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APM_Control: pass in aircraft parameters and expose coordinate rate offset 

this will make it possible to do rate based pitch control without
having a coordinated turn, for in ACRO mode

Pair-Programmed-With: Paul Riseborough <p_riseborough@live.com.au>
This commit is contained in:
Andrew Tridgell 2013-07-18 11:57:11 +10:00
parent fb0e48a25d
commit 3e21d0594c
6 changed files with 92 additions and 51 deletions
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91
libraries/APM_Control/AP_PitchController.cpp
View File

@ -90,13 +90,13 @@ const AP_Param::GroupInfo AP_PitchController::var_info[] PROGMEM = {
Function returns an equivalent elevator deflection in centi-degrees in the range from -4500 to 4500
A positive demand is up
Inputs are:
1) demanded pitch rate in radians/second
1) demanded pitch rate in degrees/second
2) control gain scaler = scaling_speed / aspeed
3) boolean which is true when stabilise mode is active
4) minimum FBW airspeed (metres/sec)
5) maximum FBW airspeed (metres/sec)
*/
int32_t AP_PitchController::_get_rate_out(float desired_rate, float scaler, bool stabilize, float aspeed, int16_t aspd_min)
int32_t AP_PitchController::_get_rate_out(float desired_rate, float scaler, bool stabilize, float aspeed)
{
uint32_t tnow = hal.scheduler->millis();
uint32_t dt = tnow - _last_t;
@ -120,7 +120,7 @@ int32_t AP_PitchController::_get_rate_out(float desired_rate, float scaler, bool
if (!stabilize && _K_I > 0) {
float ki_rate = _K_I * _tau;
//only integrate if gain and time step are positive and airspeed above min value.
if (dt > 0 && aspeed > 0.5f*float(aspd_min)) {
if (dt > 0 && aspeed > 0.5f*float(aparm.airspeed_min)) {
float integrator_delta = rate_error * ki_rate * delta_time;
if (_last_out < -45) {
// prevent the integrator from increasing if surface defln demand is above the upper limit
@ -167,7 +167,58 @@ int32_t AP_PitchController::_get_rate_out(float desired_rate, float scaler, bool
*/
int32_t AP_PitchController::get_rate_out(float desired_rate, float scaler)
{
return _get_rate_out(desired_rate, scaler, false, 0, 0);
return _get_rate_out(desired_rate, scaler, false, 0);
}
/*
get the rate offset in degrees/second needed for pitch in body frame
to maintain height in a coordinated turn.
Also returns the inverted flag and the estimated airspeed in m/s for
use by the rest of the pitch controller
*/
float AP_PitchController::_get_coordination_rate_offset(float &aspeed, bool &inverted) const
{
float rate_offset;
float bank_angle = _ahrs->roll;
// limit bank angle between +- 80 deg if right way up
if (fabsf(bank_angle) < radians(90)) {
bank_angle = constrain_float(bank_angle,-radians(80),radians(80));
inverted = false;
} else {
inverted = true;
if (bank_angle > 0.0f) {
bank_angle = constrain_float(bank_angle,radians(100),radians(180));
} else {
bank_angle = constrain_float(bank_angle,-radians(180),-radians(100));
}
}
if (!_ahrs->airspeed_estimate(&aspeed)) {
// If no airspeed available use average of min and max
aspeed = 0.5f*(float(aparm.airspeed_min) + float(aparm.airspeed_max));
}
if (abs(_ahrs->pitch_sensor) > 7000) {
// don't do turn coordination handling when at very high pitch angles
rate_offset = 0;
} else {
rate_offset = fabsf(ToDeg((GRAVITY_MSS / max(aspeed , float(aparm.airspeed_min))) * tanf(bank_angle) * sinf(bank_angle))) * _roll_ff;
}
if (inverted) {
rate_offset = -rate_offset;
}
return rate_offset;
}
/*
get the rate offset in degrees/second needed for pitch in body frame
to maintain height in a coordinated turn.
*/
float AP_PitchController::get_coordination_rate_offset(void) const
{
float aspeed;
bool inverted;
return _get_coordination_rate_offset(aspeed, inverted);
}
// Function returns an equivalent elevator deflection in centi-degrees in the range from -4500 to 4500
@ -179,44 +230,20 @@ int32_t AP_PitchController::get_rate_out(float desired_rate, float scaler)
// 4) minimum FBW airspeed (metres/sec)
// 5) maximum FBW airspeed (metres/sec)
//
int32_t AP_PitchController::get_servo_out(int32_t angle_err, float scaler, bool stabilize, int16_t aspd_min, int16_t aspd_max)
int32_t AP_PitchController::get_servo_out(int32_t angle_err, float scaler, bool stabilize)
{
// Calculate offset to pitch rate demand required to maintain pitch angle whilst banking
// Calculate ideal turn rate from bank angle and airspeed assuming a level coordinated turn
// Pitch rate offset is the component of turn rate about the pitch axis
float aspeed;
float rate_offset;
float bank_angle = _ahrs->roll;
bool inverted = false;
bool inverted;
if (_tau < 0.1) {
_tau = 0.1;
}
// limit bank angle between +- 80 deg if right way up
if (fabsf(bank_angle) < radians(90)) {
bank_angle = constrain_float(bank_angle,-radians(80),radians(80));
} else {
inverted = true;
if (bank_angle > 0.0f) {
bank_angle = constrain_float(bank_angle,radians(100),radians(180));
} else {
bank_angle = constrain_float(bank_angle,-radians(180),-radians(100));
}
}
if (!_ahrs->airspeed_estimate(&aspeed)) {
// If no airspeed available use average of min and max
aspeed = 0.5f*(float(aspd_min) + float(aspd_max));
}
if (abs(_ahrs->pitch_sensor) > 7000) {
// don't do turn coordination handling when at very high pitch angles
rate_offset = 0;
} else {
rate_offset = fabsf(ToDeg((GRAVITY_MSS / max(aspeed , float(aspd_min))) * tanf(bank_angle) * sinf(bank_angle))) * _roll_ff;
}
if (inverted) {
rate_offset = -rate_offset;
}
rate_offset = _get_coordination_rate_offset(aspeed, inverted);
// Calculate the desired pitch rate (deg/sec) from the angle error
float desired_rate = angle_err * 0.01f / _tau;
@ -239,7 +266,7 @@ int32_t AP_PitchController::get_servo_out(int32_t angle_err, float scaler, bool
// Apply the turn correction offset
desired_rate = desired_rate + rate_offset;
return _get_rate_out(desired_rate, scaler, stabilize, aspeed, aspd_min);
return _get_rate_out(desired_rate, scaler, stabilize, aspeed);
}
void AP_PitchController::reset_I()

