src/main/flight/pid.h

   1 /*
   2  * This file is part of Cleanflight and Betaflight.
   3  *
   4  * Cleanflight and Betaflight are free software. You can redistribute
   5  * this software and/or modify this software under the terms of the
   6  * GNU General Public License as published by the Free Software
   7  * Foundation, either version 3 of the License, or (at your option)
   8  * any later version.
   9  *
  10  * Cleanflight and Betaflight are distributed in the hope that they
  11  * will be useful, but WITHOUT ANY WARRANTY; without even the implied
  12  * warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  13  * See the GNU General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU General Public License
  16  * along with this software.
  17  *
  18  * If not, see <http://www.gnu.org/licenses/>.
  19  */
  20
  21 #pragma once
  22
  23 #include <stdbool.h>
  24 #include "common/time.h"
  25 #include "common/filter.h"
  26 #include "common/axis.h"
  27
  28 #include "pg/pg.h"
  29
  30 #define MAX_PID_PROCESS_DENOM       16
  31 #define PID_CONTROLLER_BETAFLIGHT   1
  32 #define PID_MIXER_SCALING           1000.0f
  33 #define PID_SERVO_MIXER_SCALING     0.7f
  34 #define PIDSUM_LIMIT                500
  35 #define PIDSUM_LIMIT_YAW            400
  36 #define PIDSUM_LIMIT_MIN            100
  37 #define PIDSUM_LIMIT_MAX            1000
  38
  39 #define PID_GAIN_MAX 200
  40 #define F_GAIN_MAX 2000
  41 #define D_MIN_GAIN_MAX 100
  42
  43 // Scaling factors for Pids for better tunable range in configurator for betaflight pid controller. The scaling is based on legacy pid controller or previous float
  44 #define PTERM_SCALE 0.032029f
  45 #define ITERM_SCALE 0.244381f
  46 #define DTERM_SCALE 0.000529f
  47
  48 // The constant scale factor to replace the Kd component of the feedforward calculation.
  49 // This value gives the same "feel" as the previous Kd default of 26 (26 * DTERM_SCALE)
  50 #define FEEDFORWARD_SCALE 0.013754f
  51
  52 // Full iterm suppression in setpoint mode at high-passed setpoint rate > 40deg/sec
  53 #define ITERM_RELAX_SETPOINT_THRESHOLD 40.0f
  54 #define ITERM_RELAX_CUTOFF_DEFAULT 15
  55
  56 // Anti gravity I constant
  57 #define AG_KI 21.586988f;
  58
  59 #define ITERM_ACCELERATOR_GAIN_OFF 0
  60 #define ITERM_ACCELERATOR_GAIN_MAX 30000
  61 #define PID_ROLL_DEFAULT  { 42, 85, 35, 90 }
  62 #define PID_PITCH_DEFAULT { 46, 90, 38, 95 }
  63 #define PID_YAW_DEFAULT   { 45, 90,  0, 90 }
  64 #define D_MIN_DEFAULT     { 23, 25, 0 }
  65
  66 #define DYN_LPF_DTERM_MIN_HZ_DEFAULT 70
  67 #define DYN_LPF_DTERM_MAX_HZ_DEFAULT 170
  68 #define DTERM_LOWPASS_2_HZ_DEFAULT 150
  69
  70 typedef enum {
  71     PID_ROLL,
  72     PID_PITCH,
  73     PID_YAW,
  74     PID_LEVEL,
  75     PID_MAG,
  76     PID_ITEM_COUNT
  77 } pidIndex_e;
  78
  79 typedef enum {
  80     SUPEREXPO_YAW_OFF = 0,
  81     SUPEREXPO_YAW_ON,
  82     SUPEREXPO_YAW_ALWAYS
  83 } pidSuperExpoYaw_e;
  84
  85 typedef enum {
  86     PID_STABILISATION_OFF = 0,
  87     PID_STABILISATION_ON
  88 } pidStabilisationState_e;
  89
  90 typedef enum {
  91     PID_CRASH_RECOVERY_OFF = 0,
  92     PID_CRASH_RECOVERY_ON,
  93     PID_CRASH_RECOVERY_BEEP,
  94     PID_CRASH_RECOVERY_DISARM,
  95 } pidCrashRecovery_e;
  96
  97 typedef struct pidf_s {
  98     uint8_t P;
  99     uint8_t I;
 100     uint8_t D;
 101     uint16_t F;
 102 } pidf_t;
 103
 104 typedef enum {
 105     ANTI_GRAVITY_SMOOTH,
 106     ANTI_GRAVITY_STEP
