BA
Backup 1
IMU.cpp
- Committer:
- borlanic
- Date:
- 2018-04-24
- Revision:
- 0:02dd72d1d465
File content as of revision 0:02dd72d1d465:
/*
* IMU.cpp
* Copyright (c) 2018, ZHAW
* All righSAMPLE_TIME reserved.
*/
#include "IMU.h"
#include "mbed.h"
using namespace std;
const float IMU::M_PI = 3.14159265358979323846f; // the mathematical constant PI
// Nick ====================================
const float IMU::SAMPLE_TIME = 0.001f;
const float IMU::STD_ALPHA = 0.02f; // Messrauschen sensor standardabweichung gx - R
const float IMU::STD_OMEGA = 0.034f; // Messrauschen sensor standardabweichung gx - R
//==========================================
/**
* Creates an IMU object.
* @param spi a reference to an spi controller to use.
* @param csAG the chip select output for the accelerometer and the gyro sensor.
* @param csM the chip select output for the magnetometer.
*/
IMU::IMU(SPI& spi, DigitalOut& csAG, DigitalOut& csM) : spi(spi), csAG(csAG), csM(csM), thread(osPriorityHigh, STACK_SIZE)
{
// initialize SPI interface
spi.format(8, 3);
spi.frequency(1000000);
// reset chip select lines to logical high
csAG = 1;
csM = 1;
// initialize accelerometer and gyro
writeRegister(csAG, CTRL_REG1_G, 0xC3); // ODR 952 Hz, full scale 245 deg/s
writeRegister(csAG, CTRL_REG2_G, 0x00); // disable interrupt generation
writeRegister(csAG, CTRL_REG3_G, 0x00); // disable low power mode, disable high pass filter, high pass cutoff frequency 57 Hz
writeRegister(csAG, CTRL_REG4, 0x38); // enable gyro in all 3 axis
writeRegister(csAG, CTRL_REG5_XL, 0x38); // no decimation, enable accelerometer in all 3 axis
writeRegister(csAG, CTRL_REG6_XL, 0xC0); // ODR 952 Hz, full scale 2g
writeRegister(csAG, CTRL_REG7_XL, 0x00); // high res mode disabled, filter bypassed
writeRegister(csAG, CTRL_REG8, 0x00); // 4-wire SPI interface, LSB at lower address
writeRegister(csAG, CTRL_REG9, 0x04); // disable gyro sleep mode, disable I2C interface, disable FIFO
writeRegister(csAG, CTRL_REG10, 0x00); // self test disabled
// initialize magnetometer
writeRegister(csM, CTRL_REG1_M, 0x10); // temperature not compensated, low power mode for x & y axis, data rate 10 Hz
writeRegister(csM, CTRL_REG2_M, 0x00); // full scale 4 gauss
writeRegister(csM, CTRL_REG3_M, 0x80); // disable I2C interface, low power mode, SPI write only, continuous conversion mode
writeRegister(csM, CTRL_REG4_M, 0x00); // low power mode for z axis, LSB at lower address
writeRegister(csM, CTRL_REG5_M, 0x00); // fast read disabled
gammaXFilter.setPeriod(SAMPLE_TIME);
gammaXFilter.setFrequency(80.0f);
gammaYFilter.setPeriod(SAMPLE_TIME);
gammaYFilter.setFrequency(80.0f);
d_gammaXFilter.setPeriod(SAMPLE_TIME);
d_gammaXFilter.setFrequency(80.0f);
d_gammaYFilter.setPeriod(SAMPLE_TIME);
d_gammaYFilter.setFrequency(80.0f);
thread.start(callback(this, &IMU::kalman));
}
/**
* Deletes the IMU object.
*/
IMU::~IMU() {}
/**
* This private method allows to write a register value.
* @param cs the chip select output to use, either csAG or csM.
* @param address the 7 bit address of the register.
* @param value the value to write into the register.
