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Code Issues Wiki Activity

PID code cleanup // refactoring

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borisbstyle 2016-12-30 12:04:44 +01:00
parent 4e3704374a
commit 1030df294d
8 changed files with 110 additions and 86 deletions
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130
src/main/flight/pid.c
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@ -28,6 +28,7 @@
#include "common/maths.h"
#include "common/filter.h"
#include "fc/fc_main.h"
#include "fc/rc_controls.h"
#include "fc/runtime_config.h"
@ -38,17 +39,11 @@
#include "sensors/gyro.h"
#include "sensors/acceleration.h"
extern float rcInput[3];
extern float setpointRate[3];
uint32_t targetPidLooptime;
static bool pidStabilisationEnabled;
float axisPIDf[3];
// PIDweight is a scale factor for PIDs which is derived from the throttle and TPA setting, and 100 = 100% scale means no PID reduction
uint8_t PIDweight[3];
#ifdef BLACKBOX
int32_t axisPID_P[3], axisPID_I[3], axisPID_D[3];
#endif
@ -145,8 +140,7 @@ void pidInitFilters(const pidProfile_t *pidProfile)
}
}
static float Kp[3], Ki[3], Kd[3], c[3];
static float rollPitchMaxVelocity, yawMaxVelocity, relaxFactor[3];
static float Kp[3], Ki[3], Kd[3], c[3], levelGain, horizonGain, horizonTransition, maxVelocity[3], relaxFactor[3];
void pidInitConfig(const pidProfile_t *pidProfile) {
for(int axis = FD_ROLL; axis <= FD_YAW; axis++) {
@ -156,70 +150,85 @@ void pidInitConfig(const pidProfile_t *pidProfile) {
c[axis] = pidProfile->dtermSetpointWeight / 100.0f;
relaxFactor[axis] = 1.0f - (pidProfile->setpointRelaxRatio / 100.0f);
}
yawMaxVelocity = pidProfile->yawRateAccelLimit * 1000 * dT;
rollPitchMaxVelocity = pidProfile->rateAccelLimit * 1000 * dT;
levelGain = pidProfile->P8[PIDLEVEL] / 10.0f;
horizonGain = pidProfile->I8[PIDLEVEL] / 10.0f;
horizonTransition = 100.0f / pidProfile->D8[PIDLEVEL];
maxVelocity[FD_ROLL] = maxVelocity[FD_PITCH] = pidProfile->rateAccelLimit * 1000 * dT;
maxVelocity[FD_YAW] = pidProfile->yawRateAccelLimit * 1000 * dT;
}
float currentPidSetpoint = 0, horizonLevelStrength = 1.0f;
void calcHorizonLevelStrength(const pidProfile_t *pidProfile) {
const float mostDeflectedPos = MAX(getRcDeflection(FD_ROLL), getRcDeflection(FD_PITCH));
// Progressively turn off the horizon self level strength as the stick is banged over
horizonLevelStrength = (1.0f - mostDeflectedPos); // 1 at centre stick, 0 = max stick deflection
if(pidProfile->D8[PIDLEVEL] == 0){
horizonLevelStrength = 0;
} else {
horizonLevelStrength = constrainf(((horizonLevelStrength - 1) * horizonTransition) + 1, 0, 1);
}
}
void pidLevel(int axis, const pidProfile_t *pidProfile, const rollAndPitchTrims_t *angleTrim) {
// calculate error angle and limit the angle to the max inclination
float errorAngle = pidProfile->levelSensitivity * rcCommand[axis];
#ifdef GPS
errorAngle += GPS_angle[axis];
#endif
errorAngle = constrainf(errorAngle, -pidProfile->max_angle_inclination, pidProfile->max_angle_inclination);
errorAngle = (errorAngle - ((attitude.raw[axis] + angleTrim->raw[axis]) / 10.0f));
if(FLIGHT_MODE(ANGLE_MODE)) {
// ANGLE mode - control is angle based, so control loop is needed
currentPidSetpoint = errorAngle * levelGain;
} else {
// HORIZON mode - direct sticks control is applied to rate PID
// mix up angle error to desired AngleRate to add a little auto-level feel
currentPidSetpoint = currentPidSetpoint + (errorAngle * horizonGain * horizonLevelStrength);
}
}
void accelerationLimit(int axis) {
static float previousSetpoint[3];
const float currentVelocity = currentPidSetpoint- previousSetpoint[axis];
if(ABS(currentVelocity) > maxVelocity[axis])
currentPidSetpoint = (currentVelocity > 0) ? previousSetpoint[axis] + maxVelocity[axis] : previousSetpoint[axis] - maxVelocity[axis];
previousSetpoint[axis] = currentPidSetpoint;
}
// Betaflight pid controller, which will be maintained in the future with additional features specialised for current (mini) multirotor usage.
