stm32 mpu6050 cubemx 卡尔曼滤波法读取角度

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前言

本文简述使用mpu6050读取原始数据后解算出角度。
网上大多都是dmp库来解算，但是这种情况操作起来相对复杂。
更方便的方法是使用卡尔曼滤波法来解算出角度，好处是代码量少且移植相对简单许多，弊端是没有航向角。

文件

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一、cubemx配置

只要打开硬件i2c即可。选择为fast模式

如果想用串口输出的话还可以打开usart。

二、mpu6050文件移植

只需要把我下面两个文件添加到你的项目中即可
要注意！！！使用到了微库所以一定要把keil中的微库勾选！！！

mpu6050.c

#include 
#include "mpu6050.h"

#define RAD_TO_DEG 57.295779513082320876798154814105

#define WHO_AM_I_REG 0x75
#define PWR_MGMT_1_REG 0x6B
#define SMPLRT_DIV_REG 0x19
#define ACCEL_CONFIG_REG 0x1C
#define ACCEL_XOUT_H_REG 0x3B
#define TEMP_OUT_H_REG 0x41
#define GYRO_CONFIG_REG 0x1B
#define GYRO_XOUT_H_REG 0x43

// Setup MPU6050
#define MPU6050_ADDR 0xD0
const uint16_t i2c_timeout = 100;
const double Accel_Z_corrector = 14418.0;

uint32_t timer;

Kalman_t KalmanX = {
        .Q_angle = 0.001f,
        .Q_bias = 0.003f,
        .R_measure = 0.03f
};

Kalman_t KalmanY = {
        .Q_angle = 0.001f,
        .Q_bias = 0.003f,
        .R_measure = 0.03f,
};

uint8_t MPU6050_Init(I2C_HandleTypeDef *I2Cx) {
    uint8_t check;
    uint8_t Data;

    // check device ID WHO_AM_I

    HAL_I2C_Mem_Read(I2Cx, MPU6050_ADDR, WHO_AM_I_REG, 1, &check, 1, i2c_timeout);

    if (check == 104)  // 0x68 will be returned by the sensor if everything goes well
    {
        // power management register 0X6B we should write all 0's to wake the sensor up
        Data = 0;
        HAL_I2C_Mem_Write(I2Cx, MPU6050_ADDR, PWR_MGMT_1_REG, 1, &Data, 1, i2c_timeout);

        // Set DATA RATE of 1KHz by writing SMPLRT_DIV register
        Data = 0x07;
        HAL_I2C_Mem_Write(I2Cx, MPU6050_ADDR, SMPLRT_DIV_REG, 1, &Data, 1, i2c_timeout);

        // Set accelerometer configuration in ACCEL_CONFIG Register
        // XA_ST=0,YA_ST=0,ZA_ST=0, FS_SEL=0 -> ? 2g
        Data = 0x00;
        HAL_I2C_Mem_Write(I2Cx, MPU6050_ADDR, ACCEL_CONFIG_REG, 1, &Data, 1, i2c_timeout);

        // Set Gyroscopic configuration in GYRO_CONFIG Register
        // XG_ST=0,YG_ST=0,ZG_ST=0, FS_SEL=0 -> ? 250 ?/s
        Data = 0x00;
        HAL_I2C_Mem_Write(I2Cx, MPU6050_ADDR, GYRO_CONFIG_REG, 1, &Data, 1, i2c_timeout);
        return 0;
    }
    return 1;
}


void MPU6050_Read_Accel(I2C_HandleTypeDef *I2Cx, MPU6050_t *DataStruct) {
    uint8_t Rec_Data[6];

    // Read 6 BYTES of data starting from ACCEL_XOUT_H register

    HAL_I2C_Mem_Read(I2Cx, MPU6050_ADDR, ACCEL_XOUT_H_REG, 1, Rec_Data, 6, i2c_timeout);

    DataStruct->Accel_X_RAW = (int16_t) (Rec_Data[0] << 8 | Rec_Data[1]);
    DataStruct->Accel_Y_RAW = (int16_t) (Rec_Data[2] << 8 | Rec_Data[3]);
    DataStruct->Accel_Z_RAW = (int16_t) (Rec_Data[4] << 8 | Rec_Data[5]);

    /*** convert the RAW values into acceleration in 'g'
         we have to divide according to the Full scale value set in FS_SEL
         I have configured FS_SEL = 0. So I am dividing by 16384.0
         for more details check ACCEL_CONFIG Register              ****/

