#include <stdlib.h>
#include <avr/io.h>
#include <stdlib.h>
#include "attitude.h"
#include "dongfangMath.h"
#include "commands.h"
// For scope debugging only!
#include "rc.h"
// where our main data flow comes from.
#include "analog.h"
#include "configuration.h"
#include "output.h"
// Some calculations are performed depending on some stick related things.
#include "controlMixer.h"
#define CHECK_MIN_MAX(value, min, max) {if(value < min) value = min; else if(value > max) value = max;}
/*
* Gyro readings, as read from the analog module. It would have been nice to flow
* them around between the different calculations as a struct or array (doing
* things functionally without side effects) but this is shorter and probably
* faster too.
* The variables are overwritten at each attitude calculation invocation - the values
* are not preserved or reused.
*/
int16_t rate_ATT
[2], yawRate
;
// With different (less) filtering
int16_t rate_PID
[2];
int16_t differential
[2];
/*
* Gyro readings, after performing "axis coupling" - that is, the transfomation
* of rotation rates from the airframe-local coordinate system to a ground-fixed
* coordinate system. If axis copling is disabled, the gyro readings will be
* copied into these directly.
* These are global for the same pragmatic reason as with the gyro readings.
* The variables are overwritten at each attitude calculation invocation - the values
* are not preserved or reused.
*/
int16_t ACRate
[2], ACYawRate
;
/*
* Gyro integrals. These are the rotation angles of the airframe compared to the
* horizontal plane, yaw relative to yaw at start.
*/
int32_t attitude
[2];
//int readingHeight = 0;
// Yaw angle and compass stuff.
int32_t headingError
;
// The difference between the above 2 (heading - course) on a -180..179 degree interval.
// Not necessary. Never read anywhere.
// int16_t compassOffCourse = 0;
uint16_t ignoreCompassTimer
= 0;// 500;
int32_t heading
; // Yaw Gyro Integral supported by compass
int16_t yawGyroDrift
;
int16_t correctionSum
[2] = { 0, 0 };
// For NaviCTRL use.
int16_t averageAcc
[2] = { 0, 0 }, averageAccCount
= 0;
/*
* Experiment: Compensating for dynamic-induced gyro biasing.
*/
int16_t driftComp
[2] = { 0, 0 }, driftCompYaw
= 0;
// int16_t savedDynamicOffsetPitch = 0, savedDynamicOffsetRoll = 0;
// int32_t dynamicCalPitch, dynamicCalRoll, dynamicCalYaw;
// int16_t dynamicCalCount;
// uint16_t accVector;
// uint32_t gyroActivity;
/************************************************************************
* Set inclination angles from the acc. sensor data.
* If acc. sensors are not used, set to zero.
* TODO: One could use inverse sine to calculate the angles more
* accurately, but since: 1) the angles are rather small at times when
* it makes sense to set the integrals (standing on ground, or flying at
* constant speed, and 2) at small angles a, sin(a) ~= constant * a,
* it is hardly worth the trouble.
************************************************************************/
int32_t getAngleEstimateFromAcc
(uint8_t axis
) {
//int32_t correctionTerm = (dynamicParams.levelCorrection[axis] - 128) * 256L;
return (int32_t) GYRO_ACC_FACTOR
* (int32_t) filteredAcc
[axis
]; // + correctionTerm;
// return 342L * filteredAcc[axis];
}
void setStaticAttitudeAngles
(void) {
#ifdef ATTITUDE_USE_ACC_SENSORS
attitude
[PITCH
] = getAngleEstimateFromAcc
(PITCH
);
attitude
[ROLL
] = getAngleEstimateFromAcc
(ROLL
);
#else
attitude
[PITCH
] = attitude
[ROLL
] = 0;
#endif
}
/************************************************************************
* Neutral Readings
************************************************************************/
void attitude_setNeutral
(void) {
// Servo_Off(); // disable servo output. TODO: Why bother? The servos are going to make a jerk anyway.
