIOS_WDG_STABILIZATION);
#endif
return 0;
}
/**
* Module initialization
*/
int32_t StabilizationInitialize()
{
// Initialize variables
StabilizationSettingsInitialize();
ActuatorDesiredInitialize();
#ifdef DIAG_RATEDESIRED
RateDesiredInitialize();
#endif
#ifdef REVOLUTION
AirspeedStateInitialize();
#endif
// Code required for relay tuning
sin_lookup_initalize();
RelayTuningSettingsInitialize();
RelayTuningInitialize();
return 0;
}
MODULE_INITCALL(StabilizationInitialize, StabilizationStart);
/**
* Module task
*/
static void stabilizationTask(__attribute__((unused)) void *parameters)
{
UAVObjEvent ev;
uint32_t timeval = PIOS_DELAY_GetRaw();
ActuatorDesiredData actuatorDesired;
StabilizationDesiredData stabDesired;
RateDesiredData rateDesired;
AttitudeStateData attitudeState;
GyroStateData gyroStateData;
FlightStatusData flightStatus;
#ifdef REVOLUTION
AirspeedStateData airspeedState;
#endif
SettingsUpdatedCb((UAVObjEvent *)NULL);
// Main task loop
ZeroPids();
while (1) {
float dT;
#ifdef PIOS_INCLUDE_WDG
PIOS_WDG_UpdateFlag(PIOS_WDG_STABILIZATION);
#endif
// Wait until the Gyro object is updated, if a timeout then go to failsafe
if (xQueueReceive(queue, &ev, FAILSAFE_TIMEOUT_MS / portTICK_RATE_MS) != pdTRUE) {
AlarmsSet(SYSTEMALARMS_ALARM_STABILIZATION, SYSTEMALARMS_ALARM_WARNING);
continue;
}
dT = PIOS_DELAY_DiffuS(timeval) * 1.0e-6f;
timeval = PIOS_DELAY_GetRaw();
FlightStatusGet(&flightStatus);
StabilizationDesiredGet(&stabDesired);
AttitudeStateGet(&attitudeState);
GyroStateGet(&gyroStateData);
#ifdef DIAG_RATEDESIRED
RateDesiredGet(&rateDesired);
#endif
#ifdef REVOLUTION
float speedScaleFactor;
// Scale PID coefficients based on current airspeed estimation - needed for fixed wing planes
AirspeedStateGet(&airspeedState);
if (settings.ScaleToAirspeed < 0.1f || airspeedState.CalibratedAirspeed < 0.1f) {
// feature has been turned off
speedScaleFactor = 1.0f;
} else {
// scale the factor to be 1.0 at the specified airspeed (for example 10m/s) but scaled by 1/speed^2
speedScaleFactor = (settings.ScaleToAirspeed * settings.ScaleToAirspeed) / (airspeedState.CalibratedAirspeed * airspeedState.CalibratedAirspeed);
if (speedScaleFactor < settings.ScaleToAirspeedLimits.Min) {
speedScaleFactor = settings.ScaleToAirspeedLimits.Min;
}
if (speedScaleFactor > settings.ScaleToAirspeedLimits.Max) {
speedScaleFactor = settings.ScaleToAirspeedLimits.Max;
}
}
#else
const float speedScaleFactor = 1.0f;
#endif
#if defined(PIOS_QUATERNION_STABILIZATION)
// Quaternion calculation of error in each axis. Uses more memory.