// Based on 2DOF reference design (matlab)
void pidController(const pidProfile_t *pidProfile, uint16_t max_angle_inclination, const rollAndPitchTrims_t *angleTrim, uint16_t midrc)
void pidController(const pidProfile_t *pidProfile, const rollAndPitchTrims_t *angleTrim)
{
static float previousRateError[2];
static float previousSetpoint[3];
float horizonLevelStrength = 1;
if (FLIGHT_MODE(HORIZON_MODE)) {
// Figure out the raw stick positions
const int32_t stickPosAil = ABS(getRcStickDeflection(FD_ROLL, midrc));
const int32_t stickPosEle = ABS(getRcStickDeflection(FD_PITCH, midrc));
const int32_t mostDeflectedPos = MAX(stickPosAil, stickPosEle);
// Progressively turn off the horizon self level strength as the stick is banged over
horizonLevelStrength = (float)(500 - mostDeflectedPos) / 500; // 1 at centre stick, 0 = max stick deflection
if(pidProfile->D8[PIDLEVEL] == 0){
horizonLevelStrength = 0;
} else {
horizonLevelStrength = constrainf(((horizonLevelStrength - 1) * (100 / pidProfile->D8[PIDLEVEL])) + 1, 0, 1);
}
}
if(FLIGHT_MODE(HORIZON_MODE))
calcHorizonLevelStrength(pidProfile);
// ----------PID controller----------
const float tpaFactor = PIDweight[0] / 100.0f; // tpa is now float
const float tpaFactor = getThrottlePIDAttenuation();
for (int axis = FD_ROLL; axis <= FD_YAW; axis++) {
// Limit abrupt yaw inputs / stops
const float maxVelocity = (axis == FD_YAW) ? yawMaxVelocity : rollPitchMaxVelocity;
if (maxVelocity) {
const float currentVelocity = setpointRate[axis] - previousSetpoint[axis];
if (ABS(currentVelocity) > maxVelocity) {
setpointRate[axis] = (currentVelocity > 0) ? previousSetpoint[axis] + maxVelocity : previousSetpoint[axis] - maxVelocity;
}
}
currentPidSetpoint = getSetpointRate(axis);
if(maxVelocity[axis])
accelerationLimit(axis);
// Yaw control is GYRO based, direct sticks control is applied to rate PID
if ((FLIGHT_MODE(ANGLE_MODE) || FLIGHT_MODE(HORIZON_MODE)) && axis != YAW) {
// calculate error angle and limit the angle to the max inclination
float errorAngle = pidProfile->levelSensitivity * rcCommand[axis];
#ifdef GPS
errorAngle += GPS_angle[axis];
#endif
errorAngle = constrainf(errorAngle, -max_angle_inclination, max_angle_inclination);
errorAngle = (errorAngle - attitude.raw[axis] + angleTrim->raw[axis]) / 10.0f;
if (FLIGHT_MODE(ANGLE_MODE)) {
// ANGLE mode - control is angle based, so control loop is needed
setpointRate[axis] = errorAngle * pidProfile->P8[PIDLEVEL] / 10.0f;
} else {
// HORIZON mode - direct sticks control is applied to rate PID
// mix up angle error to desired AngleRate to add a little auto-level feel
setpointRate[axis] = setpointRate[axis] + (errorAngle * pidProfile->I8[PIDLEVEL] * horizonLevelStrength / 10.0f);
}
pidLevel(axis, pidProfile, angleTrim);
}
const float PVRate = gyro.gyroADCf[axis]; // Process variable from gyro output in deg/sec