    DataStruct->Ax = DataStruct->Accel_X_RAW / 16384.0;
    DataStruct->Ay = DataStruct->Accel_Y_RAW / 16384.0;
    DataStruct->Az = DataStruct->Accel_Z_RAW / Accel_Z_corrector;
}


void MPU6050_Read_Gyro(I2C_HandleTypeDef *I2Cx, MPU6050_t *DataStruct) {
    uint8_t Rec_Data[6];

    // Read 6 BYTES of data starting from GYRO_XOUT_H register

    HAL_I2C_Mem_Read(I2Cx, MPU6050_ADDR, GYRO_XOUT_H_REG, 1, Rec_Data, 6, i2c_timeout);

    DataStruct->Gyro_X_RAW = (int16_t) (Rec_Data[0] << 8 | Rec_Data[1]);
    DataStruct->Gyro_Y_RAW = (int16_t) (Rec_Data[2] << 8 | Rec_Data[3]);
    DataStruct->Gyro_Z_RAW = (int16_t) (Rec_Data[4] << 8 | Rec_Data[5]);

    /*** convert the RAW values into dps (?/s)
         we have to divide according to the Full scale value set in FS_SEL
         I have configured FS_SEL = 0. So I am dividing by 131.0
         for more details check GYRO_CONFIG Register              ****/

    DataStruct->Gx = DataStruct->Gyro_X_RAW / 131.0;
    DataStruct->Gy = DataStruct->Gyro_Y_RAW / 131.0;
    DataStruct->Gz = DataStruct->Gyro_Z_RAW / 131.0;
}

void MPU6050_Read_Temp(I2C_HandleTypeDef *I2Cx, MPU6050_t *DataStruct) {
    uint8_t Rec_Data[2];
    int16_t temp;

    // Read 2 BYTES of data starting from TEMP_OUT_H_REG register

    HAL_I2C_Mem_Read(I2Cx, MPU6050_ADDR, TEMP_OUT_H_REG, 1, Rec_Data, 2, i2c_timeout);

    temp = (int16_t) (Rec_Data[0] << 8 | Rec_Data[1]);
    DataStruct->Temperature = (float) ((int16_t) temp / (float) 340.0 + (float) 36.53);
}

void MPU6050_Read_All(I2C_HandleTypeDef *I2Cx, MPU6050_t *DataStruct) {
    uint8_t Rec_Data[14];
    int16_t temp;

    // Read 14 BYTES of data starting from ACCEL_XOUT_H register

    HAL_I2C_Mem_Read(I2Cx, MPU6050_ADDR, ACCEL_XOUT_H_REG, 1, Rec_Data, 14, i2c_timeout);

    DataStruct->Accel_X_RAW = (int16_t) (Rec_Data[0] << 8 | Rec_Data[1]);
    DataStruct->Accel_Y_RAW = (int16_t) (Rec_Data[2] << 8 | Rec_Data[3]);
    DataStruct->Accel_Z_RAW = (int16_t) (Rec_Data[4] << 8 | Rec_Data[5]);
    temp = (int16_t) (Rec_Data[6] << 8 | Rec_Data[7]);
    DataStruct->Gyro_X_RAW = (int16_t) (Rec_Data[8] << 8 | Rec_Data[9]);
    DataStruct->Gyro_Y_RAW = (int16_t) (Rec_Data[10] << 8 | Rec_Data[11]);
    DataStruct->Gyro_Z_RAW = (int16_t) (Rec_Data[12] << 8 | Rec_Data[13]);

    DataStruct->Ax = DataStruct->Accel_X_RAW / 16384.0;
    DataStruct->Ay = DataStruct->Accel_Y_RAW / 16384.0;
    DataStruct->Az = DataStruct->Accel_Z_RAW / Accel_Z_corrector;
    DataStruct->Temperature = (float) ((int16_t) temp / (float) 340.0 + (float) 36.53);
    DataStruct->Gx = DataStruct->Gyro_X_RAW / 131.0;
    DataStruct->Gy = DataStruct->Gyro_Y_RAW / 131.0;
    DataStruct->Gz = DataStruct->Gyro_Z_RAW / 131.0;

