建议编辑一下这个帖子作为滤波专用的,这样大家查起来也方便。下面是卡尔曼滤波,不是扩展的,但是输出平稳的俯仰和滚转应该够了(凑乎用吧我也不是专业写代码的,欢迎大家拍)
- #include <Wire.h> // I2C library, gyroscope
- // Accelerometer ADXL345
- #define ACC (0x53) //ADXL345 ACC address
- #define A_TO_READ (6) //num of bytes we are going to read each time (two bytes for each axis)
- // Gyroscope ITG3200
- #define GYRO 0x68 // gyro address, binary = 11101000 when AD0 is connected to Vcc (see schematics of your breakout board)
- #define G_SMPLRT_DIV 0x15
- #define G_DLPF_FS 0x16
- #define G_INT_CFG 0x17
- #define G_PWR_MGM 0x3E
- #define G_TO_READ 8 // 2 bytes for each axis x, y, z
- // offsets are chip specific.
- int a_offx = 0;
- int a_offy = 0;
- int a_offz = 0;
- int g_offx = 0;
- int g_offy = 0;
- int g_offz = 0;
- ////////////////////////
- ////////////////////////
- char str[512];
- void initAcc() {
- //Turning on the ADXL345
- writeTo(ACC, 0x2D, 0);
- writeTo(ACC, 0x2D, 16);
- writeTo(ACC, 0x2D, 8);
- //by default the device is in +-2g range reading
- }
- void getAccelerometerData(int* result) {
- int regAddress = 0x32; //first axis-acceleration-data register on the ADXL345
- byte buff[A_TO_READ];
-
- readFrom(ACC, regAddress, A_TO_READ, buff); //read the acceleration data from the ADXL345
-
- //each axis reading comes in 10 bit resolution, ie 2 bytes. Least Significat Byte first!!
- //thus we are converting both bytes in to one int
- result[0] = (((int)buff[1]) << 8) | buff[0] + a_offx;
- result[1] = (((int)buff[3]) << 8) | buff[2] + a_offy;
- result[2] = (((int)buff[5]) << 8) | buff[4] + a_offz;
- }
- //initializes the gyroscope
- void initGyro()
- {
- /*****************************************
- * ITG 3200
- * power management set to:
- * clock select = internal oscillator
- * no reset, no sleep mode
- * no standby mode
- * sample rate to = 125Hz
- * parameter to +/- 2000 degrees/sec
- * low pass filter = 5Hz
- * no interrupt
- ******************************************/
- writeTo(GYRO, G_PWR_MGM, 0x00);
- writeTo(GYRO, G_SMPLRT_DIV, 0x07); // EB, 50, 80, 7F, DE, 23, 20, FF
- writeTo(GYRO, G_DLPF_FS, 0x1E); // +/- 2000 dgrs/sec, 1KHz, 1E, 19
- writeTo(GYRO, G_INT_CFG, 0x00);
- }
- void getGyroscopeData(int * result)
- {
- /**************************************
- Gyro ITG-3200 I2C
- registers:
- temp MSB = 1B, temp LSB = 1C
- x axis MSB = 1D, x axis LSB = 1E
- y axis MSB = 1F, y axis LSB = 20
- z axis MSB = 21, z axis LSB = 22
- *************************************/
- int regAddress = 0x1B;
- int temp, x, y, z;
- byte buff[G_TO_READ];
-
- readFrom(GYRO, regAddress, G_TO_READ, buff); //read the gyro data from the ITG3200
-
- result[0] = ((buff[2] << 8) | buff[3]) + g_offx;
- result[1] = ((buff[4] << 8) | buff[5]) + g_offy;
- result[2] = ((buff[6] << 8) | buff[7]) + g_offz;
- result[3] = (buff[0] << 8) | buff[1]; // temperature
-
- }
- float xz=0,yx=0,yz=0;
- float p_xz=1,p_yx=1,p_yz=1;
- float q_xz=0.0025,q_yx=0.0025,q_yz=0.0025;
- float k_xz=0,k_yx=0,k_yz=0;
- float r_xz=0.25,r_yx=0.25,r_yz=0.25;
