Subversion Repositories FlightCtrl

// ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

// + Copyright (c) 04.2007 Holger Buss

// + Nur für den privaten Gebrauch

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#include <stdlib.h>

#include <avr/io.h>

#include "eeprom.h"

#include "flight.h"

// Only for debug. Remove.

//#include "analog.h"

//#include "rc.h"

// Necessary for external control and motor test

#include "uart0.h"

// for scope debugging

// #include "rc.h"

#include "twimaster.h"

#include "attitude.h"

#include "controlMixer.h"

#include "commands.h"

#ifdef USE_MK3MAG

#include "gps.h"

#endif

#define CHECK_MIN_MAX(value, min, max) {if(value < min) value = min; else if(value > max) value = max;}

/*

 * These are no longer maintained, just left at 0. The original implementation just summed the acc.

 * value to them every 2 ms. No filtering or anything. Just a case for an eventual overflow?? Hey???

 */

// int16_t naviAccPitch = 0, naviAccRoll = 0, naviCntAcc = 0;

uint8_t gyroPFactor, gyroIFactor; // the PD factors for the attitude control

uint8_t yawPFactor, yawIFactor; // the PD factors for the yaw control

// Some integral weight constant...

uint16_t Ki = 10300 / 33;

uint8_t RequiredMotors = 0;

// No support for altitude control right now.

// int16_t SetPointHeight = 0;

/************************************************************************/

/*  Filter for motor value smoothing (necessary???)                     */

/************************************************************************/

int16_t motorFilter(int16_t newvalue, int16_t oldvalue) {

        switch (dynamicParams.UserParams[5]) {

        case 0:

                return newvalue;

        case 1:

                return (oldvalue + newvalue) / 2;

        case 2:

                if (newvalue > oldvalue)

                        return (1 * (int16_t) oldvalue + newvalue) / 2; //mean of old and new

                else

                        return newvalue - (oldvalue - newvalue) * 1; // 2 * new - old

        case 3:

                if (newvalue < oldvalue)

                        return (1 * (int16_t) oldvalue + newvalue) / 2; //mean of old and new

                else

                        return newvalue - (oldvalue - newvalue) * 1; // 2 * new - old

        default:

                return newvalue;

        }

}

/************************************************************************/

/*  Neutral Readings                                                    */

/************************************************************************/

void flight_setNeutral() {

        MKFlags |= MKFLAG_CALIBRATE;

        // not really used here any more.

        dynamicParams.KalmanK = -1;

        dynamicParams.KalmanMaxDrift = 0;

        dynamicParams.KalmanMaxFusion = 32;

        controlMixer_initVariables();

}

void setFlightParameters(uint8_t _Ki, uint8_t _gyroPFactor,

                uint8_t _gyroIFactor, uint8_t _yawPFactor, uint8_t _yawIFactor) {

        Ki = 10300 / _Ki;

        gyroPFactor = _gyroPFactor;

        gyroIFactor = _gyroIFactor;

        yawPFactor = _yawPFactor;

        yawIFactor = _yawIFactor;

}

void setNormalFlightParameters(void) {

        setFlightParameters(dynamicParams.IFactor + 1, dynamicParams.GyroP + 10,

                        staticParams.GlobalConfig & CFG_HEADING_HOLD ? 0 : dynamicParams.GyroI,

                        dynamicParams.GyroP + 10, dynamicParams.UserParams[6]);

}

void setStableFlightParameters(void) {

        setFlightParameters(33, 90, 120, 90, 120);

}

/************************************************************************/

/*  Main Flight Control                                                 */

/************************************************************************/

void flight_control(void) {

        int16_t tmp_int;

        // Mixer Fractions that are combined for Motor Control

        int16_t yawTerm, throttleTerm, term[2];

        // PID controller variables

        int16_t PDPart[2], PDPartYaw, PPart[2];

        static int32_t IPart[2] = { 0, 0 };

        //  static int32_t yawControlRate = 0;

        // Removed. Too complicated, and apparently not necessary with MEMS gyros anyway.

        // static int32_t IntegralGyroPitchError = 0, IntegralGyroRollError = 0;

        // static int32_t CorrectionPitch, CorrectionRoll;

        static uint16_t emergencyFlightTime;

        static int8_t debugDataTimer = 1;

        // High resolution motor values for smoothing of PID motor outputs

        static int16_t motorFilters[MAX_MOTORS];

        uint8_t i, axis;

        controlMixer_update();

        // Fire the main flight attitude calculation, including integration of angles.

        calculateFlightAttitude();

        throttleTerm = controlThrottle;

        // This check removed. Is done on a per-motor basis, after output matrix multiplication.

