TWI757856B - Footsteps tracking method and system thereof - Google Patents

Abstract

A footsteps tracking method, including the steps of: receiving a first sound signal of a user's first footstep; calculating a first position of the first footstep according to relative position relationship of at least three microphones in the microphone array and time differences of sound arrival of the first sound signal received by the three microphones respectively; receiving a second sound signal of a second footstep of the user, wherein an audio frequency of the second sound signal is the same as an audio frequency of the first sound signal; and calculating a second position of the second footstep according to the first position, a time difference between receiving the first sound signal and the second sound signal, receiving angles between the first sound signal and a pair of the three microphones, and receiving angles between the second sound signal and the pair of the three microphones.

Description

Track tracking method and system therefor

The present invention relates to a track tracking method and system, in particular to a track tracking method and system for tracking the user's next step and the change of the radio angle after locating the first step of the user.

In the prior art, a sensor is usually used to monitor the user's movement, and at the same time, the frequency and intensity of a person's footsteps and other related data are collected through monitoring, so as to achieve the purpose of identifying the movement. However, in order to accurately monitor the movement of the user, a plurality of sensors must be arranged in the surrounding environment for monitoring, which requires a relatively high cost. Therefore, how to achieve the purpose of identifying different users and locating footsteps at a lower cost is a problem that needs to be solved at present.

In view of this, there is a need for a track tracking method and system that can track the movements of different users only by using a microphone array.

The present invention provides a track tracking method. The method includes: receiving a first sound signal corresponding to a user's first footsteps through a microphone array; The first position of the sound corresponding to the first footstep sound is calculated from the time difference of the sound of the first sound signal received by each of the microphones; the first position corresponding to the user's second footstep sound is received through the microphone array. two audio signals, wherein the audio of the second audio signal is the same as the audio of the first audio signal; and the first audio signal and the second audio signal are received by the processing unit according to the first position The time difference of the sound signal, the first A second position corresponding to the second footstep sound is calculated by calculating the included angle between the sound signal and a pair of microphones among the three microphones and the included angle between the second sound signal and the pair of microphones.

The present invention also provides a track tracking system, which includes a microphone array and a processing unit. The microphone array is composed of at least three microphones, and is used to receive a first sound signal corresponding to the user's first footsteps and a second sound signal corresponding to the user's second footsteps, wherein the first sound The audio of the second sound signal is the same as the audio of the first sound signal. The processing unit is configured to calculate a first position corresponding to the first footstep sound according to the relative positional relationship of the three microphones and the sound arrival time difference of the first sound signal received by the three microphones, and according to the first position, the time difference between receiving the first sound signal and the second sound signal, the angle between the first sound signal and a pair of microphones in the microphone array, and the second sound signal and the The calculation of the included angle of sound collection of the pair of microphones corresponds to the second position of the second footstep sound.

According to an embodiment of the present invention, when the difference between the sound collection angle of the first sound signal and the pair of microphones and the sound collection angle of the second sound signal and the pair of microphones is equal to 0 or When less than a predetermined value, the second position is equal to the first position.

According to another embodiment of the present invention, the processing unit further selects different step sizes according to the magnitude of the time difference between receiving the first sound signal and the second sound signal.

According to another embodiment of the present invention, the microphone array has five microphones, the microphone array is in a regular pentagon shape, and the distance between every two adjacent microphones is 20 mm.

The present invention is described in detail below with reference to the accompanying drawings and specific embodiments, but is not intended to limit the present invention.

100: Track Tracking System

110: Microphone Array

120: Processing unit

130: storage unit

201-205: Microphones

L1, L2: positioning curve

Lab: Step

S501~S506: Step flow

θa1, θa2, θb1, θb2: the included angle of the sound

θab: difference in included angle

FIG. 1 is a block diagram of a track tracking system according to an embodiment of the present invention.

FIG. 2 is a schematic diagram of a microphone array 110 according to an embodiment of the present invention.

FIG. 3 is a schematic diagram of user positioning according to an embodiment of the present invention.

Figures 4a and 4b are schematic diagrams of calculating the position of the second step according to an embodiment of the present invention.

FIG. 5 is a flowchart of a track tracking method according to an embodiment of the present invention.

Further scope of applicability to the systems and methods of the present invention will become apparent from the detailed description provided hereinafter. It must be understood that the following detailed description and specific embodiments, while presenting exemplary embodiments of the track tracking method and system thereof, are for descriptive purposes only and are not intended to limit the scope of the present invention.

