如何爲iPhone加速計實現高通濾波器？

Question

我記得幾天前在示例中的某個地方看到了高通濾波器的代碼，但我現在無法在任何地方找到它！有人能記住我的高通濾波器實現代碼的位置嗎？

還是更好的發佈算法？

謝謝！

Answer 1

From the idevkit.com forums:

#define kFilteringFactor 0.1 
static UIAccelerationValue rollingX=0, rollingY=0, rollingZ=0; 


- (void)accelerometer:(UIAccelerometer *)accelerometer didAccelerate:(UIAcceleration *)acceleration { 

    // Calculate low pass values 

    rollingX = (acceleration.x * kFilteringFactor) + (rollingX * (1.0 - kFilteringFactor)); 
    rollingY = (acceleration.y * kFilteringFactor) + (rollingY * (1.0 - kFilteringFactor)); 
    rollingZ = (acceleration.z * kFilteringFactor) + (rollingZ * (1.0 - kFilteringFactor)); 

    // Subtract the low-pass value from the current value to get a simplified high-pass filter 

    float accelX = acceleration.x - rollingX; 
    float accelY = acceleration.y - rollingY; 
    float accelZ = acceleration.z - rollingZ; 

    // Use the acceleration data. 

} 

Answer 2

以防萬一有人想知道，高通濾波器可以在Accelerometer Graph sample找到。

Answer 3

這是鏈接，我也在找這個鏈接。這是自適應/非自適應高通和低通濾波器的一個例子：Apple iOS Reference Library - AccelerometerGraph Example