        // if(throttleTerm < staticParams.MinThrottle + 10) throttleTerm = staticParams.MinThrottle + 10;

        // else if(throttleTerm > staticParams.MaxThrottle - 20) throttleTerm = (staticParams.MaxThrottle - 20);

        /************************************************************************/

        /* RC-signal is bad                                                     */

        /* This part could be abstracted, as having yet another control input   */

        /* to the control mixer: An emergency autopilot control.                */

        /************************************************************************/

        if (controlMixer_getSignalQuality() <= SIGNAL_BAD) { // the rc-frame signal is not reveived or noisy

                RED_ON;

                beepRCAlarm();

                if (emergencyFlightTime) {

                        // continue emergency flight

                        emergencyFlightTime--;

                        if (isFlying > 256) {

                                // We're probably still flying. Descend slowly.

                                throttleTerm = staticParams.EmergencyGas; // Set emergency throttle

                                MKFlags |= (MKFLAG_EMERGENCY_LANDING); // Set flag for emergency landing

                                setStableFlightParameters();

                        } else {

                                MKFlags &= ~(MKFLAG_MOTOR_RUN); // Probably not flying, and bad R/C signal. Kill motors.

                        }

                } else {

                        // end emergency flight (just cut the motors???)

                        MKFlags &= ~(MKFLAG_MOTOR_RUN | MKFLAG_EMERGENCY_LANDING);

                }

        } else {

                // signal is acceptable

                if (controlMixer_getSignalQuality() > SIGNAL_BAD) {

                        // Reset emergency landing control variables.

                        MKFlags &= ~(MKFLAG_EMERGENCY_LANDING); // clear flag for emergency landing

                        // The time is in whole seconds.

                        emergencyFlightTime = (uint16_t) staticParams.EmergencyGasDuration * 488;

                }

                // If some throttle is given, and the motor-run flag is on, increase the probability that we are flying.

                if (throttleTerm > 40 && (MKFlags & MKFLAG_MOTOR_RUN)) {

                        // increment flight-time counter until overflow.

                        if (isFlying != 0xFFFF)

                                isFlying++;

                } else

                /*

                 * When standing on the ground, do not apply I controls and zero the yaw stick.

                 * Probably to avoid integration effects that will cause the copter to spin

                 * or flip when taking off.

                 */

                if (isFlying < 256) {

                        IPart[PITCH] = IPart[ROLL] = 0;

                        // TODO: Don't stomp on other modules' variables!!!

                        // controlYaw = 0;

                        PDPartYaw = 0; // instead.

                        if (isFlying == 250) {

                                // HC_setGround();

                                updateCompassCourse = 1;

                                yawAngleDiff = 0;

                        }

                } else {

                        // Set fly flag. TODO: Hmmm what can we trust - the isFlying counter or the flag?

                        // Answer: The counter. The flag is not read from anywhere anyway... except the NC maybe.

                        MKFlags |= (MKFLAG_FLY);

                }

                commands_handleCommands();

                // if(controlMixer_getSignalQuality() >= SIGNAL_GOOD) {

                setNormalFlightParameters();

                // }

        } // end else (not bad signal case)

        // end part1a: 750-800 usec.

        /*

         * Looping the H&I way basically is just a matter of turning off attitude angle measurement

         * by integration (because 300 deg/s gyros are too slow) and turning down the throttle.

         * This is the throttle part.

         */

        if (looping) {

                if (throttleTerm > staticParams.LoopGasLimit)

                        throttleTerm = staticParams.LoopGasLimit;

        }

        /************************************************************************/

        /*  Yawing                                                              */

        /************************************************************************/

        if (abs(controlYaw) > 4 * staticParams.StickYawP) { // yaw stick is activated

                ignoreCompassTimer = 1000;

                if (!(staticParams.GlobalConfig & CFG_COMPASS_FIX)) {

                        updateCompassCourse = 1;

                }

        }

        //  yawControlRate = controlYaw;

        // Trim drift of yawAngleDiff with controlYaw.

        // TODO: We want NO feedback of control related stuff to the attitude related stuff.

        // This seems to be used as: Difference desired <--> real heading.

        yawAngleDiff -= controlYaw;

        // limit the effect

        CHECK_MIN_MAX(yawAngleDiff, -50000, 50000);

        /************************************************************************/

        /* Compass is currently not supported.                                  */

        /************************************************************************/

        if (staticParams.GlobalConfig & (CFG_COMPASS_ACTIVE | CFG_GPS_ACTIVE)) {

                updateCompass();

        }

#if defined (USE_NAVICTRL)

        /************************************************************************/

        /* GPS is currently not supported.                                      */

        /************************************************************************/

        if(staticParams.GlobalConfig & CFG_GPS_ACTIVE) {

                GPS_Main();

                MKFlags &= ~(MKFLAG_CALIBRATE | MKFLAG_START);

        } else {

                // GPSStickPitch = 0;

                // GPSStickRoll = 0;

        }

#endif

        // end part 1: 750-800 usec.