// dynamicParams.axisCoupling1 = dynamicParams.axisCoupling2 = 0;
driftComp
[PITCH
] = driftComp
[ROLL
] = yawGyroDrift
= driftCompYaw
= 0;
correctionSum
[PITCH
] = correctionSum
[ROLL
] = 0;
// Calibrate hardware.
analog_setNeutral
();
// reset gyro integrals to acc guessing
setStaticAttitudeAngles
();
#ifdef USE_MK3MAG
attitude_resetHeadingToMagnetic
();
#endif
// Servo_On(); //enable servo output
}
/************************************************************************
* Get sensor data from the analog module, and release the ADC
* TODO: Ultimately, the analog module could do this (instead of dumping
* the values into variables).
* The rate variable end up in a range of about [-1024, 1023].
*************************************************************************/
void getAnalogData
(void) {
uint8_t axis
;
analog_update
();
for (axis
= PITCH
; axis
<= ROLL
; axis
++) {
rate_PID
[axis
] = gyro_PID
[axis
] + driftComp
[axis
];
rate_ATT
[axis
] = gyro_ATT
[axis
] + driftComp
[axis
];
differential
[axis
] = gyroD
[axis
];
averageAcc
[axis
] += acc
[axis
];
}
averageAccCount
++;
yawRate
= yawGyro
+ driftCompYaw
;
}
/*
* This is the standard flight-style coordinate system transformation
* (from airframe-local axes to a ground-based system). For some reason
* the MK uses a left-hand coordinate system. The tranformation has been
* changed accordingly.
*/
void trigAxisCoupling
(void) {
int16_t rollAngleInDegrees
= attitude
[ROLL
] / GYRO_DEG_FACTOR_PITCHROLL
;
int16_t pitchAngleInDegrees
= attitude
[PITCH
] / GYRO_DEG_FACTOR_PITCHROLL
;
int16_t cospitch
= cos_360
(pitchAngleInDegrees
);
int16_t cosroll
= cos_360
(rollAngleInDegrees
);
int16_t sinroll
= sin_360
(rollAngleInDegrees
);
ACRate
[PITCH
] = (((int32_t) rate_ATT
[PITCH
] * cosroll
- (int32_t) yawRate
* sinroll
) >> LOG_MATH_UNIT_FACTOR
);
ACRate
[ROLL
] = rate_ATT
[ROLL
]
+ (((((int32_t) rate_ATT
[PITCH
] * sinroll
+ (int32_t) yawRate
* cosroll
)
>> LOG_MATH_UNIT_FACTOR
) * tan_360
(pitchAngleInDegrees
))
>> LOG_MATH_UNIT_FACTOR
);
ACYawRate
=
((int32_t) rate_ATT
[PITCH
] * sinroll
+ (int32_t) yawRate
* cosroll
)
/ cospitch
;
}
// 480 usec with axis coupling - almost no time without.
void integrate
(void) {
// First, perform axis coupling. If disabled xxxRate is just copied to ACxxxRate.
uint8_t axis
;
if (staticParams.
bitConfig & CFG_AXIS_COUPLING_ENABLED
) {
trigAxisCoupling
();
} else {
ACRate
[PITCH
] = rate_ATT
[PITCH
];
ACRate
[ROLL
] = rate_ATT
[ROLL
];
ACYawRate
= yawRate
;
}
/*
* Yaw
* Calculate yaw gyro integral (~ to rotation angle)
* Limit heading proportional to 0 deg to 360 deg
*/
heading
+= ACYawRate
;
intervalWrap
(&heading
, YAWOVER360
);
headingError
+= ACYawRate
;
/*
* Pitch axis integration and range boundary wrap.
*/
for (axis
= PITCH
; axis
<= ROLL
; axis
++) {
attitude
[axis
] += ACRate
[axis
];
if (attitude
[axis
] > PITCHROLLOVER180
) {
attitude
[axis
] -= PITCHROLLOVER360
;
} else if (attitude
[axis
] <= -PITCHROLLOVER180
) {
attitude
[axis
] += PITCHROLLOVER360
;
}
}
}
/************************************************************************
* A kind of 0'th order integral correction, that corrects the integrals
* directly. This is the "gyroAccFactor" stuff in the original code.
