Step counting method and a pedometer based on a 3-axis accelerometer

A pedometer based on a three-axis accelerometer, comprising:

• a collecting unit, used to collect a three-axis acceleration of a user;
• a first calculating unit, used to calculate a sum of squares of the collected three-axis acceleration for generating a standard acceleration;
• a smoothing unit, used to smooth the standard acceleration for generating a processed acceleration;
• an acquiring unit, used to acquire a maximum and a minimum of all the processed accelerations generated in a period;
• a second calculating unit, used to calculate a difference between the maximum and the minimum;
• a setting unit, used to set a current time window according to the difference, the setting unit further comprising:
• a second design module, used to design two threshold ranges and the corresponding time window;
• a second setting module, used to set the current time window as [T1,T2] when the difference is within a first threshold range, wherein 0.2 s≦T1<T2≦2 s;
• and
• a third setting module, used to set the current time window as [T3,T4] when the difference is within a second threshold range, wherein T3>T1 and T4<T2;
• a first determining unit, used to determine whether there exists at least three serial processed accelerations decrease progressively;
• a confirming unit, used to confirm a step started time when the first determining unit determines that there exist three serial processed accelerations decrease progressively, wherein the time corresponds to the first processed acceleration of the three serial processed accelerations is designated as the step started time;
• a second determining unit, used to determine whether a time difference of two serial step started time is within the current time window;
• and
• a step counting unit, used to add a step count if the second determining unit determines that the time difference of the two serial step started time is within the current time window.

A pedometer based on a three-axis accelerometer, comprising:

• a collecting process device, used to collect a three-axis acceleration of a user and process the three-axis acceleration for generating a processed acceleration;
• an acquiring unit, used to acquire a maximum and a minimum of all the processed accelerations generated in a period;
• a second calculating unit, used to calculate a difference between the maximum and the minimum;
• a setting unit, used to set a current time window according to the difference, the setting unit further comprising:
• a second design module, used to design two threshold ranges and the corresponding time window;
• a second setting module, used to set the current time window as [T1,T2] when the difference is within a first threshold range, wherein 0.2 s≦T1<T2≦2 s;
• and
• a third setting module, used to set the current time window as [T3,T4] when the difference is within a second threshold range, wherein T3>T1 and T4<T2;
• a first determining unit, used to determine whether there exists at least three serial processed accelerations decrease progressively;
• a confirming unit, used to confirm a step started time when the first determining unit determines that there exist three serial processed accelerations decrease progressively, wherein the time corresponds to the first processed acceleration of the three serial processed accelerations is designated as the step started time;
• a second determining unit, used to determine whether a time difference of two serial step started time is within the current time window;
• and
• a step counting unit, used to add a step count if the second determining unit determines that the time difference of the two serial step started time is within the current time window.