//============================================================================================= // MahonyAHRS.c //============================================================================================= // // Madgwick's implementation of Mayhony's AHRS algorithm. // See: http://www.x-io.co.uk/open-source-imu-and-ahrs-algorithms/ // // From the x-io website "Open-source resources available on this website are // provided under the GNU General Public Licence unless an alternative licence // is provided in source." // // Date Author Notes // 29/09/2011 SOH Madgwick Initial release // 02/10/2011 SOH Madgwick Optimised for reduced CPU load // // Algorithm paper: // http://ieeexplore.ieee.org/xpl/login.jsp?tp=&arnumber=4608934&url=http%3A%2F%2Fieeexplore.ieee.org%2Fstamp%2Fstamp.jsp%3Ftp%3D%26arnumber%3D4608934 // //============================================================================================= //------------------------------------------------------------------------------------------- // Header files #include "MahonyAHRS.h" #include "bll_imu.h" #include #include "system.h" //------------------------------------------------------------------------------------------- // Definitions float twoKi; // 2 * integral gain (Ki) float q0, q1, q2, q3; // quaternion of sensor frame relative to auxiliary frame float integralFBx, integralFBy, integralFBz; // integral error terms scaled by Ki float invSampleFreq; float roll, pitch, yaw; char anglesComputed; //#define twoKpDef (5.0f * 0.5f) // 2 * proportional gain //#define twoKiDef (0.5f * 1.0f) // 2 * integral gain #define twoKpDef (10.0f * 0.5f) // 2 * proportional gain #define twoKiDef (0.0f * 1.0f) // 2 * integral gain void Mahony_Init(float sampleFrequency) { twoKi = twoKiDef; // 2 * integral gain (Ki) q0 = 1.0f; q1 = 0.0f; q2 = 0.0f; q3 = 0.0f; integralFBx = 0.0f; integralFBy = 0.0f; integralFBz = 0.0f; anglesComputed = 0; invSampleFreq = 1.0f / sampleFrequency; } float Mahony_invSqrt(float x) { float halfx = 0.5f * x; float y = x; long i = *(long*)&y; i = 0x5f3759df - (i>>1); y = *(float*)&i; y = y * (1.5f - (halfx * y * y)); y = y * (1.5f - (halfx * y * y)); return y; } void Mahony_update(float gx, float gy, float gz, float ax, float ay, float az, float mx, float my, float mz) { float recipNorm; float q0q0, q0q1, q0q2, q0q3, q1q1, q1q2, q1q3, q2q2, q2q3, q3q3; float hx, hy, bx, bz; float halfvx, halfvy, halfvz, halfwx, halfwy, halfwz; float halfex, halfey, halfez; float qa, qb, qc; // Compute feedback only if accelerometer measurement valid // (avoids NaN in accelerometer normalisation) if(!((ax == 0.0f) && (ay == 0.0f) && (az == 0.0f))) { // Normalise accelerometer measurement recipNorm = Mahony_invSqrt(ax * ax + ay * ay + az * az); ax *= recipNorm; ay *= recipNorm; az *= recipNorm; // Normalise magnetometer measurement recipNorm = Mahony_invSqrt(mx * mx + my * my + mz * mz); mx *= recipNorm; my *= recipNorm; mz *= recipNorm; // Auxiliary variables to avoid repeated arithmetic q0q0 = q0 * q0; q0q1 = q0 * q1; q0q2 = q0 * q2; q0q3 = q0 * q3; q1q1 = q1 * q1; q1q2 = q1 * q2; q1q3 = q1 * q3; q2q2 = q2 * q2; q2q3 = q2 * q3; q3q3 = q3 * q3; // Reference direction of Earth's magnetic field hx = 2.0f * (mx * (0.5f - q2q2 - q3q3) + my * (q1q2 - q0q3) + mz * (q1q3 + q0q2)); hy = 2.0f * (mx * (q1q2 + q0q3) + my * (0.5f - q1q1 - q3q3) + mz * (q2q3 - q0q1)); bx = sqrtf(hx * hx + hy * hy); bz = 2.0f * (mx * (q1q3 - q0q2) + my * (q2q3 + q0q1) + mz * (0.5f - q1q1 - q2q2)); // Estimated direction of gravity and magnetic field halfvx = q1q3 - q0q2; halfvy = q0q1 + q2q3; halfvz = q0q0 - 0.5f + q3q3; halfwx = bx * (0.5f - q2q2 - q3q3) + bz * (q1q3 - q0q2); halfwy = bx * (q1q2 - q0q3) + bz * (q0q1 + q2q3); halfwz = bx * (q0q2 + q1q3) + bz * (0.5f - q1q1 - q2q2); // Error is sum of cross product between estimated direction // and measured direction of field vectors halfex = (ay * halfvz - az * halfvy) + (my * halfwz - mz * halfwy); halfey = (az * halfvx - ax * halfvz) + (mz * halfwx - mx * halfwz); halfez = (ax * halfvy - ay * halfvx) + (mx * halfwy - my * halfwx); // Compute and apply integral feedback if enabled if(twoKi > 0.0f) { // integral error scaled by Ki integralFBx += twoKi * halfex * invSampleFreq; integralFBy += twoKi * halfey * invSampleFreq; integralFBz += twoKi * halfez * invSampleFreq; gx += integralFBx; // apply integral feedback gy += integralFBy; gz += integralFBz; } else { integralFBx = 0.0f; // prevent integral windup integralFBy = 0.0f; integralFBz = 0.0f; } // Apply proportional feedback gx += twoKpDef * halfex; gy += twoKpDef * halfey; gz += twoKpDef * halfez; } // Integrate rate of change of quaternion gx *= (0.5f * invSampleFreq); // pre-multiply common factors gy *= (0.5f * invSampleFreq); gz *= (0.5f * invSampleFreq); qa = q0; qb = q1; qc = q2; q0 += (-qb * gx - qc * gy - q3 * gz); q1 += (qa * gx + qc * gz - q3 * gy); q2 += (qa * gy - qb * gz + q3 * gx); q3 += (qa * gz + qb * gy - qc * gx); // Normalise quaternion recipNorm = Mahony_invSqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3); q0 *= recipNorm; q1 *= recipNorm; q2 *= recipNorm; q3 *= recipNorm; anglesComputed = 0; } void Mahony_computeAngles() { roll = atan2f(q0*q1 + q2*q3, 0.5f - q1*q1 - q2*q2); pitch = asinf(-2.0f * (q1*q3 - q0*q2)); yaw = atan2f(q1*q2 + q0*q3, 0.5f - q2*q2 - q3*q3); anglesComputed = 1; } float getRoll() { if (!anglesComputed) Mahony_computeAngles(); return roll * 57.29578f; } float getPitch() { if (!anglesComputed) Mahony_computeAngles(); return pitch * 57.29578f; } float getYaw() { if (!anglesComputed) Mahony_computeAngles(); return yaw * 57.29578f; } static float acc_x,acc_y,acc_z; static float groy_x,groy_y,groy_z; static float mag_x,mag_y,mag_z; extern unsigned int send_bytes_client(unsigned char *bytes, uint16_t len); void Mahony_send_ANO(uint8_t fun,uint8_t* p,int len) { uint8_t buf[256]; int L=0; uint8_t ver = 0; buf[L] = 0xAA; ver += buf[L++]; buf[L] = 0x05; ver += buf[L++]; buf[L] = 0xAF; ver += buf[L++]; buf[L] = fun; ver += buf[L++]; buf[L] = len; ver += buf[L++]; for(int i=0;i>8); buf[L++] = (uint8_t)(rol>>0); buf[L++] = (uint8_t)(pitch>>8); buf[L++] = (uint8_t)(pitch>>0); buf[L++] = (uint8_t)(yaw>>8); buf[L++] = (uint8_t)(yaw>>0); // buf[L++] = (uint8_t)(dis>>24); // buf[L++] = (uint8_t)(dis>>16); // buf[L++] = (uint8_t)(dis>>8); // buf[L++] = (uint8_t)(dis>>0); // if(dis<500&&pitch>-4000) buf[L++] = 1; // else buf[L++] = 0; // buf[L++] = 0; // buf[L++] = 0; buf[L++] = 0; buf[L++] = 0; buf[L++] = 0; buf[L++] = 0; buf[L++] = 0; buf[L++] = 0; buf[L++] = 0; Mahony_send_ANO(0x01,buf,L); } void Mahony_send_ANO_SENSER(int16_t gx, int16_t gy, int16_t gz, int16_t ax, int16_t ay, int16_t az, int16_t mx, int16_t my, int16_t mz) { uint8_t buf[256]; uint8_t