triangle/arduino/kalman/kalman.ino

112 lines
3.3 KiB
C++

#include <Wire.h>
#include <Kalman.h> // Source: https://github.com/TKJElectronics/KalmanFilter
#define gyroZ_OFF -0.72
Kalman kalmanZ;
/* ----IMU Data---- */
double accX, accY, accZ;
double gyroX, gyroY, gyroZ;
int16_t tempRaw;
double gyroZangle; // Angle calculate using the gyro only
double compAngleZ; // Calculated angle using a complementary filter
double kalAngleZ; // Calculated angle using a Kalman filter
uint32_t timer;
uint8_t i2cData[14]; // Buffer for I2C data
/* ----FOC Data---- */
// driver instance
double acc2rotation(double x, double y);
void setup() {
Serial.begin(115200);
/* ----IMU init---- */
Wire.begin(19, 18,400000);// Set I2C frequency to 400kHz
i2cData[0] = 7; // Set the sample rate to 1000Hz - 8kHz/(7+1) = 1000Hz
i2cData[1] = 0x00; // Disable FSYNC and set 260 Hz Acc filtering, 256 Hz Gyro filtering, 8 KHz sampling
i2cData[2] = 0x00; // Set Gyro Full Scale Range to ±250deg/s
i2cData[3] = 0x00; // Set Accelerometer Full Scale Range to ±2g
while (i2cWrite(0x19, i2cData, 4, false))
; // Write to all four registers at once
while (i2cWrite(0x6B, 0x01, true))
; // PLL with X axis gyroscope reference and disable sleep mode
while (i2cRead(0x75, i2cData, 1))
;
if (i2cData[0] != 0x68)
{ // Read "WHO_AM_I" register
Serial.print(F("Error reading sensor"));
while (1)
;
}
delay(100); // Wait for sensor to stabilize
/* Set kalman and gyro starting angle */
while (i2cRead(0x3B, i2cData, 6))
;
accX = (int16_t)((i2cData[0] << 8) | i2cData[1]);
accY = (int16_t)((i2cData[2] << 8) | i2cData[3]);
accZ = (int16_t)((i2cData[4] << 8) | i2cData[5]);
double pitch = acc2rotation(accX, accY);
kalmanZ.setAngle(pitch);
gyroZangle = pitch;
timer = micros();
/* ----FOC init---- */
}
void loop() {
/*----IMU loop----*/
while (i2cRead(0x3B, i2cData, 14));
accX = (int16_t)((i2cData[0] << 8) | i2cData[1]);
accY = (int16_t)((i2cData[2] << 8) | i2cData[3]);
accZ = (int16_t)((i2cData[4] << 8) | i2cData[5]);
tempRaw = (int16_t)((i2cData[6] << 8) | i2cData[7]);
gyroX = (int16_t)((i2cData[8] << 8) | i2cData[9]);
gyroY = (int16_t)((i2cData[10] << 8) | i2cData[11]);
gyroZ = (int16_t)((i2cData[12] << 8) | i2cData[13]);
double dt = (double)(micros() - timer) / 1000000; // Calculate delta time
timer = micros();
double pitch = acc2rotation(accX, accY);
double gyroZrate = gyroZ / 131.0; // Convert to deg/s
kalAngleZ = kalmanZ.getAngle(pitch, gyroZrate + gyroZ_OFF, dt);
gyroZangle += (gyroZrate + gyroZ_OFF) * dt;
compAngleZ = 0.93 * (compAngleZ + (gyroZrate + gyroZ_OFF) * dt) + 0.07 * pitch;
// Reset the gyro angle when it has drifted too much
if (gyroZangle < -180 || gyroZangle > 180)
gyroZangle = kalAngleZ;
#if 1 // Set to 1 to activate
Serial.print(pitch); Serial.print("\t");
Serial.print(gyroZangle); Serial.print("\t");
Serial.print(compAngleZ); Serial.print("\t");
Serial.print(kalAngleZ); Serial.print("\t");
#endif
Serial.print("\r\n");
delay(2);
}
/* mpu6050加速度转换为角度
acc2rotation(ax, ay)
acc2rotation(az, ay) */
double acc2rotation(double x, double y)
{
if (y < 0)
{
return atan(x / y) / 1.570796 * 90 + 180;
}
else if (x < 0)
{
return (atan(x / y) / 1.570796 * 90 + 360);
}
else
{
return (atan(x / y) / 1.570796 * 90);
}
}