Apparatus and method for detecting step in a personal navigator
View Patent ↗A step detecting apparatus and method in a personal navigator where acceleration signals in at least two directions are acquired from an accelerometer sensor, as a pedestrian moves. Variances of the acceleration signals are calculated and summed. The variance sum is compared with a threshold. If the variance sum is greater than the threshold, it is determined that a detected step is a walking step. If the variance sum is less than the threshold, it is determined that the detected step is a mark-time step.
1. A step detecting apparatus in a personal navigator, comprising:
an accelerometer sensor for outputting acceleration signals with respect to at least two directions; and
a step detector configured to calculate variances of acceleration signals in the at least two directions received from the accelerometer sensor, summing the variances, comparing the variance sum with a threshold, and determining whether a detected step is a mark-time step or a walking step according to the comparison,
wherein two of the at least two directions are a forward direction and a downward direction from the pedestrian.
2. The step detecting apparatus of claim 1 , wherein the step detector counts mark-time steps and walking steps according to the determination.
3. The step detecting apparatus of claim 1 , wherein the accelerometer sensor is an at least two-axis accelerometer sensor.
4. The step detecting apparatus of claim 1 , wherein the threshold is a value for distinguishing a mark-time step and a walking step.
5. The step detecting apparatus of claim 1 , wherein the step detector eliminates noise from the acceleration signals by sliding window summing.
6. A step detecting method in a personal navigator, comprising the steps of:
acquiring acceleration signals in at least two directions from an accelerometer sensor;
calculating variances of the acceleration signals and summing the variances;
comparing the variance sum with a threshold;
determining that a detected step is a walking step if the variance sum is greater than the threshold;
determining that the detected step is a mark-time step if the variance sum is less than the threshold; and
storing the determined walking step and/or mark-time step in the personal navigator,
wherein two of the at least two directions are a forward direction and a downward direction from the pedestrian.
7. The step detecting method of claim 6 , further comprising counting mark-time steps and walking steps according to the determination.
8. The step detecting method of claim 6 , wherein the threshold is a value for distinguishing a mark-time step and a walking step.
9. The step detecting method of claim 6 , further comprising eliminating noise from the acceleration signals by sliding window summing.
10. A step detecting method in a personal navigator, comprising the steps of:
(a) setting a walking step count, a mark-time step, and a step detection count to initial values;
(b) acquiring acceleration signals in at least two directions from an accelerometer sensor, and determining whether a step is detected;
(c) increasing the step detection count by one, upon detection of a step, calculating variances of the acceleration signals, and summing the variances;
(d) increasing the walking step count by one if the variance sum is greater than the threshold and increasing the mark-time step count by one if the variance sum is less than the threshold;
(e) counting walking steps, mark-time steps, and step detections by repeating steps (b)-(d), and
(f) storing the counted walking steps, mark-time steps and step detections in the personal navigator,
wherein two of the at least two directions are a forward direction and a downward direction from the pedestrian.
11. The step detecting method of claim 10 , wherein the threshold is a value for distinguishing a mark-time step and a walking step.