用ARDUINO MINI+6050试了一下，能出数据，（rollpitch）地磁坏了，加不了.......
大部份代码来自网上，这是凑起来的......
解算的步骤是这样的：
初始化IMU--由加计和地磁计算出静止初始状态下的欧拉（roll,pitch,yaw)---由初始欧拉计算出初始四元素值----- MadgwickAHRSupdate(就是这个关键算法，老外的！以GYRO为主更新四元素，其中还有加计和地磁的数据融合）--四元素转欧拉输出！
#include "Wire.h"
#include "I2Cdev.h"
#include "MPU6050.h"
#include "HMC5883L.h"
#include <math.h>
#define sampleFreq 145.0f // sample frequency in Hz,我程序跑了一下，DT=6-7ms，所以取145
#define betaDef 0.1f // 2 * proportional gain
float beta2 = betaDef; // 2 * proportional gain (Kp) KP值是可以调的........
float q0 = 1.0f, q1 = 0.0f, q2 = 0.0f, q3 = 0.0f; //这个不是初值，
long timer = 0,dt;
//---------------------------------------------------------------------------------------------------
MPU6050 accelgyro;
HMC5883L mag;
int16_t ax, ay, az;
int16_t gx, gy, gz;
int16_t mx, my, mz;
int16_t gx_offset, gy_offset, gz_offset;
float roll,pitch,yaw;
int32_t lastMicros;
#define LED_PIN 13
bool blinkState = false;
void setup() {
#if I2CDEV_IMPLEMENTATION == I2CDEV_ARDUINO_WIRE
Wire.begin();
#elif I2CDEV_IMPLEMENTATION == I2CDEV_BUILTIN_FASTWIRE
Fastwire::setup(400, true);
#endif
Serial.begin(115200);
Serial.println("Initializing MPU6050 devices...");
accelgyro.initialize();
Serial.println("Testing MPU6050 connections...");
Serial.println(accelgyro.testConnection() ? "MPU6050 connection successful" : "MPU6050 connection failed");
delay(500);
accelgyro.setFullScaleGyroRange(MPU6050_GYRO_FS_500); // 65.5 LSB/deg/s
accelgyro.setFullScaleAccelRange(MPU6050_ACCEL_FS_4); //4096 LSB/mg
//accelgyro.setDLPFMode(MPU6050_DLPF_BW_188);
accelgyro.setIntI2CMasterEnabled(0);
accelgyro.setI2CBypassEnabled(1);
if((!accelgyro.getI2CMasterModeEnabled()) && accelgyro.getI2CBypassEnabled())
Serial.println("Set MPU6050 Bypass Mode success!");
Serial.println("Initializing HMC5883L devices...");
mag.initialize();
Serial.println("Testing HMC5883L connections...");
Serial.println(mag.testConnection() ? "HMC5883L connection successful" : "HMC5883L connection failed");
delay(1000);
pinMode(LED_PIN, OUTPUT);
Serial.println("Initializing first euler Angle...");
GetGyroOffset(gx_offset,gy_offset,gz_offset);
getMPU6050Arguments();
for (int i = 0; i<5;i++){
getHMC5883LArguments();
delay(10);
}
roll = atan2(ay, az);
pitch = -asin(ax/1.0); //1g=9.82
yaw = -atan2(mx*cos(roll) + my*sin(roll)*sin(pitch) + mz*sin(roll)*cos(pitch),
my*cos(pitch) - mz*sin(pitch)); //atan2(mx, my);
q0 = cos(0.5*roll)*cos(0.5*pitch)*cos(0.5*yaw) + sin(0.5*roll)*sin(0.5*pitch)*sin(0.5*yaw); //w
q1 = sin(0.5*roll)*cos(0.5*pitch)*cos(0.5*yaw) - cos(0.5*roll)*sin(0.5*pitch)*sin(0.5*yaw); //x 绕x轴旋转是roll
q2 = cos(0.5*roll)*sin(0.5*pitch)*cos(0.5*yaw) + sin(0.5*roll)*cos(0.5*pitch)*sin(0.5*yaw); //y 绕y轴旋转是pitch
q3 = cos(0.5*roll)*cos(0.5*pitch)*sin(0.5*yaw) - sin(0.5*roll)*sin(0.5*pitch)*cos(0.5*yaw); //z 绕z轴旋转是Yaw
}
void loop() {
getMPU6050Arguments();
getHMC5883LArguments();
MadgwickAHRSupdate(gx,gy,gz,ax,ay,az,mx,my,mz);
OutEulerAngle();
Serial.print("roll: ");
Serial.println(roll,3);
Serial.print("pitch: ");
Serial.println(pitch,3);
Serial.print("yaw: ");
Serial.println(yaw,3);
Serial.print("dt: ");
Serial.println(dt);
//delay(500);
//blinkState = !blinkState;
//digitalWrite(LED_PIN, blinkState);
}
void getMPU6050Arguments(){
// read raw accel/gyro measurements from device
accelgyro.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);
// display tab-separated accel/gyro x/y/z values
ax = (float)(ax*0.000244); //0.000244 = 1/4096
ay = (float)(ay*0.000244);
az = (float)((az+600)*0.000244);
gx = (float)((gx-gx_offset)*0.000266);//单位转化成：弧度/s，0.000266=1/(Gyro_500_Scale_Factor * 57.295780)
gy = (float)((gy-gy_offset)*0.000266);
gz = (float)((gz-gz_offset)*0.000266);
}
void getHMC5883LArguments(){
mag.getHeading(&mx, &my, &mz);
// display tab-separated gyro x/y/z values
mx =(float)1.046632*mx-1.569948; //参考MEMSense的校准方法,进行x y轴的校准，未对z轴进行校准!