FIG. 1 is a block diagram of a track tracking system 100 according to an embodiment of the present invention. The track tracking system 100 at least includes a microphone array 110 , a processing unit 120 and a storage unit 130 . The microphone array 110 is composed of at least three microphones disposed at different positions, and is used for receiving sound signals from different directions corresponding to different sound sources. The processing unit 120 is used for receiving sound signals from the microphone array 110 and determining the position of the sound source according to the relative positional relationship between each two microphones in the microphone array 110, the time and angle at which the sound signals are received, and the characteristics of the sound signals. The processing unit 120 can be, for example, a dedicated hardware circuit or general-purpose hardware (eg, a single processor, a multiprocessor with parallel processing capability, a graphics processor, or other processors with computing capability), and executes the code Or software, provides the functions described later. The storage unit 130 can be a non-volatile storage device such as a hard disk, a flash drive, etc., and is used to store the position of each microphone in the microphone array 110 and the relative positional relationship between each two adjacent microphones, corresponding to various types of sound sources. The frequency of the sound and various algorithms required in the execution of the calculation process, etc., can be accessed by the processing unit 120 . Wherein, if the object emitting the sound source is a human being, whether it belongs to the same user can be determined according to the sound frequency and/or footstep sound emitted by different types of shoes.

FIG. 2 is a schematic diagram of a microphone array 110 according to an embodiment of the present invention. In the example of the present invention, the microphone array 110 is composed of the microphones 201-205 and is in the shape of a regular pentagon. Wherein, the distance between every two adjacent microphones (ie, the distances between the microphones 201 and 202, the microphones 202 and 203, the microphones 203 and 204, the microphones 204 and 205, and the distances between the microphones 205 and 201) Both are 20mm. It is worth noting that the regular pentagon microphone array shown in FIG. 2 is only a preferred embodiment, but not limited to the regular pentagon, and the distance between every two adjacent microphones can also be used to customize it.

FIG. 3 is a schematic diagram of user positioning according to an embodiment of the present invention. First, when the processing unit 120 receives the audio signal corresponding to the current footsteps of the user through the microphone array 110 When the signal is entered, the audio corresponding to the footstep sound is first analyzed from the sound signal to determine whether the footstep sound has appeared before. However, when the audio corresponding to the current footstep sound does not appear within a predetermined period of time (for example, within the first 5 seconds), the processing unit 120 determines that the user has stepped into the sound collection range of the microphone array 110 for the first time or is standing in a certain area. The fixed point has not moved for a long time, and then the current position of the user is judged through the Time Difference of Arrival (TDOA) positioning technology. For example, as shown in FIG. 3 , when the footsteps of the user appear at point a and the audio corresponding to the footsteps has never appeared, since the distances between point a and the microphones 201 , 202 and 205 are all different, so The processing unit 120 can obtain the hyperbolas L1 and L2 corresponding to the microphones 201 , 202 and the microphones 201 , 205 respectively according to the sound arrival time difference of the sound transmitted to the microphones 201 , 202 and 205 respectively, and the intersection point a of the hyperbolas L1 and L2 That is, the position corresponding to the user's footsteps.

Next, after calculating the position corresponding to point a, the processing unit 120 further calculates the angle between the pair of microphones in the microphone array 110 and the closest pair of microphones, as a reference for judging the user's subsequent movement state. For example, as shown in Fig. 4a, after obtaining the position of point a, the two microphones closest to point a are microphones 201 and 202, and the processing unit 120 then obtains the angle θa1 and θa1 of the microphone 201 corresponding to point a. Point a corresponds to the included angle θa2 of the microphone 202 , and is stored in the storage unit 130 . Then, when the processing unit 120 receives the sound signal corresponding to the next footsteps of the user through the microphone array 110 (for example, by determining the audio and/or volume corresponding to the footsteps), the processing unit 120 further calculates the corresponding sound of the footsteps. The included angle θb1 of the microphone 201 corresponds to the included angle θb2 of the microphone 202 (as shown in Fig. 4b). Then, the processing unit 120 can determine the movement trajectory of the user according to the angle and the step distance. The step distance can be estimated according to the time difference between the user's current footsteps and the previous footsteps. For example, when the time difference is less than 1.5 steps per second, it means that the user walks at a slower speed, and the corresponding step distance is usually shorter (eg, 70 cm). When the time difference is 1.5-2 steps per second, it means that the user walks at a normal speed, and the corresponding step distance is about 85 cm. However, when the time difference is more than 2 steps per second, it means that the user is walking, and the corresponding step distance is larger, usually about 100 cm. In other words, when the walking speed is faster (ie, the distance between the footsteps is shorter), the step distance is larger. It is worth noting that the aforementioned step distance is obtained according to the walking speed of an ordinary adult, which can be modified according to different ages, and is not limited thereto.

According to an embodiment of the present invention, when the difference between the included angle θa1 and the included angle θb1 and the included angle θa2 and the included angle θb2 is 0 or less than a predetermined value (for example, less than 5 degrees), it means that the user is stepping on the spot without moving, Then the processing unit 120 determines that the current location of the user is the same as the previous location. Conversely, when the difference between the included angle θa1 and the included angle θb1 or the difference between the included angle θa2 and the included angle θb2 is greater than a predetermined value (that is, greater than 5 degrees), it means that the user is in a moving state, and the processing unit 120 can determine the value corresponding to point a. The position corresponding to point b is obtained by using the coordinates, the previously calculated angles θa1, θb1, θa2, θb2 and the step distance. For example, as shown in Figure 4b, after calculating the angle θab, the coordinates of point b (Xb, Yb) can be obtained from the coordinates of point a (Xa, Xb) = (Xa+Lab*Sinθab, Ya+Lab *Cosθab). Among them, Lab is the step distance described in the previous paragraph. By analogy, when the user walks within the sound collection range of the microphone array 110 , the user's movement trajectory can be tracked through the aforementioned method.