* There is (there) also a drift compensation
* - it corrects the differential of the integral = the gyro offsets.
* That should only be necessary with drifty gyros like ENC-03.
************************************************************************/
#define LOG_DIVIDER 12
#define DIVIDER (1L << LOG_DIVIDER)
void correctIntegralsByAcc0thOrder
(void) {
// TODO: Consider changing this to: Only correct when integrals are less than ...., or only correct when angular velocities
// are less than ....., or reintroduce Kalman.
// Well actually the Z axis acc. check is not so silly.
uint8_t axis
;
int32_t temp
;
debugOut.
analog[12] = IMUConfig.
zerothOrderCorrection;
uint16_t ca
= gyroActivity
>> 14;
uint8_t gyroActivityWeighted
= ca
/ IMUConfig.
rateTolerance;
debugOut.
analog[15] = gyroActivityWeighted
;
if (!gyroActivityWeighted
) gyroActivityWeighted
= 1;
uint8_t accPart
= IMUConfig.
zerothOrderCorrection / gyroActivityWeighted
;
debugOut.
analog[28] = IMUConfig.
rateTolerance;
debugOut.
digital[0] &= ~DEBUG_ACC0THORDER
;
debugOut.
digital[1] &= ~DEBUG_ACC0THORDER
;
if (gyroActivityWeighted
< 8) {
debugOut.
digital[0] |= DEBUG_ACC0THORDER
;
}
if (gyroActivityWeighted
<= 2) {
debugOut.
digital[1] |= DEBUG_ACC0THORDER
;
}
/*
* Add to each sum: The amount by which the angle is changed just below.
*/
for (axis
= PITCH
; axis
<= ROLL
; axis
++) {
int32_t accDerived
= getAngleEstimateFromAcc
(axis
);
//debugOut.analog[9 + axis] = accDerived / (GYRO_DEG_FACTOR_PITCHROLL / 10);
// 1000 * the correction amount that will be added to the gyro angle in next line.
temp
= attitude
[axis
];
attitude
[axis
] = ((int32_t) (DIVIDER
- accPart
) * temp
+ (int32_t)accPart
* accDerived
) >> LOG_DIVIDER
;
correctionSum
[axis
] += attitude
[axis
] - temp
;
}
}
/************************************************************************
* This is an attempt to correct not the error in the angle integrals
* (that happens in correctIntegralsByAcc0thOrder above) but rather the
* cause of it: Gyro drift, vibration and rounding errors.
* All the corrections made in correctIntegralsByAcc0thOrder over
* DRIFTCORRECTION_TIME cycles are summed up. This number is
* then divided by DRIFTCORRECTION_TIME to get the approx.
* correction that should have been applied to each iteration to fix
* the error. This is then added to the dynamic offsets.
************************************************************************/
// 2 times / sec. = 488/2
#define DRIFTCORRECTION_TIME 256L
void driftCorrection
(void) {
static int16_t timer
= DRIFTCORRECTION_TIME
;
int16_t deltaCorrection
;
int16_t round
;
uint8_t axis
;
if (!--timer
) {
timer
= DRIFTCORRECTION_TIME
;
for (axis
= PITCH
; axis
<= ROLL
; axis
++) {
// Take the sum of corrections applied, add it to delta
if (correctionSum
[axis
] >= 0)
round
= DRIFTCORRECTION_TIME
/ 2;
else
round
= -DRIFTCORRECTION_TIME
/ 2;
deltaCorrection
= (correctionSum
[axis
] + round
) / DRIFTCORRECTION_TIME
;
// Add the delta to the compensation. So positive delta means, gyro should have higher value.
driftComp
[axis
] += deltaCorrection
/ IMUConfig.
driftCompDivider;
CHECK_MIN_MAX
(driftComp
[axis
], -IMUConfig.
driftCompLimit, IMUConfig.