 107 } antiGravityMode_e;
 108
 109 typedef enum {
 110     ITERM_RELAX_OFF,
 111     ITERM_RELAX_RP,
 112     ITERM_RELAX_RPY,
 113     ITERM_RELAX_RP_INC,
 114     ITERM_RELAX_RPY_INC,
 115     ITERM_RELAX_COUNT,
 116 } itermRelax_e;
 117
 118 typedef enum {
 119     ITERM_RELAX_GYRO,
 120     ITERM_RELAX_SETPOINT,
 121     ITERM_RELAX_TYPE_COUNT,
 122 } itermRelaxType_e;
 123
 124 typedef enum feedforwardAveraging_e {
 125     FEEDFORWARD_AVERAGING_OFF,
 126     FEEDFORWARD_AVERAGING_2_POINT,
 127     FEEDFORWARD_AVERAGING_3_POINT,
 128     FEEDFORWARD_AVERAGING_4_POINT,
 129 } feedforwardAveraging_t;
 130
 131 #define MAX_PROFILE_NAME_LENGTH 8u
 132
 133 typedef struct pidProfile_s {
 134     uint16_t yaw_lowpass_hz;                // Additional yaw filter when yaw axis too noisy
 135     uint16_t dterm_lowpass_hz;              // Delta Filter in hz
 136     uint16_t dterm_notch_hz;                // Biquad dterm notch hz
 137     uint16_t dterm_notch_cutoff;            // Biquad dterm notch low cutoff
 138
 139     pidf_t  pid[PID_ITEM_COUNT];
 140
 141     uint8_t dterm_filter_type;              // Filter selection for dterm
 142     uint8_t itermWindupPointPercent;        // iterm windup threshold, percent motor saturation
 143     uint16_t pidSumLimit;
 144     uint16_t pidSumLimitYaw;
 145     uint8_t pidAtMinThrottle;               // Disable/Enable pids on zero throttle. Normally even without airmode P and D would be active.
 146     uint8_t levelAngleLimit;                // Max angle in degrees in level mode
 147
 148     uint8_t horizon_tilt_effect;            // inclination factor for Horizon mode
 149     uint8_t horizon_tilt_expert_mode;       // OFF or ON
 150
 151     // Betaflight PID controller parameters
 152     uint8_t  antiGravityMode;             // type of anti gravity method
 153     uint16_t itermThrottleThreshold;        // max allowed throttle delta before iterm accelerated in ms
 154     uint16_t itermAcceleratorGain;          // Iterm Accelerator Gain when itermThrottlethreshold is hit
 155     uint16_t yawRateAccelLimit;             // yaw accel limiter for deg/sec/ms
 156     uint16_t rateAccelLimit;                // accel limiter roll/pitch deg/sec/ms
 157     uint16_t crash_dthreshold;              // dterm crash value
 158     uint16_t crash_gthreshold;              // gyro crash value
 159     uint16_t crash_setpoint_threshold;      // setpoint must be below this value to detect crash, so flips and rolls are not interpreted as crashes
 160     uint16_t crash_time;                    // ms
 161     uint16_t crash_delay;                   // ms
 162     uint8_t crash_recovery_angle;           // degrees
 163     uint8_t crash_recovery_rate;            // degree/second
 164     uint8_t feedforwardTransition;          // Feedforward attenuation around centre sticks
 165     uint16_t crash_limit_yaw;               // limits yaw errorRate, so crashes don't cause huge throttle increase
 166     uint16_t itermLimit;
 167     uint16_t dterm_lowpass2_hz;             // Extra PT1 Filter on D in hz
 168     uint8_t crash_recovery;                 // off, on, on and beeps when it is in crash recovery mode
 169     uint8_t throttle_boost;                 // how much should throttle be boosted during transient changes 0-100, 100 adds 10x hpf filtered throttle
 170     uint8_t throttle_boost_cutoff;          // Which cutoff frequency to use for throttle boost. higher cutoffs keep the boost on for shorter. Specified in hz.