float rpy_desired[3];
float q_desired[4];
float q_error[4];
float local_error[3];
// Essentially zero errors for anything in rate or none
if (stabDesired.StabilizationMode.Roll == STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE) {
rpy_desired[0] = stabDesired.Roll;
} else {
rpy_desired[0] = attitudeState.Roll;
}
if (stabDesired.StabilizationMode.Pitch == STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE) {
rpy_desired[1] = stabDesired.Pitch;
} else {
rpy_desired[1] = attitudeState.Pitch;
}
if (stabDesired.StabilizationMode.Yaw == STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE) {
rpy_desired[2] = stabDesired.Yaw;
} else {
rpy_desired[2] = attitudeState.Yaw;
}
RPY2Quaternion(rpy_desired, q_desired);
quat_inverse(q_desired);
quat_mult(q_desired, &attitudeState.q1, q_error);
quat_inverse(q_error);
Quaternion2RPY(q_error, local_error);
#else /* if defined(PIOS_QUATERNION_STABILIZATION) */
// Simpler algorithm for CC, less memory
float local_error[3] = { stabDesired.Roll - attitudeState.Roll,
stabDesired.Pitch - attitudeState.Pitch,
stabDesired.Yaw - attitudeState.Yaw };
// find shortest way
float modulo = fmodf(local_error[2] + 180.0f, 360.0f);
if (modulo < 0) {
local_error[2] = modulo + 180.0f;
} else {
local_error[2] = modulo - 180.0f;
}
#endif /* if defined(PIOS_QUATERNION_STABILIZATION) */
float gyro_filtered[3];
gyro_filtered[0] = gyro_filtered[0] * gyro_alpha + gyroStateData.x * (1 - gyro_alpha);
gyro_filtered[1] = gyro_filtered[1] * gyro_alpha + gyroStateData.y * (1 - gyro_alpha);
gyro_filtered[2] = gyro_filtered[2] * gyro_alpha + gyroStateData.z * (1 - gyro_alpha);
float *stabDesiredAxis = &stabDesired.Roll;
float *actuatorDesiredAxis = &actuatorDesired.Roll;
float *rateDesiredAxis = &rateDesired.Roll;
ActuatorDesiredGet(&actuatorDesired);
// A flag to track which stabilization mode each axis is in
static uint8_t previous_mode[MAX_AXES] = { 255, 255, 255 };
bool error = false;
// Run the selected stabilization algorithm on each axis:
for (uint8_t i = 0; i < MAX_AXES; i++) {
// Check whether this axis mode needs to be reinitialized
bool reinit = (cast_struct_to_array(stabDesired.StabilizationMode, stabDesired.StabilizationMode.Roll)[i] != previous_mode[i]);
previous_mode[i] = cast_struct_to_array(stabDesired.StabilizationMode, stabDesired.StabilizationMode.Roll)[i];
// Apply the selected control law
switch (cast_struct_to_array(stabDesired.StabilizationMode, stabDesired.StabilizationMode.Roll)[i]) {
case STABILIZATIONDESIRED_STABILIZATIONMODE_RATE:
if (reinit) {
pids[PID_RATE_ROLL + i].iAccumulator = 0;
}
// Store to rate desired variable for storing to UAVO
rateDesiredAxis[i] =
bound(stabDesiredAxis[i], cast_struct_to_array(settings.ManualRate, settings.ManualRate.Roll)[i]);
// Compute the inner loop
actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_RATE_ROLL + i], speedScaleFactor, rateDesiredAxis[i], gyro_filtered[i], dT);
actuatorDesiredAxis[i] = bound(actuatorDesiredAxis[i], 1.0f);
break;
case STABILIZATIONDESIRED_STABILIZATIONMODE_ATTITUDE:
if (reinit) {
pids[PID_ROLL + i].iAccumulator = 0;
pids[PID_RATE_ROLL + i].iAccumulator = 0;
}
// Compute the outer loop
rateDesiredAxis[i] = pid_apply(&pids[PID_ROLL + i], local_error[i], dT);
rateDesiredAxis[i] = bound(rateDesiredAxis[i],
cast_struct_to_array(settings.MaximumRate, settings.MaximumRate.Roll)[i]);
// Compute the inner loop
actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_RATE_ROLL + i], speedScaleFactor, rateDesiredAxis[i], gyro_filtered[i], dT);
actuatorDesiredAxis[i] = bound(actuatorDesiredAxis[i], 1.0f);
break;
case STABILIZATIONDESIRED_STABILIZATIONMODE_RATTITUDE:
// A parameterization from Attitude mode at center stick
// - to Rate mode at full stick
// This is done by parameterizing to use the rotation rate that Attitude mode
// - would use at center stick to using the rotation rate that Rate mode
// - would use at full stick in a weighted average sort of way.
