CN111722181A

CN111722181A - Method for indoor positioning and speed measurement by using speed difference of radio wave and sound wave

Info

Publication number: CN111722181A
Application number: CN202010605451.3A
Authority: CN
Inventors: 王柳怡; 李晓科; 王惟
Original assignee: Individual
Current assignee: Individual
Priority date: 2020-06-29
Filing date: 2020-06-29
Publication date: 2020-09-29

Abstract

The invention discloses a method for indoor positioning and speed measurement by utilizing the speed difference of radio waves and sound waves, which comprises 3 and more than 3 reference points, and is mainly used for transmitting the radio waves and the sound waves, wherein the radio waves and the sound waves contain ID (identity) and time information of the reference points, a receiving end can receive wireless signals and sound wave signals transmitted by the reference points and can analyze the signals transmitted by the reference points, the positioning is carried out by utilizing a three-point positioning principle, and the position of the receiving end is accurately calculated; meanwhile, the method can effectively measure the accurate indoor position of the article and the indoor moving speed of the article, is widely applied to the field of Internet of things, has great practical value and economic value, and has a ground-overturning effect particularly in the field of future IOT.

Description

Method for indoor positioning and speed measurement by using speed difference of radio wave and sound wave

Technical Field

The invention belongs to the technical field of indoor positioning and speed measurement, and particularly relates to a method for performing indoor positioning and speed measurement by using a speed difference between radio waves and sound waves.

Background

Positioning technology has been widely used, particularly satellite positioning technology, which utilizes the signals transmitted by satellites in the sky to perform positioning; however, the wireless signals transmitted by the satellites are very weak, and the satellite radio waves cannot penetrate buildings due to the fact that the satellite radio waves cannot penetrate through the buildings, so that indoor positioning is always a difficult problem.

In the prior art, positioning satellite signals such as GPS and Beidou can not penetrate indoors and can not be positioned, and other indoor positioning technologies are as follows: WIFI, ultra-wideband, bluetooth radio wave location technology, because radio waves are circular wave propagation technology, it cannot be determined precisely; the reflection type ultrasonic technology is easily influenced by multipath effect and non-line-of-sight propagation, and the positioning precision is reduced; meanwhile, the method also needs a large amount of investment of bottom hardware facilities, and the total cost is higher, so the practical value is not high.

As is well known, the speed of radio wave propagation in space is 30 kilometres per second, while the speed of sound wave propagation in air is only 344 meters per second, object a emits radio wave and ultrasonic wave simultaneously, object B receives a time difference t between the emission of radio wave and sound wave by object a, and then the relative distance between object a and object B is: 344 × t. Therefore, the position, distance and speed of the indoor space and the closed space can be measured and calculated by using the relative distance of the plurality of points.

Disclosure of Invention

Aiming at the defects in the prior art, the invention provides a method for performing indoor positioning and speed measurement by utilizing the speed difference of radio waves and sound waves, which can perform positioning in places where positioning satellite signals cannot cover, such as indoors, basements, tunnels, cabins and the like.

In order to achieve the purpose, the technical scheme of the invention is as follows:

a method for indoor positioning and speed measurement by using speed difference of radio waves and sound waves comprises the following steps:

(1) three or more reference devices are arranged in an indoor space or a closed environment; the object to be positioned is provided with a receiver which can receive the wireless signal and the sound wave signal of the datum point;

(2) each reference device sends out a signal with self ID at the same time by using radio waves and sound waves;

(3) the receiver can receive signals of the reference equipment and can receive the time difference between the wireless signal time and the sound wave signal time of certain reference equipment; calculating and obtaining the distance from the receiver to the reference equipment; the specific distance from the receiver to each reference device is also obtained respectively;

(4) testing the relative position of the receiver relative to each datum device respectively through the specific distances to acquire the indoor position of the receiver;

(5) the speed of the receiver moving indoors can be measured and calculated through the position change of the receiver in unit time.