 171     uint8_t iterm_rotation;                 // rotates iterm to translate world errors to local coordinate system
 172     uint8_t iterm_relax_type;               // Specifies type of relax algorithm
 173     uint8_t iterm_relax_cutoff;             // This cutoff frequency specifies a low pass filter which predicts average response of the quad to setpoint
 174     uint8_t iterm_relax;                    // Enable iterm suppression during stick input
 175     uint8_t acro_trainer_angle_limit;       // Acro trainer roll/pitch angle limit in degrees
 176     uint8_t acro_trainer_debug_axis;        // The axis for which record debugging values are captured 0=roll, 1=pitch
 177     uint8_t acro_trainer_gain;              // The strength of the limiting. Raising may reduce overshoot but also lead to oscillation around the angle limit
 178     uint16_t acro_trainer_lookahead_ms;     // The lookahead window in milliseconds used to reduce overshoot
 179     uint8_t abs_control_gain;               // How strongly should the absolute accumulated error be corrected for
 180     uint8_t abs_control_limit;              // Limit to the correction
 181     uint8_t abs_control_error_limit;        // Limit to the accumulated error
 182     uint8_t abs_control_cutoff;             // Cutoff frequency for path estimation in abs control
 183     uint8_t dterm_filter2_type;             // Filter selection for 2nd dterm
 184     uint16_t dyn_lpf_dterm_min_hz;
 185     uint16_t dyn_lpf_dterm_max_hz;
 186     uint8_t launchControlMode;              // Whether launch control is limited to pitch only (launch stand or top-mount) or all axes (on battery)
 187     uint8_t launchControlThrottlePercent;   // Throttle percentage to trigger launch for launch control
 188     uint8_t launchControlAngleLimit;        // Optional launch control angle limit (requires ACC)
 189     uint8_t launchControlGain;              // Iterm gain used while launch control is active
 190     uint8_t launchControlAllowTriggerReset; // Controls trigger behavior and whether the trigger can be reset
 191     uint8_t use_integrated_yaw;             // Selects whether the yaw pidsum should integrated
 192     uint8_t integrated_yaw_relax;           // Specifies how much integrated yaw should be reduced to offset the drag based yaw component
 193     uint8_t thrustLinearization;            // Compensation factor for pid linearization
 194     uint8_t d_min[XYZ_AXIS_COUNT];          // Minimum D value on each axis
 195     uint8_t d_min_gain;                     // Gain factor for amount of gyro / setpoint activity required to boost D
 196     uint8_t d_min_advance;                  // Percentage multiplier for setpoint input to boost algorithm
 197     uint8_t motor_output_limit;             // Upper limit of the motor output (percent)
 198     int8_t auto_profile_cell_count;         // Cell count for this profile to be used with if auto PID profile switching is used
 199     uint8_t transient_throttle_limit;       // Maximum DC component of throttle change to mix into throttle to prevent airmode mirroring noise
 200     uint8_t feedforward_boost;              // amount of setpoint acceleration to add to feedforward, 10 means 100% added
 201     char profileName[MAX_PROFILE_NAME_LENGTH + 1]; // Descriptive name for profile
 202
 203     uint8_t dyn_idle_min_rpm;                   // minimum motor speed enforced by the dynamic idle controller
 204     uint8_t dyn_idle_p_gain;                // P gain during active control of rpm
 205     uint8_t dyn_idle_i_gain;                // I gain during active control of rpm
 206     uint8_t dyn_idle_d_gain;                // D gain for corrections around rapid changes in rpm
 207     uint8_t dyn_idle_max_increase;          // limit on maximum possible increase in motor idle drive during active control
 208
 209     uint8_t feedforward_averaging;          // Number of packets to average when averaging is on
 210     uint8_t feedforward_max_rate_limit;     // Maximum setpoint rate percentage for feedforward
 211     uint8_t feedforward_smooth_factor;      // Amount of lowpass type smoothing for feedforward steps