16
libraries/APM_Control/AP_PitchController.h
View File

@ -5,24 +5,29 @@
#include <AP_AHRS.h>
#include <AP_Common.h>
#include <math.h> // for fabs()
#include <AP_SpdHgtControl.h>
#include <math.h>
class AP_PitchController {
public:
AP_PitchController() {
AP_PitchController(const AP_SpdHgtControl::AircraftParameters &parms) :
aparm(parms)
{
AP_Param::setup_object_defaults(this, var_info);
}
void set_ahrs(AP_AHRS *ahrs) { _ahrs = ahrs; }
int32_t get_rate_out(float desired_rate, float scaler = 1.0);
int32_t get_servo_out(int32_t angle_err, float scaler = 1.0, bool stabilize = false, int16_t aspd_min = 0, int16_t aspd_max = 0);
int32_t get_rate_out(float desired_rate, float scaler);
int32_t get_servo_out(int32_t angle_err, float scaler, bool stabilize);
float get_coordination_rate_offset(void) const;
void reset_I();
static const struct AP_Param::GroupInfo var_info[];
private:
const AP_SpdHgtControl::AircraftParameters &aparm;
AP_Float _tau;
AP_Float _K_P;
AP_Float _K_I;
@ -36,7 +41,8 @@ private:
float _integrator;
int32_t _get_rate_out(float desired_rate, float scaler, bool stabilize, float aspeed, int16_t aspd_min);
int32_t _get_rate_out(float desired_rate, float scaler, bool stabilize, float aspeed);
float _get_coordination_rate_offset(float &aspeed, bool &inverted) const;
AP_AHRS *_ahrs;

10
libraries/APM_Control/AP_RollController.cpp
View File

@ -73,7 +73,7 @@ const AP_Param::GroupInfo AP_RollController::var_info[] PROGMEM = {
internal rate controller, called by attitude and rate controller
public functions
*/
int32_t AP_RollController::_get_rate_out(float desired_rate, float scaler, bool stabilize, int16_t aspd_min)
int32_t AP_RollController::_get_rate_out(float desired_rate, float scaler, bool stabilize)
{
uint32_t tnow = hal.scheduler->millis();
uint32_t dt = tnow - _last_t;
@ -116,7 +116,7 @@ int32_t AP_RollController::_get_rate_out(float desired_rate, float scaler, bool
// Don't integrate if in stabilise mode as the integrator will wind up against the pilots inputs
if (!stabilize && ki_rate > 0) {
//only integrate if gain and time step are positive and airspeed above min value.
if (dt > 0 && aspeed > float(aspd_min)) {
if (dt > 0 && aspeed > float(aparm.airspeed_min)) {
float integrator_delta = rate_error * ki_rate * delta_time;
// prevent the integrator from increasing if surface defln demand is above the upper limit
if (_last_out < -45) {
@ -157,7 +157,7 @@ int32_t AP_RollController::_get_rate_out(float desired_rate, float scaler, bool
*/
int32_t AP_RollController::get_rate_out(float desired_rate, float scaler)
{
return _get_rate_out(desired_rate, scaler, true, 0);
return _get_rate_out(desired_rate, scaler, true);
}
/*
@ -169,7 +169,7 @@ int32_t AP_RollController::get_rate_out(float desired_rate, float scaler)
3) boolean which is true when stabilise mode is active
4) minimum FBW airspeed (metres/sec)
*/
int32_t AP_RollController::get_servo_out(int32_t angle_err, float scaler, bool stabilize, int16_t aspd_min)
int32_t AP_RollController::get_servo_out(int32_t angle_err, float scaler, bool stabilize)
{
if (_tau < 0.1) {
_tau = 0.1;
@ -178,7 +178,7 @@ int32_t AP_RollController::get_servo_out(int32_t angle_err, float scaler, bool s
// Calculate the desired roll rate (deg/sec) from the angle error
float desired_rate = angle_err * 0.01f / _tau;
return _get_rate_out(desired_rate, scaler, stabilize, aspd_min);
return _get_rate_out(desired_rate, scaler, stabilize);
}
void AP_RollController::reset_I()