*/
void IMU::writeRegister(DigitalOut& cs, uint8_t address, uint8_t value)
{
cs = 0;
spi.write(0x7F & address);
spi.write(value & 0xFF);
cs = 1;
}
/**
* This private method allows to read a register value.
* @param cs the chip select output to use, either csAG or csM.
* @param address the 7 bit address of the register.
* @return the value read from the register.
*/
uint8_t IMU::readRegister(DigitalOut& cs, uint8_t address)
{
cs = 0;
spi.write(0x80 | address);
int32_t value = spi.write(0xFF);
cs = 1;
return static_cast<uint8_t>(value & 0xFF);
}
/**
* Reads the gyroscope about the x-axis.
* @return the rotational speed about the x-axis given in [rad/s].
*/
float IMU::readGyroX()
{
uint8_t low = readRegister(csAG, OUT_X_L_G);
uint8_t high = readRegister(csAG, OUT_X_H_G);
int16_t value = static_cast<int16_t>((static_cast<uint16_t>(high) << 8) | static_cast<uint16_t>(low));
return static_cast<float>(value)/32768.0f*245.0f*M_PI/180.0f;
}
/**
* Reads the gyroscope about the y-axis.
* @return the rotational speed about the y-axis given in [rad/s].
*/
float IMU::readGyroY()
{
uint8_t low = readRegister(csAG, OUT_Y_L_G);
uint8_t high = readRegister(csAG, OUT_Y_H_G);
int16_t value = static_cast<int16_t>((static_cast<uint16_t>(high) << 8) | static_cast<uint16_t>(low));
return static_cast<float>(value)/32768.0f*245.0f*M_PI/180.0f;
}
/**
* Reads the gyroscope about the z-axis.
* @return the rotational speed about the z-axis given in [rad/s].
*/
float IMU::readGyroZ()
{
uint8_t low = readRegister(csAG, OUT_Z_L_G);
uint8_t high = readRegister(csAG, OUT_Z_H_G);
int16_t value = static_cast<int16_t>((static_cast<uint16_t>(high) << 8) | static_cast<uint16_t>(low));
return static_cast<float>(value)/32768.0f*245.0f*M_PI/180.0f;
}
/**
* Reads the acceleration in x-direction.
* @return the acceleration in x-direction, given in [m/s2].
*/
float IMU::readAccelerationX()
{
uint8_t low = readRegister(csAG, OUT_X_L_XL);
uint8_t high = readRegister(csAG, OUT_X_H_XL);
int16_t value = static_cast<int16_t>((static_cast<uint16_t>(high) << 8) | static_cast<uint16_t>(low));
return static_cast<float>(value)/32768.0f*2.0f*9.81f;
}
/**
* Reads the acceleration in y-direction.
* @return the acceleration in y-direction, given in [m/s2].
*/
float IMU::readAccelerationY()
{
uint8_t low = readRegister(csAG, OUT_Y_L_XL);
uint8_t high = readRegister(csAG, OUT_Y_H_XL);
int16_t value = static_cast<int16_t>((static_cast<uint16_t>(high) << 8) | static_cast<uint16_t>(low));
return static_cast<float>(value)/32768.0f*2.0f*9.81f;
}
/**
* Reads the acceleration in z-direction.
* @return the acceleration in z-direction, given in [m/s2].
*/
float IMU::readAccelerationZ()
{
uint8_t low = readRegister(csAG, OUT_Z_L_XL);
uint8_t high = readRegister(csAG, OUT_Z_H_XL);
int16_t value = static_cast<int16_t>((static_cast<uint16_t>(high) << 8) | static_cast<uint16_t>(low));
return static_cast<float>(value)/32768.0f*2.0f*9.81f;
}
/**
* Reads the magnetic field in x-direction.
* @return the magnetic field in x-direction, given in [Gauss].