    // Kalman angle solve
    double dt = (double) (HAL_GetTick() - timer) / 1000;
    timer = HAL_GetTick();
    double roll;
    double roll_sqrt = sqrt(
            DataStruct->Accel_X_RAW * DataStruct->Accel_X_RAW + DataStruct->Accel_Z_RAW * DataStruct->Accel_Z_RAW);
    if (roll_sqrt != 0.0) {
        roll = atan(DataStruct->Accel_Y_RAW / roll_sqrt) * RAD_TO_DEG;
    } else {
        roll = 0.0;
    }
    double pitch = atan2(-DataStruct->Accel_X_RAW, DataStruct->Accel_Z_RAW) * RAD_TO_DEG;
    if ((pitch < -90 && DataStruct->KalmanAngleY > 90) || (pitch > 90 && DataStruct->KalmanAngleY < -90)) {
        KalmanY.angle = pitch;
        DataStruct->KalmanAngleY = pitch;
    } else {
        DataStruct->KalmanAngleY = Kalman_getAngle(&KalmanY, pitch, DataStruct->Gy, dt);
    }
    if (fabs(DataStruct->KalmanAngleY) > 90)
        DataStruct->Gx = -DataStruct->Gx;
    DataStruct->KalmanAngleX = Kalman_getAngle(&KalmanX, roll, DataStruct->Gy, dt);

}

double Kalman_getAngle(Kalman_t *Kalman, double newAngle, double newRate, double dt) {
    double rate = newRate - Kalman->bias;
    Kalman->angle += dt * rate;

    Kalman->P[0][0] += dt * (dt * Kalman->P[1][1] - Kalman->P[0][1] - Kalman->P[1][0] + Kalman->Q_angle);
    Kalman->P[0][1] -= dt * Kalman->P[1][1];
    Kalman->P[1][0] -= dt * Kalman->P[1][1];
    Kalman->P[1][1] += Kalman->Q_bias * dt;

    double S = Kalman->P[0][0] + Kalman->R_measure;
    double K[2];
    K[0] = Kalman->P[0][0] / S;
    K[1] = Kalman->P[1][0] / S;

    double y = newAngle - Kalman->angle;
    Kalman->angle += K[0] * y;
    Kalman->bias += K[1] * y;

    double P00_temp = Kalman->P[0][0];
    double P01_temp = Kalman->P[0][1];

    Kalman->P[0][0] -= K[0] * P00_temp;
    Kalman->P[0][1] -= K[0] * P01_temp;
    Kalman->P[1][0] -= K[1] * P00_temp;
    Kalman->P[1][1] -= K[1] * P01_temp;

    return Kalman->angle;
};

mpu6050.h

#ifndef INC_GY521_H_
#define INC_GY521_H_

#endif /* INC_GY521_H_ */

#include 
#include "i2c.h"

// MPU6050 structure
typedef struct {

    int16_t Accel_X_RAW;
    int16_t Accel_Y_RAW;
    int16_t Accel_Z_RAW;
    double Ax;
    double Ay;
    double Az;

    int16_t Gyro_X_RAW;
    int16_t Gyro_Y_RAW;
    int16_t Gyro_Z_RAW;
    double Gx;
    double Gy;
    double Gz;

    float Temperature;

    double KalmanAngleX;
    double KalmanAngleY;
} MPU6050_t;


// Kalman structure
typedef struct {
    double Q_angle;
    double Q_bias;
    double R_measure;
    double angle;
    double bias;
    double P[2][2];
} Kalman_t;


uint8_t MPU6050_Init(I2C_HandleTypeDef *I2Cx);

void MPU6050_Read_Accel(I2C_HandleTypeDef *I2Cx, MPU6050_t *DataStruct);

void MPU6050_Read_Gyro(I2C_HandleTypeDef *I2Cx, MPU6050_t *DataStruct);

void MPU6050_Read_Temp(I2C_HandleTypeDef *I2Cx, MPU6050_t *DataStruct);

void MPU6050_Read_All(I2C_HandleTypeDef *I2Cx, MPU6050_t *DataStruct);

double Kalman_getAngle(Kalman_t *Kalman, double newAngle, double newRate, double dt);

这样子就移植完成了。

三、主函数

主函数中只要调用两个函数即可。
首先是主循环之前的初始化。 MPU6050_Init(&hi2c1);这里要注意的就是初始化的时候一定要是你配置的那个i2c。
在主循环中调用：

		MPU6050_Read_All(&hi2c1, &MPU6050);

那么我们看一下结构体里面都有什么。最后两个KalmanAngle就是你要的两个角度。只需要MPU6050.KalmanAngleY即可调用。

typedef struct {

    int16_t Accel_X_RAW;
    int16_t Accel_Y_RAW;
    int16_t Accel_Z_RAW;
    double Ax;
    double Ay;
    double Az;

    int16_t Gyro_X_RAW;
    int16_t Gyro_Y_RAW;
    int16_t Gyro_Z_RAW;
    double Gx;
    double Gy;
    double Gz;

    float Temperature;

    double KalmanAngleX;
    double KalmanAngleY;
} MPU6050_t;