12
libraries/APM_Control/AP_RollController.h
View File

@ -5,24 +5,28 @@
#include <AP_AHRS.h>
#include <AP_Common.h>
#include <math.h> // for fabs()
#include <AP_SpdHgtControl.h>
#include <math.h>
class AP_RollController {
public:
AP_RollController() {
AP_RollController(const AP_SpdHgtControl::AircraftParameters &parms) :
aparm(parms)
{
AP_Param::setup_object_defaults(this, var_info);
}
void set_ahrs(AP_AHRS *ahrs) { _ahrs = ahrs; }
int32_t get_rate_out(float desired_rate, float scaler=1.0);
int32_t get_servo_out(int32_t angle_err, float scaler=1.0, bool stabilize=false, int16_t aspd_min = 0);
int32_t get_servo_out(int32_t angle_err, float scaler=1.0, bool stabilize=false);
void reset_I();
static const struct AP_Param::GroupInfo var_info[];
private:
const AP_SpdHgtControl::AircraftParameters &aparm;
AP_Float _tau;
AP_Float _K_P;
AP_Float _K_I;
@ -34,7 +38,7 @@ private:
float _integrator;
int32_t _get_rate_out(float desired_rate, float scaler, bool stabilize, int16_t aspd_min);
int32_t _get_rate_out(float desired_rate, float scaler, bool stabilize);
AP_AHRS *_ahrs;

5
libraries/APM_Control/AP_YawController.cpp
View File

@ -62,7 +62,7 @@ const AP_Param::GroupInfo AP_YawController::var_info[] PROGMEM = {
AP_GROUPEND
};
int32_t AP_YawController::get_servo_out(float scaler, bool stabilize, int16_t aspd_min, int16_t aspd_max)
int32_t AP_YawController::get_servo_out(float scaler, bool stabilize)
{
uint32_t tnow = hal.scheduler->millis();
uint32_t dt = tnow - _last_t;
@ -75,6 +75,7 @@ int32_t AP_YawController::get_servo_out(float scaler, bool stabilize, int16_t as
return 0;
}
int16_t aspd_min = aparm.airspeed_min;
if (aspd_min < 1) {
aspd_min = 1;
}
@ -91,7 +92,7 @@ int32_t AP_YawController::get_servo_out(float scaler, bool stabilize, int16_t as
}
if (!_ahrs->airspeed_estimate(&aspeed)) {
// If no airspeed available use average of min and max
aspeed = 0.5f*(float(aspd_min) + float(aspd_max));
aspeed = 0.5f*(float(aspd_min) + float(aparm.airspeed_max));
}
rate_offset = (GRAVITY_MSS / max(aspeed , float(aspd_min))) * tanf(bank_angle) * cosf(bank_angle) * _K_FF;

9
libraries/APM_Control/AP_YawController.h
View File

@ -5,11 +5,13 @@
#include <AP_AHRS.h>
#include <AP_Common.h>
#include <math.h> // for fabs()
#include <AP_SpdHgtControl.h>
#include <math.h>
class AP_YawController {
public:
AP_YawController()
AP_YawController(const AP_SpdHgtControl::AircraftParameters &parms) :
aparm(parms)
{
AP_Param::setup_object_defaults(this, var_info);
}
@ -19,13 +21,14 @@ public:
_ins = _ahrs->get_ins();
}
int32_t get_servo_out(float scaler = 1.0, bool stabilize = false, int16_t aspd_min = 0, int16_t aspd_max = 0);
int32_t get_servo_out(float scaler = 1.0, bool stabilize = false);
void reset_I();
static const struct AP_Param::GroupInfo var_info[];
private:
const AP_SpdHgtControl::AircraftParameters &aparm;
AP_Float _K_A;
AP_Float _K_I;
AP_Float _K_D;