        // start part 3: 350 - 400 usec.

#define SENSOR_LIMIT  (4096 * 4)

        /************************************************************************/

        /* Calculate control feedback from angle (gyro integral)                */

        /* and angular velocity (gyro signal)                                   */

        /************************************************************************/

        // The P-part is the P of the PID controller. That's the angle integrals (not rates).

        for (axis = PITCH; axis <= ROLL; axis++) {

                if (looping & ((1 << 4) << axis)) {

                        PPart[axis] = 0;

                } else { // TODO: Where do the 44000 come from???

                        PPart[axis] = angle[axis] * gyroIFactor / (44000 / CONTROL_SCALING); // P-Part - Proportional to Integral

                }

                /*

                 * Now blend in the D-part - proportional to the Differential of the integral = the rate.

                 * Read this as: PDPart = PPart + rate_PID * pfactor * CONTROL_SCALING

                 * where pfactor is in [0..1].

                 */

                PDPart[axis] = PPart[axis] + (int32_t) ((int32_t) rate_PID[axis]

                                * gyroPFactor / (256L / CONTROL_SCALING)) + (differential[axis]

                                * (int16_t) dynamicParams.GyroD) / 16;

                CHECK_MIN_MAX(PDPart[axis], -SENSOR_LIMIT, SENSOR_LIMIT);

        }

        PDPartYaw = (int32_t) (yawRate * 2 * (int32_t) yawPFactor) / (256L

                        / CONTROL_SCALING) + (int32_t) (yawAngleDiff * yawIFactor) / (2 * (44000

                        / CONTROL_SCALING));

        // limit control feedback

        CHECK_MIN_MAX(PDPartYaw, -SENSOR_LIMIT, SENSOR_LIMIT);

        /*

         * Compose throttle term.

         * If a Bl-Ctrl is missing, prevent takeoff.

         */

        if (missingMotor) {

                // if we are in the lift off condition. Hmmmmmm when is throttleTerm == 0 anyway???

                if (isFlying > 1 && isFlying < 50 && throttleTerm > 0)

                        isFlying = 1; // keep within lift off condition

                throttleTerm = staticParams.MinThrottle; // reduce gas to min to avoid lift of

        }

        // Scale up to higher resolution. Hmm why is it not (from controlMixer and down) scaled already?

        throttleTerm *= CONTROL_SCALING;

        /*

         * Compose yaw term.

         * The yaw term is limited: Absolute value is max. = the throttle term / 2.

         * However, at low throttle the yaw term is limited to a fixed value,

         * and at high throttle it is limited by the throttle reserve (the difference

         * between current throttle and maximum throttle).

         */

#define MIN_YAWGAS (40 * CONTROL_SCALING)  // yaw also below this gas value

        yawTerm = PDPartYaw - controlYaw * CONTROL_SCALING;

        // Limit yawTerm

        if (throttleTerm > MIN_YAWGAS) {

                CHECK_MIN_MAX(yawTerm, - (throttleTerm / 2), (throttleTerm / 2));

        } else {

                CHECK_MIN_MAX(yawTerm, - (MIN_YAWGAS / 2), (MIN_YAWGAS / 2));

        }

        tmp_int = staticParams.MaxThrottle * CONTROL_SCALING;

        CHECK_MIN_MAX(yawTerm, -(tmp_int - throttleTerm), (tmp_int - throttleTerm));

        tmp_int = (int32_t) ((int32_t) dynamicParams.DynamicStability

                        * (int32_t) (throttleTerm + abs(yawTerm) / 2)) / 64;

        for (axis = PITCH; axis <= ROLL; axis++) {

                /*

                 * Compose pitch and roll terms. This is finally where the sticks come into play.

                 */

                if (gyroIFactor) {

                        // Integration mode: Integrate (angle - stick) = the difference between angle and stick pos.

                        // That means: Holding the stick a little forward will, at constant flight attitude, cause this to grow (decline??) over time.

                        // TODO: Find out why this seems to be proportional to stick position - not integrating it at all.

                        IPart[axis] += PPart[axis] - control[axis]; // Integrate difference between P part (the angle) and the stick pos.