driftCompLimit);
// DebugOut.Analog[11 + axis] = correctionSum[axis];
debugOut.
analog[18 + axis
] = correctionSum
[axis
];
debugOut.
analog[13 + axis
] = driftComp
[axis
];
correctionSum
[axis
] = 0;
}
}
}
/*
void calculateAccVector(void) {
int16_t temp;
temp = filteredAcc[0] >> 3;
accVector = temp * temp;
temp = filteredAcc[1] >> 3;
accVector += temp * temp;
temp = filteredAcc[2] >> 3;
accVector += temp * temp;
}
*/
#ifdef USE_MK3MAG
void attitude_resetHeadingToMagnetic
(void) {
if (commands_isCalibratingCompass
())
return;
// Compass is off, skip.
if (!(staticParams.
bitConfig & CFG_COMPASS_ENABLED
))
return;
// Compass is invalid, skip.
if (magneticHeading
< 0)
return;
heading
= (int32_t) magneticHeading
* GYRO_DEG_FACTOR_YAW
;
//targetHeading = heading;
headingError
= 0;
}
void correctHeadingToMagnetic
(void) {
int32_t error
;
if (commands_isCalibratingCompass
()) {
//debugOut.analog[30] = -1;
return;
}
// Compass is off, skip.
// Naaah this is assumed.
// if (!(staticParams.bitConfig & CFG_COMPASS_ACTIVE))
// return;
// Compass is invalid, skip.
if (magneticHeading
< 0) {
//debugOut.analog[30] = -2;
return;
}
// Spinning fast, skip
if (abs(yawRate
) > 128) {
// debugOut.analog[30] = -3;
return;
}
// Otherwise invalidated, skip
if (ignoreCompassTimer
) {
ignoreCompassTimer
--;
//debugOut.analog[30] = -4;
return;
}
//debugOut.analog[30] = magneticHeading;
// TODO: Find computational cost of this.
error
= ((int32_t)magneticHeading
*GYRO_DEG_FACTOR_YAW
- heading
);
if (error
<= -YAWOVER180
) error
+= YAWOVER360
;
else if (error
> YAWOVER180
) error
-= YAWOVER360
;
// We only correct errors larger than the resolution of the compass, or else we would keep rounding the
// better resolution of the gyros to the worse resolution of the compass all the time.
// The correction should really only serve to compensate for gyro drift.
if(abs(error
) < GYRO_DEG_FACTOR_YAW
) return;
int32_t correction
= (error
* staticParams.
compassYawCorrection) >> 8;
//debugOut.analog[30] = correction;
debugOut.
digital[0] &= ~DEBUG_COMPASS
;
debugOut.
digital[1] &= ~DEBUG_COMPASS
;
if (correction
> 0) {
debugOut.
digital[0] ^= DEBUG_COMPASS
;
} else if (correction
< 0) {
debugOut.
digital[1] ^= DEBUG_COMPASS
;
}
// The correction is added both to current heading (the direction in which the copter thinks it is pointing)
// and to the heading error (the angle of yaw that the copter is off the set heading).
heading
+= correction
;
headingError
+= correction
;
intervalWrap
(&heading
, YAWOVER360
);
// If we want a transparent flight wrt. compass correction (meaning the copter does not change attitude all
// when the compass corrects the heading - it only corrects numbers!) we want to add:
// This will however cause drift to remain uncorrected!
// headingError += correction;
//debugOut.analog[29] = 0;
}
#endif
/************************************************************************
* Main procedure.
************************************************************************/
void calculateFlightAttitude
(void) {
getAnalogData
();
// calculateAccVector();
integrate
();
#ifdef ATTITUDE_USE_ACC_SENSORS
correctIntegralsByAcc0thOrder
();
driftCorrection
();
#endif
// We are done reading variables from the analog module.
// Interrupt-driven sensor reading may restart.
startAnalogConversionCycle
();
#ifdef USE_MK3MAG
if (staticParams.
bitConfig & CFG_COMPASS_ENABLED
) {
correctHeadingToMagnetic
();
}
#endif
}