 212     uint8_t feedforward_jitter_factor;      // Number of RC steps below which to attenuate feedforward
 213     uint8_t dyn_lpf_curve_expo;             // set the curve for dynamic dterm lowpass filter
 214     uint8_t level_race_mode;                // NFE race mode - when true pitch setpoint calcualtion is gyro based in level mode
 215     uint8_t vbat_sag_compensation;          // Reduce motor output by this percentage of the maximum compensation amount
 216
 217     uint8_t simplified_pids_mode;
 218     uint8_t simplified_master_multiplier;
 219     uint8_t simplified_roll_pitch_ratio;
 220     uint8_t simplified_i_gain;
 221     uint8_t simplified_pd_ratio;
 222     uint8_t simplified_pd_gain;
 223     uint8_t simplified_dmin_ratio;
 224     uint8_t simplified_feedforward_gain;
 225
 226     uint8_t simplified_dterm_filter;
 227     uint8_t simplified_dterm_filter_multiplier;
 228 } pidProfile_t;
 229
 230 PG_DECLARE_ARRAY(pidProfile_t, PID_PROFILE_COUNT, pidProfiles);
 231
 232 typedef struct pidConfig_s {
 233     uint8_t pid_process_denom;              // Processing denominator for PID controller vs gyro sampling rate
 234     uint8_t runaway_takeoff_prevention;          // off, on - enables pidsum runaway disarm logic
 235     uint16_t runaway_takeoff_deactivate_delay;   // delay in ms for "in-flight" conditions before deactivation (successful flight)
 236     uint8_t runaway_takeoff_deactivate_throttle; // minimum throttle percent required during deactivation phase
 237 } pidConfig_t;
 238
 239 PG_DECLARE(pidConfig_t, pidConfig);
 240
 241 union rollAndPitchTrims_u;
 242 void pidController(const pidProfile_t *pidProfile, timeUs_t currentTimeUs);
 243
 244 typedef struct pidAxisData_s {
 245     float P;
 246     float I;
 247     float D;
 248     float F;
 249
 250     float Sum;
 251 } pidAxisData_t;
 252
 253 typedef union dtermLowpass_u {
 254     pt1Filter_t pt1Filter;
 255     biquadFilter_t biquadFilter;
 256     pt2Filter_t pt2Filter;
 257     pt3Filter_t pt3Filter;
 258 } dtermLowpass_t;
 259
 260 typedef struct pidCoefficient_s {
 261     float Kp;
 262     float Ki;
 263     float Kd;
 264     float Kf;
 265 } pidCoefficient_t;
 266
 267 typedef struct pidRuntime_s {
 268     float dT;
 269     float pidFrequency;
 270     bool pidStabilisationEnabled;
 271     float previousPidSetpoint[XYZ_AXIS_COUNT];
 272     filterApplyFnPtr dtermNotchApplyFn;
 273     biquadFilter_t dtermNotch[XYZ_AXIS_COUNT];
 274     filterApplyFnPtr dtermLowpassApplyFn;
 275     dtermLowpass_t dtermLowpass[XYZ_AXIS_COUNT];
 276     filterApplyFnPtr dtermLowpass2ApplyFn;
 277     dtermLowpass_t dtermLowpass2[XYZ_AXIS_COUNT];
 278     filterApplyFnPtr ptermYawLowpassApplyFn;
 279     pt1Filter_t ptermYawLowpass;
 280     bool antiGravityEnabled;
 281     uint8_t antiGravityMode;
 282     pt1Filter_t antiGravityThrottleLpf;
 283     pt1Filter_t antiGravitySmoothLpf;
 284     float antiGravityOsdCutoff;
 285     float antiGravityThrottleHpf;
 286     float antiGravityPBoost;
 287     float ffBoostFactor;
 288     float itermAccelerator;
 289     uint16_t itermAcceleratorGain;
 290     float feedforwardTransition;
 291     pidCoefficient_t pidCoefficient[XYZ_AXIS_COUNT];
 292     float levelGain;
 293     float horizonGain;
 294     float horizonTransition;
 295     float horizonCutoffDegrees;
 296     float horizonFactorRatio;
 297     uint8_t horizonTiltExpertMode;
 298     float maxVelocity[XYZ_AXIS_COUNT];
 299     float itermWindupPointInv;
 300     bool inCrashRecoveryMode;
 301     timeUs_t crashDetectedAtUs;
 302     timeDelta_t crashTimeLimitUs;
 303     timeDelta_t crashTimeDelayUs;
 304     int32_t crashRecoveryAngleDeciDegrees;
 305     float crashRecoveryRate;
 306     float crashGyroThreshold;
 307     float crashDtermThreshold;
 308     float crashSetpointThreshold;
 309     float crashLimitYaw;
 310     float itermLimit;
 311     bool itermRotation;
 312     bool zeroThrottleItermReset;
 313     bool levelRaceMode;
 314
 315 #ifdef USE_ITERM_RELAX
 316     pt1Filter_t windupLpf[XYZ_AXIS_COUNT];
 317     uint8_t itermRelax;
 318     uint8_t itermRelaxType;
