src/main/flight/pid.h

   1 /*
   2  * This file is part of Cleanflight.
   3  *
   4  * Cleanflight is free software: you can redistribute it and/or modify
   5  * it under the terms of the GNU General Public License as published by
   6  * the Free Software Foundation, either version 3 of the License, or
   7  * (at your option) any later version.
   8  *
   9  * Cleanflight is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with Cleanflight.  If not, see <http://www.gnu.org/licenses/>.
  16  */
  17
  18 #pragma once
  19
  20 #include "config/parameter_group.h"
  21 #include "fc/runtime_config.h"
  22 #include "common/time.h"
  23
  24 #define GYRO_SATURATION_LIMIT       1800        // 1800dps
  25 #define PID_SUM_LIMIT_MIN           100
  26 #define PID_SUM_LIMIT_MAX           1000
  27 #define PID_SUM_LIMIT_DEFAULT       500
  28 #define PID_SUM_LIMIT_YAW_DEFAULT   400
  29
  30 #define HEADING_HOLD_RATE_LIMIT_MIN 10
  31 #define HEADING_HOLD_RATE_LIMIT_MAX 250
  32 #define HEADING_HOLD_RATE_LIMIT_DEFAULT 90
  33
  34 #define AXIS_ACCEL_MIN_LIMIT        50
  35
  36 #define HEADING_HOLD_ERROR_LPF_FREQ 2
  37
  38 /*
  39 FP-PID has been rescaled to match LuxFloat (and MWRewrite) from Cleanflight 1.13
  40 */
  41 #define FP_PID_RATE_FF_MULTIPLIER   31.0f
  42 #define FP_PID_RATE_P_MULTIPLIER    31.0f
  43 #define FP_PID_RATE_I_MULTIPLIER    4.0f
  44 #define FP_PID_RATE_D_MULTIPLIER    1905.0f
  45 #define FP_PID_RATE_D_FF_MULTIPLIER   7270.0f
  46 #define FP_PID_LEVEL_P_MULTIPLIER   1.0f / 6.56f       // Level P gain units is [1/sec] and angle error is [deg] => [deg/s]
  47 #define FP_PID_YAWHOLD_P_MULTIPLIER 80.0f
  48
  49 #define MC_ITERM_RELAX_SETPOINT_THRESHOLD 40.0f
  50 #define MC_ITERM_RELAX_CUTOFF_DEFAULT 15
  51
  52 #define ANTI_GRAVITY_THROTTLE_FILTER_CUTOFF 15  // The anti gravity throttle highpass filter cutoff
  53
  54 #define FIXED_WING_LEVEL_TRIM_DEADBAND_DEFAULT 5
  55
  56 #define TASK_AUX_RATE_HZ   100 //In Hz
  57
  58 typedef enum {
  59     /* PID              MC      FW  */
  60     PID_ROLL,       //   +       +
  61     PID_PITCH,      //   +       +
  62     PID_YAW,        //   +       +
  63     PID_POS_Z,      //   +       +
  64     PID_POS_XY,     //   +       +
  65     PID_VEL_XY,     //   +       n/a
  66     PID_SURFACE,    //   n/a     n/a
  67     PID_LEVEL,      //   +       +
  68     PID_HEADING,    //   +       +
  69     PID_VEL_Z,      //   +       n/a
  70     PID_POS_HEADING,//   n/a     +
  71     PID_ITEM_COUNT
  72 } pidIndex_e;
  73
  74 // TODO(agh): PIDFF
  75 typedef enum {
  76     PID_TYPE_NONE = 0,  // Not used in the current platform/mixer/configuration
  77     PID_TYPE_PID,   // Uses P, I and D terms
  78     PID_TYPE_PIFF,  // Uses P, I, D and FF
  79     PID_TYPE_AUTO,  // Autodetect
  80 } pidType_e;
  81
  82 typedef struct pid8_s {
  83     uint16_t P;
  84     uint16_t I;
  85     uint16_t D;
  86     uint16_t FF;
  87 } pid8_t;
  88
  89 typedef struct pidBank_s {
  90     pid8_t  pid[PID_ITEM_COUNT];
  91 } pidBank_t;
  92
  93 typedef enum {
  94     ITERM_RELAX_OFF = 0,
  95     ITERM_RELAX_RP,
  96     ITERM_RELAX_RPY
  97 } itermRelax_e;
  98
  99 typedef struct pidProfile_s {
 100     uint8_t pidControllerType;
 101     pidBank_t bank_fw;
 102     pidBank_t bank_mc;
 103
 104     uint8_t dterm_lpf_type;                 // Dterm LPF type: PT1, BIQUAD
 105     uint16_t dterm_lpf_hz;
 106
 107     uint8_t yaw_lpf_hz;
 108
 109     uint8_t heading_hold_rate_limit;        // Maximum rotation rate HEADING_HOLD mode can feed to yaw rate PID controller
 110
 111     uint8_t itermWindupPointPercent;        // Experimental ITerm windup threshold, percent of motor saturation
 112
 113     uint32_t axisAccelerationLimitYaw;          // Max rate of change of yaw angular rate setpoint (deg/s^2 = dps/s)
 114     uint32_t axisAccelerationLimitRollPitch;    // Max rate of change of roll/pitch angular rate setpoint (deg/s^2 = dps/s)
 115
 116     int16_t max_angle_inclination[ANGLE_INDEX_COUNT];       // Max possible inclination (roll and pitch axis separately
 117
 118     uint16_t pidItermLimitPercent;
 119
 120     // Airplane-specific parameters
 121     float       fixedWingReferenceAirspeed;     // Reference tuning airspeed for the airplane - the speed for which PID gains are tuned
 122     float       fixedWingCoordinatedYawGain;    // This is the gain of the yaw rate required to keep the yaw rate consistent with the turn rate for a coordinated turn.