- //int acc_temp[3];
- //float acc[3];
- int acc[3];
- int gyro[4];
- float Axz;
- float Ayx;
- float Ayz;
- float t=0.025;
- void setup()
- {
- Serial.begin(9600);
- Wire.begin();
- initAcc();
- initGyro();
-
- }
- //unsigned long timer = 0;
- //float o;
- void loop()
- {
-
- getAccelerometerData(acc);
- getGyroscopeData(gyro);
- //timer = millis();
- sprintf(str, "%d,%d,%d,%d,%d,%d", acc[0],acc[1],acc[2],gyro[0],gyro[1],gyro[2]);
-
- //acc[0]=acc[0];
- //acc[2]=acc[2];
- //acc[1]=acc[1];
- //r=sqrt(acc[0]*acc[0]+acc[1]*acc[1]+acc[2]*acc[2]);
- gyro[0]=gyro[0]/ 14.375;
- gyro[1]=gyro[1]/ (-14.375);
- gyro[2]=gyro[2]/ 14.375;
-
-
- Axz=(atan2(acc[0],acc[2]))*180/PI;
- Ayx=(atan2(acc[0],acc[1]))*180/PI;
- /*if((acc[0]!=0)&&(acc[1]!=0))
- {
- Ayx=(atan2(acc[0],acc[1]))*180/PI;
- }
- else
- {
- Ayx=t*gyro[2];
- }*/
- Ayz=(atan2(acc[1],acc[2]))*180/PI;
-
-
- //kalman filter
- calculate_xz();
- calculate_yx();
- calculate_yz();
-
- //sprintf(str, "%d,%d,%d", xz_1, xy_1, x_1);
- //Serial.print(xz);Serial.print(",");
- //Serial.print(yx);Serial.print(",");
- //Serial.print(yz);Serial.print(",");
- //sprintf(str, "%d,%d,%d,%d,%d,%d", acc[0],acc[1],acc[2],gyro[0],gyro[1],gyro[2]);
- //sprintf(str, "%d,%d,%d",gyro[0],gyro[1],gyro[2]);
- Serial.print(Axz);Serial.print(",");
- //Serial.print(Ayx);Serial.print(",");
- //Serial.print(Ayz);Serial.print(",");
- //Serial.print(str);
- //o=gyro[2];//w=acc[2];
- //Serial.print(o);Serial.print(",");
- //Serial.print(w);Serial.print(",");
- Serial.print("\n");
-
- //delay(50);
- }
- void calculate_xz()
- {
- xz=xz+t*gyro[1];
- p_xz=p_xz+q_xz;
- k_xz=p_xz/(p_xz+r_xz);
- xz=xz+k_xz*(Axz-xz);
- p_xz=(1-k_xz)*p_xz;
- }
- void calculate_yx()
- {
-
- yx=yx+t*gyro[2];
- p_yx=p_yx+q_yx;
- k_yx=p_yx/(p_yx+r_yx);
- yx=yx+k_yx*(Ayx-yx);
- p_yx=(1-k_yx)*p_yx;
- }
- void calculate_yz()
- {
- yz=yz+t*gyro[0];
- p_yz=p_yz+q_yz;
- k_yz=p_yz/(p_yz+r_yz);
- yz=yz+k_yz*(Ayz-yz);
- p_yz=(1-k_yz)*p_yz;
-
- }
- //---------------- Functions
- //Writes val to address register on ACC
- void writeTo(int DEVICE, byte address, byte val) {
- Wire.beginTransmission(DEVICE); //start transmission to ACC
- Wire.write(address); // send register address
- Wire.write(val); // send value to write
- Wire.endTransmission(); //end transmission
- }
- //reads num bytes starting from address register on ACC in to buff array
- void readFrom(int DEVICE, byte address, int num, byte buff[]) {
- Wire.beginTransmission(DEVICE); //start transmission to ACC
- Wire.write(address); //sends address to read from
- Wire.endTransmission(); //end transmission
-
- Wire.beginTransmission(DEVICE); //start transmission to ACC
- Wire.requestFrom(DEVICE, num); // request 6 bytes from ACC
-
- int i = 0;
- while(Wire.available()) //ACC may send less than requested (abnormal)
- {
- buff[i] = Wire.read(); // receive a byte
- i++;
- }
- Wire.endTransmission(); //end transmission
- }
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