my =(float)my - 8.0;
mz =(float)mz;
/*To calculate heading in degrees. 0 degree indicates North
float heading = atan2(my, mx);
if(heading < 0)
heading += 2 * M_PI;
Serial.print("heading:\t");
Serial.println(heading * 180/M_PI); */
}
void GetGyroOffset(int gx_offset,int gy_offset,int gz_offset){
int i=0;
for (i=0;i<200;i++){
accelgyro.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);
gx_offset += gx;
gy_offset += gy;
gz_offset += gz;
}
gx_offset = gx_offset/i;
gy_offset = gy_offset/i;
gz_offset = gz_offset/i;
}
void OutEulerAngle(){
long halfT = (1/sampleFreq)/2.0;
pitch = (asin(-2 * q1 * q3 + 2 * q0 * q2))*57.3; //俯仰角，绕y轴转动
roll = (atan2(2 * q2 * q3 + 2 * q0 * q1, -2 * q1 * q1 - 2 * q2* q2 + 1))*57.3; //滚动角，绕x轴转动]
yaw = (atan2(2*q1*q2 + 2*q0*q3,-2*q2*q2 - 2*q3*q3 + 1)) * 57.3;
//yaw = -(0.9 * (-yaw + gz*2*halfT) + 5.73 *atan2(mx*cos(roll) + my*sin(roll)*sin(pitch) + mz*sin(roll)*cos(pitch), my*cos(pitch) - mz*sin(pitch)));
}
//---------------------------------------------------------------------------------------------------
// Function declarations
float invSqrt(float x);
//====================================================================================================
// Functions
//---------------------------------------------------------------------------------------------------
// AHRS algorithm update
void MadgwickAHRSupdate(float gx, float gy, float gz, float ax, float ay, float az, float mx, float my, float mz) {
float recipNorm;
float s0, s1, s2, s3;
float qDot1, qDot2, qDot3, qDot4;
float hx, hy;
float _2q0mx, _2q0my, _2q0mz, _2q1mx, _2bx, _2bz, _4bx, _4bz, _2q0, _2q1, _2q2, _2q3, _2q0q2, _2q2q3, q0q0, q0q1, q0q2, q0q3, q1q1, q1q2, q1q3, q2q2, q2q3, q3q3;
// Use IMU algorithm if magnetometer measurement invalid (avoids NaN in magnetometer normalisation)
/*if((mx == 0.0f) && (my == 0.0f) && (mz == 0.0f)) {
MadgwickAHRSupdateIMU(gx, gy, gz, ax, ay, az);
return;
}*/
long o_timer = timer;
timer = millis();
dt = timer - o_timer;
// Rate of change of quaternion from gyroscope
qDot1 = 0.5f * (-q1 * gx - q2 * gy - q3 * gz);
qDot2 = 0.5f * (q0 * gx + q2 * gz - q3 * gy);
qDot3 = 0.5f * (q0 * gy - q1 * gz + q3 * gx);
qDot4 = 0.5f * (q0 * gz + q1 * gy - q2 * gx);
// 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 = invSqrt(ax * ax + ay * ay + az * az);
ax *= recipNorm;
ay *= recipNorm;
az *= recipNorm;
// Normalise magnetometer measurement
recipNorm = invSqrt(mx * mx + my * my + mz * mz);
mx *= recipNorm;
my *= recipNorm;
mz *= recipNorm;
// Auxiliary variables to avoid repeated arithmetic
_2q0mx = 2.0f * q0 * mx;
_2q0my = 2.0f * q0 * my;
_2q0mz = 2.0f * q0 * mz;
_2q1mx = 2.0f * q1 * mx;
_2q0 = 2.0f * q0;
_2q1 = 2.0f * q1;
_2q2 = 2.0f * q2;
_2q3 = 2.0f * q3;
_2q0q2 = 2.0f * q0 * q2;