*/
float IMU::readMagnetometerX()
{
uint8_t low = readRegister(csM, OUT_X_L_M);
uint8_t high = readRegister(csM, OUT_X_H_M);
int16_t value = static_cast<int16_t>((static_cast<uint16_t>(high) << 8) | static_cast<uint16_t>(low));
return static_cast<float>(value)/32768.0f*4.0f;
}
/**
* Reads the magnetic field in x-direction.
* @return the magnetic field in x-direction, given in [Gauss].
*/
float IMU::readMagnetometerY()
{
uint8_t low = readRegister(csM, OUT_Y_L_M);
uint8_t high = readRegister(csM, OUT_Y_H_M);
int16_t value = static_cast<int16_t>((static_cast<uint16_t>(high) << 8) | static_cast<uint16_t>(low));
return static_cast<float>(value)/32768.0f*4.0f;
}
/**
* Reads the magnetic field in x-direction.
* @return the magnetic field in x-direction, given in [Gauss].
*/
float IMU::readMagnetometerZ()
{
uint8_t low = readRegister(csM, OUT_Z_L_M);
uint8_t high = readRegister(csM, OUT_Z_H_M);
int16_t value = static_cast<int16_t>((static_cast<uint16_t>(high) << 8) | static_cast<uint16_t>(low));
return static_cast<float>(value)/32768.0f*4.0f;
}
float IMU::getGammaX()
{
return gammaX;
}
float IMU::getGammaY()
{
return gammaY;
}
float IMU::getGammaZ()
{
return gammaZ;
}
float IMU::getDGammaX()
{
return d_gammaX;
}
float IMU::getDGammaY()
{
return d_gammaY;
}
float IMU::getDGammaZ()
{
return d_gammaZ;
}
void IMU::kalman()
{
Serial pc1(USBTX, USBRX); // tx, rx
pc1.baud(100000);
// Messrauschen sensor standardabweichung gx - R
float R11 = STD_ALPHA*STD_ALPHA;
float R22 = STD_OMEGA*STD_OMEGA;
// Messrauschen prozessor - Q
float Q11 = 0.001f;
float Q22 = 0.001f;
// Matrix A
float A11 = 1.0f;
float A12 = SAMPLE_TIME;
float A21 = 0.0f;
float A22 = 1.0f;
// rot X
float alpha_p_x = 0.0f;
float omega_p_x = 0.0f;
float Pk_x11 = 0.0f;
float Pk_x12 = 0.0f;
float Pk_x21 = 0.0f;
float Pk_x22 = 0.0f;
float alpha_korr_x = 0.0f;
float omega_korr_x = 0.0f;
// rot Y
float alpha_p_y = 0.0f;
float omega_p_y = 0.0f;
float Pk_y11 = 0.0f;
float Pk_y12 = 0.0f;
float Pk_y21 = 0.0f;
float Pk_y22 = 0.0f;
float alpha_korr_y = 0.0f;
float omega_korr_y = 0.0f;
// rot Z
float alpha_p_z = 0.0f;
float omega_p_z = 0.0f;
float Pk_z11 = 0.0f;
float Pk_z12 = 0.0f;
float Pk_z21 = 0.0f;
float Pk_z22 = 0.0f;
float alpha_korr_z = 0.0f;
float omega_korr_z = 0.0f;