{
if (reinit) {
pids[PID_ROLL + i].iAccumulator = 0;
pids[PID_RATE_ROLL + i].iAccumulator = 0;
pids[PID_RATEA_ROLL + i].iAccumulator = 0;
}
// Compute what Rate mode would give for this stick angle's rate
// Save Rate's rate in a temp for later merging with Attitude's rate
float rateDesiredAxisRate;
rateDesiredAxisRate = bound(stabDesiredAxis[i], 1.0f)
* cast_struct_to_array(settings.ManualRate, settings.ManualRate.Roll)[i];
// Compute what Attitude mode would give for this stick angle's rate
// stabDesired for this mode is [-1.0f,+1.0f]
// - multiply by Attitude mode max angle to get desired angle
// - subtract off the actual angle to get the angle error
// This is what local_error[] holds for Attitude mode
float attitude_error = stabDesiredAxis[i]
* cast_struct_to_array(settings.RollMax, settings.RollMax)[i]
- cast_struct_to_array(attitudeState.Roll, attitudeState.Roll)[i];
// Compute the outer loop just like Attitude mode does
float rateDesiredAxisAttitude;
rateDesiredAxisAttitude = pid_apply(&pids[PID_ROLL + i], attitude_error, dT);
rateDesiredAxisAttitude = bound(rateDesiredAxisAttitude,
cast_struct_to_array(settings.MaximumRate,
settings.MaximumRate.Roll)[i]);
// Compute the weighted average rate desired
// Using max() rather than sqrt() for cpu speed;
// - this makes the stick region into a square;
// - this is a feature!
// - hold a roll angle and add just pitch without the stick sensitivity changing
// magnitude = sqrt(stabDesired.Roll*stabDesired.Roll + stabDesired.Pitch*stabDesired.Pitch);
float magnitude;
magnitude = fmaxf(fabsf(stabDesired.Roll), fabsf(stabDesired.Pitch));
rateDesiredAxis[i] = (1.0f-magnitude) * rateDesiredAxisAttitude
+ magnitude * rateDesiredAxisRate;
// Compute the inner loop for both Rate mode and Attitude mode
// actuatorDesiredAxis[i] is the weighted average of the two PIDs from the two rates
actuatorDesiredAxis[i] =
(1.0f-magnitude) * pid_apply_setpoint(&pids[PID_RATEA_ROLL + i], speedScaleFactor, rateDesiredAxis[i], gyro_filtered[i], dT)
+ magnitude * pid_apply_setpoint(&pids[PID_RATE_ROLL + i], speedScaleFactor, rateDesiredAxis[i], gyro_filtered[i], dT);
actuatorDesiredAxis[i] = bound(actuatorDesiredAxis[i], 1.0f);
// settings.RattitudeAntiWindup controls the iAccumulator zeroing
// - so both iAccs don't wind up too far;
// - nor do both iAccs get held too close to zero at mid stick
// I suspect that there would be windup without it
// - since rate and attitude fight each other here
// - rate trying to pull it over the top and attitude trying to pull it back down
// Wind-up increases linearly with cycles for a fixed error.
// We must never increase the iAcc or we risk oscillation.
