问题
Possible Duplicate:
How to Count the Number of Steps Using the Accelerometer
Are there any well known algorithms to count steps based on the accelerometer?
Hi i have developed android application. In one module I have to create a pedometer. Now at this stage I have to count the steps user walked by using accelormeter. I have search on internet and found different methods but none of that working. I have tried this
Does anyone have an idea how to achieve my goal? Any help is appreciated.
回答1:
The simplest solution would be to have a time-window and a number of thresholds. The signal gets a form of a double wave, and you can split a step into several parts. You may need to have several windows and corresponding threshold values to recognise one step. But keep in mind that this signal will change if someone is walking upstairs/downstairs or running or just walking with different pace. You will get great variability if you actually going to try it with several participants.
Threshold values will differ greatly between devices. Frequency of measurements will also have an impact. Standard frequency that allows one to detect walking with normal pace is about 10Hz, some devices use 20Hz, if you go over this you will get lots of data and little information. Manufacturers do use different versions of accelerometers, so if your software works on one phone, there is no guarantee it will work on the other device even of the same model.
I would start from plotting your signal first. Also don't forget that the phone can be in different positions in a pocket (unless you fix it somehow) so the threshold values will float. All clinical pedometers are usually affixed to the leg in a certain position.
Consider using mono-axial accelerometry instead of 3-axial, the signal analysis gets much more easier to begin with. Also take a look at the Fourier transformations and wavelet analyses.
See the image below to get a basic idea of how walking looks with a 3-axial accelerometer. I made it when was doing similar task (walking is the noisy bit).
And this is how walking looks with a mono-axial accelerometer (again noisy bits)
回答2:
This seems to be pretty reasonable and accurate:
Enhancing the Performance of Pedometers Using a Single Accelerometer
Anyhow, I am also interested in finding a good algorithm.
来源：https://stackoverflow.com/questions/11241208/count-steps-using-accelometer-in-android