double mx_f_vor=this->readMagnetometerX();
double mx_vor=this->readMagnetometerX();
double my_f_vor=this->readMagnetometerY();
double my_vor=this->readMagnetometerY();
int t = 0;
float gamma_z_int = 0;
// messung
int * T_IMU = new int[2000];
float * GX_IMU = new float[2000];
float * GY_IMU = new float[2000];
while (true) {
/*Kalman Filter--------------------------------------------------*/
/* Send IMU MEasure
if(t==5100) {
pc1.printf("invio dati IMU:\r\n\n");
for(int j=0; j<2000; j++) {
pc1.printf("%d %.7f %.7f\r\n",*(T_IMU+j),*(GX_IMU+j),*(GY_IMU+j));
}
pc1.printf("fine dati IMU:\r\n\n");
delete T_IMU;
delete GX_IMU;
delete GY_IMU;
}
*/
mutex.lock();
//printf("IMU start\r\n");
float ax = this->readAccelerationX();
float ay = this->readAccelerationY();
float az = this->readAccelerationZ();
float gx = this->readGyroX();
float gy = this->readGyroY();
float gz = this->readGyroZ();
float mx = this->readMagnetometerX();
float my = this->readMagnetometerY();
float mz = this->readMagnetometerZ();
// LowPass Magnetometer
float RC = 1.0/(10*2*3.14); // Cutoff 10Hz
float dt = 1.0/SAMPLE_TIME;
float alpha = dt/(RC+dt);
float mx_f = mx_f_vor + (alpha*(mx-mx_vor));
float my_f = my_f_vor + (alpha*(my-my_vor));
mx_f_vor = mx_f;
mx_vor = mx;
my_f_vor = my_f;
my_vor = my;
// rot x
float alpha_x = atan2(-ay,az);
float omega_x = gx;
// rot y
float alpha_y = atan2(-ax,az);
float omega_y = -gy;
// rot z
float mx_fil = (mx_f+0.3614f)*11.5937f;
float my_fil = (my_f-0.4466f)*15.2002f;
float alpha_z = atan2(my_fil,mx_fil);// Sostituire con calcolo gamma encoder
float omega_z = gz;
/*
float alpha_z = 0.024f/(0.095f*3.0f*0.7071f)*(w1+w2+w3)
*/
// Prediction
// x
alpha_p_x = alpha_p_x + SAMPLE_TIME*omega_x;
omega_p_x = omega_p_x;
Pk_x11 = Q11 + A11*(A11*Pk_x11 + A12*Pk_x21) + A12*(A11*Pk_x12 + A12*Pk_x22);
Pk_x12 = A21*(A11*Pk_x11 + A12*Pk_x21) + A22*(A11*Pk_x12 + A12*Pk_x22);
Pk_x21 = A11*(A21*Pk_x11 + A22*Pk_x21) + A12*(A21*Pk_x12 + A22*Pk_x22);
Pk_x22 = Q22 + A21*(A21*Pk_x11 + A22*Pk_x21) + A22*(A21*Pk_x12 + A22*Pk_x22);
// y
alpha_p_y = alpha_p_y + SAMPLE_TIME*omega_y;
omega_p_y = omega_p_y;
Pk_y11 = Q11 + A11*(A11*Pk_y11 + A12*Pk_y21) + A12*(A11*Pk_y12 + A12*Pk_y22);
Pk_y12 = A21*(A11*Pk_y11 + A12*Pk_y21) + A22*(A11*Pk_y12 + A12*Pk_y22);