const float gyroRate = gyro.gyroADCf[axis]; // Process variable from gyro output in deg/sec
// --------low-level gyro-based PID based on 2DOF PID controller. ----------
// ---------- 2-DOF PID controller with optional filter on derivative term. b = 1 and only c can be tuned (amount derivative on measurement or error). ----------
// -----calculate error rate
const float errorRate = setpointRate[axis] - PVRate; // r - y
const float errorRate = currentPidSetpoint - gyroRate; // r - y
// -----calculate P component and add Dynamic Part based on stick input
float PTerm = Kp[axis] * errorRate * tpaFactor;
@ -227,7 +236,7 @@ void pidController(const pidProfile_t *pidProfile, uint16_t max_angle_inclinatio
// -----calculate I component
// Reduce strong Iterm accumulation during higher stick inputs
const float accumulationThreshold = (axis == FD_YAW) ? pidProfile->yawItermIgnoreRate : pidProfile->rollPitchItermIgnoreRate;
const float setpointRateScaler = constrainf(1.0f - (ABS(setpointRate[axis]) / accumulationThreshold), 0.0f, 1.0f);
const float setpointRateScaler = constrainf(1.0f - (ABS(currentPidSetpoint) / accumulationThreshold), 0.0f, 1.0f);
float ITerm = previousGyroIf[axis];
ITerm += Ki[axis] * errorRate * dT * setpointRateScaler;
@ -240,16 +249,17 @@ void pidController(const pidProfile_t *pidProfile, uint16_t max_angle_inclinatio
if (axis != FD_YAW) {
float dynC = c[axis];
if (pidProfile->setpointRelaxRatio < 100) {
const float rcDeflection = getRcDeflection(axis);
dynC = c[axis];
if (setpointRate[axis] > 0) {
if ((setpointRate[axis] - previousSetpoint[axis]) < previousSetpoint[axis])
dynC = dynC * sq(rcInput[axis]) * relaxFactor[axis] + dynC * (1-relaxFactor[axis]);
} else if (setpointRate[axis] < 0) {
if ((setpointRate[axis] - previousSetpoint[axis]) > previousSetpoint[axis])
dynC = dynC * sq(rcInput[axis]) * relaxFactor[axis] + dynC * (1-relaxFactor[axis]);
if (currentPidSetpoint > 0) {
if ((currentPidSetpoint - previousSetpoint[axis]) < previousSetpoint[axis])
dynC = dynC * sq(rcDeflection) * relaxFactor[axis] + dynC * (1-relaxFactor[axis]);
} else if (currentPidSetpoint < 0) {
if ((currentPidSetpoint - previousSetpoint[axis]) > previousSetpoint[axis])
dynC = dynC * sq(rcDeflection) * relaxFactor[axis] + dynC * (1-relaxFactor[axis]);
}
}
const float rD = dynC * setpointRate[axis] - PVRate; // cr - y
const float rD = dynC * currentPidSetpoint - gyroRate; // cr - y
// Divide rate change by dT to get differential (ie dr/dt)
const float delta = (rD - previousRateError[axis]) / dT;
previousRateError[axis] = rD;
@ -264,7 +274,7 @@ void pidController(const pidProfile_t *pidProfile, uint16_t max_angle_inclinatio
} else {
PTerm = ptermYawFilterApplyFn(ptermYawFilter, PTerm);
}
previousSetpoint[axis] = setpointRate[axis];
previousSetpoint[axis] = currentPidSetpoint;
// -----calculate total PID output
axisPIDf[axis] = PTerm + ITerm + DTerm;