// Use the powf() function to make two anti-windup curves
// - one for zeroing rate close to center stick
// - the other for zeroing attitude close to max stick
// the bigger the dT the more anti windup needed
// the bigger the PID[].i the more anti windup needed
// more anti windup is achieved with a lower powf() power
// a doubling of e.g. PID[].i should cause the runtime anti windup factor
// to get twice as far away from 1.0 (towards zero)
// e.g. from .90 to .80
// magic numbers
// these generate the inverted parabola like curves that go through [0,1] and [1,0]
// the higher the power, the closer the curve is to a straight line
// from [0,1] to [1,1] to [1,0] and the less anti windup is applied
// the UAVO RattitudeAntiWindup varies from 0 to 31
// 0 turns off anti windup
// 1 gives very little anti-windup because the power given to powf() is 31
// 31 gives a lot of anti-windup because the power given to powf() is 1
// the 32.1 is what does this
// the 7.966 and 17.668 cancel the default PID value and dT given to log2f()
// if these are non-default, tweaking is thus done so the user doesn't have to readjust
// the default value of 10 for UAVO RattitudeAntiWindup gives a power of 22
// these calculations are for magnitude = 0.5, so 22 corresponds to the number of bits
// used in the mantissa of the float
// i.e. 1.0-(0.5^22) almost underflows
// This may only be useful for aircraft with large Ki values and limits
if (dT > 0.0f && rattitude_anti_windup > 0.0f) {
float factor;
// At magnitudes close to one, the Attitude accumulators gets zeroed
if (pids[PID_ROLL+i].i > 0.0f) {
factor = 1.0f - stab_powf(magnitude, ((uint8_t) (32.1f - 7.966f - stab_log2f(dT * pids[PID_ROLL+i].i))) - rattitude_anti_windup);
pids[PID_ROLL+i].iAccumulator *= factor;
}
if (pids[PID_RATEA_ROLL+i].i > 0.0f) {
factor = 1.0f - stab_powf(magnitude, ((uint8_t) (32.1f - 17.668f - stab_log2f(dT * pids[PID_RATEA_ROLL+i].i))) - rattitude_anti_windup);
pids[PID_RATEA_ROLL+i].iAccumulator *= factor;
}
// At magnitudes close to zero, the Rate accumulator gets zeroed
if (pids[PID_RATE_ROLL+i].i > 0.0f) {
factor = 1.0f - stab_powf(1.0f-magnitude, ((uint8_t) (32.1f - 17.668f - stab_log2f(dT * pids[PID_RATE_ROLL+i].i))) - rattitude_anti_windup);
pids[PID_RATE_ROLL+i].iAccumulator *= factor;
}
}
break;
}
case STABILIZATIONDESIRED_STABILIZATIONMODE_VIRTUALBAR:
// Store for debugging output
rateDesiredAxis[i] = stabDesiredAxis[i];
// Run a virtual flybar stabilization algorithm on this axis
stabilization_virtual_flybar(gyro_filtered[i], rateDesiredAxis[i], &actuatorDesiredAxis[i], dT, reinit, i, &settings);
break;
case STABILIZATIONDESIRED_STABILIZATIONMODE_WEAKLEVELING:
// FIXME: local_error[] is rate - attitude for Weak Leveling
// The only ramifications are:
// Weak Leveling Kp is off by a factor of 3 to 12 and may need a different default in GCS
// Changing Rate mode max rate currently requires a change to Kp
// That would be changed to Attitude mode max angle affecting Kp
// Also does not take dT into account
{
if (reinit) {
pids[PID_RATE_ROLL + i].iAccumulator = 0;
}
float weak_leveling = local_error[i] * weak_leveling_kp;
weak_leveling = bound(weak_leveling, weak_leveling_max);
// Compute desired rate as input biased towards leveling
rateDesiredAxis[i] = stabDesiredAxis[i] + weak_leveling;
actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_RATE_ROLL + i], speedScaleFactor, rateDesiredAxis[i], gyro_filtered[i], dT);
actuatorDesiredAxis[i] = bound(actuatorDesiredAxis[i], 1.0f);
break;
}