Pk_y21 = A11*(A21*Pk_y11 + A22*Pk_y21) + A12*(A21*Pk_y12 + A22*Pk_y22);
Pk_y22 = Q22 + A21*(A21*Pk_y11 + A22*Pk_y21) + A22*(A21*Pk_y12 + A22*Pk_y22);
// z
alpha_p_z = alpha_p_z + SAMPLE_TIME*omega_z;
omega_p_z = omega_p_z;
Pk_z11 = Q11 + A11*(A11*Pk_z11 + A12*Pk_z21) + A12*(A11*Pk_z12 + A12*Pk_z22);
Pk_z12 = A21*(A11*Pk_z11 + A12*Pk_z21) + A22*(A11*Pk_z12 + A12*Pk_z22);
Pk_z21 = A11*(A21*Pk_z11 + A22*Pk_z21) + A12*(A21*Pk_z12 + A22*Pk_z22);
Pk_z22 = Q22 + A21*(A21*Pk_z11 + A22*Pk_z21) + A22*(A21*Pk_z12 + A22*Pk_z22);
// Correction
// x
float Kk_x11 = (Pk_x11*(Pk_x22 + R22))/(Pk_x11*R22 + Pk_x22*R11 + R11*R22 + Pk_x11*Pk_x22 - Pk_x12*Pk_x21) - (Pk_x12*Pk_x21)/(Pk_x11*R22 + Pk_x22*R11 + R11*R22 + Pk_x11*Pk_x22 - Pk_x12*Pk_x21);
float Kk_x12 = (Pk_x12*(Pk_x11 + R11))/(Pk_x11*R22 + Pk_x22*R11 + R11*R22 + Pk_x11*Pk_x22 - Pk_x12*Pk_x21) - (Pk_x11*Pk_x12)/(Pk_x11*R22 + Pk_x22*R11 + R11*R22 + Pk_x11*Pk_x22 - Pk_x12*Pk_x21);
float Kk_x21 = (Pk_x21*(Pk_x22 + R22))/(Pk_x11*R22 + Pk_x22*R11 + R11*R22 + Pk_x11*Pk_x22 - Pk_x12*Pk_x21) - (Pk_x21*Pk_x22)/(Pk_x11*R22 + Pk_x22*R11 + R11*R22 + Pk_x11*Pk_x22 - Pk_x12*Pk_x21);
float Kk_x22 = (Pk_x22*(Pk_x11 + R11))/(Pk_x11*R22 + Pk_x22*R11 + R11*R22 + Pk_x11*Pk_x22 - Pk_x12*Pk_x21) - (Pk_x12*Pk_x21)/(Pk_x11*R22 + Pk_x22*R11 + R11*R22 + Pk_x11*Pk_x22 - Pk_x12*Pk_x21);
alpha_korr_x = alpha_p_x + Kk_x11*(alpha_x-alpha_p_x) + Kk_x12*(omega_x - omega_p_x);
omega_korr_x = omega_p_x + Kk_x21*(alpha_x-alpha_p_x) + Kk_x22*(omega_x-omega_p_x);
// y
float Kk_y11 = (Pk_y11*(Pk_y22 + R22))/(Pk_y11*R22 + Pk_y22*R11 + R11*R22 + Pk_y11*Pk_y22 - Pk_y12*Pk_y21) - (Pk_y12*Pk_y21)/(Pk_y11*R22 + Pk_y22*R11 + R11*R22 + Pk_y11*Pk_y22 - Pk_y12*Pk_y21);
float Kk_y12 = (Pk_y12*(Pk_y11 + R11))/(Pk_y11*R22 + Pk_y22*R11 + R11*R22 + Pk_y11*Pk_y22 - Pk_y12*Pk_y21) - (Pk_y11*Pk_y12)/(Pk_y11*R22 + Pk_y22*R11 + R11*R22 + Pk_y11*Pk_y22 - Pk_y12*Pk_y21);
float Kk_y21 = (Pk_y21*(Pk_y22 + R22))/(Pk_y11*R22 + Pk_y22*R11 + R11*R22 + Pk_y11*Pk_y22 - Pk_y12*Pk_y21) - (Pk_y21*Pk_y22)/(Pk_y11*R22 + Pk_y22*R11 + R11*R22 + Pk_y11*Pk_y22 - Pk_y12*Pk_y21);
float Kk_y22 = (Pk_y22*(Pk_y11 + R11))/(Pk_y11*R22 + Pk_y22*R11 + R11*R22 + Pk_y11*Pk_y22 - Pk_y12*Pk_y21) - (Pk_y12*Pk_y21)/(Pk_y11*R22 + Pk_y22*R11 + R11*R22 + Pk_y11*Pk_y22 - Pk_y12*Pk_y21);