L=0; buf[L++] = (uint8_t)(ax>>8); buf[L++] = (uint8_t)(ax>>0); buf[L++] = (uint8_t)(ay>>8); buf[L++] = (uint8_t)(ay>>0); buf[L++] = (uint8_t)(az>>8); buf[L++] = (uint8_t)(az>>0); buf[L++] = (uint8_t)(gx>>8); buf[L++] = (uint8_t)(gx>>0); buf[L++] = (uint8_t)(gy>>8); buf[L++] = (uint8_t)(gy>>0); buf[L++] = (uint8_t)(gz>>8); buf[L++] = (uint8_t)(gz>>0); buf[L++] = (uint8_t)(mx>>8); buf[L++] = (uint8_t)(mx>>0); buf[L++] = (uint8_t)(my>>8); buf[L++] = (uint8_t)(my>>0); buf[L++] = (uint8_t)(mz>>8); buf[L++] = (uint8_t)(mz>>0); Mahony_send_ANO(0x02,buf,L); } void Mahony_send_My_SENSER(int16_t gx, int16_t gy, int16_t gz, int16_t ax, int16_t ay, int16_t az, int16_t mx, int16_t my, int16_t mz) { uint8_t buf[256]; uint8_t L=0; int16_t _q0 = (int16_t)(q0*100); int16_t _q1 = (int16_t)(q1*100); int16_t _q2 = (int16_t)(q2*100); int16_t _q3 = (int16_t)(q3*100); int16_t rol = (int16_t)(getRoll()*100); int16_t pit = (int16_t)(getPitch()*100); int16_t yaw = (int16_t)(getYaw()*100); int16_t ds = 3210; int16_t pf = 12; int16_t pb = 34; int16_t ptx = 56; int16_t pty = 78; int16_t ptz = 90; buf[L++] = (uint8_t)(ax>>8); buf[L++] = (uint8_t)(ax>>0); buf[L++] = (uint8_t)(ay>>8); buf[L++] = (uint8_t)(ay>>0); buf[L++] = (uint8_t)(az>>8); buf[L++] = (uint8_t)(az>>0); buf[L++] = (uint8_t)(gx>>8); buf[L++] = (uint8_t)(gx>>0); buf[L++] = (uint8_t)(gy>>8); buf[L++] = (uint8_t)(gy>>0); buf[L++] = (uint8_t)(gz>>8); buf[L++] = (uint8_t)(gz>>0); buf[L++] = (uint8_t)(mx>>8); buf[L++] = (uint8_t)(mx>>0); buf[L++] = (uint8_t)(my>>8); buf[L++] = (uint8_t)(my>>0); buf[L++] = (uint8_t)(mz>>8); buf[L++] = (uint8_t)(mz>>0); buf[L++] = (uint8_t)(pf>>8); buf[L++] = (uint8_t)(pf>>0); buf[L++] = (uint8_t)(pb>>8); buf[L++] = (uint8_t)(pb>>0); buf[L++] = (uint8_t)(ds>>8); buf[L++] = (uint8_t)(ds>>0); buf[L++] = (uint8_t)(rol>>8); buf[L++] = (uint8_t)(rol>>0); buf[L++] = (uint8_t)(pit>>8); buf[L++] = (uint8_t)(pit>>0); buf[L++] = (uint8_t)(yaw>>8); buf[L++] = (uint8_t)(yaw>>0); buf[L++] = (uint8_t)(ptx>>8); buf[L++] = (uint8_t)(ptx>>0); buf[L++] = (uint8_t)(pty>>8); buf[L++] = (uint8_t)(pty>>0); buf[L++] = (uint8_t)(ptz>>8); buf[L++] = (uint8_t)(ptz>>0); buf[L++] = (uint8_t)(_q0>>8); buf[L++] = (uint8_t)(_q0>>0); buf[L++] = (uint8_t)(_q1>>8); buf[L++] = (uint8_t)(_q1>>0); buf[L++] = (uint8_t)(_q2>>8); buf[L++] = (uint8_t)(_q2>>0); buf[L++] = (uint8_t)(_q3>>8); buf[L++] = (uint8_t)(_q3>>0); Mahony_send_ANO(0xEE,buf,L); } //void Mahony_process(int16_t gx, int16_t gy, int16_t gz, int16_t ax, int16_t ay, int16_t az, int16_t mx, int16_t my, int16_t mz) //{ // static uint8_t tt = 0; // acc_x = ax/4096.0f; // acc_y = ay/4096.0f; // acc_z = az/4096.0f; // // int16_t rol = (int16_t)(getRoll()*100); // // Mahony_update(groy_x,groy_y,groy_z,acc_x,acc_y,acc_z,mag_x,mag_y,mag_z); //// DEBUG_LOG("rol :%d\r\n", rol); // if(++tt>=10){tt = 0; // Mahony_send_ANO_STATUS(); // Mahony_send_ANO_SENSER(gx,gy,gz,ax,ay,az,mx,my,mz); //// Mahony_send_My_SENSER(gx,gy,gz,ax,ay,az,mx,my,mz); // } //} void Mahony_process(int16_t gx, int16_t gy, int16_t gz, int16_t ax, int16_t ay, int16_t az, int16_t mx, int16_t my, int16_t mz) { acc_x = ax/4096.0f; acc_y = ay/4096.0f; acc_z = az/4096.0f; Mahony_update(groy_x,groy_y,groy_z,acc_x,acc_y,acc_z,mag_x,mag_y,mag_z); } //============================================================================================ // END OF CODE //============================================================================================