case STABILIZATIONDESIRED_STABILIZATIONMODE_AXISLOCK:
if (reinit) {
pids[PID_RATE_ROLL + i].iAccumulator = 0;
}
if (fabsf(stabDesiredAxis[i]) > max_axislock_rate) {
// While getting strong commands act like rate mode
rateDesiredAxis[i] = stabDesiredAxis[i];
axis_lock_accum[i] = 0;
} else {
// For weaker commands or no command simply attitude lock (almost) on no gyro change
axis_lock_accum[i] += (stabDesiredAxis[i] - gyro_filtered[i]) * dT;
axis_lock_accum[i] = bound(axis_lock_accum[i], max_axis_lock);
rateDesiredAxis[i] = pid_apply(&pids[PID_ROLL + i], axis_lock_accum[i], dT);
}
rateDesiredAxis[i] = bound(rateDesiredAxis[i],
cast_struct_to_array(settings.ManualRate, settings.ManualRate.Roll)[i]);
actuatorDesiredAxis[i] = pid_apply_setpoint(&pids[PID_RATE_ROLL + i], speedScaleFactor, rateDesiredAxis[i], gyro_filtered[i], dT);
actuatorDesiredAxis[i] = bound(actuatorDesiredAxis[i], 1.0f);
break;
case STABILIZATIONDESIRED_STABILIZATIONMODE_RELAYRATE:
// Store to rate desired variable for storing to UAVO
rateDesiredAxis[i] = bound(stabDesiredAxis[i],
cast_struct_to_array(settings.ManualRate, settings.ManualRate.Roll)[i]);
// Run the relay controller which also estimates the oscillation parameters
stabilization_relay_rate(rateDesiredAxis[i] - gyro_filtered[i], &actuatorDesiredAxis[i], i, reinit);
actuatorDesiredAxis[i] = bound(actuatorDesiredAxis[i], 1.0f);
break;
case STABILIZATIONDESIRED_STABILIZATIONMODE_RELAYATTITUDE:
if (reinit) {
pids[PID_ROLL + i].iAccumulator = 0;
}
// Compute the outer loop like attitude mode
rateDesiredAxis[i] = pid_apply(&pids[PID_ROLL + i], local_error[i], dT);
rateDesiredAxis[i] = bound(rateDesiredAxis[i],
cast_struct_to_array(settings.MaximumRate, settings.MaximumRate.Roll)[i]);
// Run the relay controller which also estimates the oscillation parameters
stabilization_relay_rate(rateDesiredAxis[i] - gyro_filtered[i], &actuatorDesiredAxis[i], i, reinit);
actuatorDesiredAxis[i] = bound(actuatorDesiredAxis[i], 1.0f);
break;
case STABILIZATIONDESIRED_STABILIZATIONMODE_NONE:
actuatorDesiredAxis[i] = bound(stabDesiredAxis[i], 1.0f);
break;
default:
error = true;
break;
}
}
if (settings.VbarPiroComp == STABILIZATIONSETTINGS_VBARPIROCOMP_TRUE) {
stabilization_virtual_flybar_pirocomp(gyro_filtered[2], dT);
}
#ifdef DIAG_RATEDESIRED
RateDesiredSet(&rateDesired);
#endif
// Save dT
actuatorDesired.UpdateTime = dT * 1000;
actuatorDesired.Throttle = stabDesired.Throttle;
// Suppress desired output while disarmed or throttle low, for configured axis
if (flightStatus.Armed != FLIGHTSTATUS_ARMED_ARMED || stabDesired.Throttle < 0) {
if (lowThrottleZeroAxis[ROLL]) {
actuatorDesired.Roll = 0.0f;
}
if (lowThrottleZeroAxis[PITCH]) {
actuatorDesired.Pitch = 0.0f;
}
if (lowThrottleZeroAxis[YAW]) {
actuatorDesired.Yaw = 0.0f;
}
}
// modify throttle according to 1/cos(bank angle)
// to maintain same altitdue with changing bank angle
// but without manually adjusting throttle
// do it here and all the various flight modes (e.g. Altitude Hold) can use it
if (cruise_control_max_power_factor > 0.0001f) {
static uint8_t toggle;
static float factor;
float angle;
// get attitude state and calculate angle
// do it every 8th iteration to save CPU
if ((toggle++ & 7) == 0) {
// spherical right triangle
// 0 <= acosf() <= Pi
angle = RAD2DEG(acosf(cos_lookup_deg(attitudeState.Roll) * cos_lookup_deg(attitudeState.Pitch)));
// if past the cutoff angle (60 to 180 (180 means never))
if (angle > cruise_control_max_angle) {
// -1 reversed collective, 0 zero power, or 1 normal power
// these are all unboosted