Has the advantages that: according to the invention, the relative distance between the reference device and the receiver can be calculated through the speed difference of electric waves and acoustic waves, and the position of the object is determined through algorithms such as triangulation location and the like; the positioning precision of the whole positioning is higher, and the system structure is simple. For a change in position of the receptor, a change in velocity of the receptor can be calculated. The invention can be widely applied to positioning and speed measurement of equipment in indoor or closed space and application of the Internet of things.

Drawings

Fig. 1 is a two-dimensional schematic diagram of the present invention for localization using the difference between the propagation velocity of radio waves and the propagation velocity of sound waves.

Detailed Description

The invention is illustrated below with reference to specific examples. It will be understood by those skilled in the art that these examples are for illustrative purposes only and are not intended to limit the scope of the present invention in any way.

The embodiment of the invention comprises the following steps:

1. indoor positioning is carried out through the speed difference of radio waves and sound waves;

2. the speed difference of the radio wave and the sound wave makes an indoor speed measurement.

A method for indoor positioning and speed measurement by utilizing the speed difference of electric waves and acoustic waves comprises the following steps:

(1) in an indoor space or a closed space, three reference devices are arranged, and the ID of each reference device is as follows: A. b, C, respectively; the object to be positioned is provided with a receiver D which can receive the wireless signal and the sound wave signal of the datum point;

(2) the reference equipment sends out a signal with self ID at the same time by using radio waves and sound waves; a (a1, RA1, USA 1); b (B1, RB1, USB 1); c (C1, RC1, USC 1);

(3) the receiver D can receive a signal of the reference device A, B, C, and the time difference t between the time t1 of the wireless signal RA1 and the time t2 of the sound wave signal USA1 is t2-t 1; the distance L from D to A can be calculated; similarly, the distance D to B and the distance D to C can be calculated;

(4) the distance between the AD, BD and CD can be used to test the relative position of the receptor with respect to the reference device A, B, C, so that the indoor position of the receptor D can be known.

Further, through the above steps (1) to (4), the receiver D measures the position (x) at the time point T1₁，y₁) At time point T2 position (x)₂，y₂) (ii) a Distance between two points is l, time difference: t, the velocity v ═ l/t can be calculated.

As shown in FIG. 1, the above method is simplified to a plane, the transmitters are placed at points A and B, the radio wave signal and the sound wave signal are transmitted, and r can be calculated by using the time difference between the reception of the radio wave signal and the sound wave signal₁And r₂Therefore, the coordinates of the C-point receiver can be measured; calculation process

The time difference between the radio wave and the sound wave at the point A and the point C is T₁；

The time difference between the radio wave and the sound wave at the point B to the point C is T₂；

AB two points distance is L (known)

The speed of sound propagation in air is known to be 344 m/s; distance:

R₁＝T₁×344；

R₂＝T₂×344。

for spatial orientation, the mathematical model is the intersection of three spheres at a point! Can be simplified into a point where two circles intersect; because the intersection of the two spheres is a circle, the two circles can be intersected; a calculation formula simplified into a two-dimensional flat graph is obtained as follows: the distance between AB and the slope of AB is L, and the slope of CD is

EB²＝(L-AE)²

CE²＝CF²+EF²

CF＝EF·K₂

x_c＝x₀-EF

y_c＝y_o+CF

x_d＝x₀+EF

y_d＝y_o-CF

y_c＝y₀+K₂(x_c-。

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.

Claims

1. A method for indoor positioning and speed measurement by using speed difference of radio waves and sound waves is characterized in that: the method comprises the following steps:

(2) each reference device sends out a signal with self ID and time at the same time by using radio waves and sound waves;

(3) the receiver receives a signal of the reference equipment and can receive the time difference between the wireless signal time and the sound wave signal time of certain reference equipment; calculating and obtaining the distance from the receiver to the reference equipment; the specific distance from the receiver to each reference device is also obtained respectively;

2. The method for indoor positioning and speed measurement using the speed difference of radio waves and sound waves as claimed in claim 1, wherein: the indoor position of the receiver obtains and improves accurate longitude and latitude information through the preset accurate coordinate signal of each datum device.