                } else {

                        // "HH" mode: Integrate (rate - stick) = the difference between rotation rate and stick pos.

                        // To keep up with a full stick PDPart should be about 156...

                        IPart[axis] += PDPart[axis] - control[axis]; // With gyroIFactor == 0, PDPart is really just a D-part. Integrate D-part (the rot. rate) and the stick pos.

                }

                // TODO: From which planet comes the 16000?

                CHECK_MIN_MAX(IPart[axis], -(CONTROL_SCALING * 16000L), (CONTROL_SCALING * 16000L));

                // Add (P, D) parts minus stick pos. to the scaled-down I part.

                term[axis] = PDPart[axis] - control[axis] + IPart[axis] / Ki; // PID-controller for pitch

                /*

                 * Apply "dynamic stability" - that is: Limit pitch and roll terms to a growing function of throttle and yaw(!).

                 * The higher the dynamic stability parameter, the wider the bounds. 64 seems to be a kind of unity

                 * (max. pitch or roll term is the throttle value).

                 * TODO: Why a growing function of yaw?

                 */

                CHECK_MIN_MAX(term[axis], -tmp_int, tmp_int);

        }

        // end part 3: 350 - 400 usec.

        // +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

        // Universal Mixer

        // Each (pitch, roll, throttle, yaw) term is in the range [0..255 * CONTROL_SCALING].

        // +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

        DebugOut.Analog[12] = term[PITCH];

        DebugOut.Analog[13] = term[ROLL];

        DebugOut.Analog[14] = yawTerm;

        DebugOut.Analog[15] = throttleTerm;

        for (i = 0; i < MAX_MOTORS; i++) {

                int16_t tmp;

                if (MKFlags & MKFLAG_MOTOR_RUN && Mixer.Motor[i][MIX_THROTTLE] > 0) {

                        tmp = ((int32_t) throttleTerm * Mixer.Motor[i][MIX_THROTTLE]) / 64L;

                        tmp += ((int32_t) term[PITCH] * Mixer.Motor[i][MIX_PITCH]) / 64L;

                        tmp += ((int32_t) term[ROLL] * Mixer.Motor[i][MIX_ROLL]) / 64L;

                        tmp += ((int32_t) yawTerm * Mixer.Motor[i][MIX_YAW]) / 64L;

                        motorFilters[i] = motorFilter(tmp, motorFilters[i]);

                        // Now we scale back down to a 0..255 range.

                        tmp = motorFilters[i] / CONTROL_SCALING;

                        // So this was the THIRD time a throttle was limited. But should the limitation

                        // apply to the common throttle signal (the one used for setting the "power" of

                        // all motors together) or should it limit the throttle set for each motor,

                        // including mix components of pitch, roll and yaw? I think only the common

                        // throttle should be limited.

                        // --> WRONG. This caused motors to stall completely in tight maneuvers.

                        // Apply to individual signals instead.

                        CHECK_MIN_MAX(tmp, staticParams.MinThrottle, staticParams.MaxThrottle);

                        CHECK_MIN_MAX(tmp, 1, 255);

                        motor[i].SetPoint = tmp;

                } else if (motorTestActive) {

                        motor[i].SetPoint = motorTest[i];

                } else {

                        motor[i].SetPoint = 0;

                }

                if (i < 4)

                        DebugOut.Analog[22 + i] = motor[i].SetPoint;

        }

        I2C_Start(TWI_STATE_MOTOR_TX);

        // +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

        // Debugging

        // +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++

        if (!(--debugDataTimer)) {

                debugDataTimer = 24; // update debug outputs at 488 / 24 = 20.3 Hz.

                DebugOut.Analog[0] = (10 * angle[PITCH]) / GYRO_DEG_FACTOR_PITCHROLL; // in 0.1 deg

                DebugOut.Analog[1] = (10 * angle[ROLL]) / GYRO_DEG_FACTOR_PITCHROLL; // in 0.1 deg

                DebugOut.Analog[2] = yawGyroHeading / GYRO_DEG_FACTOR_YAW;

                /*

                 DebugOut.Analog[23] = (yawRate * 2 * (int32_t)yawPFactor) / (256L / CONTROL_SCALING);

                 DebugOut.Analog[24] = controlYaw;

                 DebugOut.Analog[25] = yawAngleDiff / 100L;

                 DebugOut.Analog[26] = accNoisePeak[PITCH];

                 DebugOut.Analog[27] = accNoisePeak[ROLL];

                 DebugOut.Analog[30] = gyroNoisePeak[PITCH];

                 DebugOut.Analog[31] = gyroNoisePeak[ROLL];

                 */

        }

}