FIG. 5 is a flowchart of a track tracking method according to an embodiment of the present invention. In step S501, the microphone array 110 receives the current sound signal corresponding to the current footsteps of the user, and outputs the corresponding current sound signal to the processing unit. In step S502, the processing unit 120 analyzes the audio corresponding to the current audio signal, and determines whether an audio signal with the same audio has appeared within a predetermined time. If the sound signal with the same audio frequency has not been received within the predetermined time, the process proceeds to step S503, and the processing unit 120 calculates the corresponding sound signal according to the relative positional relationship of the at least three microphones in the microphone array and the sound arrival time difference of the sound signals received by the three microphones respectively. the current position of the player's current footsteps. On the other hand, if the microphone array 110 has received a sound signal with the same audio frequency within a predetermined time, the process proceeds to step S504, and the processing unit 120 receives the current sound signal corresponding to the current footstep sound and the previous sound signal corresponding to the previous footstep sound. time difference to obtain the step distance. In step S505, the processing unit 120 calculates the current position corresponding to the current footstep sound according to the step distance, the angle at which the at least two microphones in the microphone array receive the current sound source respectively, and the previous position corresponding to the previous footstep sound. When the angle at which the microphone receives the current sound source is the same as the angle at which the microphone receives the previous sound source, the processing unit 120 determines that the user only steps on the spot, that is, the current position is the same as the previous position.

It is worth noting that although the above method has been described on the basis of a flowchart using a series of steps or blocks, the invention is not limited to the order of these steps and some steps may be performed in a different order or the remaining steps can be performed simultaneously. Furthermore, those skilled in the art will appreciate that the steps shown in the flowchart are not exclusive and that other steps of the flowchart may be included, or one or more steps may be deleted without affecting the scope of the present invention.

To sum up, according to the track tracking method and system proposed by some embodiments of the present invention, after obtaining the position corresponding to the first footstep sound of the user through the time-of-arrival positioning technology, the following The user's movement trajectory can be calculated by monitoring the time difference and sound collection angle of the user's subsequent footsteps, so that the purpose of locating the user's position can be achieved only through a microphone array. In addition, different users can be distinguished by identifying the audio of the shoes corresponding to the footsteps, and multiple users can be located at the same time without additional sensors, thereby reducing the cost of monitoring.

It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solutions of the present invention can be Modifications or equivalent substitutions can be made without departing from the spirit and scope of the technical solutions of the present invention.

S501~S505: Step flow

Claims (8)

A track tracking method, the method comprises: receiving a first sound signal corresponding to a user's first footsteps through a microphone array; The microphones respectively receive the sound arrival time difference of the first sound signal to calculate the first position corresponding to the first footstep sound; receive the second sound signal corresponding to the user's second footstep sound through the microphone array , wherein the audio of the second sound signal is the same as the audio of the first sound signal; and the processing unit receives the audio of the first sound signal and the second sound signal according to the first position. The second position corresponding to the second footstep sound is calculated from the time difference, the included angle between the first sound signal and a pair of microphones in the three microphones, and the included angle between the second sound signal and the pair of microphones. The track tracking method according to claim 1, wherein when the difference between the sound collection angle of the first sound signal and the pair of microphones and the sound collection angle of the second sound signal and the pair of microphones is When the value is equal to 0 or less than a predetermined value, the second position is equal to the first position. The track tracking method according to claim 1, wherein the processing unit further selects different step sizes according to the magnitude of the time difference between receiving the first sound signal and the second sound signal. The track tracking method of claim 1, wherein the microphone array has five microphones, the microphone array is in a regular pentagon shape, and the distance between every two adjacent microphones is 20 mm. A track tracking system, the system includes: A microphone array, consisting of at least three microphones, is used to receive a first sound signal corresponding to the user's first footsteps and a second sound signal corresponding to the user's second footsteps, wherein the second sound The audio of the sound signal is the same as the audio of the first sound signal; and the processing unit is used for calculating according to the relative positional relationship of the three microphones and the sound time difference of the first sound signal received by the three microphones a first position corresponding to the first footstep sound, and according to the first position, the time difference between the first sound signal and the second sound signal received, the first sound signal and the microphone array The included angle between the pair of microphones and the included angle between the second sound signal and the pair of microphones is calculated to correspond to the second position of the second footstep sound. The track tracking system of claim 5, wherein when the difference between the sound collection angle of the first sound signal and the pair of microphones and the sound collection angle of the second sound signal and the pair of microphones When the value is equal to 0 or less than a predetermined value, the second position is equal to the first position. The track tracking system according to claim 5, wherein the processing unit further selects different step sizes according to the magnitude of the time difference between receiving the first sound signal and the second sound signal. The track tracking system of claim 5, wherein the microphone array has five of the microphones, the microphone array is in a regular pentagon shape, and the distance between every two adjacent microphones is 20 mm.

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