factor = cruise_control_inverted_power_switch;
} else {
// avoid singularity
if (angle > 89.999f && angle < 90.001f) {
factor = cruise_control_max_power_factor;
} else {
factor = 1.0f / fabsf(cos_lookup_deg(angle));
if (factor > cruise_control_max_power_factor) {
factor = cruise_control_max_power_factor;
}
}
// factor in the power trim, no effect at 1.0, linear effect increases with factor
factor = (factor - 1.0f) * cruise_control_power_trim + 1.0f;
// if inverted and they want negative boost
if (angle > 90.0f && cruise_control_inverted_power_switch == (int8_t) -1) {
factor = -factor;
// as long as throttle is getting reversed
// we may as well do pitch and yaw for a complete "invert switch"
actuatorDesired.Pitch = -actuatorDesired.Pitch;
actuatorDesired.Yaw = -actuatorDesired.Yaw;
}
}
}
// also don't adjust throttle if <= 0, leaves neg alone and zero throttle stops motors
if (actuatorDesired.Throttle > cruise_control_min_throttle)
{
// quad example factor of 2 at hover power of 40%: (0.4 - 0.0) * 2.0 + 0.0 = 0.8
// CP heli example factor of 2 at hover stick of 60%: (0.6 - 0.5) * 2.0 + 0.5 = 0.7
actuatorDesired.Throttle = (actuatorDesired.Throttle - cruise_control_neutral_thrust) * factor + cruise_control_neutral_thrust;
if (actuatorDesired.Throttle > cruise_control_max_throttle) {
actuatorDesired.Throttle = cruise_control_max_throttle;
} else if (actuatorDesired.Throttle < cruise_control_min_throttle) {
actuatorDesired.Throttle = cruise_control_min_throttle;
}
}
}
if (PARSE_FLIGHT_MODE(flightStatus.FlightMode) != FLIGHTMODE_MANUAL) {
ActuatorDesiredSet(&actuatorDesired);
} else {
// Force all axes to reinitialize when engaged
for (uint8_t i = 0; i < MAX_AXES; i++) {
previous_mode[i] = 255;
}
}
if (flightStatus.Armed != FLIGHTSTATUS_ARMED_ARMED ||
(lowThrottleZeroIntegral && stabDesired.Throttle < 0)) {
// Force all axes to reinitialize when engaged
for (uint8_t i = 0; i < MAX_AXES; i++) {
previous_mode[i] = 255;
}
}
// Clear or set alarms. Done like this to prevent toggline each cycle
// and hammering system alarms
if (error) {
AlarmsSet(SYSTEMALARMS_ALARM_STABILIZATION, SYSTEMALARMS_ALARM_ERROR);
} else {
AlarmsClear(SYSTEMALARMS_ALARM_STABILIZATION);
}
}
}
/**
* Clear the accumulators and derivatives for all the axes
*/
static void ZeroPids(void)
{
for (uint32_t i = 0; i < PID_MAX; i++) {
pid_zero(&pids[i]);
}
for (uint8_t i = 0; i < 3; i++) {
axis_lock_accum[i] = 0.0f;
}
}
/**
* Bound input value between limits
*/
static float bound(float val, float range)
{
if (val < -range) {
return -range;
} else if (val > range) {
return range;
}
return val;
}
// x small (0.0 < x < .01) so interpolation of fractional part is reasonable
static float stab_log2f(float x)
{
union
{
volatile float f;
volatile uint32_t i;
volatile unsigned char c[4];
} __attribute__((packed)) u1, u2;
u2.f = u1.f = x;
u1.i <<= 1;
u2.i &= 0xff800000;
// get and unbias the exponent, add in a linear interpolation of the fractional part
return (float) (u1.c[3] - 127) + (x / u2.f) - 1.0f;
}
// 0<=x<=1, 0<=p<=31
static float stab_powf(float x, uint8_t p)
{
float retval = 1.0f;
while (p)
{
if (p&1)
{
retval *= x;
}
x *= x;
p >>= 1;
}
return retval;
}
static void SettingsUpdatedCb(__attribute__((unused)) UAVObjEvent *ev)
{
StabilizationSettingsGet(&settings);
// Set the roll rate PID constants
pid_configure(&pids[PID_RATE_ROLL],
settings.RollRatePID.Kp,
settings.RollRatePID.Ki,
settings.RollRatePID.Kd,
settings.RollRatePID.ILimit);
// Set the pitch rate PID constants
pid_configure(&pids[PID_RATE_PITCH],