_2q2q3 = 2.0f * q2 * q3;
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 = mx * q0q0 - _2q0my * q3 + _2q0mz * q2 + mx * q1q1 + _2q1 * my * q2 + _2q1 * mz * q3 - mx * q2q2 - mx * q3q3;
hy = _2q0mx * q3 + my * q0q0 - _2q0mz * q1 + _2q1mx * q2 - my * q1q1 + my * q2q2 + _2q2 * mz * q3 - my * q3q3;
_2bx = sqrt(hx * hx + hy * hy);
_2bz = -_2q0mx * q2 + _2q0my * q1 + mz * q0q0 + _2q1mx * q3 - mz * q1q1 + _2q2 * my * q3 - mz * q2q2 + mz * q3q3;
_4bx = 2.0f * _2bx;
_4bz = 2.0f * _2bz;
// Gradient decent algorithm corrective step
s0 = -_2q2 * (2.0f * q1q3 - _2q0q2 - ax) + _2q1 * (2.0f * q0q1 + _2q2q3 - ay) - _2bz * q2 * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (-_2bx * q3 + _2bz * q1) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + _2bx * q2 * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
s1 = _2q3 * (2.0f * q1q3 - _2q0q2 - ax) + _2q0 * (2.0f * q0q1 + _2q2q3 - ay) - 4.0f * q1 * (1 - 2.0f * q1q1 - 2.0f * q2q2 - az) + _2bz * q3 * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (_2bx * q2 + _2bz * q0) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + (_2bx * q3 - _4bz * q1) * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
s2 = -_2q0 * (2.0f * q1q3 - _2q0q2 - ax) + _2q3 * (2.0f * q0q1 + _2q2q3 - ay) - 4.0f * q2 * (1 - 2.0f * q1q1 - 2.0f * q2q2 - az) + (-_4bx * q2 - _2bz * q0) * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (_2bx * q1 + _2bz * q3) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + (_2bx * q0 - _4bz * q2) * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
s3 = _2q1 * (2.0f * q1q3 - _2q0q2 - ax) + _2q2 * (2.0f * q0q1 + _2q2q3 - ay) + (-_4bx * q3 + _2bz * q1) * (_2bx * (0.5f - q2q2 - q3q3) + _2bz * (q1q3 - q0q2) - mx) + (-_2bx * q0 + _2bz * q2) * (_2bx * (q1q2 - q0q3) + _2bz * (q0q1 + q2q3) - my) + _2bx * q1 * (_2bx * (q0q2 + q1q3) + _2bz * (0.5f - q1q1 - q2q2) - mz);
recipNorm = invSqrt(s0 * s0 + s1 * s1 + s2 * s2 + s3 * s3); // normalise step magnitude
s0 *= recipNorm;
s1 *= recipNorm;
s2 *= recipNorm;
s3 *= recipNorm;
// Apply feedback step
qDot1 -= beta2 * s0;
qDot2 -= beta2 * s1;
qDot3 -= beta2 * s2;
qDot4 -= beta2 * s3;
}
// Integrate rate of change of quaternion to yield quaternion
q0 += qDot1 * (1.0f / sampleFreq);
q1 += qDot2 * (1.0f / sampleFreq);
q2 += qDot3 * (1.0f / sampleFreq);
q3 += qDot4 * (1.0f / sampleFreq);
// Normalise quaternion
recipNorm = invSqrt(q0 * q0 + q1 * q1 + q2 * q2 + q3 * q3);
q0 *= recipNorm;
q1 *= recipNorm;
q2 *= recipNorm;
q3 *= recipNorm;
}
//---------------------------------------------------------------------------------------------------
// Fast inverse square-root
// See: http://en.wikipedia.org/wiki/Fast_inverse_square_root
float 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));
return y;
} |
发表于 2014-6-14 10:45:37