 123     float       fixedWingCoordinatedPitchGain;    // This is the gain of the pitch rate to keep the pitch angle constant during coordinated turns.
 124     uint16_t    fixedWingYawItermBankFreeze;       // Freeze yaw Iterm when bank angle is more than this many degrees
 125
 126     float       navVelXyDTermLpfHz;
 127     uint8_t navVelXyDtermAttenuation;       // VEL_XY dynamic Dterm scale: Dterm will be attenuatedby this value (in percent) when UAV is traveling with more than navVelXyDtermAttenuationStart percents of max velocity
 128     uint8_t navVelXyDtermAttenuationStart;  // VEL_XY dynamic Dterm scale: Dterm attenuation will begin at this percent of max velocity
 129     uint8_t navVelXyDtermAttenuationEnd;    // VEL_XY dynamic Dterm scale: Dterm will be fully attenuated at this percent of max velocity
 130     uint8_t iterm_relax_cutoff;             // This cutoff frequency specifies a low pass filter which predicts average response of the quad to setpoint
 131     uint8_t iterm_relax;                    // Enable iterm suppression during stick input
 132
 133 #ifdef USE_D_BOOST
 134     float dBoostMin;
 135     float dBoostMax;
 136     float dBoostMaxAtAlleceleration;
 137     uint8_t dBoostGyroDeltaLpfHz;
 138 #endif
 139
 140 #ifdef USE_ANTIGRAVITY
 141     float antigravityGain;
 142     float antigravityAccelerator;
 143     uint8_t antigravityCutoff;
 144 #endif
 145
 146     uint16_t navFwPosHdgPidsumLimit;
 147     uint8_t controlDerivativeLpfHz;
 148
 149     float fixedWingLevelTrim;
 150     float fixedWingLevelTrimGain;
 151
 152     uint8_t fwAltControlResponseFactor;
 153 #ifdef USE_SMITH_PREDICTOR
 154     float smithPredictorStrength;
 155     float smithPredictorDelay;
 156     uint16_t smithPredictorFilterHz;
 157 #endif
 158
 159
 160     uint16_t fwItermLockTimeMaxMs;
 161     uint8_t fwItermLockRateLimit;
 162     uint8_t fwItermLockEngageThreshold;
 163
 164 } pidProfile_t;
 165
 166 typedef struct pidAutotuneConfig_s {
 167     uint16_t    fw_detect_time;             // Time [ms] to detect sustained undershoot or overshoot
 168     uint8_t     fw_min_stick;               // Minimum stick input required to update rates and gains
 169     uint8_t     fw_ff_to_p_gain;            // FF to P gain (strength relationship) [%]
 170     uint8_t     fw_p_to_d_gain;             // P to D gain (strength relationship) [%]
 171     uint16_t    fw_ff_to_i_time_constant;   // FF to I time (defines time for I to reach the same level of response as FF) [ms]
 172     uint8_t     fw_rate_adjustment;         // Adjust rate settings during autotune?
 173     uint8_t     fw_max_rate_deflection;     // Percentage of max mixer output used for calculating the rates
 174 } pidAutotuneConfig_t;
 175
 176 typedef enum {
 177     FIXED,
 178     LIMIT,
 179     AUTO,
 180 } fw_autotune_rate_adjustment_e;
 181
 182 PG_DECLARE_PROFILE(pidProfile_t, pidProfile);
 183 PG_DECLARE(pidAutotuneConfig_t, pidAutotuneConfig);
 184
 185 const pidBank_t * pidBank(void);
 186 pidBank_t * pidBankMutable(void);
 187
 188 extern int16_t axisPID[];
 189 extern int32_t axisPID_P[], axisPID_I[], axisPID_D[], axisPID_F[], axisPID_Setpoint[];
 190
 191 void pidInit(void);
 192 bool pidInitFilters(void);
 193 void pidResetErrorAccumulators(void);
 194 void pidReduceErrorAccumulators(int8_t delta, uint8_t axis);
 195 float getAxisIterm(uint8_t axis);
 196 float getTotalRateTarget(void);
 197 void pidResetTPAFilter(void);
 198
 199 struct controlRateConfig_s;
 200 struct motorConfig_s;
 201 struct rxConfig_s;
 202
 203 void schedulePidGainsUpdate(void);
 204 void updatePIDCoefficients(void);
 205 void pidController(float dT);
 206
 207 float pidRateToRcCommand(float rateDPS, uint8_t rate);
 208 int16_t pidAngleToRcCommand(float angleDeciDegrees, int16_t maxInclination);
 209
 210 enum {
 211     HEADING_HOLD_DISABLED = 0,
 212     HEADING_HOLD_UPDATE_HEADING,
 213     HEADING_HOLD_ENABLED
 214 };
 215
 216 void updateHeadingHoldTarget(int16_t heading);
 217 void resetHeadingHoldTarget(int16_t heading);
 218 int16_t getHeadingHoldTarget(void);
 219
 220 void autotuneUpdateState(void);
 221 void autotuneFixedWingUpdate(const flight_dynamics_index_t axis, float desiredRateDps, float reachedRateDps, float pidOutput);
 222
 223 pidType_e pidIndexGetType(pidIndex_e pidIndex);
 224
 225 bool isFixedWingLevelTrimActive(void);
 226 void updateFixedWingLevelTrim(timeUs_t currentTimeUs);
 227 float getFixedWingLevelTrim(void);
 228 bool isAngleHoldLevel(void);
 229 uint16_t getPidSumLimit(const flight_dynamics_index_t axis);