void calibrateIMU(float coeff[12]) { float th[SAMPLES], pr[SAMPLES], data[3], regPara[2] ; uint8_t i ; chprintf((BaseSequentialStream *)&OUTPUT, "Calibrating Gyroscope....Keep the board stable..\r\n") ; chThdSleepMilliseconds(1000) ; for(i = 0 ; i < SAMPLES ; i++) { readIMUData(GYRO_RAW_DATA, data) ; pr[i] = data[0] ; chThdSleepMilliseconds(2) ; } coeff[6] = (-1.0f * average(pr, SAMPLES)) ; coeff[7] = 1.0f ; for(i = 0 ; i < SAMPLES ; i++) { readIMUData(GYRO_RAW_DATA, data) ; pr[i] = data[1] ; chThdSleepMilliseconds(2) ; } coeff[8] = (-1.0f * average(pr, SAMPLES)) ; coeff[9] = 1.0f ; for(i = 0 ; i < SAMPLES ; i++) { readIMUData(GYRO_RAW_DATA, data) ; pr[i] = data[2] ; chThdSleepMilliseconds(2) ; } coeff[10] = (-1.0f * average(pr, SAMPLES)) ; coeff[11] = 1.0f ; coeff[0] = 0.0f ; coeff[1] = 1.0f ; coeff[2] = 0.0f ; coeff[3] = 1.0f ; coeff[4] = 0.0f ; coeff[5] = 1.0f ; }
int main() { // open data files pImuFile = fopen ("IMU.txt","r"); pMagFile = fopen ("MAG.txt","r"); pGpsFile = fopen ("GPS.txt","r"); pAhrsFile = fopen ("ATT.txt","r"); pAdsFile = fopen ("NTUN.txt","r"); pTimeFile = fopen ("timing.txt","r"); pStateOutFile = fopen ("StateDataOut.txt","w"); pEulOutFile = fopen ("EulDataOut.txt","w"); pCovOutFile = fopen ("CovDataOut.txt","w"); pRefPosVelOutFile = fopen ("RefVelPosDataOut.txt","w"); pVelPosFuseFile = fopen ("VelPosFuse.txt","w"); pMagFuseFile = fopen ("MagFuse.txt","w"); pTasFuseFile = fopen ("TasFuse.txt","w"); pGpsRawINFile = fopen ("GPSraw.txt","r"); pGpsRawOUTFile = fopen ("GPSrawOut.txt","w"); memset(gpsRaw, 0, sizeof(gpsRaw)); // read test data from files for first timestamp readIMUData(); readGpsData(); readMagData(); readAirSpdData(); readAhrsData(); readTimingData(); while (!endOfData) { if ((IMUmsec >= msecStartTime) && (IMUmsec <= msecEndTime)) { // Initialise states, covariance and other data if ((IMUmsec > msecAlignTime) && !statesInitialised && (GPSstatus == 3)) { InitialiseFilter(); } // If valid IMU data and states initialised, predict states and covariances if (statesInitialised) { // Run the strapdown INS equations every IMU update UpdateStrapdownEquationsNED(); // debug code - could be tunred into a filter mnitoring/watchdog function float tempQuat[4]; for (uint8_t j=0; j<=3; j++) tempQuat[j] = states[j]; quat2eul(eulerEst, tempQuat); for (uint8_t j=0; j<=2; j++) eulerDif[j] = eulerEst[j] - ahrsEul[j]; if (eulerDif[2] > pi) eulerDif[2] -= 2*pi; if (eulerDif[2] < -pi) eulerDif[2] += 2*pi; // store the predicted states for subsequent use by measurement fusion StoreStates(); // Check if on ground - status is used by covariance prediction OnGroundCheck(); // sum delta angles and time used by covariance prediction summedDelAng = summedDelAng + correctedDelAng; summedDelVel = summedDelVel + correctedDelVel; dt += dtIMU; // perform a covariance prediction if the total delta angle has exceeded the limit // or the time limit will be exceeded at the next IMU update if ((dt >= (covTimeStepMax - dtIMU)) || (summedDelAng.length() > covDelAngMax)) { CovariancePrediction(); summedDelAng = summedDelAng.zero(); summedDelVel = summedDelVel.zero(); dt = 0.0f; } } // Fuse GPS Measurements if (newDataGps && statesInitialised) { // Convert GPS measurements to Pos NE, hgt and Vel NED calcvelNED(velNED, gpsCourse, gpsGndSpd, gpsVelD); calcposNED(posNED, gpsLat, gpsLon, gpsHgt, latRef, lonRef, hgtRef); posNE[0] = posNED[0]; posNE[1] = posNED[1]; hgtMea = -posNED[2]; // set fusion flags fuseVelData = true; fusePosData = true; fuseHgtData = true; // recall states stored at time of measurement after adjusting for delays RecallStates(statesAtVelTime, (IMUmsec - msecVelDelay)); RecallStates(statesAtPosTime, (IMUmsec - msecPosDelay)); RecallStates(statesAtHgtTime, (IMUmsec - msecHgtDelay)); // run the fusion step FuseVelposNED(); } else { fuseVelData = false; fusePosData = false; fuseHgtData = false; } // Fuse Magnetometer Measurements if (newDataMag && statesInitialised) { fuseMagData = true; RecallStates(statesAtMagMeasTime, (IMUmsec - msecMagDelay)); // Assume 50 msec avg delay for magnetometer data } else { fuseMagData = false; } if (statesInitialised) FuseMagnetometer(); // Fuse Airspeed Measurements if (newAdsData && statesInitialised && VtasMeas > 8.0f) { fuseVtasData = true; RecallStates(statesAtVtasMeasTime, (IMUmsec - msecTasDelay)); // assume 100 msec avg delay for airspeed data FuseAirspeed(); } else { fuseVtasData = false; } // debug output //printf("Euler Angle Difference = %3.1f , %3.1f , %3.1f deg\n", rad2deg*eulerDif[0],rad2deg*eulerDif[1],rad2deg*eulerDif[2]); WriteFilterOutput(); } // read test data from files for next timestamp readIMUData(); readGpsData(); readMagData(); readAirSpdData(); readAhrsData(); if (IMUmsec > msecEndTime) { CloseFiles(); endOfData = true; } } }