alpha_korr_y = alpha_p_y + Kk_y11*(alpha_y-alpha_p_y) + Kk_y12*(omega_y - omega_p_y);
omega_korr_y = omega_p_y + Kk_y21*(alpha_y-alpha_p_y) + Kk_y22*(omega_y-omega_p_y);
// z
float Kk_z11 = (Pk_z11*(Pk_z22 + R22))/(Pk_z11*R22 + Pk_z22*R11 + R11*R22 + Pk_z11*Pk_z22 - Pk_z12*Pk_z21) - (Pk_z12*Pk_z21)/(Pk_z11*R22 + Pk_z22*R11 + R11*R22 + Pk_z11*Pk_y22 - Pk_z12*Pk_z21);
float Kk_z12 = (Pk_z12*(Pk_z11 + R11))/(Pk_z11*R22 + Pk_z22*R11 + R11*R22 + Pk_z11*Pk_z22 - Pk_z12*Pk_z21) - (Pk_z11*Pk_z12)/(Pk_z11*R22 + Pk_z22*R11 + R11*R22 + Pk_z11*Pk_y22 - Pk_z12*Pk_z21);
float Kk_z21 = (Pk_z21*(Pk_z22 + R22))/(Pk_z11*R22 + Pk_z22*R11 + R11*R22 + Pk_z11*Pk_z22 - Pk_z12*Pk_z21) - (Pk_z21*Pk_z22)/(Pk_z11*R22 + Pk_z22*R11 + R11*R22 + Pk_z11*Pk_z22 - Pk_z12*Pk_z21);
float Kk_z22 = (Pk_z22*(Pk_z11 + R11))/(Pk_z11*R22 + Pk_z22*R11 + R11*R22 + Pk_z11*Pk_z22 - Pk_z12*Pk_z21) - (Pk_z12*Pk_z21)/(Pk_z11*R22 + Pk_z22*R11 + R11*R22 + Pk_z11*Pk_z22 - Pk_z12*Pk_z21);
alpha_korr_z = alpha_p_z + Kk_z11*(alpha_z-alpha_p_z) + Kk_z12*(omega_z - omega_p_z);
omega_korr_z = omega_p_z + Kk_z21*(alpha_z-alpha_p_z) + Kk_z22*(omega_z-omega_p_z);
// rot in z simple integration
gamma_z_int = gz*0.05f + gamma_z_int;
float f = t*t*(0.000000014370490f)+t*(-0.0012f) + 0.03f;
t++;
//printf("%.7f %.7f\r\n",alpha_korr_x,gammaXFilter.filter(alpha_korr_x));
this->gammaX = gammaXFilter.filter(alpha_korr_x);
this->gammaY = gammaYFilter.filter(alpha_korr_y);
this->gammaZ = gamma_z_int-f;
this->d_gammaX = d_gammaXFilter.filter(omega_korr_x-0.01f);
this->d_gammaY = d_gammaYFilter.filter(omega_korr_y+0.006f);
this->d_gammaZ = gz;
if(t<2001) {
*(T_IMU+t) = t;
*(GX_IMU+t) = gammaX;
*(GY_IMU+t) = gammaY;
}
/*
if(t<1001) {
if(count==10) {
M[0][i]=gammaX;
i++;
count=0;
} else {
count++;
}
}
if(t==1100) {
for(int j=0; j<100;j++) {
pc1.printf("IMU %.7f\r\n",M[0][j]);
}
}
*/
//pc1.printf("%.2f %.7f %.7f\r\n", t/1000.0f,alpha_korr_x,omega_korr_x);
//this->gammaX = alpha_korr_x;
//this->gammaY = alpha_korr_y;
//this->gammaZ = (gamma_z_int-f);
//this->d_gammaX = omega_korr_x-0.01f;
//this->d_gammaY = omega_korr_y+0.006f;
//this->d_gammaZ = gz;
//printf("IMU end\r\n");
//printf("%.2f %.2f %.2f %.2f %.2f %.2f\r\n",gammaX,gammaY,gammaZ,d_gammaX,d_gammaY,d_gammaZ);
mutex.unlock();
thread.wait(1.0);
}
}