 319     uint8_t itermRelaxCutoff;
 320 #endif
 321
 322 #ifdef USE_ABSOLUTE_CONTROL
 323     float acCutoff;
 324     float acGain;
 325     float acLimit;
 326     float acErrorLimit;
 327     pt1Filter_t acLpf[XYZ_AXIS_COUNT];
 328     float oldSetpointCorrection[XYZ_AXIS_COUNT];
 329 #endif
 330
 331 #ifdef USE_D_MIN
 332     biquadFilter_t dMinRange[XYZ_AXIS_COUNT];
 333     pt1Filter_t dMinLowpass[XYZ_AXIS_COUNT];
 334     float dMinPercent[XYZ_AXIS_COUNT];
 335     float dMinGyroGain;
 336     float dMinSetpointGain;
 337 #endif
 338
 339 #ifdef USE_AIRMODE_LPF
 340     pt1Filter_t airmodeThrottleLpf1;
 341     pt1Filter_t airmodeThrottleLpf2;
 342 #endif
 343
 344 #ifdef USE_RC_SMOOTHING_FILTER
 345     pt3Filter_t feedforwardPt3[XYZ_AXIS_COUNT];
 346     bool feedforwardLpfInitialized;
 347     uint8_t rcSmoothingDebugAxis;
 348     uint8_t rcSmoothingFilterType;
 349 #endif // USE_RC_SMOOTHING_FILTER
 350
 351 #ifdef USE_ACRO_TRAINER
 352     float acroTrainerAngleLimit;
 353     float acroTrainerLookaheadTime;
 354     uint8_t acroTrainerDebugAxis;
 355     float acroTrainerGain;
 356     bool acroTrainerActive;
 357     int acroTrainerAxisState[2];  // only need roll and pitch
 358 #endif
 359
 360 #ifdef USE_DYN_LPF
 361     uint8_t dynLpfFilter;
 362     uint16_t dynLpfMin;
 363     uint16_t dynLpfMax;
 364     uint8_t dynLpfCurveExpo;
 365 #endif
 366
 367 #ifdef USE_LAUNCH_CONTROL
 368     uint8_t launchControlMode;
 369     uint8_t launchControlAngleLimit;
 370     float launchControlKi;
 371 #endif
 372
 373 #ifdef USE_INTEGRATED_YAW_CONTROL
 374     bool useIntegratedYaw;
 375     uint8_t integratedYawRelax;
 376 #endif
 377
 378 #ifdef USE_THRUST_LINEARIZATION
 379     float thrustLinearization;
 380     float throttleCompensateAmount;
 381 #endif
 382
 383 #ifdef USE_AIRMODE_LPF
 384     float airmodeThrottleOffsetLimit;
 385 #endif
 386
 387 #ifdef USE_FEEDFORWARD
 388     feedforwardAveraging_t feedforwardAveraging;
 389     float ffSmoothFactor;
 390     float ffJitterFactor;
 391 #endif
 392 } pidRuntime_t;
 393
 394 extern pidRuntime_t pidRuntime;
 395
 396 extern const char pidNames[];
 397
 398 extern pidAxisData_t pidData[3];
 399
 400 extern uint32_t targetPidLooptime;
 401
 402 extern float throttleBoost;
 403 extern pt1Filter_t throttleLpf;
 404
 405 void pidResetIterm(void);
 406 void pidStabilisationState(pidStabilisationState_e pidControllerState);
 407 void pidSetItermAccelerator(float newItermAccelerator);
 408 bool crashRecoveryModeActive(void);
 409 void pidAcroTrainerInit(void);
 410 void pidSetAcroTrainerState(bool newState);
 411 void pidUpdateAntiGravityThrottleFilter(float throttle);
 412 bool pidOsdAntiGravityActive(void);
 413 bool pidOsdAntiGravityMode(void);
 414 void pidSetAntiGravityState(bool newState);
 415 bool pidAntiGravityEnabled(void);
 416
 417 #ifdef USE_THRUST_LINEARIZATION
 418 float pidApplyThrustLinearization(float motorValue);
 419 float pidCompensateThrustLinearization(float throttle);
 420 #endif
 421
 422 #ifdef USE_AIRMODE_LPF
 423 void pidUpdateAirmodeLpf(float currentOffset);
 424 float pidGetAirmodeThrottleOffset();
 425 #endif
 426
 427 #ifdef UNIT_TEST
 428 #include "sensors/acceleration.h"
 429 extern float axisError[XYZ_AXIS_COUNT];
 430 void applyItermRelax(const int axis, const float iterm,
 431     const float gyroRate, float *itermErrorRate, float *currentPidSetpoint);
 432 void applyAbsoluteControl(const int axis, const float gyroRate, float *currentPidSetpoint, float *itermErrorRate);
 433 void rotateItermAndAxisError();
 434 float pidLevel(int axis, const pidProfile_t *pidProfile,
 435     const rollAndPitchTrims_t *angleTrim, float currentPidSetpoint);
 436 float calcHorizonLevelStrength(void);
 437 #endif
 438 void dynLpfDTermUpdate(float throttle);
 439 void pidSetItermReset(bool enabled);
 440 float pidGetPreviousSetpoint(int axis);
 441 float pidGetDT();
 442 float pidGetPidFrequency();
 443 float pidGetFfBoostFactor();
 444 float pidGetFfSmoothFactor();
 445 float pidGetFfJitterFactor();
 446 float dynLpfCutoffFreq(float throttle, uint16_t dynLpfMin, uint16_t dynLpfMax, uint8_t expo);