如何为iPhone加速度计实现高通滤波器？

Question

我记得几天前在样本的某个地方看到了高通滤波器的代码，但是我现在无法在任何地方找到它！有人能记住我在Highpass过滤器实现代码的位置吗？

或者更好的发布算法？

谢谢！

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

如果有人想知道，可以在Accelerometer Graph sample中找到高通滤波器。

Answer 3

这是链接，我也在寻找这个。这是自适应/非自适应高通和低通滤波器的示例：Apple iOS Reference Library - AccelerometerGraph Example