Android的加速度计采样率/延迟稳定 [英] Android accelerometer sampling rate/delay stabilization

问题描述

我试图通过使用从加速度计和用该方法onTouch的数据，以检测一个抽头的力的强度

I'm trying to detect the force strength of a tap by using the data from the accelerometer and with the method onTouch.

据我知道，对于加速最快的采样频率为200-202Hz，而是试图以匹配加速度计数据的onTouch事件的时间戳和峰值时，这种变化是给我的问题。

As far as I know, the fastest sampling frequency for the accelerometer is 200-202Hz, but this variability is giving me problems when trying to match the timestamps for the onTouch event and the peak in the accelerometer data.

有没有办法来稳定加速度计的读数，以避免这个问题？像控制特定线程什么？

Is there a way to stabilize the readings of the accelerometer to avoid this problem? Like controlling the specific thread or something?

推荐答案

如果你想匹配的硬件提供的时间（event.timestamp）和系统时间，你可以通过调整时间做到这一点。

If you want to match the hardware-provided time (event.timestamp) and the System time you can do this by adjusting the times.

一般的时间是不一样的，但他们只是通过毫秒恒定量不同。我建议你​​打印出两次并进行比较。然后你会发现偏移量是什么：

Usually the times are not the same, but they just differ by a constant amount of milliseconds. I suggest you to print out both times and compare them. You will then notice what the offset is:

在我的问题，Ormi734建议使用以下code：

In my question, Ormi734 suggested to use the following code:

private long timeDiff = 0l; // this will be used to adjust the offset between the times
private boolean offsetDetermined = false;

@Override
public void onSensorChanged(SensorEvent event) {

    // just determine the offset once, since it should remain constant
    // you could also adjust it every n samples if it needs to be really accurate
    if (!offsetDetermined) {
        long MiliTime = System.currentTimeMillis();
        long NanoTime = event.timestamp;
        timeDiff = MiliTime - NanoTime / 1000000;

        log.info("Synchornizing sensor clock. Current time= " + MiliTime+ ", difference between clocks = " + timeDiff);

        offsetDetermined = true;
    }

    float x = event.values[0];
    float y = event.values[1];
    float z = event.values[2];
    long ts = event.timestamp / 1000000 + timeDiff;

    // do your stuff here   
}

<一个href=\"http://stackoverflow.com/questions/15647841/accelerometer-logger-experiencing-occasional-long-delays-between-frames?noredirect=1#comment36392316_15647841\">Accelerometer记录：在经历帧之间偶有长期拖延

这篇关于Android的加速度计采样率/延迟稳定的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！