settings.PitchRatePID.Kp,
settings.PitchRatePID.Ki,
settings.PitchRatePID.Kd,
settings.PitchRatePID.ILimit);
// Set the yaw rate PID constants
pid_configure(&pids[PID_RATE_YAW],
settings.YawRatePID.Kp,
settings.YawRatePID.Ki,
settings.YawRatePID.Kd,
settings.YawRatePID.ILimit);
// Set the roll attitude PI constants
pid_configure(&pids[PID_ROLL],
settings.RollPI.Kp,
settings.RollPI.Ki,
0,
settings.RollPI.ILimit);
// Set the pitch attitude PI constants
pid_configure(&pids[PID_PITCH],
settings.PitchPI.Kp,
settings.PitchPI.Ki,
0,
settings.PitchPI.ILimit);
// Set the yaw attitude PI constants
pid_configure(&pids[PID_YAW],
settings.YawPI.Kp,
settings.YawPI.Ki,
0,
settings.YawPI.ILimit);
// Set the Rattitude roll rate PID constants
pid_configure(&pids[PID_RATEA_ROLL],
settings.RollRatePID.Kp,
settings.RollRatePID.Ki,
settings.RollRatePID.Kd,
settings.RollRatePID.ILimit);
// Set the Rattitude pitch rate PID constants
pid_configure(&pids[PID_RATEA_PITCH],
settings.PitchRatePID.Kp,
settings.PitchRatePID.Ki,
settings.PitchRatePID.Kd,
settings.PitchRatePID.ILimit);
// Set the Rattitude yaw rate PID constants
pid_configure(&pids[PID_RATEA_YAW],
settings.YawRatePID.Kp,
settings.YawRatePID.Ki,
settings.YawRatePID.Kd,
settings.YawRatePID.ILimit);
// Set up the derivative term
pid_configure_derivative(settings.DerivativeCutoff, settings.DerivativeGamma);
// Maximum deviation to accumulate for axis lock
max_axis_lock = settings.MaxAxisLock;
max_axislock_rate = settings.MaxAxisLockRate;
// Settings for weak leveling
weak_leveling_kp = settings.WeakLevelingKp;
weak_leveling_max = settings.MaxWeakLevelingRate;
// Whether to zero the PID integrals while throttle is low
lowThrottleZeroIntegral = settings.LowThrottleZeroIntegral == STABILIZATIONSETTINGS_LOWTHROTTLEZEROINTEGRAL_TRUE;
// Whether to suppress (zero) the StabilizationDesired output for each axis while disarmed or throttle is low
lowThrottleZeroAxis[ROLL] = settings.LowThrottleZeroAxis.Roll == STABILIZATIONSETTINGS_LOWTHROTTLEZEROAXIS_TRUE;
lowThrottleZeroAxis[PITCH] = settings.LowThrottleZeroAxis.Pitch == STABILIZATIONSETTINGS_LOWTHROTTLEZEROAXIS_TRUE;
lowThrottleZeroAxis[YAW] = settings.LowThrottleZeroAxis.Yaw == STABILIZATIONSETTINGS_LOWTHROTTLEZEROAXIS_TRUE;
// The dT has some jitter iteration to iteration that we don't want to
// make thie result unpredictable. Still, it's nicer to specify the constant
// based on a time (in ms) rather than a fixed multiplier. The error between
// update rates on OP (~300 Hz) and CC (~475 Hz) is negligible for this
// calculation
const float fakeDt = 0.0025f;
if (settings.GyroTau < 0.0001f) {
gyro_alpha = 0; // not trusting this to resolve to 0
} else {
gyro_alpha = expf(-fakeDt / settings.GyroTau);
}
// Compute time constant for vbar decay term based on a tau
vbar_decay = expf(-fakeDt / settings.VbarTau);
// Rattitude flight mode anti-windup factor
rattitude_anti_windup = settings.RattitudeAntiWindup;
cruise_control_min_throttle = (float) settings.CruiseControlMinThrottle / 100.0f;
cruise_control_max_throttle = (float) settings.CruiseControlMaxThrottle / 100.0f;
cruise_control_max_angle = settings.CruiseControlMaxAngle;
cruise_control_max_power_factor = settings.CruiseControlMaxPowerFactor;
cruise_control_power_trim = settings.CruiseControlPowerTrim / 100.0f;
cruise_control_inverted_power_switch = settings.CruiseControlInvertedPowerSwitch;
cruise_control_neutral_thrust = (float) settings.CruiseControlNeutralThrust / 100.0f;
}
/**
* @}
* @}
*/
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